Declare locals final where not reassigned (#8564)

Covers lib/ in package:flutter.

packages/flutter/lib/src/animation/animation_controller.dart

@@ -146,7 +146,7 @@ class AnimationController extends Animation<double>
 
   /// Recreates the [Ticker] with the new [TickerProvider].
   void resync(TickerProvider vsync) {
-    Ticker oldTicker = _ticker;
+    final Ticker oldTicker = _ticker;
     _ticker = vsync.createTicker(_tick);
     _ticker.absorbTicker(oldTicker);
   }
@@ -279,8 +279,8 @@ class AnimationController extends Animation<double>
         }
         return true;
       });
-      double range = upperBound - lowerBound;
+      final double range = upperBound - lowerBound;
-      double remainingFraction = range.isFinite ? (target - _value).abs() / range : 1.0;
+      final double remainingFraction = range.isFinite ? (target - _value).abs() / range : 1.0;
       simulationDuration = this.duration * remainingFraction;
     }
     stop();
@@ -326,7 +326,7 @@ class AnimationController extends Animation<double>
     _direction = velocity < 0.0 ? _AnimationDirection.reverse : _AnimationDirection.forward;
     final double target = velocity < 0.0 ? lowerBound - _kFlingTolerance.distance
                                          : upperBound + _kFlingTolerance.distance;
-    Simulation simulation = new SpringSimulation(_kFlingSpringDescription, value, target, velocity)
+    final Simulation simulation = new SpringSimulation(_kFlingSpringDescription, value, target, velocity)
       ..tolerance = _kFlingTolerance;
     return animateWith(simulation);
   }
@@ -343,7 +343,7 @@ class AnimationController extends Animation<double>
     _simulation = simulation;
     _lastElapsedDuration = Duration.ZERO;
     _value = simulation.x(0.0).clamp(lowerBound, upperBound);
-    Future<Null> result = _ticker.start();
+    final Future<Null> result = _ticker.start();
     _status = (_direction == _AnimationDirection.forward) ?
       AnimationStatus.forward :
       AnimationStatus.reverse;
@@ -381,7 +381,7 @@ class AnimationController extends Animation<double>
 
   AnimationStatus _lastReportedStatus = AnimationStatus.dismissed;
   void _checkStatusChanged() {
-    AnimationStatus newStatus = status;
+    final AnimationStatus newStatus = status;
     if (_lastReportedStatus != newStatus) {
       _lastReportedStatus = newStatus;
       notifyStatusListeners(newStatus);
@@ -390,7 +390,7 @@ class AnimationController extends Animation<double>
 
   void _tick(Duration elapsed) {
     _lastElapsedDuration = elapsed;
-    double elapsedInSeconds = elapsed.inMicroseconds.toDouble() / Duration.MICROSECONDS_PER_SECOND;
+    final double elapsedInSeconds = elapsed.inMicroseconds.toDouble() / Duration.MICROSECONDS_PER_SECOND;
     assert(elapsedInSeconds >= 0.0);
     _value = _simulation.x(elapsedInSeconds).clamp(lowerBound, upperBound);
     if (_simulation.isDone(elapsedInSeconds)) {
@@ -405,10 +405,10 @@ class AnimationController extends Animation<double>
 
   @override
   String toStringDetails() {
-    String paused = isAnimating ? '' : '; paused';
+    final String paused = isAnimating ? '' : '; paused';
-    String ticker = _ticker == null ? '; DISPOSED' : (_ticker.muted ? '; silenced' : '');
+    final String ticker = _ticker == null ? '; DISPOSED' : (_ticker.muted ? '; silenced' : '');
-    String label = debugLabel == null ? '' : '; for $debugLabel';
+    final String label = debugLabel == null ? '' : '; for $debugLabel';
-    String more = '${super.toStringDetails()} ${value.toStringAsFixed(3)}';
+    final String more = '${super.toStringDetails()} ${value.toStringAsFixed(3)}';
     return '$more$paused$ticker$label';
   }
 }
@@ -428,7 +428,7 @@ class _InterpolationSimulation extends Simulation {
 
   @override
   double x(double timeInSeconds) {
-    double t = (timeInSeconds / _durationInSeconds).clamp(0.0, 1.0);
+    final double t = (timeInSeconds / _durationInSeconds).clamp(0.0, 1.0);
     if (t == 0.0)
       return _begin;
     else if (t == 1.0)
@@ -439,7 +439,7 @@ class _InterpolationSimulation extends Simulation {
 
   @override
   double dx(double timeInSeconds) {
-    double epsilon = tolerance.time;
+    final double epsilon = tolerance.time;
     return (x(timeInSeconds + epsilon) - x(timeInSeconds - epsilon)) / (2 * epsilon);
   }
 

packages/flutter/lib/src/animation/animations.dart

@@ -384,9 +384,9 @@ class CurvedAnimation extends Animation<double> with AnimationWithParentMixin<do
 
   @override
   double get value {
-    Curve activeCurve = _useForwardCurve ? curve : reverseCurve;
+    final Curve activeCurve = _useForwardCurve ? curve : reverseCurve;
 
-    double t = parent.value;
+    final double t = parent.value;
     if (activeCurve == null)
       return t;
     if (t == 0.0 || t == 1.0) {
@@ -501,7 +501,7 @@ class TrainHoppingAnimation extends Animation<double>
         _statusChangeHandler(_currentTrain.status);
       }
     }
-    double newValue = value;
+    final double newValue = value;
     if (newValue != _lastValue) {
       notifyListeners();
       _lastValue = newValue;

packages/flutter/lib/src/animation/curves.dart

@@ -190,8 +190,8 @@ class Cubic extends Curve {
     double start = 0.0;
     double end = 1.0;
     while (true) {
-      double midpoint = (start + end) / 2;
+      final double midpoint = (start + end) / 2;
-      double estimate = _evaluateCubic(a, c, midpoint);
+      final double estimate = _evaluateCubic(a, c, midpoint);
       if ((t - estimate).abs() < _kCubicErrorBound)
         return _evaluateCubic(b, d, midpoint);
       if (estimate < t)
@@ -326,7 +326,7 @@ class ElasticInCurve extends Curve {
   @override
   double transform(double t) {
     assert(t >= 0.0 && t <= 1.0);
-    double s = period / 4.0;
+    final double s = period / 4.0;
     t = t - 1.0;
     return -math.pow(2.0, 10.0 * t) * math.sin((t - s) * (math.PI * 2.0) / period);
   }
@@ -350,7 +350,7 @@ class ElasticOutCurve extends Curve {
   @override
   double transform(double t) {
     assert(t >= 0.0 && t <= 1.0);
-    double s = period / 4.0;
+    final double s = period / 4.0;
     return math.pow(2.0, -10 * t) * math.sin((t - s) * (math.PI * 2.0) / period) + 1.0;
   }
 
@@ -373,7 +373,7 @@ class ElasticInOutCurve extends Curve {
   @override
   double transform(double t) {
     assert(t >= 0.0 && t <= 1.0);
-    double s = period / 4.0;
+    final double s = period / 4.0;
     t = 2.0 * t - 1.0;
     if (t < 0.0)
       return -0.5 * math.pow(2.0, 10.0 * t) * math.sin((t - s) * (math.PI * 2.0) / period);

packages/flutter/lib/src/animation/tween.dart

@@ -60,7 +60,7 @@ class _ChainedEvaluation<T> extends Animatable<T> {
 
   @override
   T evaluate(Animation<double> animation) {
-    double value = _parent.evaluate(animation);
+    final double value = _parent.evaluate(animation);
     return _evaluatable.evaluate(new AlwaysStoppedAnimation<double>(value));
   }
 
@@ -240,7 +240,7 @@ class CurveTween extends Animatable<double> {
 
   @override
   double evaluate(Animation<double> animation) {
-    double t = animation.value;
+    final double t = animation.value;
     if (t == 0.0 || t == 1.0) {
       assert(curve.transform(t).round() == t);
       return t;

packages/flutter/lib/src/cupertino/thumb_painter.dart

@@ -21,7 +21,7 @@ class CupertinoThumbPainter {
   void paint(Canvas canvas, Rect rect) {
     final RRect rrect = new RRect.fromRectAndRadius(rect, new Radius.circular(rect.shortestSide / 2.0));
 
-    Paint paint = new Paint()
+    final Paint paint = new Paint()
       ..color = shadowColor
       ..maskFilter = _kShadowMaskFilter;
     canvas.drawRRect(rrect, paint);

packages/flutter/lib/src/foundation/assertions.dart

@@ -214,7 +214,7 @@ class FlutterError extends AssertionError {
       if ((details.exception is AssertionError) && (details.exception is! FlutterError)) {
         bool ourFault = true;
         if (stackLines != null) {
-          List<String> stackList = stackLines.take(2).toList();
+          final List<String> stackList = stackLines.take(2).toList();
           if (stackList.length >= 2) {
             final RegExp throwPattern = new RegExp(r'^#0 +_AssertionError._throwNew \(dart:.+\)$');
             final RegExp assertPattern = new RegExp(r'^#1 +[^(]+ \((.+?):([0-9]+)(?::[0-9]+)?\)$');
@@ -247,7 +247,7 @@ class FlutterError extends AssertionError {
           debugPrint(line, wrapWidth: _kWrapWidth);
       }
       if (details.informationCollector != null) {
-        StringBuffer information = new StringBuffer();
+        final StringBuffer information = new StringBuffer();
         details.informationCollector(information);
         debugPrint('\n$information', wrapWidth: _kWrapWidth);
       }
@@ -285,11 +285,11 @@ class FlutterError extends AssertionError {
     final List<String> result = <String>[];
     final List<String> skipped = <String>[];
     for (String line in frames) {
-      Match match = stackParser.firstMatch(line);
+      final Match match = stackParser.firstMatch(line);
       if (match != null) {
         assert(match.groupCount == 2);
         if (filteredPackages.contains(match.group(2))) {
-          Match packageMatch = packageParser.firstMatch(match.group(2));
+          final Match packageMatch = packageParser.firstMatch(match.group(2));
           if (packageMatch != null && packageMatch.group(1) == 'package') {
             skipped.add('package ${packageMatch.group(2)}'); // avoid "package package:foo"
           } else {
@@ -307,7 +307,7 @@ class FlutterError extends AssertionError {
     if (skipped.length == 1) {
       result.add('(elided one frame from ${skipped.single})');
     } else if (skipped.length > 1) {
-      List<String> where = new Set<String>.from(skipped).toList()..sort();
+      final List<String> where = new Set<String>.from(skipped).toList()..sort();
       if (where.length > 1)
         where[where.length - 1] = 'and ${where.last}';
       if (where.length > 2) {

packages/flutter/lib/src/foundation/licenses.dart

@@ -132,7 +132,7 @@ class LicenseEntryWithLineBreaks extends LicenseEntry {
     int currentLineIndent = 0;
     int currentParagraphIndentation;
     _LicenseEntryWithLineBreaksParserState state = _LicenseEntryWithLineBreaksParserState.beforeParagraph;
-    List<String> lines = <String>[];
+    final List<String> lines = <String>[];
 
     void addLine() {
       assert(lineStart < currentPosition);

packages/flutter/lib/src/foundation/print.dart

@@ -64,7 +64,7 @@ void _debugPrintTask() {
     _debugPrintedCharacters = 0;
   }
   while (_debugPrintedCharacters < _kDebugPrintCapacity && _debugPrintBuffer.isNotEmpty) {
-    String line = _debugPrintBuffer.removeFirst();
+    final String line = _debugPrintBuffer.removeFirst();
     _debugPrintedCharacters += line.length; // TODO(ianh): Use the UTF-8 byte length instead
     print(line);
   }
@@ -108,8 +108,8 @@ Iterable<String> debugWordWrap(String message, int width, { String wrapIndent: '
     yield message;
     return;
   }
-  Match prefixMatch = _indentPattern.matchAsPrefix(message);
+  final Match prefixMatch = _indentPattern.matchAsPrefix(message);
-  String prefix = wrapIndent + ' ' * prefixMatch.group(0).length;
+  final String prefix = wrapIndent + ' ' * prefixMatch.group(0).length;
   int start = 0;
   int startForLengthCalculations = 0;
   bool addPrefix = false;

packages/flutter/lib/src/foundation/synchronous_future.dart

@@ -35,7 +35,7 @@ class SynchronousFuture<T> implements Future<T> {
 
   @override
   Future<E> then<E>(dynamic f(T value), { Function onError }) {
-    dynamic result = f(_value);
+    final dynamic result = f(_value);
     if (result is Future<E>)
       return result;
     return new SynchronousFuture<E>(result);
@@ -49,7 +49,7 @@ class SynchronousFuture<T> implements Future<T> {
   @override
   Future<T> whenComplete(dynamic action()) {
     try {
-      dynamic result = action();
+      final dynamic result = action();
       if (result is Future)
         return result.then<T>((dynamic value) => _value);
       return this;

packages/flutter/lib/src/gestures/arena.dart

@@ -75,7 +75,7 @@ class GestureArenaManager {
 
   /// Adds a new member (e.g., gesture recognizer) to the arena.
   GestureArenaEntry add(int pointer, GestureArenaMember member) {
-    _GestureArena state = _arenas.putIfAbsent(pointer, () => new _GestureArena());
+    final _GestureArena state = _arenas.putIfAbsent(pointer, () => new _GestureArena());
     state.add(member);
     return new GestureArenaEntry._(this, pointer, member);
   }
@@ -84,7 +84,7 @@ class GestureArenaManager {
   ///
   /// Called after the framework has finished dispatching the pointer down event.
   void close(int pointer) {
-    _GestureArena state = _arenas[pointer];
+    final _GestureArena state = _arenas[pointer];
     if (state == null)
       return;  // This arena either never existed or has been resolved.
     state.isOpen = false;
@@ -105,7 +105,7 @@ class GestureArenaManager {
   ///  * [hold]
   ///  * [release]
   void sweep(int pointer) {
-    _GestureArena state = _arenas[pointer];
+    final _GestureArena state = _arenas[pointer];
     if (state == null)
       return;  // This arena either never existed or has been resolved.
     assert(!state.isOpen);
@@ -136,7 +136,7 @@ class GestureArenaManager {
   ///  * [sweep]
   ///  * [release]
   void hold(int pointer) {
-    _GestureArena state = _arenas[pointer];
+    final _GestureArena state = _arenas[pointer];
     if (state == null)
       return;  // This arena either never existed or has been resolved.
     state.isHeld = true;
@@ -152,7 +152,7 @@ class GestureArenaManager {
   ///  * [sweep]
   ///  * [hold]
   void release(int pointer) {
-    _GestureArena state = _arenas[pointer];
+    final _GestureArena state = _arenas[pointer];
     if (state == null)
       return;  // This arena either never existed or has been resolved.
     state.isHeld = false;
@@ -184,7 +184,7 @@ class GestureArenaManager {
   }
 
   void _resolve(int pointer, GestureArenaMember member, GestureDisposition disposition) {
-    _GestureArena state = _arenas[pointer];
+    final _GestureArena state = _arenas[pointer];
     if (state == null)
       return;  // This arena has already resolved.
     assert(state.members.contains(member));

packages/flutter/lib/src/gestures/converter.dart

@@ -53,7 +53,7 @@ class PointerEventConverter {
       switch (datum.change) {
         case ui.PointerChange.add:
           assert(!_pointers.containsKey(datum.device));
-          _PointerState state = _ensureStateForPointer(datum, position);
+          final _PointerState state = _ensureStateForPointer(datum, position);
           assert(state.lastPosition == position);
           yield new PointerAddedEvent(
             timeStamp: timeStamp,
@@ -73,7 +73,7 @@ class PointerEventConverter {
           break;
         case ui.PointerChange.hover:
           final bool alreadyAdded = _pointers.containsKey(datum.device);
-          _PointerState state = _ensureStateForPointer(datum, position);
+          final _PointerState state = _ensureStateForPointer(datum, position);
           assert(!state.down);
           if (!alreadyAdded) {
             assert(state.lastPosition == position);
@@ -93,7 +93,7 @@ class PointerEventConverter {
               tilt: datum.tilt
             );
           }
-          Offset offset = position - state.lastPosition;
+          final Offset offset = position - state.lastPosition;
           state.lastPosition = position;
           yield new PointerHoverEvent(
             timeStamp: timeStamp,
@@ -118,7 +118,7 @@ class PointerEventConverter {
           break;
         case ui.PointerChange.down:
           final bool alreadyAdded = _pointers.containsKey(datum.device);
-          _PointerState state = _ensureStateForPointer(datum, position);
+          final _PointerState state = _ensureStateForPointer(datum, position);
           assert(!state.down);
           if (!alreadyAdded) {
             assert(state.lastPosition == position);
@@ -142,7 +142,7 @@ class PointerEventConverter {
             // Not all sources of pointer packets respect the invariant that
             // they hover the pointer to the down location before sending the
             // down event. We restore the invariant here for our clients.
-            Offset offset = position - state.lastPosition;
+            final Offset offset = position - state.lastPosition;
             state.lastPosition = position;
             yield new PointerHoverEvent(
               timeStamp: timeStamp,
@@ -192,9 +192,9 @@ class PointerEventConverter {
           // start sending us ADDED and REMOVED data points.
           // See also: https://github.com/flutter/flutter/issues/720
           assert(_pointers.containsKey(datum.device));
-          _PointerState state = _pointers[datum.device];
+          final _PointerState state = _pointers[datum.device];
           assert(state.down);
-          Offset offset = position - state.lastPosition;
+          final Offset offset = position - state.lastPosition;
           state.lastPosition = position;
           yield new PointerMoveEvent(
             timeStamp: timeStamp,
@@ -220,7 +220,7 @@ class PointerEventConverter {
         case ui.PointerChange.up:
         case ui.PointerChange.cancel:
           assert(_pointers.containsKey(datum.device));
-          _PointerState state = _pointers[datum.device];
+          final _PointerState state = _pointers[datum.device];
           assert(state.down);
           if (position != state.lastPosition) {
             // Not all sources of pointer packets respect the invariant that
@@ -228,7 +228,7 @@ class PointerEventConverter {
             // event. For example, in the iOS simulator, of you drag outside the
             // window, you'll get a stream of pointers that violates that
             // invariant. We restore the invariant here for our clients.
-            Offset offset = position - state.lastPosition;
+            final Offset offset = position - state.lastPosition;
             state.lastPosition = position;
             yield new PointerMoveEvent(
               timeStamp: timeStamp,
@@ -293,7 +293,7 @@ class PointerEventConverter {
           break;
         case ui.PointerChange.remove:
           assert(_pointers.containsKey(datum.device));
-          _PointerState state = _pointers[datum.device];
+          final _PointerState state = _pointers[datum.device];
           if (state.down) {
             yield new PointerCancelEvent(
               timeStamp: timeStamp,

packages/flutter/lib/src/gestures/drag.dart

@@ -283,10 +283,10 @@ abstract class DragGestureRecognizer extends OneSequenceGestureRecognizer {
   void handleEvent(PointerEvent event) {
     assert(_state != _DragState.ready);
     if (event is PointerMoveEvent) {
-      VelocityTracker tracker = _velocityTrackers[event.pointer];
+      final VelocityTracker tracker = _velocityTrackers[event.pointer];
       assert(tracker != null);
       tracker.addPosition(event.timeStamp, event.position);
-      Offset delta = event.delta;
+      final Offset delta = event.delta;
       if (_state == _DragState.accepted) {
         if (onUpdate != null) {
           invokeCallback<Null>('onUpdate', () => onUpdate(new DragUpdateDetails( // ignore: STRONG_MODE_INVALID_CAST_FUNCTION_EXPR, https://github.com/dart-lang/sdk/issues/27504
@@ -308,7 +308,7 @@ abstract class DragGestureRecognizer extends OneSequenceGestureRecognizer {
   void acceptGesture(int pointer) {
     if (_state != _DragState.accepted) {
       _state = _DragState.accepted;
-      Offset delta = _pendingDragOffset;
+      final Offset delta = _pendingDragOffset;
       _pendingDragOffset = Offset.zero;
       if (onStart != null) {
         invokeCallback<Null>('onStart', () => onStart(new DragStartDetails( // ignore: STRONG_MODE_INVALID_CAST_FUNCTION_EXPR, https://github.com/dart-lang/sdk/issues/27504
@@ -339,10 +339,10 @@ abstract class DragGestureRecognizer extends OneSequenceGestureRecognizer {
         invokeCallback<Null>('onCancel', onCancel); // ignore: STRONG_MODE_INVALID_CAST_FUNCTION_EXPR, https://github.com/dart-lang/sdk/issues/27504
       return;
     }
-    bool wasAccepted = (_state == _DragState.accepted);
+    final bool wasAccepted = (_state == _DragState.accepted);
     _state = _DragState.ready;
     if (wasAccepted && onEnd != null) {
-      VelocityTracker tracker = _velocityTrackers[pointer];
+      final VelocityTracker tracker = _velocityTrackers[pointer];
       assert(tracker != null);
 
       Velocity velocity = tracker.getVelocity();

packages/flutter/lib/src/gestures/lsq_solver.dart

@@ -94,14 +94,14 @@ class LeastSquaresSolver {
     if (degree > x.length) // Not enough data to fit a curve.
       return null;
 
-    PolynomialFit result = new PolynomialFit(degree);
+    final PolynomialFit result = new PolynomialFit(degree);
 
     // Shorthands for the purpose of notation equivalence to original C++ code.
     final int m = x.length;
     final int n = degree + 1;
 
     // Expand the X vector to a matrix A, pre-multiplied by the weights.
-    _Matrix a = new _Matrix(n, m);
+    final _Matrix a = new _Matrix(n, m);
     for (int h = 0; h < m; h += 1) {
       a.set(0, h, w[h]);
       for (int i = 1; i < n; i += 1)
@@ -111,25 +111,25 @@ class LeastSquaresSolver {
     // Apply the Gram-Schmidt process to A to obtain its QR decomposition.
 
     // Orthonormal basis, column-major ordVectorer.
-    _Matrix q = new _Matrix(n, m);
+    final _Matrix q = new _Matrix(n, m);
     // Upper triangular matrix, row-major order.
-    _Matrix r = new _Matrix(n, n);
+    final _Matrix r = new _Matrix(n, n);
     for (int j = 0; j < n; j += 1) {
       for (int h = 0; h < m; h += 1)
         q.set(j, h, a.get(j, h));
       for (int i = 0; i < j; i += 1) {
-        double dot = q.getRow(j) * q.getRow(i);
+        final double dot = q.getRow(j) * q.getRow(i);
         for (int h = 0; h < m; h += 1)
           q.set(j, h, q.get(j, h) - dot * q.get(i, h));
       }
 
-      double norm = q.getRow(j).norm();
+      final double norm = q.getRow(j).norm();
       if (norm < 0.000001) {
         // Vectors are linearly dependent or zero so no solution.
         return null;
       }
 
-      double inverseNorm = 1.0 / norm;
+      final double inverseNorm = 1.0 / norm;
       for (int h = 0; h < m; h += 1)
         q.set(j, h, q.get(j, h) * inverseNorm);
       for (int i = 0; i < n; i += 1)
@@ -138,7 +138,7 @@ class LeastSquaresSolver {
 
     // Solve R B = Qt W Y to find B.  This is easy because R is upper triangular.
     // We just work from bottom-right to top-left calculating B's coefficients.
-    _Vector wy = new _Vector(m);
+    final _Vector wy = new _Vector(m);
     for (int h = 0; h < m; h += 1)
       wy[h] = y[h] * w[h];
     for (int i = n - 1; i >= 0; i -= 1) {

packages/flutter/lib/src/gestures/multidrag.dart

@@ -206,7 +206,7 @@ abstract class MultiDragGestureRecognizer<T extends MultiDragPointerState> exten
     assert(event.pointer != null);
     assert(event.position != null);
     assert(!_pointers.containsKey(event.pointer));
-    T state = createNewPointerState(event);
+    final T state = createNewPointerState(event);
     _pointers[event.pointer] = state;
     GestureBinding.instance.pointerRouter.addRoute(event.pointer, _handleEvent);
     state._setArenaEntry(GestureBinding.instance.gestureArena.add(event.pointer, this));
@@ -223,7 +223,7 @@ abstract class MultiDragGestureRecognizer<T extends MultiDragPointerState> exten
     assert(event.timeStamp != null);
     assert(event.position != null);
     assert(_pointers.containsKey(event.pointer));
-    T state = _pointers[event.pointer];
+    final T state = _pointers[event.pointer];
     if (event is PointerMoveEvent) {
       state._move(event);
       // We might be disposed here.
@@ -248,7 +248,7 @@ abstract class MultiDragGestureRecognizer<T extends MultiDragPointerState> exten
   @override
   void acceptGesture(int pointer) {
     assert(_pointers != null);
-    T state = _pointers[pointer];
+    final T state = _pointers[pointer];
     if (state == null)
       return; // We might already have canceled this drag if the up comes before the accept.
     state.accepted((Point initialPosition) => _startDrag(initialPosition, pointer));
@@ -256,7 +256,7 @@ abstract class MultiDragGestureRecognizer<T extends MultiDragPointerState> exten
 
   Drag _startDrag(Point initialPosition, int pointer) {
     assert(_pointers != null);
-    T state = _pointers[pointer];
+    final T state = _pointers[pointer];
     assert(state != null);
     assert(state._pendingDelta != null);
     Drag drag;
@@ -274,7 +274,7 @@ abstract class MultiDragGestureRecognizer<T extends MultiDragPointerState> exten
   void rejectGesture(int pointer) {
     assert(_pointers != null);
     if (_pointers.containsKey(pointer)) {
-      T state = _pointers[pointer];
+      final T state = _pointers[pointer];
       assert(state != null);
       state.rejected();
       _removeState(pointer);

packages/flutter/lib/src/gestures/multitap.dart

@@ -60,7 +60,7 @@ class _TapTracker {
   }
 
   bool isWithinTolerance(PointerEvent event, double tolerance) {
-    Offset offset = event.position - _initialPosition;
+    final Offset offset = event.position - _initialPosition;
     return offset.distance <= tolerance;
   }
 }
@@ -103,7 +103,7 @@ class DoubleTapGestureRecognizer extends GestureRecognizer {
         !_firstTap.isWithinTolerance(event, kDoubleTapSlop))
       return;
     _stopDoubleTapTimer();
-    _TapTracker tracker = new _TapTracker(
+    final _TapTracker tracker = new _TapTracker(
       event: event,
       entry: GestureBinding.instance.gestureArena.add(event.pointer, this)
     );
@@ -112,7 +112,7 @@ class DoubleTapGestureRecognizer extends GestureRecognizer {
   }
 
   void _handleEvent(PointerEvent event) {
-    _TapTracker tracker = _trackers[event.pointer];
+    final _TapTracker tracker = _trackers[event.pointer];
     assert(tracker != null);
     if (event is PointerUpEvent) {
       if (_firstTap == null)
@@ -166,7 +166,7 @@ class DoubleTapGestureRecognizer extends GestureRecognizer {
     if (_firstTap != null) {
       // Note, order is important below in order for the resolve -> reject logic
       // to work properly.
-      _TapTracker tracker = _firstTap;
+      final _TapTracker tracker = _firstTap;
       _firstTap = null;
       _reject(tracker);
       GestureBinding.instance.gestureArena.release(tracker.pointer);
@@ -196,7 +196,7 @@ class DoubleTapGestureRecognizer extends GestureRecognizer {
   }
 
   void _clearTrackers() {
-    List<_TapTracker> localTrackers = new List<_TapTracker>.from(_trackers.values);
+    final List<_TapTracker> localTrackers = new List<_TapTracker>.from(_trackers.values);
     for (_TapTracker tracker in localTrackers)
       _reject(tracker);
     assert(_trackers.isEmpty);

packages/flutter/lib/src/gestures/pointer_router.dart

@@ -24,7 +24,7 @@ class PointerRouter {
   /// Routes added reentrantly within [PointerRouter.route] will take effect when
   /// routing the next event.
   void addRoute(int pointer, PointerRoute route) {
-    LinkedHashSet<PointerRoute> routes = _routeMap.putIfAbsent(pointer, () => new LinkedHashSet<PointerRoute>());
+    final LinkedHashSet<PointerRoute> routes = _routeMap.putIfAbsent(pointer, () => new LinkedHashSet<PointerRoute>());
     assert(!routes.contains(route));
     routes.add(route);
   }
@@ -38,7 +38,7 @@ class PointerRouter {
   /// immediately.
   void removeRoute(int pointer, PointerRoute route) {
     assert(_routeMap.containsKey(pointer));
-    LinkedHashSet<PointerRoute> routes = _routeMap[pointer];
+    final LinkedHashSet<PointerRoute> routes = _routeMap[pointer];
     assert(routes.contains(route));
     routes.remove(route);
     if (routes.isEmpty)
@@ -93,8 +93,8 @@ class PointerRouter {
   /// Routes are called in the order in which they were added to the
   /// PointerRouter object.
   void route(PointerEvent event) {
-    LinkedHashSet<PointerRoute> routes = _routeMap[event.pointer];
+    final LinkedHashSet<PointerRoute> routes = _routeMap[event.pointer];
-    List<PointerRoute> globalRoutes = new List<PointerRoute>.from(_globalRoutes);
+    final List<PointerRoute> globalRoutes = new List<PointerRoute>.from(_globalRoutes);
     if (routes != null) {
       for (PointerRoute route in new List<PointerRoute>.from(routes)) {
         if (routes.contains(route))

packages/flutter/lib/src/gestures/recognizer.dart

@@ -113,7 +113,7 @@ abstract class OneSequenceGestureRecognizer extends GestureRecognizer {
   @protected
   @mustCallSuper
   void resolve(GestureDisposition disposition) {
-    List<GestureArenaEntry> localEntries = new List<GestureArenaEntry>.from(_entries.values);
+    final List<GestureArenaEntry> localEntries = new List<GestureArenaEntry>.from(_entries.values);
     _entries.clear();
     for (GestureArenaEntry entry in localEntries)
       entry.resolve(disposition);
@@ -303,7 +303,7 @@ abstract class PrimaryPointerGestureRecognizer extends OneSequenceGestureRecogni
   }
 
   double _getDistance(PointerEvent event) {
-    Offset offset = event.position - initialPosition;
+    final Offset offset = event.position - initialPosition;
     return offset.distance;
   }
 

packages/flutter/lib/src/gestures/scale.dart

@@ -136,7 +136,7 @@ class ScaleGestureRecognizer extends OneSequenceGestureRecognizer {
     assert(_state != ScaleState.ready);
     bool configChanged = false;
     if (event is PointerMoveEvent) {
-      VelocityTracker tracker = _velocityTrackers[event.pointer];
+      final VelocityTracker tracker = _velocityTrackers[event.pointer];
       assert(tracker != null);
       tracker.addPosition(event.timeStamp, event.position);
       _pointerLocations[event.pointer] = event.position;
@@ -154,7 +154,7 @@ class ScaleGestureRecognizer extends OneSequenceGestureRecognizer {
   }
 
   void _update(bool configChanged, int pointer) {
-    int count = _pointerLocations.keys.length;
+    final int count = _pointerLocations.keys.length;
 
     // Compute the focal point
     Point focalPoint = Point.origin;
@@ -172,7 +172,7 @@ class ScaleGestureRecognizer extends OneSequenceGestureRecognizer {
       _initialSpan = _currentSpan;
       if (_state == ScaleState.started) {
         if (onEnd != null) {
-          VelocityTracker tracker = _velocityTrackers[pointer];
+          final VelocityTracker tracker = _velocityTrackers[pointer];
           assert(tracker != null);
 
           Velocity velocity = tracker.getVelocity();

packages/flutter/lib/src/gestures/team.dart

@@ -52,7 +52,7 @@ class _CombiningGestureArenaMember extends GestureArenaMember {
   void _close() {
     assert(!_resolved);
     _resolved = true;
-    _CombiningGestureArenaMember combiner = _owner._combiners.remove(_pointer);
+    final _CombiningGestureArenaMember combiner = _owner._combiners.remove(_pointer);
     assert(combiner == this);
   }
 
@@ -100,7 +100,7 @@ class GestureArenaTeam {
   /// To assign a gesture recognizer to a team, see
   /// [OneSequenceGestureRecognizer.team].
   GestureArenaEntry add(int pointer, GestureArenaMember member) {
-    _CombiningGestureArenaMember combiner = _combiners.putIfAbsent(
+    final _CombiningGestureArenaMember combiner = _combiners.putIfAbsent(
         pointer, () => new _CombiningGestureArenaMember(this, pointer));
     return combiner._add(pointer, member);
   }

packages/flutter/lib/src/gestures/velocity_tracker.dart

@@ -63,30 +63,30 @@ class _LeastSquaresVelocityTrackerStrategy extends _VelocityTrackerStrategy {
   @override
   _Estimate getEstimate() {
     // Iterate over movement samples in reverse time order and collect samples.
-    List<double> x = new List<double>();
+    final List<double> x = new List<double>();
-    List<double> y = new List<double>();
+    final List<double> y = new List<double>();
-    List<double> w = new List<double>();
+    final List<double> w = new List<double>();
-    List<double> time = new List<double>();
+    final List<double> time = new List<double>();
     int m = 0;
     int index = _index;
 
-    _Movement newestMovement = _movements[index];
+    final _Movement newestMovement = _movements[index];
     _Movement previousMovement = newestMovement;
     if (newestMovement == null)
       return null;
 
     do {
-      _Movement movement = _movements[index];
+      final _Movement movement = _movements[index];
       if (movement == null)
         break;
 
-      double age = (newestMovement.eventTime - movement.eventTime).inMilliseconds.toDouble();
+      final double age = (newestMovement.eventTime - movement.eventTime).inMilliseconds.toDouble();
-      double delta = (movement.eventTime - previousMovement.eventTime).inMilliseconds.abs().toDouble();
+      final double delta = (movement.eventTime - previousMovement.eventTime).inMilliseconds.abs().toDouble();
       previousMovement = movement;
       if (age > kHorizonMilliseconds || delta > kAssumePointerMoveStoppedMilliseconds)
         break;
 
-      Point position = movement.position;
+      final Point position = movement.position;
       x.add(position.x);
       y.add(position.y);
       w.add(1.0);
@@ -102,11 +102,11 @@ class _LeastSquaresVelocityTrackerStrategy extends _VelocityTrackerStrategy {
       n = m - 1;
 
     if (n >= 1) {
-      LeastSquaresSolver xSolver = new LeastSquaresSolver(time, x, w);
+      final LeastSquaresSolver xSolver = new LeastSquaresSolver(time, x, w);
-      PolynomialFit xFit = xSolver.solve(n);
+      final PolynomialFit xFit = xSolver.solve(n);
       if (xFit != null) {
-        LeastSquaresSolver ySolver = new LeastSquaresSolver(time, y, w);
+        final LeastSquaresSolver ySolver = new LeastSquaresSolver(time, y, w);
-        PolynomialFit yFit = ySolver.solve(n);
+        final PolynomialFit yFit = ySolver.solve(n);
         if (yFit != null) {
           return new _Estimate(
             xCoefficients: xFit.coefficients,
@@ -223,7 +223,7 @@ class VelocityTracker {
   /// getVelocity() will return null if no estimate is available or if
   /// the velocity is zero.
   Velocity getVelocity() {
-    _Estimate estimate = _strategy.getEstimate();
+    final _Estimate estimate = _strategy.getEstimate();
     if (estimate != null && estimate.degree >= 1) {
       return new Velocity(
         pixelsPerSecond: new Offset( // convert from pixels/ms to pixels/s

packages/flutter/lib/src/material/about.dart

@@ -460,7 +460,7 @@ class _LicensePageState extends State<LicensePage> {
 }
 
 String _defaultApplicationName(BuildContext context) {
-  Title ancestorTitle = context.ancestorWidgetOfExactType(Title);
+  final Title ancestorTitle = context.ancestorWidgetOfExactType(Title);
   return ancestorTitle?.title ?? Platform.resolvedExecutable.split(Platform.pathSeparator).last;
 }
 

packages/flutter/lib/src/material/app.dart

@@ -209,7 +209,7 @@ class _MaterialAppState extends State<MaterialApp> {
 
   @override
   Widget build(BuildContext context) {
-    ThemeData theme = config.theme ?? new ThemeData.fallback();
+    final ThemeData theme = config.theme ?? new ThemeData.fallback();
     Widget result = new AnimatedTheme(
       data: theme,
       isMaterialAppTheme: true,

packages/flutter/lib/src/material/app_bar.dart

@@ -337,7 +337,7 @@ class _AppBarState extends State<AppBar> {
   @override
   void dependenciesChanged() {
     super.dependenciesChanged();
-    ScaffoldState scaffold = Scaffold.of(context);
+    final ScaffoldState scaffold = Scaffold.of(context);
     _hasDrawer = scaffold?.hasDrawer ?? false;
     _canPop = ModalRoute.of(context)?.canPop ?? false;
   }
@@ -354,7 +354,7 @@ class _AppBarState extends State<AppBar> {
     TextStyle centerStyle = config.textTheme?.title ?? themeData.primaryTextTheme.title;
     TextStyle sideStyle = config.textTheme?.body1 ?? themeData.primaryTextTheme.body1;
 
-    Brightness brightness = config.brightness ?? themeData.primaryColorBrightness;
+    final Brightness brightness = config.brightness ?? themeData.primaryColorBrightness;
     SystemChrome.setSystemUIOverlayStyle(brightness == Brightness.dark
       ? SystemUiOverlayStyle.light
       : SystemUiOverlayStyle.dark);
@@ -419,7 +419,7 @@ class _AppBarState extends State<AppBar> {
       );
     }
 
-    Widget toolbar = new Padding(
+    final Widget toolbar = new Padding(
       padding: const EdgeInsets.only(right: 4.0),
       child: new CustomMultiChildLayout(
         delegate: new _ToolbarLayout(

packages/flutter/lib/src/material/arc.dart

@@ -167,7 +167,7 @@ T _maxBy<T>(Iterable<T> input, _KeyFunc<T> keyFunc) {
   T maxValue;
   dynamic maxKey;
   for (T value in input) {
-    dynamic key = keyFunc(value);
+    final dynamic key = keyFunc(value);
     if (maxKey == null || key > maxKey) {
       maxValue = value;
       maxKey = key;

packages/flutter/lib/src/material/bottom_navigation_bar.dart

@@ -285,7 +285,7 @@ class BottomNavigationBarState extends State<BottomNavigationBar> with TickerPro
         )..controller.addStatusListener((AnimationStatus status) {
           if (status == AnimationStatus.completed) {
             setState(() {
-              _Circle circle = _circles.removeFirst();
+              final _Circle circle = _circles.removeFirst();
               _backgroundColor = circle.color;
               circle.dispose();
             });
@@ -575,8 +575,8 @@ class _RadialPainter extends CustomPainter {
       final Paint paint = new Paint()..color = circle.color;
       final Rect rect = new Rect.fromLTWH(0.0, 0.0, size.width, size.height);
       canvas.clipRect(rect);
-      double navWidth = math.min(bottomNavMaxWidth, size.width);
+      final double navWidth = math.min(bottomNavMaxWidth, size.width);
-      Point center = new Point(
+      final Point center = new Point(
         (size.width - navWidth) / 2.0 + circle.offset.dx * navWidth,
         circle.offset.dy * size.height
       );

packages/flutter/lib/src/material/bottom_sheet.dart

@@ -109,7 +109,7 @@ class _BottomSheetState extends State<BottomSheet> {
     if (_dismissUnderway)
       return;
     if (details.velocity.pixelsPerSecond.dy > _kMinFlingVelocity) {
-      double flingVelocity = -details.velocity.pixelsPerSecond.dy / _childHeight;
+      final double flingVelocity = -details.velocity.pixelsPerSecond.dy / _childHeight;
       if (config.animationController.value > 0.0)
         config.animationController.fling(velocity: flingVelocity);
       if (flingVelocity < 0.0)

packages/flutter/lib/src/material/button.dart

@@ -100,7 +100,7 @@ class ButtonTheme extends InheritedWidget {
   /// ButtonTheme theme = ButtonTheme.of(context);
   /// ```
   static ButtonTheme of(BuildContext context) {
-    ButtonTheme result = context.inheritFromWidgetOfExactType(ButtonTheme);
+    final ButtonTheme result = context.inheritFromWidgetOfExactType(ButtonTheme);
     return result ?? const ButtonTheme();
   }
 

packages/flutter/lib/src/material/checkbox.dart

@@ -91,7 +91,7 @@ class _CheckboxState extends State<Checkbox> with TickerProviderStateMixin {
   @override
   Widget build(BuildContext context) {
     assert(debugCheckHasMaterial(context));
-    ThemeData themeData = Theme.of(context);
+    final ThemeData themeData = Theme.of(context);
     return new _CheckboxRenderObjectWidget(
       value: config.value,
       activeColor: config.activeColor ?? themeData.accentColor,
@@ -174,40 +174,40 @@ class _RenderCheckbox extends RenderToggleable {
 
     paintRadialReaction(canvas, offset, size.center(Point.origin));
 
-    double t = position.value;
+    final double t = position.value;
 
     Color borderColor = inactiveColor;
     if (onChanged != null)
       borderColor = t >= 0.25 ? activeColor : Color.lerp(inactiveColor, activeColor, t * 4.0);
 
-    Paint paint = new Paint()
+    final Paint paint = new Paint()
       ..color = borderColor;
 
-    double inset = 1.0 - (t - 0.5).abs() * 2.0;
+    final double inset = 1.0 - (t - 0.5).abs() * 2.0;
-    double rectSize = _kEdgeSize - inset * _kStrokeWidth;
+    final double rectSize = _kEdgeSize - inset * _kStrokeWidth;
-    Rect rect = new Rect.fromLTWH(offsetX + inset, offsetY + inset, rectSize, rectSize);
+    final Rect rect = new Rect.fromLTWH(offsetX + inset, offsetY + inset, rectSize, rectSize);
 
-    RRect outer = new RRect.fromRectAndRadius(rect, _kEdgeRadius);
+    final RRect outer = new RRect.fromRectAndRadius(rect, _kEdgeRadius);
     if (t <= 0.5) {
       // Outline
-      RRect inner = outer.deflate(math.min(rectSize / 2.0, _kStrokeWidth + rectSize * t));
+      final RRect inner = outer.deflate(math.min(rectSize / 2.0, _kStrokeWidth + rectSize * t));
       canvas.drawDRRect(outer, inner, paint);
     } else {
       // Background
       canvas.drawRRect(outer, paint);
 
       // White inner check
-      double value = (t - 0.5) * 2.0;
+      final double value = (t - 0.5) * 2.0;
       paint
         ..color = const Color(0xFFFFFFFF)
         ..style = PaintingStyle.stroke
         ..strokeWidth = _kStrokeWidth;
-      Path path = new Path();
+      final Path path = new Path();
-      Point start = const Point(_kEdgeSize * 0.15, _kEdgeSize * 0.45);
+      final Point start = const Point(_kEdgeSize * 0.15, _kEdgeSize * 0.45);
-      Point mid = const Point(_kEdgeSize * 0.4, _kEdgeSize * 0.7);
+      final Point mid = const Point(_kEdgeSize * 0.4, _kEdgeSize * 0.7);
-      Point end = const Point(_kEdgeSize * 0.85, _kEdgeSize * 0.25);
+      final Point end = const Point(_kEdgeSize * 0.85, _kEdgeSize * 0.25);
-      Point drawStart = Point.lerp(start, mid, 1.0 - value);
+      final Point drawStart = Point.lerp(start, mid, 1.0 - value);
-      Point drawEnd = Point.lerp(mid, end, value);
+      final Point drawEnd = Point.lerp(mid, end, value);
       path.moveTo(offsetX + drawStart.x, offsetY + drawStart.y);
       path.lineTo(offsetX + mid.x, offsetY + mid.y);
       path.lineTo(offsetX + drawEnd.x, offsetY + drawEnd.y);

packages/flutter/lib/src/material/chip.dart

@@ -69,7 +69,7 @@ class Chip extends StatelessWidget {
     double leftPadding = 12.0;
     double rightPadding = 12.0;
 
-    List<Widget> children = <Widget>[];
+    final List<Widget> children = <Widget>[];
 
     if (avatar != null) {
       leftPadding = 0.0;

packages/flutter/lib/src/material/data_table.dart

@@ -317,7 +317,7 @@ class DataTable extends StatelessWidget {
   static int _initOnlyTextColumn(List<DataColumn> columns) {
     int result;
     for (int index = 0; index < columns.length; index += 1) {
-      DataColumn column = columns[index];
+      final DataColumn column = columns[index];
       if (!column.numeric) {
         if (result != null)
           return null;
@@ -507,8 +507,8 @@ class DataTable extends StatelessWidget {
     final bool showCheckboxColumn = rows.any((DataRow row) => row.onSelectChanged != null);
     final bool allChecked = showCheckboxColumn && !rows.any((DataRow row) => row.onSelectChanged != null && !row.selected);
 
-    List<TableColumnWidth> tableColumns = new List<TableColumnWidth>(columns.length + (showCheckboxColumn ? 1 : 0));
+    final List<TableColumnWidth> tableColumns = new List<TableColumnWidth>(columns.length + (showCheckboxColumn ? 1 : 0));
-    List<TableRow> tableRows = new List<TableRow>.generate(
+    final List<TableRow> tableRows = new List<TableRow>.generate(
       rows.length + 1, // the +1 is for the header row
       (int index) {
         return new TableRow(
@@ -544,7 +544,7 @@ class DataTable extends StatelessWidget {
     }
 
     for (int dataColumnIndex = 0; dataColumnIndex < columns.length; dataColumnIndex += 1) {
-      DataColumn column = columns[dataColumnIndex];
+      final DataColumn column = columns[dataColumnIndex];
       final EdgeInsets padding = new EdgeInsets.fromLTRB(
         dataColumnIndex == 0 ? showCheckboxColumn ? _kTablePadding / 2.0 : _kTablePadding : _kColumnSpacing / 2.0,
         0.0,
@@ -568,7 +568,7 @@ class DataTable extends StatelessWidget {
       );
       rowIndex = 1;
       for (DataRow row in rows) {
-        DataCell cell = row.cells[dataColumnIndex];
+        final DataCell cell = row.cells[dataColumnIndex];
         tableRows[rowIndex].children[displayColumnIndex] = _buildDataCell(
           context: context,
           padding: padding,
@@ -629,22 +629,22 @@ class TableRowInkWell extends InkResponse {
     return () {
       RenderObject cell = referenceBox;
       AbstractNode table = cell.parent;
-      Matrix4 transform = new Matrix4.identity();
+      final Matrix4 transform = new Matrix4.identity();
       while (table is RenderObject && table is! RenderTable) {
-        RenderTable parentBox = table;
+        final RenderTable parentBox = table;
         parentBox.applyPaintTransform(cell, transform);
         assert(table == cell.parent);
         cell = table;
         table = table.parent;
       }
       if (table is RenderTable) {
-        TableCellParentData cellParentData = cell.parentData;
+        final TableCellParentData cellParentData = cell.parentData;
         assert(cellParentData.y != null);
-        Rect rect = table.getRowBox(cellParentData.y);
+        final Rect rect = table.getRowBox(cellParentData.y);
         // The rect is in the table's coordinate space. We need to change it to the
         // TableRowInkWell's coordinate space.
         table.applyPaintTransform(cell, transform);
-        Offset offset = MatrixUtils.getAsTranslation(transform);
+        final Offset offset = MatrixUtils.getAsTranslation(transform);
         if (offset != null)
           return rect.shift(-offset);
       }
@@ -734,7 +734,7 @@ class _SortArrowState extends State<_SortArrow> with TickerProviderStateMixin {
   void didUpdateConfig(_SortArrow oldConfig) {
     super.didUpdateConfig(oldConfig);
     bool skipArrow = false;
-    bool newDown = config.down != null ? config.down : _down;
+    final bool newDown = config.down != null ? config.down : _down;
     if (oldConfig.visible != config.visible) {
       if (config.visible && (_opacityController.status == AnimationStatus.dismissed)) {
         _orientationController.stop();

packages/flutter/lib/src/material/date_picker.dart

@@ -68,8 +68,8 @@ class _DatePickerHeader extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    ThemeData themeData = Theme.of(context);
+    final ThemeData themeData = Theme.of(context);
-    TextTheme headerTextTheme = themeData.primaryTextTheme;
+    final TextTheme headerTextTheme = themeData.primaryTextTheme;
     Color dayColor;
     Color yearColor;
     switch(themeData.primaryColorBrightness) {
@@ -82,8 +82,8 @@ class _DatePickerHeader extends StatelessWidget {
         yearColor = mode == _DatePickerMode.year ? Colors.white : Colors.white70;
         break;
     }
-    TextStyle dayStyle = headerTextTheme.display1.copyWith(color: dayColor, height: 1.4);
+    final TextStyle dayStyle = headerTextTheme.display1.copyWith(color: dayColor, height: 1.4);
-    TextStyle yearStyle = headerTextTheme.subhead.copyWith(color: yearColor, height: 1.4);
+    final TextStyle yearStyle = headerTextTheme.subhead.copyWith(color: yearColor, height: 1.4);
 
     Color backgroundColor;
     switch (themeData.brightness) {
@@ -386,7 +386,7 @@ class _MonthPickerState extends State<MonthPicker> {
 
   void _updateCurrentDate() {
     _todayDate = new DateTime.now();
-    DateTime tomorrow = new DateTime(_todayDate.year, _todayDate.month, _todayDate.day + 1);
+    final DateTime tomorrow = new DateTime(_todayDate.year, _todayDate.month, _todayDate.day + 1);
     Duration timeUntilTomorrow = tomorrow.difference(_todayDate);
     timeUntilTomorrow += const Duration(seconds: 1);  // so we don't miss it by rounding
     if (_timer != null)
@@ -668,13 +668,13 @@ class _DatePickerDialogState extends State<_DatePickerDialog> {
 
   @override
   Widget build(BuildContext context) {
-    Widget picker = new Flexible(
+    final Widget picker = new Flexible(
       child: new SizedBox(
         height: _kMaxDayPickerHeight,
         child: _buildPicker(),
       ),
     );
-    Widget actions = new ButtonTheme.bar(
+    final Widget actions = new ButtonTheme.bar(
       child: new ButtonBar(
         children: <Widget>[
           new FlatButton(
@@ -692,7 +692,7 @@ class _DatePickerDialogState extends State<_DatePickerDialog> {
     return new Dialog(
       child: new OrientationBuilder(
         builder: (BuildContext context, Orientation orientation) {
-          Widget header = new _DatePickerHeader(
+          final Widget header = new _DatePickerHeader(
             selectedDate: _selectedDate,
             mode: _mode,
             onModeChanged: _handleModeChanged,

packages/flutter/lib/src/material/debug.dart

@@ -22,7 +22,7 @@ import 'material.dart';
 bool debugCheckHasMaterial(BuildContext context) {
   assert(() {
     if (context.widget is! Material && context.ancestorWidgetOfExactType(Material) == null) {
-      Element element = context;
+      final Element element = context;
       throw new FlutterError(
         'No Material widget found.\n'
         '${context.widget.runtimeType} widgets require a Material widget ancestor.\n'

packages/flutter/lib/src/material/drawer.dart

@@ -148,7 +148,7 @@ class DrawerControllerState extends State<DrawerController> with SingleTickerPro
 
   void _ensureHistoryEntry() {
     if (_historyEntry == null) {
-      ModalRoute<dynamic> route = ModalRoute.of(context);
+      final ModalRoute<dynamic> route = ModalRoute.of(context);
       if (route != null) {
         _historyEntry = new LocalHistoryEntry(onRemove: _handleHistoryEntryRemoved);
         route.addLocalHistoryEntry(_historyEntry);
@@ -196,7 +196,7 @@ class DrawerControllerState extends State<DrawerController> with SingleTickerPro
   }
 
   double get _width {
-    RenderBox drawerBox = _drawerKey.currentContext?.findRenderObject();
+    final RenderBox drawerBox = _drawerKey.currentContext?.findRenderObject();
     if (drawerBox != null)
       return drawerBox.size.width;
     return _kWidth; // drawer not being shown currently

packages/flutter/lib/src/material/drawer_item.dart

@@ -84,7 +84,7 @@ class DrawerItem extends StatelessWidget {
   }
 
   TextStyle _getTextStyle(ThemeData themeData) {
-    TextStyle result = themeData.textTheme.body2;
+    final TextStyle result = themeData.textTheme.body2;
     if (selected) {
       switch (themeData.brightness) {
         case Brightness.light:
@@ -99,9 +99,9 @@ class DrawerItem extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     assert(debugCheckHasMaterial(context));
-    ThemeData themeData = Theme.of(context);
+    final ThemeData themeData = Theme.of(context);
 
-    List<Widget> children = <Widget>[];
+    final List<Widget> children = <Widget>[];
     if (icon != null) {
       children.add(
         new Padding(

packages/flutter/lib/src/material/expansion_panel.dart

@@ -114,7 +114,7 @@ class ExpansionPanelList extends StatelessWidget {
       if (_isChildExpanded(i) && i != 0 && !_isChildExpanded(i - 1))
         items.add(new MaterialGap(key: new ValueKey<int>(i * 2 - 1)));
 
-      Row header = new Row(
+      final Row header = new Row(
         children: <Widget>[
           new Expanded(
             child: new AnimatedContainer(

packages/flutter/lib/src/material/flexible_space_bar.dart

@@ -94,7 +94,7 @@ class _FlexibleSpaceBarState extends State<FlexibleSpaceBar> {
 
   @override
   Widget build(BuildContext context) {
-    _FlexibleSpaceBarSettings settings = context.inheritFromWidgetOfExactType(_FlexibleSpaceBarSettings);
+    final _FlexibleSpaceBarSettings settings = context.inheritFromWidgetOfExactType(_FlexibleSpaceBarSettings);
     assert(settings != null, 'A FlexibleSpaceBar must be wrapped in the widget returned by FlexibleSpaceBar.createSettings().');
 
     final List<Widget> children = <Widget>[];

packages/flutter/lib/src/material/grid_tile_bar.dart

@@ -73,8 +73,8 @@ class GridTileBar extends StatelessWidget {
     if (leading != null)
       children.add(new Padding(padding: const EdgeInsets.only(right: 8.0), child: leading));
 
-    ThemeData theme = Theme.of(context);
+    final ThemeData theme = Theme.of(context);
-    ThemeData darkTheme = new ThemeData(
+    final ThemeData darkTheme = new ThemeData(
       brightness: Brightness.dark,
       accentColor: theme.accentColor,
       accentColorBrightness: theme.accentColorBrightness

packages/flutter/lib/src/material/icon_theme.dart

@@ -56,12 +56,12 @@ class IconTheme extends InheritedWidget {
   /// IconThemeData theme = IconTheme.of(context);
   /// ```
   static IconThemeData of(BuildContext context) {
-    IconThemeData iconThemeData = _getInheritedIconThemData(context);
+    final IconThemeData iconThemeData = _getInheritedIconThemData(context);
     return iconThemeData.isConcrete ? iconThemeData : const IconThemeData.fallback().merge(iconThemeData);
   }
 
   static IconThemeData _getInheritedIconThemData(BuildContext context) {
-    IconTheme iconTheme = context.inheritFromWidgetOfExactType(IconTheme);
+    final IconTheme iconTheme = context.inheritFromWidgetOfExactType(IconTheme);
     return iconTheme?.data ?? Theme.of(context).iconTheme;
   }
 

packages/flutter/lib/src/material/icon_theme_data.dart

@@ -87,7 +87,7 @@ class IconThemeData {
 
   @override
   String toString() {
-    List<String> result = <String>[];
+    final List<String> result = <String>[];
     if (color != null)
       result.add('color: $color');
     if (_opacity != null)

packages/flutter/lib/src/material/ink_splash.dart

@@ -35,10 +35,10 @@ double _getTargetRadius(RenderBox referenceBox, bool containedInkWell, RectCallb
 }
 
 double _getSplashRadiusForPoistionInSize(Size bounds, Point position) {
-  double d1 = (position - bounds.topLeft(Point.origin)).distance;
+  final double d1 = (position - bounds.topLeft(Point.origin)).distance;
-  double d2 = (position - bounds.topRight(Point.origin)).distance;
+  final double d2 = (position - bounds.topRight(Point.origin)).distance;
-  double d3 = (position - bounds.bottomLeft(Point.origin)).distance;
+  final double d3 = (position - bounds.bottomLeft(Point.origin)).distance;
-  double d4 = (position - bounds.bottomRight(Point.origin)).distance;
+  final double d4 = (position - bounds.bottomRight(Point.origin)).distance;
   return math.max(math.max(d1, d2), math.max(d3, d4)).ceilToDouble();
 }
 

packages/flutter/lib/src/material/input.dart

@@ -157,7 +157,7 @@ class _InputFieldState extends State<InputField> {
     ];
 
     if (config.hintText != null && value.text.isEmpty) {
-      TextStyle hintStyle = config.hintStyle ??
+      final TextStyle hintStyle = config.hintStyle ??
         textStyle.copyWith(color: themeData.hintColor);
       stackChildren.add(
         new Positioned(
@@ -255,8 +255,8 @@ class _InputContainerState extends State<InputContainer> {
   @override
   Widget build(BuildContext context) {
     assert(debugCheckHasMaterial(context));
-    ThemeData themeData = Theme.of(context);
+    final ThemeData themeData = Theme.of(context);
-    String errorText = config.errorText;
+    final String errorText = config.errorText;
 
     final TextStyle textStyle = config.style ?? themeData.textTheme.subhead;
     Color activeColor = themeData.hintColor;
@@ -272,7 +272,7 @@ class _InputContainerState extends State<InputContainer> {
     }
     double topPadding = config.isDense ? 12.0 : 16.0;
 
-    List<Widget> stackChildren = <Widget>[];
+    final List<Widget> stackChildren = <Widget>[];
 
     // If we're not focused, there's not value, and labelText was provided,
     // then the label appears where the hint would. And we will not show
@@ -308,7 +308,7 @@ class _InputContainerState extends State<InputContainer> {
     }
 
     if (config.hintText != null) {
-      TextStyle hintStyle = textStyle.copyWith(color: themeData.hintColor);
+      final TextStyle hintStyle = textStyle.copyWith(color: themeData.hintColor);
       stackChildren.add(
         new Positioned(
           left: 0.0,
@@ -325,19 +325,19 @@ class _InputContainerState extends State<InputContainer> {
       );
     }
 
-    Color borderColor = errorText == null ? activeColor : themeData.errorColor;
+    final Color borderColor = errorText == null ? activeColor : themeData.errorColor;
-    double bottomPadding = config.isDense ? 8.0 : 1.0;
+    final double bottomPadding = config.isDense ? 8.0 : 1.0;
-    double bottomBorder = 2.0;
+    final double bottomBorder = 2.0;
-    double bottomHeight = config.isDense ? 14.0 : 18.0;
+    final double bottomHeight = config.isDense ? 14.0 : 18.0;
 
-    EdgeInsets padding = new EdgeInsets.only(top: topPadding, bottom: bottomPadding);
+    final EdgeInsets padding = new EdgeInsets.only(top: topPadding, bottom: bottomPadding);
-    Border border = new Border(
+    final Border border = new Border(
       bottom: new BorderSide(
         color: borderColor,
         width: bottomBorder,
       )
     );
-    EdgeInsets margin = new EdgeInsets.only(bottom: bottomHeight - (bottomPadding + bottomBorder));
+    final EdgeInsets margin = new EdgeInsets.only(bottom: bottomHeight - (bottomPadding + bottomBorder));
 
     Widget divider;
     if (!config.showDivider) {
@@ -361,7 +361,7 @@ class _InputContainerState extends State<InputContainer> {
     stackChildren.add(divider);
 
     if (!config.isDense) {
-      TextStyle errorStyle = themeData.textTheme.caption.copyWith(color: themeData.errorColor);
+      final TextStyle errorStyle = themeData.textTheme.caption.copyWith(color: themeData.errorColor);
       stackChildren.add(new Positioned(
         left: 0.0,
         bottom: 0.0,
@@ -372,8 +372,8 @@ class _InputContainerState extends State<InputContainer> {
     Widget textField = new Stack(children: stackChildren);
 
     if (config.icon != null) {
-      double iconSize = config.isDense ? 18.0 : 24.0;
+      final double iconSize = config.isDense ? 18.0 : 24.0;
-      double iconTop = topPadding + (textStyle.fontSize - iconSize) / 2.0;
+      final double iconTop = topPadding + (textStyle.fontSize - iconSize) / 2.0;
       textField = new Row(
         crossAxisAlignment: CrossAxisAlignment.start,
         children: <Widget>[

packages/flutter/lib/src/material/material.dart

@@ -203,10 +203,10 @@ class _MaterialState extends State<Material> with TickerProviderStateMixin {
 
   @override
   Widget build(BuildContext context) {
-    Color backgroundColor = _getBackgroundColor(context);
+    final Color backgroundColor = _getBackgroundColor(context);
     assert(backgroundColor != null || config.type == MaterialType.transparency);
     Widget contents = config.child;
-    BorderRadius radius = config.borderRadius ?? kMaterialEdges[config.type];
+    final BorderRadius radius = config.borderRadius ?? kMaterialEdges[config.type];
     if (contents != null) {
       contents = new AnimatedDefaultTextStyle(
         style: config.textStyle ?? Theme.of(context).textTheme.body1,
@@ -216,7 +216,7 @@ class _MaterialState extends State<Material> with TickerProviderStateMixin {
     }
     contents = new NotificationListener<LayoutChangedNotification>(
       onNotification: (LayoutChangedNotification notification) {
-        _RenderInkFeatures renderer = _inkFeatureRenderer.currentContext.findRenderObject();
+        final _RenderInkFeatures renderer = _inkFeatureRenderer.currentContext.findRenderObject();
         renderer._didChangeLayout();
         return true;
       },

packages/flutter/lib/src/material/mergeable_material.dart

@@ -239,7 +239,7 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
   }
 
   void _removeChild(int index) {
-    MergeableMaterialItem child = _children.removeAt(index);
+    final MergeableMaterialItem child = _children.removeAt(index);
 
     if (child is MaterialGap)
       _animationTuples[child.key] = null;
@@ -316,7 +316,7 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
 
               while (startOld < j) {
                 if (_children[startOld] is MaterialGap) {
-                  MaterialGap gap = _children[startOld];
+                  final MaterialGap gap = _children[startOld];
                   gapSizeSum += gap.size;
                 }
 
@@ -357,7 +357,7 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
 
               for (int k = startNew; k < i; k += 1) {
                 if (newChildren[k] is MaterialGap) {
-                  MaterialGap gap = newChildren[k];
+                  final MaterialGap gap = newChildren[k];
                   gapSizeSum += gap.size;
                 }
               }
@@ -366,7 +366,7 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
               // animate to their actual size.
               for (int k = startNew; k < i; k += 1) {
                 if (newChildren[k] is MaterialGap) {
-                  MaterialGap gap = newChildren[k];
+                  final MaterialGap gap = newChildren[k];
 
                   _animationTuples[gap.key].gapStart = gapSize * gap.size /
                       gapSizeSum;
@@ -382,7 +382,7 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
               _insertChild(startOld + k, newChildren[startNew + k]);
 
               if (newChildren[startNew + k] is MaterialGap) {
-                MaterialGap gap = newChildren[startNew + k];
+                final MaterialGap gap = newChildren[startNew + k];
                 _animationTuples[gap.key].controller.forward();
               }
             }
@@ -397,7 +397,7 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
 
             while (startOld < j) {
               if (_children[startOld] is MaterialGap) {
-                MaterialGap gap = _children[startOld];
+                final MaterialGap gap = _children[startOld];
                 gapSizeSum += gap.size;
               }
 
@@ -406,7 +406,7 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
             }
 
             if (gapSizeSum != 0.0) {
-              MaterialGap gap = new MaterialGap(
+              final MaterialGap gap = new MaterialGap(
                 key: new UniqueKey(),
                 size: gapSizeSum
               );
@@ -420,7 +420,7 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
             }
           } else if (oldLength == 1) {
             // Shrink gap.
-            MaterialGap gap = _children[startOld];
+            final MaterialGap gap = _children[startOld];
             _animationTuples[gap.key].gapStart = 0.0;
             _animationTuples[gap.key].controller.reverse();
           }
@@ -487,7 +487,7 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
   }
 
   double _getGapSize(int index) {
-    MaterialGap gap = _children[index];
+    final MaterialGap gap = _children[index];
 
     return lerpDouble(
       _animationTuples[gap.key].gapStart,
@@ -537,7 +537,7 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
           )
         );
       } else {
-        MaterialSlice slice = _children[i];
+        final MaterialSlice slice = _children[i];
         Widget child = slice.child;
 
         if (config.hasDividers) {
@@ -656,7 +656,7 @@ class _MergeableMaterialBlockBody extends BlockBody {
 
   @override
   void updateRenderObject(BuildContext context, RenderBlock renderObject) {
-    _MergeableMaterialRenderBlock materialRenderBlock = renderObject;
+    final _MergeableMaterialRenderBlock materialRenderBlock = renderObject;
     materialRenderBlock
       ..mainAxis = mainAxis
       ..boxShadows = boxShadows;

packages/flutter/lib/src/material/page.dart

@@ -250,7 +250,7 @@ class MaterialPageRoute<T> extends PageRoute<T> {
 
   @override
   Widget buildPage(BuildContext context, Animation<double> animation, Animation<double> forwardAnimation) {
-    Widget result = builder(context);
+    final Widget result = builder(context);
     assert(() {
       if (result == null) {
         throw new FlutterError(

packages/flutter/lib/src/material/paginated_data_table.dart

@@ -281,7 +281,7 @@ class PaginatedDataTableState extends State<PaginatedDataTable> {
   @override
   Widget build(BuildContext context) {
     // TODO(ianh): This whole build function doesn't handle RTL yet.
-    ThemeData themeData = Theme.of(context);
+    final ThemeData themeData = Theme.of(context);
     // HEADER
     final List<Widget> headerWidgets = <Widget>[];
     double leftPadding = 24.0;
@@ -318,7 +318,7 @@ class PaginatedDataTableState extends State<PaginatedDataTable> {
     final TextStyle footerTextStyle = themeData.textTheme.caption;
     final List<Widget> footerWidgets = <Widget>[];
     if (config.onRowsPerPageChanged != null) {
-      List<Widget> availableRowsPerPage = config.availableRowsPerPage
+      final List<Widget> availableRowsPerPage = config.availableRowsPerPage
         .where((int value) => value <= _rowCount)
         .map<DropdownMenuItem<int>>((int value) {
           return new DropdownMenuItem<int>(

packages/flutter/lib/src/material/popup_menu.dart

@@ -262,13 +262,13 @@ class _PopupMenu<T> extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    double unit = 1.0 / (route.items.length + 1.5); // 1.0 for the width and 0.5 for the last item's fade.
+    final double unit = 1.0 / (route.items.length + 1.5); // 1.0 for the width and 0.5 for the last item's fade.
-    List<Widget> children = <Widget>[];
+    final List<Widget> children = <Widget>[];
 
     for (int i = 0; i < route.items.length; ++i) {
       final double start = (i + 1) * unit;
       final double end = (start + 1.5 * unit).clamp(0.0, 1.0);
-      CurvedAnimation opacity = new CurvedAnimation(
+      final CurvedAnimation opacity = new CurvedAnimation(
         parent: route.animation,
         curve: new Interval(start, end)
       );
@@ -289,7 +289,7 @@ class _PopupMenu<T> extends StatelessWidget {
     final CurveTween width = new CurveTween(curve: new Interval(0.0, unit));
     final CurveTween height = new CurveTween(curve: new Interval(0.0, unit * route.items.length));
 
-    Widget child = new ConstrainedBox(
+    final Widget child = new ConstrainedBox(
       constraints: const BoxConstraints(
         minWidth: _kMenuMinWidth,
         maxWidth: _kMenuMaxWidth,

packages/flutter/lib/src/material/progress_indicator.dart

@@ -86,20 +86,20 @@ class _LinearProgressIndicatorPainter extends CustomPainter {
 
   @override
   void paint(Canvas canvas, Size size) {
-    Paint paint = new Paint()
+    final Paint paint = new Paint()
       ..color = backgroundColor
       ..style = PaintingStyle.fill;
     canvas.drawRect(Point.origin & size, paint);
 
     paint.color = valueColor;
     if (value != null) {
-      double width = value.clamp(0.0, 1.0) * size.width;
+      final double width = value.clamp(0.0, 1.0) * size.width;
       canvas.drawRect(Point.origin & new Size(width, size.height), paint);
     } else {
-      double startX = size.width * (1.5 * animationValue - 0.5);
+      final double startX = size.width * (1.5 * animationValue - 0.5);
-      double endX = startX + 0.5 * size.width;
+      final double endX = startX + 0.5 * size.width;
-      double x = startX.clamp(0.0, size.width);
+      final double x = startX.clamp(0.0, size.width);
-      double width = endX.clamp(0.0, size.width) - x;
+      final double width = endX.clamp(0.0, size.width) - x;
       canvas.drawRect(new Point(x, 0.0) & new Size(width, size.height), paint);
     }
   }
@@ -236,7 +236,7 @@ class _CircularProgressIndicatorPainter extends CustomPainter {
 
   @override
   void paint(Canvas canvas, Size size) {
-    Paint paint = new Paint()
+    final Paint paint = new Paint()
       ..color = valueColor
       ..strokeWidth = strokeWidth
       ..style = PaintingStyle.stroke;
@@ -409,12 +409,12 @@ class _RefreshProgressIndicatorPainter extends _CircularProgressIndicatorPainter
     final double innerRadius = radius - arrowheadRadius;
     final double outerRadius = radius + arrowheadRadius;
 
-    Path path = new Path()
+    final Path path = new Path()
       ..moveTo(radius + ux * innerRadius, radius + uy * innerRadius)
       ..lineTo(radius + ux * outerRadius, radius + uy * outerRadius)
       ..lineTo(arrowheadPointX, arrowheadPointY)
       ..close();
-    Paint paint = new Paint()
+    final Paint paint = new Paint()
       ..color = valueColor
       ..strokeWidth = strokeWidth
       ..style = PaintingStyle.fill;

packages/flutter/lib/src/material/radio.dart

@@ -112,7 +112,7 @@ class _RadioState<T> extends State<Radio<T>> with TickerProviderStateMixin {
   @override
   Widget build(BuildContext context) {
     assert(debugCheckHasMaterial(context));
-    ThemeData themeData = Theme.of(context);
+    final ThemeData themeData = Theme.of(context);
     return new Semantics(
       checked: config.value == config.groupValue,
       child: new _RadioRenderObjectWidget(
@@ -192,11 +192,11 @@ class _RenderRadio extends RenderToggleable {
 
     paintRadialReaction(canvas, offset, const Point(kRadialReactionRadius, kRadialReactionRadius));
 
-    Point center = (offset & size).center;
+    final Point center = (offset & size).center;
-    Color radioColor = onChanged != null ? activeColor : inactiveColor;
+    final Color radioColor = onChanged != null ? activeColor : inactiveColor;
 
     // Outer circle
-    Paint paint = new Paint()
+    final Paint paint = new Paint()
       ..color = Color.lerp(inactiveColor, radioColor, position.value)
       ..style = PaintingStyle.stroke
       ..strokeWidth = 2.0;

packages/flutter/lib/src/material/raised_button.dart

@@ -112,7 +112,7 @@ class RaisedButton extends StatelessWidget {
     } else {
       if (disabledColor != null)
         return disabledColor;
-      Brightness brightness = Theme.of(context).brightness;
+      final Brightness brightness = Theme.of(context).brightness;
       assert(brightness != null);
       switch (brightness) {
         case Brightness.light:

packages/flutter/lib/src/material/refresh_indicator.dart

@@ -303,7 +303,7 @@ class RefreshIndicatorState extends State<RefreshIndicator> with TickerProviderS
   void _show() {
     assert(_mode != _RefreshIndicatorMode.refresh);
     assert(_mode != _RefreshIndicatorMode.snap);
-    Completer<Null> completer = new Completer<Null>();
+    final Completer<Null> completer = new Completer<Null>();
     _pendingRefreshFuture = completer.future;
     _mode = _RefreshIndicatorMode.snap;
     _positionController
@@ -356,7 +356,7 @@ class RefreshIndicatorState extends State<RefreshIndicator> with TickerProviderS
 
   @override
   Widget build(BuildContext context) {
-    Widget child = new NotificationListener<ScrollNotification>(
+    final Widget child = new NotificationListener<ScrollNotification>(
       key: _key,
       onNotification: _handleScrollNotification,
       child: new NotificationListener<OverscrollIndicatorNotification>(

packages/flutter/lib/src/material/scaffold.dart

@@ -469,10 +469,10 @@ class Scaffold extends StatefulWidget {
     assert(registerForUpdates != null);
     assert(context != null);
     if (registerForUpdates) {
-      _ScaffoldScope scaffold = context.inheritFromWidgetOfExactType(_ScaffoldScope);
+      final _ScaffoldScope scaffold = context.inheritFromWidgetOfExactType(_ScaffoldScope);
       return scaffold?.hasDrawer ?? false;
     } else {
-      ScaffoldState scaffold = context.ancestorStateOfType(const TypeMatcher<ScaffoldState>());
+      final ScaffoldState scaffold = context.ancestorStateOfType(const TypeMatcher<ScaffoldState>());
       return scaffold?.hasDrawer ?? false;
     }
   }
@@ -640,12 +640,12 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin {
       _currentBottomSheet.close();
       assert(_currentBottomSheet == null);
     }
-    Completer<T> completer = new Completer<T>();
+    final Completer<T> completer = new Completer<T>();
-    GlobalKey<_PersistentBottomSheetState> bottomSheetKey = new GlobalKey<_PersistentBottomSheetState>();
+    final GlobalKey<_PersistentBottomSheetState> bottomSheetKey = new GlobalKey<_PersistentBottomSheetState>();
-    AnimationController controller = BottomSheet.createAnimationController(this)
+    final AnimationController controller = BottomSheet.createAnimationController(this)
       ..forward();
     _PersistentBottomSheet bottomSheet;
-    LocalHistoryEntry entry = new LocalHistoryEntry(
+    final LocalHistoryEntry entry = new LocalHistoryEntry(
       onRemove: () {
         assert(_currentBottomSheet._widget == bottomSheet);
         assert(bottomSheetKey.currentState != null);
@@ -758,7 +758,7 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin {
   @override
   Widget build(BuildContext context) {
     EdgeInsets padding = MediaQuery.of(context).padding;
-    ThemeData themeData = Theme.of(context);
+    final ThemeData themeData = Theme.of(context);
     if (!config.resizeToAvoidBottomPadding)
       padding = new EdgeInsets.fromLTRB(padding.left, padding.top, padding.right, 0.0);
 
@@ -783,9 +783,9 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin {
 
     if (config.appBar != null) {
       assert(config.appBar.primary || padding.top == 0.0, 'A non-primary AppBar was passed to a Scaffold but the MediaQuery in scope has top padding.');
-      double topPadding = config.appBar.primary ? padding.top : 0.0;
+      final double topPadding = config.appBar.primary ? padding.top : 0.0;
       Widget appBar = config.appBar;
-      double extent = config.appBar.minExtent + topPadding;
+      final double extent = config.appBar.minExtent + topPadding;
       if (config.appBar.flexibleSpace != null) {
         appBar = FlexibleSpaceBar.createSettings(
           currentExtent: extent,
@@ -838,7 +838,7 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin {
         bottomSheets.addAll(_dismissedBottomSheets);
       if (_currentBottomSheet != null)
         bottomSheets.add(_currentBottomSheet._widget);
-      Widget stack = new Stack(
+      final Widget stack = new Stack(
         children: bottomSheets,
         alignment: FractionalOffset.bottomCenter,
       );

packages/flutter/lib/src/material/slider.dart

@@ -162,7 +162,7 @@ class _SliderState extends State<Slider> with TickerProviderStateMixin {
   @override
   Widget build(BuildContext context) {
     assert(debugCheckHasMaterial(context));
-    ThemeData theme = Theme.of(context);
+    final ThemeData theme = Theme.of(context);
     return new _SliderRenderObjectWidget(
       value: (config.value - config.min) / (config.max - config.min),
       divisions: config.divisions,
@@ -277,7 +277,7 @@ class _RenderSlider extends RenderConstrainedBox implements SemanticsActionHandl
         super(additionalConstraints: _getAdditionalConstraints(label)) {
     assert(value != null && value >= 0.0 && value <= 1.0);
     this.label = label;
-    GestureArenaTeam team = new GestureArenaTeam();
+    final GestureArenaTeam team = new GestureArenaTeam();
     _drag = new HorizontalDragGestureRecognizer()
       ..team = team
       ..onStart = _handleDragStart
@@ -501,14 +501,14 @@ class _RenderSlider extends RenderConstrainedBox implements SemanticsActionHandl
         final double tipAttachment = _kLabelBalloonTipAttachmentRatio * radius;
 
         canvas.drawCircle(center, radius, primaryPaint);
-        Path path = new Path()
+        final Path path = new Path()
           ..moveTo(tip.x, tip.y)
           ..lineTo(center.x - tipAttachment, center.y + tipAttachment)
           ..lineTo(center.x + tipAttachment, center.y + tipAttachment)
           ..close();
         canvas.drawPath(path, primaryPaint);
         _labelPainter.layout();
-        Offset labelOffset = new Offset(
+        final Offset labelOffset = new Offset(
           center.x - _labelPainter.width / 2.0,
           center.y - _labelPainter.height / 2.0
         );

packages/flutter/lib/src/material/snack_bar.dart

@@ -190,13 +190,13 @@ class SnackBar extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     assert(animation != null);
-    ThemeData theme = Theme.of(context);
+    final ThemeData theme = Theme.of(context);
-    ThemeData darkTheme = new ThemeData(
+    final ThemeData darkTheme = new ThemeData(
       brightness: Brightness.dark,
       accentColor: theme.accentColor,
       accentColorBrightness: theme.accentColorBrightness
     );
-    List<Widget> children = <Widget>[
+    final List<Widget> children = <Widget>[
       const SizedBox(width: _kSnackBarPadding),
       new Expanded(
         child: new Container(
@@ -217,8 +217,8 @@ class SnackBar extends StatelessWidget {
     } else {
       children.add(const SizedBox(width: _kSnackBarPadding));
     }
-    CurvedAnimation heightAnimation = new CurvedAnimation(parent: animation, curve: _snackBarHeightCurve);
+    final CurvedAnimation heightAnimation = new CurvedAnimation(parent: animation, curve: _snackBarHeightCurve);
-    CurvedAnimation fadeAnimation = new CurvedAnimation(parent: animation, curve: _snackBarFadeCurve, reverseCurve: const Threshold(0.0));
+    final CurvedAnimation fadeAnimation = new CurvedAnimation(parent: animation, curve: _snackBarFadeCurve, reverseCurve: const Threshold(0.0));
     return new ClipRect(
       child: new AnimatedBuilder(
         animation: heightAnimation,

packages/flutter/lib/src/material/stepper.dart

@@ -514,7 +514,7 @@ class _StepperState extends State<Stepper> with TickerProviderStateMixin {
   }
 
   Widget _buildVertical() {
-    List<Widget> children = <Widget>[];
+    final List<Widget> children = <Widget>[];
 
     for (int i = 0; i < config.steps.length; i += 1) {
       children.add(

packages/flutter/lib/src/material/tab_controller.dart

@@ -244,7 +244,7 @@ class DefaultTabController extends StatefulWidget {
   /// TabController controller = DefaultTabBarController.of(context);
   /// ```
   static TabController of(BuildContext context) {
-    _TabControllerScope scope = context.inheritFromWidgetOfExactType(_TabControllerScope);
+    final _TabControllerScope scope = context.inheritFromWidgetOfExactType(_TabControllerScope);
     return scope?.controller;
   }
 

packages/flutter/lib/src/material/tabs.dart

@@ -431,7 +431,7 @@ class _TabBarState extends State<TabBar> {
   int _currentIndex;
 
   void _updateTabController() {
-    TabController newController = config.controller ?? DefaultTabController.of(context);
+    final TabController newController = config.controller ?? DefaultTabController.of(context);
     if (newController == _controller)
       return;
 
@@ -676,7 +676,7 @@ class _TabBarViewState extends State<TabBarView> {
   int _warpUnderwayCount = 0;
 
   void _updateTabController() {
-    TabController newController = config.controller ?? DefaultTabController.of(context);
+    final TabController newController = config.controller ?? DefaultTabController.of(context);
     if (newController == _controller)
       return;
 

packages/flutter/lib/src/material/text_selection.dart

@@ -24,7 +24,7 @@ class _TextSelectionToolbar extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    List<Widget> items = <Widget>[];
+    final List<Widget> items = <Widget>[];
 
     if (!value.selection.isCollapsed) {
       items.add(new FlatButton(child: new Text('CUT'), onPressed: _handleCut));
@@ -68,8 +68,8 @@ class _TextSelectionToolbar extends StatelessWidget {
   }
 
   Future<Null> _handlePaste() async {
-    InputValue value = this.value;  // Snapshot the input before using `await`.
+    final InputValue value = this.value;  // Snapshot the input before using `await`.
-    ClipboardData data = await Clipboard.getData(Clipboard.kTextPlain);
+    final ClipboardData data = await Clipboard.getData(Clipboard.kTextPlain);
     if (data != null) {
       delegate.inputValue = new InputValue(
         text: value.selection.textBefore(value.text) + data.text + value.selection.textAfter(value.text),
@@ -131,8 +131,8 @@ class _TextSelectionHandlePainter extends CustomPainter {
 
   @override
   void paint(Canvas canvas, Size size) {
-    Paint paint = new Paint()..color = color;
+    final Paint paint = new Paint()..color = color;
-    double radius = size.width/2.0;
+    final double radius = size.width/2.0;
     canvas.drawCircle(new Point(radius, radius), radius, paint);
     canvas.drawRect(new Rect.fromLTWH(0.0, 0.0, radius, radius), paint);
   }
@@ -164,7 +164,7 @@ class _MaterialTextSelectionControls extends TextSelectionControls {
   /// Builder for material-style text selection handles.
   @override
   Widget buildHandle(BuildContext context, TextSelectionHandleType type) {
-    Widget handle = new SizedBox(
+    final Widget handle = new SizedBox(
       width: _kHandleSize,
       height: _kHandleSize,
       child: new CustomPaint(

packages/flutter/lib/src/material/theme_data.dart

@@ -475,7 +475,7 @@ class ThemeData {
   bool operator ==(Object other) {
     if (other.runtimeType != runtimeType)
       return false;
-    ThemeData otherData = other;
+    final ThemeData otherData = other;
     return (otherData.brightness == brightness) &&
            (otherData.primaryColor == primaryColor) &&
            (otherData.primaryColorBrightness == primaryColorBrightness) &&

packages/flutter/lib/src/material/time_picker.dart

@@ -230,7 +230,7 @@ class _TimePickerHeader extends StatelessWidget {
   }
 
   void _handleChangeDayPeriod() {
-    int newHour = (selectedTime.hour + _kHoursPerPeriod) % _kHoursPerDay;
+    final int newHour = (selectedTime.hour + _kHoursPerPeriod) % _kHoursPerDay;
     onChanged(selectedTime.replacing(hour: newHour));
   }
 
@@ -250,9 +250,9 @@ class _TimePickerHeader extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    ThemeData themeData = Theme.of(context);
+    final ThemeData themeData = Theme.of(context);
-    TextTheme headerTextTheme = themeData.primaryTextTheme;
+    final TextTheme headerTextTheme = themeData.primaryTextTheme;
-    TextStyle baseHeaderStyle = _getBaseHeaderStyle(headerTextTheme);
+    final TextStyle baseHeaderStyle = _getBaseHeaderStyle(headerTextTheme);
     Color activeColor;
     Color inactiveColor;
     switch(themeData.primaryColorBrightness) {
@@ -276,20 +276,20 @@ class _TimePickerHeader extends StatelessWidget {
         break;
     }
 
-    TextStyle activeStyle = baseHeaderStyle.copyWith(color: activeColor);
+    final TextStyle activeStyle = baseHeaderStyle.copyWith(color: activeColor);
-    TextStyle inactiveStyle = baseHeaderStyle.copyWith(color: inactiveColor);
+    final TextStyle inactiveStyle = baseHeaderStyle.copyWith(color: inactiveColor);
 
-    TextStyle hourStyle = mode == _TimePickerMode.hour ? activeStyle : inactiveStyle;
+    final TextStyle hourStyle = mode == _TimePickerMode.hour ? activeStyle : inactiveStyle;
-    TextStyle minuteStyle = mode == _TimePickerMode.minute ? activeStyle : inactiveStyle;
+    final TextStyle minuteStyle = mode == _TimePickerMode.minute ? activeStyle : inactiveStyle;
 
-    TextStyle amStyle = headerTextTheme.subhead.copyWith(
+    final TextStyle amStyle = headerTextTheme.subhead.copyWith(
       color: selectedTime.period == DayPeriod.am ? activeColor: inactiveColor
     );
-    TextStyle pmStyle = headerTextTheme.subhead.copyWith(
+    final TextStyle pmStyle = headerTextTheme.subhead.copyWith(
       color: selectedTime.period == DayPeriod.pm ? activeColor: inactiveColor
     );
 
-    Widget dayPeriodPicker = new GestureDetector(
+    final Widget dayPeriodPicker = new GestureDetector(
       onTap: _handleChangeDayPeriod,
       behavior: HitTestBehavior.opaque,
       child: new Column(
@@ -302,17 +302,17 @@ class _TimePickerHeader extends StatelessWidget {
       )
     );
 
-    Widget hour = new GestureDetector(
+    final Widget hour = new GestureDetector(
       onTap: () => _handleChangeMode(_TimePickerMode.hour),
       child: new Text(selectedTime.hourOfPeriodLabel, style: hourStyle),
     );
 
-    Widget minute = new GestureDetector(
+    final Widget minute = new GestureDetector(
       onTap: () => _handleChangeMode(_TimePickerMode.minute),
       child: new Text(selectedTime.minuteLabel, style: minuteStyle),
     );
 
-    Widget colon = new Text(':', style: inactiveStyle);
+    final Widget colon = new Text(':', style: inactiveStyle);
 
     EdgeInsets padding;
     double height;
@@ -349,10 +349,10 @@ class _TimePickerHeader extends StatelessWidget {
 }
 
 List<TextPainter> _initPainters(TextTheme textTheme, List<String> labels) {
-  TextStyle style = textTheme.subhead;
+  final TextStyle style = textTheme.subhead;
-  List<TextPainter> painters = new List<TextPainter>(labels.length);
+  final List<TextPainter> painters = new List<TextPainter>(labels.length);
   for (int i = 0; i < painters.length; ++i) {
-    String label = labels[i];
+    final String label = labels[i];
     // TODO(abarth): Handle textScaleFactor.
     // https://github.com/flutter/flutter/issues/5939
     painters[i] = new TextPainter(
@@ -391,24 +391,24 @@ class _DialPainter extends CustomPainter {
 
   @override
   void paint(Canvas canvas, Size size) {
-    double radius = size.shortestSide / 2.0;
+    final double radius = size.shortestSide / 2.0;
-    Offset center = new Offset(size.width / 2.0, size.height / 2.0);
+    final Offset center = new Offset(size.width / 2.0, size.height / 2.0);
-    Point centerPoint = center.toPoint();
+    final Point centerPoint = center.toPoint();
     canvas.drawCircle(centerPoint, radius, new Paint()..color = backgroundColor);
 
     const double labelPadding = 24.0;
-    double labelRadius = radius - labelPadding;
+    final double labelRadius = radius - labelPadding;
     Offset getOffsetForTheta(double theta) {
       return center + new Offset(labelRadius * math.cos(theta),
                                  -labelRadius * math.sin(theta));
     }
 
     void paintLabels(List<TextPainter> labels) {
-      double labelThetaIncrement = -_kTwoPi / labels.length;
+      final double labelThetaIncrement = -_kTwoPi / labels.length;
       double labelTheta = math.PI / 2.0;
 
       for (TextPainter label in labels) {
-        Offset labelOffset = new Offset(-label.width / 2.0, -label.height / 2.0);
+        final Offset labelOffset = new Offset(-label.width / 2.0, -label.height / 2.0);
         label.paint(canvas, getOffsetForTheta(labelTheta) + labelOffset);
         labelTheta += labelThetaIncrement;
       }
@@ -499,7 +499,7 @@ class _DialState extends State<_Dial> with SingleTickerProviderStateMixin {
   }
 
   void _animateTo(double targetTheta) {
-    double currentTheta = _theta.value;
+    final double currentTheta = _theta.value;
     double beginTheta = _nearest(targetTheta, currentTheta, currentTheta + _kTwoPi);
     beginTheta = _nearest(targetTheta, beginTheta, currentTheta - _kTwoPi);
     _thetaTween
@@ -511,16 +511,16 @@ class _DialState extends State<_Dial> with SingleTickerProviderStateMixin {
   }
 
   double _getThetaForTime(TimeOfDay time) {
-    double fraction = (config.mode == _TimePickerMode.hour) ?
+    final double fraction = (config.mode == _TimePickerMode.hour) ?
         (time.hour / _kHoursPerPeriod) % _kHoursPerPeriod :
         (time.minute / _kMinutesPerHour) % _kMinutesPerHour;
     return (math.PI / 2.0 - fraction * _kTwoPi) % _kTwoPi;
   }
 
   TimeOfDay _getTimeForTheta(double theta) {
-    double fraction = (0.25 - (theta % _kTwoPi) / _kTwoPi) % 1.0;
+    final double fraction = (0.25 - (theta % _kTwoPi) / _kTwoPi) % 1.0;
     if (config.mode == _TimePickerMode.hour) {
-      int hourOfPeriod = (fraction * _kHoursPerPeriod).round() % _kHoursPerPeriod;
+      final int hourOfPeriod = (fraction * _kHoursPerPeriod).round() % _kHoursPerPeriod;
       return config.selectedTime.replacing(
         hour: hourOfPeriod + config.selectedTime.periodOffset
       );
@@ -534,7 +534,7 @@ class _DialState extends State<_Dial> with SingleTickerProviderStateMixin {
   void _notifyOnChangedIfNeeded() {
     if (config.onChanged == null)
       return;
-    TimeOfDay current = _getTimeForTheta(_theta.value);
+    final TimeOfDay current = _getTimeForTheta(_theta.value);
     if (current != config.selectedTime)
       config.onChanged(current);
   }
@@ -578,7 +578,7 @@ class _DialState extends State<_Dial> with SingleTickerProviderStateMixin {
 
   @override
   Widget build(BuildContext context) {
-    ThemeData themeData = Theme.of(context);
+    final ThemeData themeData = Theme.of(context);
 
     Color backgroundColor;
     switch (themeData.brightness) {
@@ -590,7 +590,7 @@ class _DialState extends State<_Dial> with SingleTickerProviderStateMixin {
         break;
     }
 
-    ThemeData theme = Theme.of(context);
+    final ThemeData theme = Theme.of(context);
     List<TextPainter> primaryLabels;
     List<TextPainter> secondaryLabels;
     switch (config.mode) {
@@ -686,7 +686,7 @@ class _TimePickerDialogState extends State<_TimePickerDialog> {
 
   @override
   Widget build(BuildContext context) {
-    Widget picker = new Padding(
+    final Widget picker = new Padding(
       padding: const EdgeInsets.all(16.0),
       child: new AspectRatio(
         aspectRatio: 1.0,
@@ -698,7 +698,7 @@ class _TimePickerDialogState extends State<_TimePickerDialog> {
       )
     );
 
-    Widget actions = new ButtonTheme.bar(
+    final Widget actions = new ButtonTheme.bar(
       child: new ButtonBar(
         children: <Widget>[
           new FlatButton(
@@ -716,7 +716,7 @@ class _TimePickerDialogState extends State<_TimePickerDialog> {
     return new Dialog(
       child: new OrientationBuilder(
         builder: (BuildContext context, Orientation orientation) {
-          Widget header = new _TimePickerHeader(
+          final Widget header = new _TimePickerHeader(
             selectedTime: _selectedTime,
             mode: _mode,
             orientation: orientation,

packages/flutter/lib/src/material/toggleable.dart

@@ -275,9 +275,9 @@ abstract class RenderToggleable extends RenderConstrainedBox implements Semantic
   void paintRadialReaction(Canvas canvas, Offset offset, Point origin) {
     if (!_reaction.isDismissed) {
       // TODO(abarth): We should have a different reaction color when position is zero.
-      Paint reactionPaint = new Paint()..color = activeColor.withAlpha(kRadialReactionAlpha);
+      final Paint reactionPaint = new Paint()..color = activeColor.withAlpha(kRadialReactionAlpha);
-      Point center = Point.lerp(_downPosition ?? origin, origin, _reaction.value);
+      final Point center = Point.lerp(_downPosition ?? origin, origin, _reaction.value);
-      double radius = _kRadialReactionRadiusTween.evaluate(_reaction);
+      final double radius = _kRadialReactionRadiusTween.evaluate(_reaction);
       canvas.drawCircle(center + offset, radius, reactionPaint);
     }
   }

packages/flutter/lib/src/material/tooltip.dart

@@ -213,7 +213,7 @@ class _TooltipPositionDelegate extends SingleChildLayoutDelegate {
     else
       y = math.max(target.y - verticalOffset - childSize.height, _kScreenEdgeMargin);
     // HORIZONTAL DIRECTION
-    double normalizedTargetX = target.x.clamp(_kScreenEdgeMargin, size.width - _kScreenEdgeMargin);
+    final double normalizedTargetX = target.x.clamp(_kScreenEdgeMargin, size.width - _kScreenEdgeMargin);
     double x;
     if (normalizedTargetX < _kScreenEdgeMargin + childSize.width / 2.0) {
       x = _kScreenEdgeMargin;
@@ -255,8 +255,8 @@ class _TooltipOverlay extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    ThemeData theme = Theme.of(context);
+    final ThemeData theme = Theme.of(context);
-    ThemeData darkTheme = new ThemeData(
+    final ThemeData darkTheme = new ThemeData(
       brightness: Brightness.dark,
       textTheme: theme.brightness == Brightness.dark ? theme.textTheme : theme.primaryTextTheme,
       platform: theme.platform,

packages/flutter/lib/src/painting/box_painter.dart

@@ -366,7 +366,7 @@ class Border {
     assert(bottom != null);
     assert(left != null);
 
-    Paint paint = new Paint()
+    final Paint paint = new Paint()
       ..strokeWidth = 0.0; // used for hairline borders
     Path path;
 
@@ -450,29 +450,29 @@ class Border {
   void _paintBorderWithRadius(Canvas canvas, Rect rect,
                               BorderRadius borderRadius) {
     assert(isUniform);
-    Paint paint = new Paint()
+    final Paint paint = new Paint()
       ..color = top.color;
-    RRect outer = borderRadius.toRRect(rect);
+    final RRect outer = borderRadius.toRRect(rect);
-    double width = top.width;
+    final double width = top.width;
     if (width == 0.0) {
       paint
         ..style = PaintingStyle.stroke
         ..strokeWidth = 0.0;
       canvas.drawRRect(outer, paint);
     } else {
-      RRect inner = outer.deflate(width);
+      final RRect inner = outer.deflate(width);
       canvas.drawDRRect(outer, inner, paint);
     }
   }
 
   void _paintBorderWithCircle(Canvas canvas, Rect rect) {
     assert(isUniform);
-    double width = top.width;
+    final double width = top.width;
-    Paint paint = new Paint()
+    final Paint paint = new Paint()
       ..color = top.color
       ..strokeWidth = width
       ..style = PaintingStyle.stroke;
-    double radius = (rect.shortestSide - width) / 2.0;
+    final double radius = (rect.shortestSide - width) / 2.0;
     canvas.drawCircle(rect.center, radius, paint);
   }
 
@@ -581,8 +581,8 @@ class BoxShadow {
       a = new List<BoxShadow>();
     if (b == null)
       b = new List<BoxShadow>();
-    List<BoxShadow> result = new List<BoxShadow>();
+    final List<BoxShadow> result = new List<BoxShadow>();
-    int commonLength = math.min(a.length, b.length);
+    final int commonLength = math.min(a.length, b.length);
     for (int i = 0; i < commonLength; ++i)
       result.add(BoxShadow.lerp(a[i], b[i], t));
     for (int i = commonLength; i < a.length; ++i)
@@ -838,8 +838,8 @@ Iterable<Rect> _generateImageTileRects(Rect outputRect, Rect fundamentalRect, Im
   int startY = 0;
   int stopX = 0;
   int stopY = 0;
-  double strideX = fundamentalRect.width;
+  final double strideX = fundamentalRect.width;
-  double strideY = fundamentalRect.height;
+  final double strideY = fundamentalRect.height;
 
   if (repeat == ImageRepeat.repeat || repeat == ImageRepeat.repeatX) {
     startX = ((outputRect.left - fundamentalRect.left) / strideX).floor();
@@ -929,7 +929,7 @@ void paintImage({
     // output rect with the image.
     repeat = ImageRepeat.noRepeat;
   }
-  Paint paint = new Paint()..isAntiAlias = false;
+  final Paint paint = new Paint()..isAntiAlias = false;
   if (colorFilter != null)
     paint.colorFilter = colorFilter;
   if (sourceSize != destinationSize) {
@@ -938,10 +938,10 @@ void paintImage({
     // to nearest-neighbor.
     paint.filterQuality = FilterQuality.low;
   }
-  double dx = (outputSize.width - destinationSize.width) * (alignment?.dx ?? 0.5);
+  final double dx = (outputSize.width - destinationSize.width) * (alignment?.dx ?? 0.5);
-  double dy = (outputSize.height - destinationSize.height) * (alignment?.dy ?? 0.5);
+  final double dy = (outputSize.height - destinationSize.height) * (alignment?.dy ?? 0.5);
-  Point destinationPosition = rect.topLeft + new Offset(dx, dy);
+  final Point destinationPosition = rect.topLeft + new Offset(dx, dy);
-  Rect destinationRect = destinationPosition & destinationSize;
+  final Rect destinationRect = destinationPosition & destinationSize;
   if (repeat != ImageRepeat.noRepeat) {
     canvas.save();
     canvas.clipRect(rect);
@@ -1200,7 +1200,7 @@ class BoxDecoration extends Decoration {
   /// span multiple lines, each prefixed by that argument.
   @override
   String toString([String prefix = '', String indentPrefix]) {
-    List<String> result = <String>[];
+    final List<String> result = <String>[];
     if (backgroundColor != null)
       result.add('${prefix}backgroundColor: $backgroundColor');
     if (backgroundImage != null)
@@ -1236,14 +1236,14 @@ class BoxDecoration extends Decoration {
     switch (shape) {
       case BoxShape.rectangle:
         if (borderRadius != null) {
-          RRect bounds = borderRadius.toRRect(Point.origin & size);
+          final RRect bounds = borderRadius.toRRect(Point.origin & size);
           return bounds.contains(position);
         }
         return true;
       case BoxShape.circle:
         // Circles are inscribed into our smallest dimension.
-        Point center = size.center(Point.origin);
+        final Point center = size.center(Point.origin);
-        double distance = (position - center).distance;
+        final double distance = (position - center).distance;
         return distance <= math.min(size.width, size.height) / 2.0;
     }
     assert(shape != null);
@@ -1272,7 +1272,7 @@ class _BoxDecorationPainter extends BoxPainter {
     if (_cachedBackgroundPaint == null ||
         (_decoration.gradient == null && _rectForCachedBackgroundPaint != null) ||
         (_decoration.gradient != null && _rectForCachedBackgroundPaint != rect)) {
-      Paint paint = new Paint();
+      final Paint paint = new Paint();
 
       if (_decoration.backgroundColor != null)
         paint.color = _decoration.backgroundColor;
@@ -1294,8 +1294,8 @@ class _BoxDecorationPainter extends BoxPainter {
     switch (_decoration.shape) {
       case BoxShape.circle:
         assert(_decoration.borderRadius == null);
-        Point center = rect.center;
+        final Point center = rect.center;
-        double radius = rect.shortestSide / 2.0;
+        final double radius = rect.shortestSide / 2.0;
         canvas.drawCircle(center, radius, paint);
         break;
       case BoxShape.rectangle:

packages/flutter/lib/src/painting/flutter_logo.dart

@@ -384,7 +384,7 @@ class _FlutterLogoPainter extends BoxPainter {
   @override
   void paint(Canvas canvas, Offset offset, ImageConfiguration configuration) {
     offset += _config.margin.topLeft;
-    Size canvasSize = _config.margin.deflateSize(configuration.size);
+    final Size canvasSize = _config.margin.deflateSize(configuration.size);
     Size logoSize;
     if (_config._position > 0.0) {
       // horizontal style

packages/flutter/lib/src/painting/text_editing.dart

@@ -73,7 +73,7 @@ class TextRange {
       return true;
     if (other is! TextRange)
       return false;
-    TextRange typedOther = other;
+    final TextRange typedOther = other;
     return typedOther.start == start
         && typedOther.end == end;
   }
@@ -181,7 +181,7 @@ class TextSelection extends TextRange {
       return true;
     if (other is! TextSelection)
       return false;
-    TextSelection typedOther = other;
+    final TextSelection typedOther = other;
     return typedOther.baseOffset == baseOffset
         && typedOther.extentOffset == extentOffset
         && typedOther.affinity == affinity

packages/flutter/lib/src/painting/text_painter.dart

@@ -137,7 +137,7 @@ class TextPainter {
   double get preferredLineHeight {
     assert(text != null);
     if (_layoutTemplate == null) {
-      ui.ParagraphBuilder builder = new ui.ParagraphBuilder(new ui.ParagraphStyle());
+      final ui.ParagraphBuilder builder = new ui.ParagraphBuilder(new ui.ParagraphStyle());
       if (text.style != null)
         builder.pushStyle(text.style.getTextStyle(textScaleFactor: textScaleFactor));
       builder.addText(_kZeroWidthSpace);
@@ -247,7 +247,7 @@ class TextPainter {
         maxLines: maxLines,
         ellipsis: ellipsis,
       );
-      ui.ParagraphBuilder builder = new ui.ParagraphBuilder(paragraphStyle);
+      final ui.ParagraphBuilder builder = new ui.ParagraphBuilder(paragraphStyle);
       _text.build(builder, textScaleFactor: textScaleFactor);
       _paragraph = builder.build();
     }
@@ -291,30 +291,30 @@ class TextPainter {
   }
 
   Offset _getOffsetFromUpstream(int offset, Rect caretPrototype) {
-    int prevCodeUnit = _text.codeUnitAt(offset - 1);
+    final int prevCodeUnit = _text.codeUnitAt(offset - 1);
     if (prevCodeUnit == null)
       return null;
-    int prevRuneOffset = _isUtf16Surrogate(prevCodeUnit) ? offset - 2 : offset - 1;
+    final int prevRuneOffset = _isUtf16Surrogate(prevCodeUnit) ? offset - 2 : offset - 1;
-    List<ui.TextBox> boxes = _paragraph.getBoxesForRange(prevRuneOffset, offset);
+    final List<ui.TextBox> boxes = _paragraph.getBoxesForRange(prevRuneOffset, offset);
     if (boxes.isEmpty)
       return null;
-    ui.TextBox box = boxes[0];
+    final ui.TextBox box = boxes[0];
-    double caretEnd = box.end;
+    final double caretEnd = box.end;
-    double dx = box.direction == TextDirection.rtl ? caretEnd : caretEnd - caretPrototype.width;
+    final double dx = box.direction == TextDirection.rtl ? caretEnd : caretEnd - caretPrototype.width;
     return new Offset(dx, box.top);
   }
 
   Offset _getOffsetFromDownstream(int offset, Rect caretPrototype) {
-    int nextCodeUnit = _text.codeUnitAt(offset + 1);
+    final int nextCodeUnit = _text.codeUnitAt(offset + 1);
     if (nextCodeUnit == null)
       return null;
-    int nextRuneOffset = _isUtf16Surrogate(nextCodeUnit) ? offset + 2 : offset + 1;
+    final int nextRuneOffset = _isUtf16Surrogate(nextCodeUnit) ? offset + 2 : offset + 1;
-    List<ui.TextBox> boxes = _paragraph.getBoxesForRange(offset, nextRuneOffset);
+    final List<ui.TextBox> boxes = _paragraph.getBoxesForRange(offset, nextRuneOffset);
     if (boxes.isEmpty)
       return null;
-    ui.TextBox box = boxes[0];
+    final ui.TextBox box = boxes[0];
-    double caretStart = box.start;
+    final double caretStart = box.start;
-    double dx = box.direction == TextDirection.rtl ? caretStart - caretPrototype.width : caretStart;
+    final double dx = box.direction == TextDirection.rtl ? caretStart - caretPrototype.width : caretStart;
     return new Offset(dx, box.top);
   }
 
@@ -323,7 +323,7 @@ class TextPainter {
   /// Valid only after [layout] has been called.
   Offset getOffsetForCaret(TextPosition position, Rect caretPrototype) {
     assert(!_needsLayout);
-    int offset = position.offset;
+    final int offset = position.offset;
     // TODO(abarth): Handle the directionality of the text painter itself.
     const Offset emptyOffset = Offset.zero;
     switch (position.affinity) {
@@ -365,7 +365,7 @@ class TextPainter {
   /// <http://www.unicode.org/reports/tr29/#Word_Boundaries>.
   TextRange getWordBoundary(TextPosition position) {
     assert(!_needsLayout);
-    List<int> indices = _paragraph.getWordBoundary(position.offset);
+    final List<int> indices = _paragraph.getWordBoundary(position.offset);
     return new TextRange(start: indices[0], end: indices[1]);
   }
 }

packages/flutter/lib/src/painting/text_span.dart

@@ -128,13 +128,13 @@ class TextSpan {
   /// Returns the text span that contains the given position in the text.
   TextSpan getSpanForPosition(TextPosition position) {
     assert(debugAssertIsValid());
-    TextAffinity affinity = position.affinity;
+    final TextAffinity affinity = position.affinity;
-    int targetOffset = position.offset;
+    final int targetOffset = position.offset;
     int offset = 0;
     TextSpan result;
     visitTextSpan((TextSpan span) {
       assert(result == null);
-      int endOffset = offset + span.text.length;
+      final int endOffset = offset + span.text.length;
       if (targetOffset == offset && affinity == TextAffinity.downstream ||
           targetOffset > offset && targetOffset < endOffset ||
           targetOffset == endOffset && affinity == TextAffinity.upstream) {
@@ -152,7 +152,7 @@ class TextSpan {
   /// Styles are not honored in this process.
   String toPlainText() {
     assert(debugAssertIsValid());
-    StringBuffer buffer = new StringBuffer();
+    final StringBuffer buffer = new StringBuffer();
     visitTextSpan((TextSpan span) {
       buffer.write(span.text);
       return true;
@@ -180,9 +180,9 @@ class TextSpan {
 
   @override
   String toString([String prefix = '']) {
-    StringBuffer buffer = new StringBuffer();
+    final StringBuffer buffer = new StringBuffer();
     buffer.writeln('$prefix$runtimeType:');
-    String indent = '$prefix  ';
+    final String indent = '$prefix  ';
     if (style != null)
       buffer.writeln(style.toString(indent));
     if (text != null)

packages/flutter/lib/src/painting/text_style.dart

@@ -290,7 +290,7 @@ class TextStyle {
 
   @override
   String toString([String prefix = '']) {
-    List<String> result = <String>[];
+    final List<String> result = <String>[];
     result.add('${prefix}inherit: $inherit');
     if (color != null)
       result.add('${prefix}color: $color');

packages/flutter/lib/src/painting/transforms.dart

@@ -19,7 +19,7 @@ class MatrixUtils {
   /// Otherwise, returns null.
   static Offset getAsTranslation(Matrix4 transform) {
     assert(transform != null);
-    Float64List values = transform.storage;
+    final Float64List values = transform.storage;
     // Values are stored in column-major order.
     if (values[0] == 1.0 && // col 1
         values[1] == 0.0 &&
@@ -95,8 +95,8 @@ class MatrixUtils {
   /// This function assumes the given point has a z-coordinate of 0.0. The
   /// z-coordinate of the result is ignored.
   static Point transformPoint(Matrix4 transform, Point point) {
-    Vector3 position3 = new Vector3(point.x, point.y, 0.0);
+    final Vector3 position3 = new Vector3(point.x, point.y, 0.0);
-    Vector3 transformed3 = transform.perspectiveTransform(position3);
+    final Vector3 transformed3 = transform.perspectiveTransform(position3);
     return new Point(transformed3.x, transformed3.y);
   }
 
@@ -107,10 +107,10 @@ class MatrixUtils {
   /// The transformed rect is then projected back into the plane with z equals
   /// 0.0 before computing its bounding rect.
   static Rect transformRect(Matrix4 transform, Rect rect) {
-    Point point1 = transformPoint(transform, rect.topLeft);
+    final Point point1 = transformPoint(transform, rect.topLeft);
-    Point point2 = transformPoint(transform, rect.topRight);
+    final Point point2 = transformPoint(transform, rect.topRight);
-    Point point3 = transformPoint(transform, rect.bottomLeft);
+    final Point point3 = transformPoint(transform, rect.bottomLeft);
-    Point point4 = transformPoint(transform, rect.bottomRight);
+    final Point point4 = transformPoint(transform, rect.bottomRight);
     return new Rect.fromLTRB(
         _min4(point1.x, point2.x, point3.x, point4.x),
         _min4(point1.y, point2.y, point3.y, point4.y),

packages/flutter/lib/src/physics/spring_simulation.dart

@@ -153,7 +153,7 @@ abstract class _SpringSolution {
     assert(spring.damping != null);
     assert(initialPosition != null);
     assert(initialVelocity != null);
-    double cmk = spring.damping * spring.damping - 4 * spring.mass * spring.springConstant;
+    final double cmk = spring.damping * spring.damping - 4 * spring.mass * spring.springConstant;
     if (cmk == 0.0)
       return new _CriticalSolution(spring, initialPosition, initialVelocity);
     if (cmk > 0.0)

packages/flutter/lib/src/rendering/binding.dart

@@ -74,7 +74,7 @@ abstract class RendererBinding extends BindingBase implements SchedulerBinding,
         name: 'repaintRainbow',
         getter: () async => debugRepaintRainbowEnabled,
         setter: (bool value) {
-          bool repaint = debugRepaintRainbowEnabled && !value;
+          final bool repaint = debugRepaintRainbowEnabled && !value;
           debugRepaintRainbowEnabled = value;
           if (repaint)
             return _forceRepaint();

packages/flutter/lib/src/rendering/block.dart

@@ -62,10 +62,10 @@ class RenderBlock extends RenderBox
   }
 
   double get _mainAxisExtent {
-    RenderBox child = lastChild;
+    final RenderBox child = lastChild;
     if (child == null)
       return 0.0;
-    BoxParentData parentData = child.parentData;
+    final BoxParentData parentData = child.parentData;
     assert(mainAxis != null);
     switch (mainAxis) {
       case Axis.horizontal:
@@ -122,7 +122,7 @@ class RenderBlock extends RenderBox
         'This is relatively expensive, however.' // (that's why we don't do it automatically)
       );
     });
-    BoxConstraints innerConstraints = _getInnerConstraints(constraints);
+    final BoxConstraints innerConstraints = _getInnerConstraints(constraints);
     double position = 0.0;
     RenderBox child = firstChild;
     while (child != null) {

packages/flutter/lib/src/rendering/box.dart

@@ -245,7 +245,7 @@ class BoxConstraints extends Constraints {
     double height = size.height;
     assert(width > 0.0);
     assert(height > 0.0);
-    double aspectRatio = width / height;
+    final double aspectRatio = width / height;
 
     if (width > maxWidth) {
       width = maxWidth;
@@ -387,13 +387,13 @@ class BoxConstraints extends Constraints {
   }) {
     assert(() {
       void throwError(String message) {
-        StringBuffer information = new StringBuffer();
+        final StringBuffer information = new StringBuffer();
         if (informationCollector != null)
           informationCollector(information);
         throw new FlutterError('$message\n${information}The offending constraints were:\n  $this');
       }
       if (minWidth.isNaN || maxWidth.isNaN || minHeight.isNaN || maxHeight.isNaN) {
-        List<String> affectedFieldsList = <String>[];
+        final List<String> affectedFieldsList = <String>[];
         if (minWidth.isNaN)
           affectedFieldsList.add('minWidth');
         if (maxWidth.isNaN)
@@ -481,7 +481,7 @@ class BoxConstraints extends Constraints {
 
   @override
   String toString() {
-    String annotation = isNormalized ? '' : '; NOT NORMALIZED';
+    final String annotation = isNormalized ? '' : '; NOT NORMALIZED';
     if (minWidth == double.INFINITY && minHeight == double.INFINITY)
       return 'BoxConstraints(biggest$annotation)';
     if (minWidth == 0 && maxWidth == double.INFINITY &&
@@ -1466,7 +1466,7 @@ abstract class RenderBox extends RenderObject {
       return false;
     });
     assert(_debugSetDoingBaseline(true));
-    double result = getDistanceToActualBaseline(baseline);
+    final double result = getDistanceToActualBaseline(baseline);
     assert(_debugSetDoingBaseline(false));
     if (result == null && !onlyReal)
       return size.height;
@@ -1534,14 +1534,14 @@ abstract class RenderBox extends RenderObject {
       }
       // verify that the size is not infinite
       if (_size.isInfinite) {
-        StringBuffer information = new StringBuffer();
+        final StringBuffer information = new StringBuffer();
         if (!constraints.hasBoundedWidth) {
           RenderBox node = this;
           while (!node.constraints.hasBoundedWidth && node.parent is RenderBox)
             node = node.parent;
           information.writeln('The nearest ancestor providing an unbounded width constraint is:');
           information.writeln('  $node');
-          List<String> description = <String>[];
+          final List<String> description = <String>[];
           node.debugFillDescription(description);
           for (String line in description)
             information.writeln('  $line');
@@ -1552,7 +1552,7 @@ abstract class RenderBox extends RenderObject {
             node = node.parent;
           information.writeln('The nearest ancestor providing an unbounded height constraint is:');
           information.writeln('  $node');
-          List<String> description = <String>[];
+          final List<String> description = <String>[];
           node.debugFillDescription(description);
           for (String line in description)
             information.writeln('  $line');
@@ -1584,7 +1584,7 @@ abstract class RenderBox extends RenderObject {
         // verify that the intrinsics are sane
         assert(!RenderObject.debugCheckingIntrinsics);
         RenderObject.debugCheckingIntrinsics = true;
-        StringBuffer failures = new StringBuffer();
+        final StringBuffer failures = new StringBuffer();
         int failureCount = 0;
 
         double testIntrinsic(double function(double extent), String name, double constraint) {
@@ -1813,7 +1813,7 @@ abstract class RenderBox extends RenderObject {
   /// object) instead of from the global coordinate system.
   Point globalToLocal(Point point, { RenderObject ancestor }) {
     final Matrix4 transform = getTransformTo(ancestor);
-    double det = transform.invert();
+    final double det = transform.invert();
     if (det == 0.0)
       return Point.origin;
     return MatrixUtils.transformPoint(transform, point);
@@ -1918,7 +1918,7 @@ abstract class RenderBox extends RenderObject {
   @protected
   void debugPaintSize(PaintingContext context, Offset offset) {
     assert(() {
-      Paint paint = new Paint()
+      final Paint paint = new Paint()
        ..style = PaintingStyle.stroke
        ..strokeWidth = 1.0
        ..color = debugPaintSizeColor;
@@ -1933,12 +1933,12 @@ abstract class RenderBox extends RenderObject {
   @protected
   void debugPaintBaselines(PaintingContext context, Offset offset) {
     assert(() {
-      Paint paint = new Paint()
+      final Paint paint = new Paint()
        ..style = PaintingStyle.stroke
        ..strokeWidth = 0.25;
       Path path;
       // ideographic baseline
-      double baselineI = getDistanceToBaseline(TextBaseline.ideographic, onlyReal: true);
+      final double baselineI = getDistanceToBaseline(TextBaseline.ideographic, onlyReal: true);
       if (baselineI != null) {
         paint.color = debugPaintIdeographicBaselineColor;
         path = new Path();
@@ -1947,7 +1947,7 @@ abstract class RenderBox extends RenderObject {
         context.canvas.drawPath(path, paint);
       }
       // alphabetic baseline
-      double baselineA = getDistanceToBaseline(TextBaseline.alphabetic, onlyReal: true);
+      final double baselineA = getDistanceToBaseline(TextBaseline.alphabetic, onlyReal: true);
       if (baselineA != null) {
         paint.color = debugPaintAlphabeticBaselineColor;
         path = new Path();
@@ -1970,7 +1970,7 @@ abstract class RenderBox extends RenderObject {
   void debugPaintPointers(PaintingContext context, Offset offset) {
     assert(() {
       if (_debugActivePointers > 0) {
-        Paint paint = new Paint()
+        final Paint paint = new Paint()
          ..color = new Color(debugPaintPointersColorValue | ((0x04000000 * depth) & 0xFF000000));
         context.canvas.drawRect(offset & size, paint);
       }
@@ -2002,7 +2002,7 @@ abstract class RenderBoxContainerDefaultsMixin<ChildType extends RenderBox, Pare
     ChildType child = firstChild;
     while (child != null) {
       final ParentDataType childParentData = child.parentData;
-      double result = child.getDistanceToActualBaseline(baseline);
+      final double result = child.getDistanceToActualBaseline(baseline);
       if (result != null)
         return result + childParentData.offset.dy;
       child = childParentData.nextSibling;
@@ -2042,7 +2042,7 @@ abstract class RenderBoxContainerDefaultsMixin<ChildType extends RenderBox, Pare
     ChildType child = lastChild;
     while (child != null) {
       final ParentDataType childParentData = child.parentData;
-      Point transformed = new Point(position.x - childParentData.offset.dx,
+      final Point transformed = new Point(position.x - childParentData.offset.dx,
                                     position.y - childParentData.offset.dy);
       if (child.hitTest(result, position: transformed))
         return true;

packages/flutter/lib/src/rendering/debug.dart

@@ -117,7 +117,7 @@ bool debugProfilePaintsEnabled = false;
 
 /// Returns a list of strings representing the given transform in a format useful for [RenderObject.debugFillDescription].
 List<String> debugDescribeTransform(Matrix4 transform) {
-  List<String> matrix = transform.toString().split('\n').map((String s) => '  $s').toList();
+  final List<String> matrix = transform.toString().split('\n').map((String s) => '  $s').toList();
   matrix.removeLast();
   return matrix;
 }

packages/flutter/lib/src/rendering/editable.dart

@@ -302,7 +302,7 @@ class RenderEditable extends RenderBox {
     final Point globalPosition = _lastTapDownPosition;
     _lastTapDownPosition = null;
     if (onSelectionChanged != null) {
-      TextPosition position = _textPainter.getPositionForOffset(globalToLocal(globalPosition).toOffset());
+      final TextPosition position = _textPainter.getPositionForOffset(globalToLocal(globalPosition).toOffset());
       onSelectionChanged(new TextSelection.fromPosition(position), this, false);
     }
   }

packages/flutter/lib/src/rendering/error.dart

@@ -43,7 +43,7 @@ class RenderErrorBox extends RenderBox {
         // Generally, the much better way to draw text in a RenderObject is to
         // use the TextPainter class. If you're looking for code to crib from,
         // see the paragraph.dart file and the RenderParagraph class.
-        ui.ParagraphBuilder builder = new ui.ParagraphBuilder(paragraphStyle);
+        final ui.ParagraphBuilder builder = new ui.ParagraphBuilder(paragraphStyle);
         builder.pushStyle(textStyle);
         builder.addText(
           '$message$_kLine$message$_kLine$message$_kLine$message$_kLine$message$_kLine$message$_kLine'
@@ -105,7 +105,7 @@ class RenderErrorBox extends RenderBox {
         // See the comment in the RenderErrorBox constructor. This is not the
         // code you want to be copying and pasting. :-)
         if (parent is RenderBox) {
-          RenderBox parentBox = parent;
+          final RenderBox parentBox = parent;
           width = parentBox.size.width;
         } else {
           width = size.width;

packages/flutter/lib/src/rendering/flex.dart

@@ -247,10 +247,10 @@ class RenderFlex extends RenderBox with ContainerRenderObjectMixin<RenderBox, Fl
       double maxFlexFractionSoFar = 0.0;
       RenderBox child = firstChild;
       while (child != null) {
-        int flex = _getFlex(child);
+        final int flex = _getFlex(child);
         totalFlex += flex;
         if (flex > 0) {
-          double flexFraction = childSize(child, extent) / _getFlex(child);
+          final double flexFraction = childSize(child, extent) / _getFlex(child);
           maxFlexFractionSoFar = math.max(maxFlexFractionSoFar, flexFraction);
         } else {
           inflexibleSpace += childSize(child, extent);
@@ -267,13 +267,13 @@ class RenderFlex extends RenderBox with ContainerRenderObjectMixin<RenderBox, Fl
       // TODO(ianh): Support baseline alignment.
 
       // Get inflexible space using the max intrinsic dimensions of fixed children in the main direction.
-      double availableMainSpace = extent;
+      final double availableMainSpace = extent;
       int totalFlex = 0;
       double inflexibleSpace = 0.0;
       double maxCrossSize = 0.0;
       RenderBox child = firstChild;
       while (child != null) {
-        int flex = _getFlex(child);
+        final int flex = _getFlex(child);
         totalFlex += flex;
         double mainSize;
         double crossSize;
@@ -297,13 +297,13 @@ class RenderFlex extends RenderBox with ContainerRenderObjectMixin<RenderBox, Fl
 
       // Determine the spacePerFlex by allocating the remaining available space.
       // When you're overconstrained spacePerFlex can be negative.
-      double spacePerFlex = math.max(0.0,
+      final double spacePerFlex = math.max(0.0,
           (availableMainSpace - inflexibleSpace) / totalFlex);
 
       // Size remaining (flexible) items, find the maximum cross size.
       child = firstChild;
       while (child != null) {
-        int flex = _getFlex(child);
+        final int flex = _getFlex(child);
         if (flex > 0)
           maxCrossSize = math.max(maxCrossSize, childSize(child, spacePerFlex * flex));
         final FlexParentData childParentData = child.parentData;
@@ -404,7 +404,7 @@ class RenderFlex extends RenderBox with ContainerRenderObjectMixin<RenderBox, Fl
                       'if it is in a $axis scrollable, it will try to shrink-wrap its children along the $axis '
                       'axis. Setting a flex on a child (e.g. using a Flexible) indicates that the child is to '
                       'expand to fill the remaining space in the $axis direction.';
-            StringBuffer information = new StringBuffer();
+            final StringBuffer information = new StringBuffer();
             RenderBox node = this;
             switch (_direction) {
               case Axis.horizontal:
@@ -423,7 +423,7 @@ class RenderFlex extends RenderBox with ContainerRenderObjectMixin<RenderBox, Fl
             if (node != null) {
               information.writeln('The nearest ancestor providing an unbounded width constraint is:');
               information.writeln('  $node');
-              List<String> description = <String>[];
+              final List<String> description = <String>[];
               node.debugFillDescription(description);
               for (String line in description)
                 information.writeln('  $line');
@@ -543,7 +543,7 @@ class RenderFlex extends RenderBox with ContainerRenderObjectMixin<RenderBox, Fl
               throw new FlutterError('To use FlexAlignItems.baseline, you must also specify which baseline to use using the "baseline" argument.');
             return true;
           });
-          double distance = child.getDistanceToBaseline(textBaseline, onlyReal: true);
+          final double distance = child.getDistanceToBaseline(textBaseline, onlyReal: true);
           if (distance != null)
             maxBaselineDistance = math.max(maxBaselineDistance, distance);
         }
@@ -638,7 +638,7 @@ class RenderFlex extends RenderBox with ContainerRenderObjectMixin<RenderBox, Fl
           childCrossPosition = 0.0;
           if (_direction == Axis.horizontal) {
             assert(textBaseline != null);
-            double distance = child.getDistanceToBaseline(textBaseline, onlyReal: true);
+            final double distance = child.getDistanceToBaseline(textBaseline, onlyReal: true);
             if (distance != null)
               childCrossPosition = maxBaselineDistance - distance;
           }
@@ -681,8 +681,8 @@ class RenderFlex extends RenderBox with ContainerRenderObjectMixin<RenderBox, Fl
       // If you do want clipping, use a RenderClip (Clip in the
       // Widgets library).
 
-      Paint markerPaint = new Paint()..color = const Color(0xE0FF0000);
+      final Paint markerPaint = new Paint()..color = const Color(0xE0FF0000);
-      Paint highlightPaint = new Paint()..color = const Color(0x7FFF0000);
+      final Paint highlightPaint = new Paint()..color = const Color(0x7FFF0000);
       const double kMarkerSize = 0.1;
       Rect markerRect, overflowRect;
       switch(direction) {

packages/flutter/lib/src/rendering/flow.dart

@@ -285,7 +285,7 @@ class RenderFlow extends RenderBox
     RenderBox child = firstChild;
     while (child != null) {
       _randomAccessChildren.add(child);
-      BoxConstraints innerConstraints = _delegate.getConstraintsForChild(i, constraints);
+      final BoxConstraints innerConstraints = _delegate.getConstraintsForChild(i, constraints);
       child.layout(innerConstraints, parentUsesSize: true);
       final FlowParentData childParentData = child.parentData;
       childParentData.offset = Offset.zero;
@@ -314,7 +314,7 @@ class RenderFlow extends RenderBox
   @override
   void paintChild(int i, { Matrix4 transform, double opacity: 1.0 }) {
     transform ??= new Matrix4.identity();
-    RenderBox child = _randomAccessChildren[i];
+    final RenderBox child = _randomAccessChildren[i];
     final FlowParentData childParentData = child.parentData;
     assert(() {
       if (childParentData._transform != null) {

packages/flutter/lib/src/rendering/layer.dart

@@ -84,11 +84,11 @@ abstract class Layer {
     String result = '$prefixLineOne$this\n';
     final String childrenDescription = debugDescribeChildren(prefixOtherLines);
     final String descriptionPrefix = childrenDescription != '' ? '$prefixOtherLines \u2502 ' : '$prefixOtherLines   ';
-    List<String> description = <String>[];
+    final List<String> description = <String>[];
     debugFillDescription(description);
     result += description.map((String description) => "$descriptionPrefix$description\n").join();
     if (childrenDescription == '') {
-      String prefix = prefixOtherLines.trimRight();
+      final String prefix = prefixOtherLines.trimRight();
       if (prefix != '')
         result += '$prefix\n';
     } else {
@@ -258,7 +258,7 @@ class ContainerLayer extends Layer {
   void removeAllChildren() {
     Layer child = _firstChild;
     while (child != null) {
-      Layer next = child.nextSibling;
+      final Layer next = child.nextSibling;
       child._previousSibling = null;
       child._nextSibling = null;
       child._parent = null;

packages/flutter/lib/src/rendering/object.dart

@@ -83,7 +83,7 @@ class PaintingContext {
       child._layer.debugCreator = child.debugCreator ?? child.runtimeType;
       return true;
     });
-    PaintingContext childContext = new PaintingContext._(child._layer, child.paintBounds);
+    final PaintingContext childContext = new PaintingContext._(child._layer, child.paintBounds);
     child._paintWithContext(childContext, Offset.zero);
     childContext._stopRecordingIfNeeded();
   }
@@ -186,14 +186,14 @@ class PaintingContext {
       return;
     assert(() {
       if (debugRepaintRainbowEnabled) {
-        Paint paint = new Paint()
+        final Paint paint = new Paint()
           ..style = PaintingStyle.stroke
           ..strokeWidth = 6.0
           ..color = debugCurrentRepaintColor.toColor();
         canvas.drawRect(_paintBounds.deflate(3.0), paint);
       }
       if (debugPaintLayerBordersEnabled) {
-        Paint paint = new Paint()
+        final Paint paint = new Paint()
           ..style = PaintingStyle.stroke
           ..strokeWidth = 1.0
           ..color = debugPaintLayerBordersColor;
@@ -582,14 +582,14 @@ class _SemanticsGeometry {
   Matrix4 transform;
   void applyAncestorChain(List<RenderObject> ancestorChain) {
     for (int index = ancestorChain.length-1; index > 0; index -= 1) {
-      RenderObject parent = ancestorChain[index];
+      final RenderObject parent = ancestorChain[index];
-      RenderObject child = ancestorChain[index-1];
+      final RenderObject child = ancestorChain[index-1];
       clipRect = _intersectClipRect(parent.describeApproximatePaintClip(child));
       if (clipRect != null) {
         if (clipRect.isEmpty) {
           clipRect = Rect.zero;
         } else {
-          Matrix4 clipTransform = new Matrix4.identity();
+          final Matrix4 clipTransform = new Matrix4.identity();
           parent.applyPaintTransform(child, clipTransform);
           clipRect = MatrixUtils.inverseTransformRect(clipTransform, clipRect);
         }
@@ -623,7 +623,7 @@ abstract class _SemanticsFragment {
     assert(() {
       if (children == null)
         return true;
-      Set<_SemanticsFragment> seenChildren = new Set<_SemanticsFragment>();
+      final Set<_SemanticsFragment> seenChildren = new Set<_SemanticsFragment>();
       for (_SemanticsFragment child in children)
         assert(seenChildren.add(child)); // check for duplicate adds
       return true;
@@ -663,7 +663,7 @@ class _CleanSemanticsFragment extends _SemanticsFragment {
   Iterable<SemanticsNode> compile({ _SemanticsGeometry geometry, SemanticsNode currentSemantics, SemanticsNode parentSemantics }) sync* {
     assert(!_debugCompiled);
     assert(() { _debugCompiled = true; return true; });
-    SemanticsNode node = renderObjectOwner._semantics;
+    final SemanticsNode node = renderObjectOwner._semantics;
     assert(node != null);
     if (geometry != null) {
       geometry.applyAncestorChain(_ancestorChain);
@@ -688,7 +688,7 @@ abstract class _InterestingSemanticsFragment extends _SemanticsFragment {
   Iterable<SemanticsNode> compile({ _SemanticsGeometry geometry, SemanticsNode currentSemantics, SemanticsNode parentSemantics }) sync* {
     assert(!_debugCompiled);
     assert(() { _debugCompiled = true; return true; });
-    SemanticsNode node = establishSemanticsNode(geometry, currentSemantics, parentSemantics);
+    final SemanticsNode node = establishSemanticsNode(geometry, currentSemantics, parentSemantics);
     if (annotator != null)
       annotator(node);
     for (_SemanticsFragment child in _children) {
@@ -726,7 +726,7 @@ class _RootSemanticsFragment extends _InterestingSemanticsFragment {
       handler: renderObjectOwner is SemanticsActionHandler ? renderObjectOwner as dynamic : null,
       owner: renderObjectOwner.owner.semanticsOwner
     );
-    SemanticsNode node = renderObjectOwner._semantics;
+    final SemanticsNode node = renderObjectOwner._semantics;
     assert(MatrixUtils.matrixEquals(node.transform, new Matrix4.identity()));
     assert(!node.wasAffectedByClip);
     node.rect = renderObjectOwner.semanticBounds;
@@ -751,7 +751,7 @@ class _ConcreteSemanticsFragment extends _InterestingSemanticsFragment {
     renderObjectOwner._semantics ??= new SemanticsNode(
       handler: renderObjectOwner is SemanticsActionHandler ? renderObjectOwner as dynamic : null
     );
-    SemanticsNode node = renderObjectOwner._semantics;
+    final SemanticsNode node = renderObjectOwner._semantics;
     if (geometry != null) {
       geometry.applyAncestorChain(_ancestorChain);
       geometry.updateSemanticsNode(rendering: renderObjectOwner, semantics: node, parentSemantics: parentSemantics);
@@ -972,7 +972,7 @@ class PipelineOwner {
     try {
       // TODO(ianh): assert that we're not allowing previously dirty nodes to redirty themeselves
       while (_nodesNeedingLayout.isNotEmpty) {
-        List<RenderObject> dirtyNodes = _nodesNeedingLayout;
+        final List<RenderObject> dirtyNodes = _nodesNeedingLayout;
         _nodesNeedingLayout = <RenderObject>[];
         for (RenderObject node in dirtyNodes..sort((RenderObject a, RenderObject b) => a.depth - b.depth)) {
           if (node._needsLayout && node.owner == this)
@@ -995,7 +995,7 @@ class PipelineOwner {
   // See [RenderObject.invokeLayoutCallback].
   void _enableMutationsToDirtySubtrees(VoidCallback callback) {
     assert(_debugDoingLayout);
-    bool oldState = _debugAllowMutationsToDirtySubtrees;
+    final bool oldState = _debugAllowMutationsToDirtySubtrees;
     _debugAllowMutationsToDirtySubtrees = true;
     try {
       callback();
@@ -1041,7 +1041,7 @@ class PipelineOwner {
     Timeline.startSync('Paint');
     _debugDoingPaint = true;
     try {
-      List<RenderObject> dirtyNodes = _nodesNeedingPaint;
+      final List<RenderObject> dirtyNodes = _nodesNeedingPaint;
       _nodesNeedingPaint = <RenderObject>[];
       // Sort the dirty nodes in reverse order (deepest first).
       for (RenderObject node in dirtyNodes..sort((RenderObject a, RenderObject b) => b.depth - a.depth)) {
@@ -1337,7 +1337,7 @@ abstract class RenderObject extends AbstractNode implements HitTestTarget {
       informationCollector: (StringBuffer information) {
         information.writeln('The following RenderObject was being processed when the exception was fired:');
         information.writeln('  ${toStringShallow('\n  ')}');
-        List<String> descendants = <String>[];
+        final List<String> descendants = <String>[];
         const int maxDepth = 5;
         int depth = 0;
         const int maxLines = 25;
@@ -1684,9 +1684,9 @@ abstract class RenderObject extends AbstractNode implements HitTestTarget {
     assert(constraints.debugAssertIsValid(
       isAppliedConstraint: true,
       informationCollector: (StringBuffer information) {
-        List<String> stack = StackTrace.current.toString().split('\n');
+        final List<String> stack = StackTrace.current.toString().split('\n');
         int targetFrame;
-        Pattern layoutFramePattern = new RegExp(r'^#[0-9]+ +RenderObject.layout \(');
+        final Pattern layoutFramePattern = new RegExp(r'^#[0-9]+ +RenderObject.layout \(');
         for (int i = 0; i < stack.length; i += 1) {
           if (layoutFramePattern.matchAsPrefix(stack[i]) != null) {
             targetFrame = i + 1;
@@ -1699,8 +1699,8 @@ abstract class RenderObject extends AbstractNode implements HitTestTarget {
             'function by the following function, which probably computed the '
             'invalid constraints in question:'
           );
-          Pattern targetFramePattern = new RegExp(r'^#[0-9]+ +(.+)$');
+          final Pattern targetFramePattern = new RegExp(r'^#[0-9]+ +(.+)$');
-          Match targetFrameMatch = targetFramePattern.matchAsPrefix(stack[targetFrame]);
+          final Match targetFrameMatch = targetFramePattern.matchAsPrefix(stack[targetFrame]);
           if (targetFrameMatch != null && targetFrameMatch.groupCount > 0) {
             information.writeln('  ${targetFrameMatch.group(1)}');
           } else {
@@ -1729,7 +1729,7 @@ abstract class RenderObject extends AbstractNode implements HitTestTarget {
         // to itself, so it has the right internal debug values.
         _debugDoingThisResize = sizedByParent;
         _debugDoingThisLayout = !sizedByParent;
-        RenderObject debugPreviousActiveLayout = _debugActiveLayout;
+        final RenderObject debugPreviousActiveLayout = _debugActiveLayout;
         _debugActiveLayout = this;
         debugResetSize();
         _debugActiveLayout = debugPreviousActiveLayout;
@@ -2005,7 +2005,7 @@ abstract class RenderObject extends AbstractNode implements HitTestTarget {
   void _updateCompositingBits() {
     if (!_needsCompositingBitsUpdate)
       return;
-    bool oldNeedsCompositing = _needsCompositing;
+    final bool oldNeedsCompositing = _needsCompositing;
     visitChildren((RenderObject child) {
       child._updateCompositingBits();
       if (child.needsCompositing)
@@ -2317,9 +2317,9 @@ abstract class RenderObject extends AbstractNode implements HitTestTarget {
     try {
       assert(_needsSemanticsUpdate);
       assert(_semantics != null || parent is! RenderObject);
-      _SemanticsFragment fragment = _getSemanticsFragment();
+      final _SemanticsFragment fragment = _getSemanticsFragment();
       assert(fragment is _InterestingSemanticsFragment);
-      SemanticsNode node = fragment.compile(parentSemantics: _semantics?.parent).single;
+      final SemanticsNode node = fragment.compile(parentSemantics: _semantics?.parent).single;
       assert(node != null);
       assert(node == _semantics);
     } catch (e, stack) {
@@ -2342,7 +2342,7 @@ abstract class RenderObject extends AbstractNode implements HitTestTarget {
         child._needsSemanticsUpdate = true;
         child._needsSemanticsGeometryUpdate = true;
       }
-      _SemanticsFragment fragment = child._getSemanticsFragment();
+      final _SemanticsFragment fragment = child._getSemanticsFragment();
       if (fragment != null) {
         fragment.addAncestor(this);
         children ??= <_SemanticsFragment>[];
@@ -2352,7 +2352,7 @@ abstract class RenderObject extends AbstractNode implements HitTestTarget {
     });
     _needsSemanticsUpdate = false;
     _needsSemanticsGeometryUpdate = false;
-    SemanticsAnnotator annotator = semanticsAnnotator;
+    final SemanticsAnnotator annotator = semanticsAnnotator;
     if (parent is! RenderObject)
       return new _RootSemanticsFragment(renderObjectOwner: this, annotator: annotator, children: children);
     if (isSemanticBoundary)
@@ -2456,19 +2456,19 @@ abstract class RenderObject extends AbstractNode implements HitTestTarget {
   /// If the prefix argument is provided, then every line in the output
   /// will be prefixed by that string.
   String toStringDeep([String prefixLineOne = '', String prefixOtherLines = '']) {
-    RenderObject debugPreviousActiveLayout = _debugActiveLayout;
+    final RenderObject debugPreviousActiveLayout = _debugActiveLayout;
     _debugActiveLayout = null;
     String result = '$prefixLineOne$this\n';
     final String childrenDescription = debugDescribeChildren(prefixOtherLines);
     final String descriptionPrefix = childrenDescription != '' ? '$prefixOtherLines \u2502 ' : '$prefixOtherLines   ';
-    List<String> description = <String>[];
+    final List<String> description = <String>[];
     debugFillDescription(description);
     result += description
       .expand((String description) => debugWordWrap(description, 65, wrapIndent: '  '))
       .map<String>((String line) => "$descriptionPrefix$line\n")
       .join();
     if (childrenDescription == '') {
-      String prefix = prefixOtherLines.trimRight();
+      final String prefix = prefixOtherLines.trimRight();
       if (prefix != '')
         result += '$prefix\n';
     } else {
@@ -2484,11 +2484,11 @@ abstract class RenderObject extends AbstractNode implements HitTestTarget {
   /// This includes the same information for this RenderObject as given by
   /// [toStringDeep], but does not recurse to any children.
   String toStringShallow([String joiner = '; ']) {
-    RenderObject debugPreviousActiveLayout = _debugActiveLayout;
+    final RenderObject debugPreviousActiveLayout = _debugActiveLayout;
     _debugActiveLayout = null;
-    StringBuffer result = new StringBuffer();
+    final StringBuffer result = new StringBuffer();
     result.write('${this}$joiner'); // TODO(ianh): https://github.com/dart-lang/sdk/issues/28206
-    List<String> description = <String>[];
+    final List<String> description = <String>[];
     debugFillDescription(description);
     result.write(description.join(joiner));
     _debugActiveLayout = debugPreviousActiveLayout;
@@ -2728,7 +2728,7 @@ abstract class ContainerRenderObjectMixin<ChildType extends RenderObject, Parent
     ChildType child = _firstChild;
     while (child != null) {
       final ParentDataType childParentData = child.parentData;
-      ChildType next = childParentData.nextSibling;
+      final ChildType next = childParentData.nextSibling;
       childParentData.previousSibling = null;
       childParentData.nextSibling = null;
       dropChild(child);

packages/flutter/lib/src/rendering/paragraph.dart

@@ -126,7 +126,7 @@ class RenderParagraph extends RenderBox {
   }
 
   void _layoutText({ double minWidth: 0.0, double maxWidth: double.INFINITY }) {
-    bool wrap = _softWrap || (_overflow == TextOverflow.ellipsis && maxLines == null);
+    final bool wrap = _softWrap || (_overflow == TextOverflow.ellipsis && maxLines == null);
     _textPainter.layout(minWidth: minWidth, maxWidth: wrap ? maxWidth : double.INFINITY);
   }
 
@@ -179,9 +179,9 @@ class RenderParagraph extends RenderBox {
     if (event is! PointerDownEvent)
       return;
     _layoutTextWithConstraints(constraints);
-    Offset offset = entry.localPosition.toOffset();
+    final Offset offset = entry.localPosition.toOffset();
-    TextPosition position = _textPainter.getPositionForOffset(offset);
+    final TextPosition position = _textPainter.getPositionForOffset(offset);
-    TextSpan span = _textPainter.text.getSpanForPosition(position);
+    final TextSpan span = _textPainter.text.getSpanForPosition(position);
     span?.recognizer?.addPointer(event);
   }
 
@@ -212,7 +212,7 @@ class RenderParagraph extends RenderBox {
           _overflowShader = null;
           break;
         case TextOverflow.fade:
-          TextPainter fadeSizePainter = new TextPainter(
+          final TextPainter fadeSizePainter = new TextPainter(
             text: new TextSpan(style: _textPainter.text.style, text: '\u2026'),
             textScaleFactor: textScaleFactor
           )..layout();
@@ -256,7 +256,7 @@ class RenderParagraph extends RenderBox {
 
     assert(() {
       if (debugRepaintTextRainbowEnabled) {
-        Paint paint = new Paint()
+        final Paint paint = new Paint()
           ..color = debugCurrentRepaintColor.toColor();
         canvas.drawRect(offset & size, paint);
       }
@@ -275,7 +275,7 @@ class RenderParagraph extends RenderBox {
     if (_hasVisualOverflow) {
       if (_overflowShader != null) {
         canvas.translate(offset.dx, offset.dy);
-        Paint paint = new Paint()
+        final Paint paint = new Paint()
           ..blendMode = BlendMode.modulate
           ..shader = _overflowShader;
         canvas.drawRect(Point.origin & size, paint);

packages/flutter/lib/src/rendering/proxy_box.dart

@@ -821,7 +821,7 @@ class RenderShaderMask extends RenderProxyBox {
   void paint(PaintingContext context, Offset offset) {
     if (child != null) {
       assert(needsCompositing);
-      Rect rect = Point.origin & size;
+      final Rect rect = Point.origin & size;
       context.pushShaderMask(offset, _shaderCallback(rect), rect, _blendMode, super.paint);
     }
   }
@@ -940,7 +940,7 @@ abstract class _RenderCustomClip<T> extends RenderProxyBox {
   set clipper (CustomClipper<T> newClipper) {
     if (_clipper == newClipper)
       return;
-    CustomClipper<T> oldClipper = _clipper;
+    final CustomClipper<T> oldClipper = _clipper;
     _clipper = newClipper;
     assert(newClipper != null || oldClipper != null);
     if (newClipper == null || oldClipper == null ||
@@ -1123,9 +1123,9 @@ class RenderClipOval extends _RenderCustomClip<Rect> {
   bool hitTest(HitTestResult result, { Point position }) {
     _updateClip();
     assert(_clip != null);
-    Point center = _clip.center;
+    final Point center = _clip.center;
     // convert the position to an offset from the center of the unit circle
-    Offset offset = new Offset((position.x - center.x) / _clip.width,
+    final Offset offset = new Offset((position.x - center.x) / _clip.width,
                                (position.y - center.y) / _clip.height);
     // check if the point is outside the unit circle
     if (offset.distanceSquared > 0.25) // x^2 + y^2 > r^2
@@ -1265,7 +1265,7 @@ class RenderPhysicalModel extends _RenderCustomClip<RRect> {
     if (_shape == BoxShape.rectangle) {
       return _borderRadius.toRRect(Point.origin & size);
     } else {
-      Rect rect = Point.origin & size;
+      final Rect rect = Point.origin & size;
       return new RRect.fromRectXY(rect, rect.width / 2, rect.height / 2);
     }
   }
@@ -1529,7 +1529,7 @@ class RenderTransform extends RenderProxyBox {
   Matrix4 get _effectiveTransform {
     if (_origin == null && _alignment == null)
       return _transform;
-    Matrix4 result = new Matrix4.identity();
+    final Matrix4 result = new Matrix4.identity();
     if (_origin != null)
       result.translate(_origin.dx, _origin.dy);
     Offset translation;
@@ -1564,8 +1564,8 @@ class RenderTransform extends RenderProxyBox {
   @override
   void paint(PaintingContext context, Offset offset) {
     if (child != null) {
-      Matrix4 transform = _effectiveTransform;
+      final Matrix4 transform = _effectiveTransform;
-      Offset childOffset = MatrixUtils.getAsTranslation(transform);
+      final Offset childOffset = MatrixUtils.getAsTranslation(transform);
       if (childOffset == null)
         context.pushTransform(needsCompositing, offset, transform, super.paint);
       else
@@ -1673,7 +1673,7 @@ class RenderFittedBox extends RenderProxyBox {
   }
 
   void _paintChildWithTransform(PaintingContext context, Offset offset) {
-    Offset childOffset = MatrixUtils.getAsTranslation(_transform);
+    final Offset childOffset = MatrixUtils.getAsTranslation(_transform);
     if (childOffset == null)
       context.pushTransform(needsCompositing, offset, _transform, super.paint);
     else
@@ -1950,7 +1950,7 @@ class RenderCustomPaint extends RenderProxyBox {
   set painter (CustomPainter newPainter) {
     if (_painter == newPainter)
       return;
-    CustomPainter oldPainter = _painter;
+    final CustomPainter oldPainter = _painter;
     _painter = newPainter;
     _didUpdatePainter(_painter, oldPainter);
   }
@@ -1975,7 +1975,7 @@ class RenderCustomPaint extends RenderProxyBox {
   set foregroundPainter (CustomPainter newPainter) {
     if (_foregroundPainter == newPainter)
       return;
-    CustomPainter oldPainter = _foregroundPainter;
+    final CustomPainter oldPainter = _foregroundPainter;
     _foregroundPainter = newPainter;
     _didUpdatePainter(_foregroundPainter, oldPainter);
   }
@@ -2057,7 +2057,7 @@ class RenderCustomPaint extends RenderProxyBox {
       // Canvas class to lock the canvas at a particular save count
       // such that restore() fails if it would take the lock count
       // below that number.
-      int debugNewCanvasSaveCount = canvas.getSaveCount();
+      final int debugNewCanvasSaveCount = canvas.getSaveCount();
       if (debugNewCanvasSaveCount > debugPreviousCanvasSaveCount) {
         throw new FlutterError(
           'The $painter custom painter called canvas.save() or canvas.saveLayer() at least '
@@ -2166,7 +2166,7 @@ class RenderPointerListener extends RenderProxyBoxWithHitTestBehavior {
   @override
   void debugFillDescription(List<String> description) {
     super.debugFillDescription(description);
-    List<String> listeners = <String>[];
+    final List<String> listeners = <String>[];
     if (onPointerDown != null)
       listeners.add('down');
     if (onPointerMove != null)
@@ -2275,7 +2275,7 @@ class RenderRepaintBoundary extends RenderProxyBox {
       if (debugSymmetricPaintCount + debugAsymmetricPaintCount == 0) {
         description.add('usefulness ratio: no metrics collected yet (never painted)');
       } else {
-        double percentage = 100.0 * debugAsymmetricPaintCount / (debugSymmetricPaintCount + debugAsymmetricPaintCount);
+        final double percentage = 100.0 * debugAsymmetricPaintCount / (debugSymmetricPaintCount + debugAsymmetricPaintCount);
         String diagnosis;
         if (debugSymmetricPaintCount + debugAsymmetricPaintCount < 5) {
           diagnosis = 'insufficient data to draw conclusion (less than five repaints)';
@@ -2350,7 +2350,7 @@ class RenderIgnorePointer extends RenderProxyBox {
   set ignoringSemantics(bool value) {
     if (value == _ignoringSemantics)
       return;
-    bool oldEffectiveValue = _effectiveIgnoringSemantics;
+    final bool oldEffectiveValue = _effectiveIgnoringSemantics;
     _ignoringSemantics = value;
     if (oldEffectiveValue != _effectiveIgnoringSemantics)
       markNeedsSemanticsUpdate();
@@ -2576,8 +2576,8 @@ class RenderSemanticsGestureHandler extends RenderProxyBox implements SemanticsA
   set onTap(GestureTapCallback value) {
     if (_onTap == value)
       return;
-    bool wasSemanticBoundary = isSemanticBoundary;
+    final bool wasSemanticBoundary = isSemanticBoundary;
-    bool hadHandler = _onTap != null;
+    final bool hadHandler = _onTap != null;
     _onTap = value;
     if ((value != null) != hadHandler)
       markNeedsSemanticsUpdate(onlyChanges: isSemanticBoundary == wasSemanticBoundary);
@@ -2589,8 +2589,8 @@ class RenderSemanticsGestureHandler extends RenderProxyBox implements SemanticsA
   set onLongPress(GestureLongPressCallback value) {
     if (_onLongPress == value)
       return;
-    bool wasSemanticBoundary = isSemanticBoundary;
+    final bool wasSemanticBoundary = isSemanticBoundary;
-    bool hadHandler = _onLongPress != null;
+    final bool hadHandler = _onLongPress != null;
     _onLongPress = value;
     if ((value != null) != hadHandler)
       markNeedsSemanticsUpdate(onlyChanges: isSemanticBoundary == wasSemanticBoundary);
@@ -2602,8 +2602,8 @@ class RenderSemanticsGestureHandler extends RenderProxyBox implements SemanticsA
   set onHorizontalDragUpdate(GestureDragUpdateCallback value) {
     if (_onHorizontalDragUpdate == value)
       return;
-    bool wasSemanticBoundary = isSemanticBoundary;
+    final bool wasSemanticBoundary = isSemanticBoundary;
-    bool hadHandler = _onHorizontalDragUpdate != null;
+    final bool hadHandler = _onHorizontalDragUpdate != null;
     _onHorizontalDragUpdate = value;
     if ((value != null) != hadHandler)
       markNeedsSemanticsUpdate(onlyChanges: isSemanticBoundary == wasSemanticBoundary);
@@ -2615,8 +2615,8 @@ class RenderSemanticsGestureHandler extends RenderProxyBox implements SemanticsA
   set onVerticalDragUpdate(GestureDragUpdateCallback value) {
     if (_onVerticalDragUpdate == value)
       return;
-    bool wasSemanticBoundary = isSemanticBoundary;
+    final bool wasSemanticBoundary = isSemanticBoundary;
-    bool hadHandler = _onVerticalDragUpdate != null;
+    final bool hadHandler = _onVerticalDragUpdate != null;
     _onVerticalDragUpdate = value;
     if ((value != null) != hadHandler)
       markNeedsSemanticsUpdate(onlyChanges: isSemanticBoundary == wasSemanticBoundary);
@@ -2750,7 +2750,7 @@ class RenderSemanticsAnnotations extends RenderProxyBox {
   set checked(bool value) {
     if (checked == value)
       return;
-    bool hadValue = checked != null;
+    final bool hadValue = checked != null;
     _checked = value;
     markNeedsSemanticsUpdate(onlyChanges: (value != null) == hadValue);
   }
@@ -2761,7 +2761,7 @@ class RenderSemanticsAnnotations extends RenderProxyBox {
   set label(String value) {
     if (label == value)
       return;
-    bool hadValue = label != null;
+    final bool hadValue = label != null;
     _label = value;
     markNeedsSemanticsUpdate(onlyChanges: (value != null) == hadValue);
   }

packages/flutter/lib/src/rendering/rotated_box.dart

@@ -93,7 +93,7 @@ class RenderRotatedBox extends RenderBox with RenderObjectWithChildMixin<RenderB
     assert(_paintTransform != null || debugNeedsLayout || child == null);
     if (child == null || _paintTransform == null)
       return false;
-    Matrix4 inverse = new Matrix4.inverted(_paintTransform);
+    final Matrix4 inverse = new Matrix4.inverted(_paintTransform);
     return child.hitTest(result, position: MatrixUtils.transformPoint(inverse, position));
   }
 

packages/flutter/lib/src/rendering/semantics.dart

@@ -99,7 +99,7 @@ class SemanticsData {
 
   @override
   String toString() {
-    StringBuffer buffer = new StringBuffer();
+    final StringBuffer buffer = new StringBuffer();
     buffer.write('$runtimeType($rect');
     if (transform != null)
       buffer.write('; $transform');
@@ -307,7 +307,7 @@ class SemanticsNode extends AbstractNode {
 
   /// Restore this node to its default state.
   void reset() {
-    bool hadInheritedMergeAllDescendantsIntoThisNode = _inheritedMergeAllDescendantsIntoThisNode;
+    final bool hadInheritedMergeAllDescendantsIntoThisNode = _inheritedMergeAllDescendantsIntoThisNode;
     _actions = 0;
     _flags = 0;
     if (hadInheritedMergeAllDescendantsIntoThisNode)
@@ -336,7 +336,7 @@ class SemanticsNode extends AbstractNode {
       return true;
     });
     assert(() {
-      Set<SemanticsNode> seenChildren = new Set<SemanticsNode>();
+      final Set<SemanticsNode> seenChildren = new Set<SemanticsNode>();
       for (SemanticsNode child in _newChildren)
         assert(seenChildren.add(child)); // check for duplicate adds
       return true;
@@ -411,7 +411,7 @@ class SemanticsNode extends AbstractNode {
         }
       }
     }
-    List<SemanticsNode> oldChildren = _children;
+    final List<SemanticsNode> oldChildren = _children;
     _children = _newChildren;
     oldChildren?.clear();
     _newChildren = oldChildren;
@@ -565,7 +565,7 @@ class SemanticsNode extends AbstractNode {
 
   @override
   String toString() {
-    StringBuffer buffer = new StringBuffer();
+    final StringBuffer buffer = new StringBuffer();
     buffer.write('$runtimeType($id');
     if (_dirty)
       buffer.write(' (${ owner != null && owner._dirtyNodes.contains(this) ? "dirty" : "STALE; owner=$owner" })');
@@ -595,7 +595,7 @@ class SemanticsNode extends AbstractNode {
     String result = '$prefixLineOne$this\n';
     if (_children != null && _children.isNotEmpty) {
       for (int index = 0; index < _children.length - 1; index += 1) {
-        SemanticsNode child = _children[index];
+        final SemanticsNode child = _children[index];
         result += '${child.toStringDeep("$prefixOtherLines \u251C", "$prefixOtherLines \u2502")}';
       }
       result += '${_children.last.toStringDeep("$prefixOtherLines \u2514", "$prefixOtherLines  ")}';
@@ -631,9 +631,9 @@ class SemanticsOwner extends ChangeNotifier {
   void sendSemanticsUpdate() {
     if (_dirtyNodes.isEmpty)
       return;
-    List<SemanticsNode> visitedNodes = <SemanticsNode>[];
+    final List<SemanticsNode> visitedNodes = <SemanticsNode>[];
     while (_dirtyNodes.isNotEmpty) {
-      List<SemanticsNode> localDirtyNodes = _dirtyNodes.where((SemanticsNode node) => !_detachedNodes.contains(node)).toList();
+      final List<SemanticsNode> localDirtyNodes = _dirtyNodes.where((SemanticsNode node) => !_detachedNodes.contains(node)).toList();
       _dirtyNodes.clear();
       _detachedNodes.clear();
       localDirtyNodes.sort((SemanticsNode a, SemanticsNode b) => a.depth - b.depth);
@@ -669,7 +669,7 @@ class SemanticsOwner extends ChangeNotifier {
       }
     }
     visitedNodes.sort((SemanticsNode a, SemanticsNode b) => a.depth - b.depth);
-    ui.SemanticsUpdateBuilder builder = new ui.SemanticsUpdateBuilder();
+    final ui.SemanticsUpdateBuilder builder = new ui.SemanticsUpdateBuilder();
     for (SemanticsNode node in visitedNodes) {
       assert(node.parent?._dirty != true); // could be null (no parent) or false (not dirty)
       // The _serialize() method marks the node as not dirty, and
@@ -712,13 +712,13 @@ class SemanticsOwner extends ChangeNotifier {
   /// this function does nothing.
   void performAction(int id, SemanticsAction action) {
     assert(action != null);
-    SemanticsActionHandler handler = _getSemanticsActionHandlerForId(id, action);
+    final SemanticsActionHandler handler = _getSemanticsActionHandlerForId(id, action);
     handler?.performAction(action);
   }
 
   SemanticsActionHandler _getSemanticsActionHandlerForPosition(SemanticsNode node, Point position, SemanticsAction action) {
     if (node.transform != null) {
-      Matrix4 inverse = new Matrix4.identity();
+      final Matrix4 inverse = new Matrix4.identity();
       if (inverse.copyInverse(node.transform) == 0.0)
         return null;
       position = MatrixUtils.transformPoint(inverse, position);
@@ -738,7 +738,7 @@ class SemanticsOwner extends ChangeNotifier {
     }
     if (node.hasChildren) {
       for (SemanticsNode child in node._children.reversed) {
-        SemanticsActionHandler handler = _getSemanticsActionHandlerForPosition(child, position, action);
+        final SemanticsActionHandler handler = _getSemanticsActionHandlerForPosition(child, position, action);
         if (handler != null)
           return handler;
       }
@@ -755,7 +755,7 @@ class SemanticsOwner extends ChangeNotifier {
     final SemanticsNode node = rootSemanticsNode;
     if (node == null)
       return;
-    SemanticsActionHandler handler = _getSemanticsActionHandlerForPosition(node, position, action);
+    final SemanticsActionHandler handler = _getSemanticsActionHandlerForPosition(node, position, action);
     handler?.performAction(action);
   }
 

packages/flutter/lib/src/rendering/shifted_box.dart

@@ -158,7 +158,7 @@ class RenderPadding extends RenderShiftedBox {
       ));
       return;
     }
-    BoxConstraints innerConstraints = constraints.deflate(padding);
+    final BoxConstraints innerConstraints = constraints.deflate(padding);
     child.layout(innerConstraints, parentUsesSize: true);
     final BoxParentData childParentData = child.parentData;
     childParentData.offset = new Offset(padding.left, padding.top);
@@ -325,7 +325,7 @@ class RenderPositionedBox extends RenderAligningShiftedBox {
         final BoxParentData childParentData = child.parentData;
         if (childParentData.offset.dy > 0.0) {
           // vertical alignment arrows
-          double headSize = math.min(childParentData.offset.dy * 0.2, 10.0);
+          final double headSize = math.min(childParentData.offset.dy * 0.2, 10.0);
           path
             ..moveTo(offset.dx + size.width / 2.0, offset.dy)
             ..relativeLineTo(0.0, childParentData.offset.dy - headSize)
@@ -343,7 +343,7 @@ class RenderPositionedBox extends RenderAligningShiftedBox {
         }
         if (childParentData.offset.dx > 0.0) {
           // horizontal alignment arrows
-          double headSize = math.min(childParentData.offset.dx * 0.2, 10.0);
+          final double headSize = math.min(childParentData.offset.dx * 0.2, 10.0);
           path
             ..moveTo(offset.dx, offset.dy + size.height / 2.0)
             ..relativeLineTo(childParentData.offset.dx - headSize, 0.0)
@@ -614,14 +614,14 @@ class RenderFractionallySizedOverflowBox extends RenderAligningShiftedBox {
     double minWidth = constraints.minWidth;
     double maxWidth = constraints.maxWidth;
     if (_widthFactor != null) {
-      double width = maxWidth * _widthFactor;
+      final double width = maxWidth * _widthFactor;
       minWidth = width;
       maxWidth = width;
     }
     double minHeight = constraints.minHeight;
     double maxHeight = constraints.maxHeight;
     if (_heightFactor != null) {
-      double height = maxHeight * _heightFactor;
+      final double height = maxHeight * _heightFactor;
       minHeight = height;
       maxHeight = height;
     }
@@ -870,7 +870,7 @@ class RenderCustomSingleChildLayoutBox extends RenderShiftedBox {
   void performLayout() {
     size = _getSize(constraints);
     if (child != null) {
-      BoxConstraints childConstraints = delegate.getConstraintsForChild(constraints);
+      final BoxConstraints childConstraints = delegate.getConstraintsForChild(constraints);
       assert(childConstraints.debugAssertIsValid(isAppliedConstraint: true));
       child.layout(childConstraints, parentUsesSize: !childConstraints.isTight);
       final BoxParentData childParentData = child.parentData;

packages/flutter/lib/src/rendering/sliver_fixed_extent_list.dart

@@ -60,7 +60,7 @@ abstract class RenderSliverFixedExtentBoxAdaptor extends RenderSliverMultiBoxAda
     assert(remainingPaintExtent >= 0.0);
     final double targetEndScrollOffset = scrollOffset + remainingPaintExtent;
 
-    BoxConstraints childConstraints = constraints.asBoxConstraints(
+    final BoxConstraints childConstraints = constraints.asBoxConstraints(
       minExtent: itemExtent,
       maxExtent: itemExtent,
     );

packages/flutter/lib/src/rendering/sliver_grid.dart

@@ -468,7 +468,7 @@ class RenderSliverGrid extends RenderSliverMultiBoxAdaptor {
     }
 
     final SliverGridGeometry firstChildGridGeometry = layout.getGeometryForChildIndex(firstIndex);
-    double leadingScrollOffset = firstChildGridGeometry.scrollOffset;
+    final double leadingScrollOffset = firstChildGridGeometry.scrollOffset;
     double trailingScrollOffset = firstChildGridGeometry.trailingScrollOffset;
 
     if (firstChild == null) {

packages/flutter/lib/src/rendering/sliver_list.dart

@@ -19,12 +19,12 @@ class RenderSliverList extends RenderSliverMultiBoxAdaptor {
     assert(childManager.debugAssertChildListLocked());
     childManager.setDidUnderflow(false);
 
-    double scrollOffset = constraints.scrollOffset;
+    final double scrollOffset = constraints.scrollOffset;
     assert(scrollOffset >= 0.0);
-    double remainingPaintExtent = constraints.remainingPaintExtent;
+    final double remainingPaintExtent = constraints.remainingPaintExtent;
     assert(remainingPaintExtent >= 0.0);
-    double targetEndScrollOffset = scrollOffset + remainingPaintExtent;
+    final double targetEndScrollOffset = scrollOffset + remainingPaintExtent;
-    BoxConstraints childConstraints = constraints.asBoxConstraints();
+    final BoxConstraints childConstraints = constraints.asBoxConstraints();
     int leadingGarbage = 0;
     int trailingGarbage = 0;
     bool reachedEnd = false;

packages/flutter/lib/src/rendering/stack.dart

@@ -105,7 +105,7 @@ class RelativeRect {
     if (a == null)
       return new RelativeRect.fromLTRB(b.left * t, b.top * t, b.right * t, b.bottom * t);
     if (b == null) {
-      double k = 1.0 - t;
+      final double k = 1.0 - t;
       return new RelativeRect.fromLTRB(b.left * k, b.top * k, b.right * k, b.bottom * k);
     }
     return new RelativeRect.fromLTRB(
@@ -179,7 +179,7 @@ class StackParentData extends ContainerBoxParentDataMixin<RenderBox> {
 
   @override
   String toString() {
-    List<String> values = <String>[];
+    final List<String> values = <String>[];
     if (top != null)
       values.add('top=$top');
     if (right != null)
@@ -493,9 +493,9 @@ class RenderIndexedStack extends RenderStack {
     if (firstChild == null || index == null)
       return false;
     assert(position != null);
-    RenderBox child = _childAtIndex();
+    final RenderBox child = _childAtIndex();
     final StackParentData childParentData = child.parentData;
-    Point transformed = new Point(position.x - childParentData.offset.dx,
+    final Point transformed = new Point(position.x - childParentData.offset.dx,
                                   position.y - childParentData.offset.dy);
     return child.hitTest(result, position: transformed);
   }
@@ -504,7 +504,7 @@ class RenderIndexedStack extends RenderStack {
   void paintStack(PaintingContext context, Offset offset) {
     if (firstChild == null || index == null)
       return;
-    RenderBox child = _childAtIndex();
+    final RenderBox child = _childAtIndex();
     final StackParentData childParentData = child.parentData;
     context.paintChild(child, childParentData.offset + offset);
   }

packages/flutter/lib/src/rendering/table.dart

@@ -295,10 +295,10 @@ class MinColumnWidth extends TableColumnWidth {
 
   @override
   double flex(Iterable<RenderBox> cells) {
-    double aFlex = a.flex(cells);
+    final double aFlex = a.flex(cells);
     if (aFlex == null)
       return b.flex(cells);
-    double bFlex = b.flex(cells);
+    final double bFlex = b.flex(cells);
     if (bFlex == null)
       return null;
     return math.min(aFlex, bFlex);
@@ -526,11 +526,11 @@ class RenderTable extends RenderBox {
     assert(value >= 0);
     if (value == columns)
       return;
-    int oldColumns = columns;
+    final int oldColumns = columns;
-    List<RenderBox> oldChildren = _children;
+    final List<RenderBox> oldChildren = _children;
     _columns = value;
     _children = new List<RenderBox>()..length = columns * rows;
-    int columnsToCopy = math.min(columns, oldColumns);
+    final int columnsToCopy = math.min(columns, oldColumns);
     for (int y = 0; y < rows; y += 1) {
       for (int x = 0; x < columnsToCopy; x += 1)
         _children[x + y * columns] = oldChildren[x + y * oldColumns];
@@ -538,7 +538,7 @@ class RenderTable extends RenderBox {
     if (oldColumns > columns) {
       for (int y = 0; y < rows; y += 1) {
         for (int x = columns; x < oldColumns; x += 1) {
-          int xy = x + y * oldColumns;
+          final int xy = x + y * oldColumns;
           if (oldChildren[xy] != null)
             dropChild(oldChildren[xy]);
         }
@@ -715,8 +715,8 @@ class RenderTable extends RenderBox {
     final Set<RenderBox> lostChildren = new HashSet<RenderBox>();
     for (int y = 0; y < _rows; y += 1) {
       for (int x = 0; x < _columns; x += 1) {
-        int xyOld = x + y * _columns;
+        final int xyOld = x + y * _columns;
-        int xyNew = x + y * columns;
+        final int xyNew = x + y * columns;
         if (_children[xyOld] != null && (x >= columns || xyNew >= cells.length || _children[xyOld] != cells[xyNew]))
           lostChildren.add(_children[xyOld]);
       }
@@ -725,8 +725,8 @@ class RenderTable extends RenderBox {
     int y = 0;
     while (y * columns < cells.length) {
       for (int x = 0; x < columns; x += 1) {
-        int xyNew = x + y * columns;
+        final int xyNew = x + y * columns;
-        int xyOld = x + y * _columns;
+        final int xyOld = x + y * _columns;
         if (cells[xyNew] != null && (x >= _columns || y >= _rows || _children[xyOld] != cells[xyNew])) {
           if (!lostChildren.remove(cells[xyNew]))
             adoptChild(cells[xyNew]);
@@ -790,7 +790,7 @@ class RenderTable extends RenderBox {
     assert(x >= 0 && x < columns && y >= 0 && y < rows);
     assert(_children.length == rows * columns);
     final int xy = x + y * columns;
-    RenderBox oldChild = _children[xy];
+    final RenderBox oldChild = _children[xy];
     if (oldChild == value)
       return;
     if (oldChild != null)
@@ -833,8 +833,8 @@ class RenderTable extends RenderBox {
     assert(_children.length == rows * columns);
     double totalMinWidth = 0.0;
     for (int x = 0; x < columns; x += 1) {
-      TableColumnWidth columnWidth = _columnWidths[x] ?? defaultColumnWidth;
+      final TableColumnWidth columnWidth = _columnWidths[x] ?? defaultColumnWidth;
-      Iterable<RenderBox> columnCells = column(x);
+      final Iterable<RenderBox> columnCells = column(x);
       totalMinWidth += columnWidth.minIntrinsicWidth(columnCells, double.INFINITY);
     }
     return totalMinWidth;
@@ -845,8 +845,8 @@ class RenderTable extends RenderBox {
     assert(_children.length == rows * columns);
     double totalMaxWidth = 0.0;
     for (int x = 0; x < columns; x += 1) {
-      TableColumnWidth columnWidth = _columnWidths[x] ?? defaultColumnWidth;
+      final TableColumnWidth columnWidth = _columnWidths[x] ?? defaultColumnWidth;
-      Iterable<RenderBox> columnCells = column(x);
+      final Iterable<RenderBox> columnCells = column(x);
       totalMaxWidth += columnWidth.maxIntrinsicWidth(columnCells, double.INFINITY);
     }
     return totalMaxWidth;
@@ -863,7 +863,7 @@ class RenderTable extends RenderBox {
       double rowHeight = 0.0;
       for (int x = 0; x < columns; x += 1) {
         final int xy = x + y * columns;
-        RenderBox child = _children[xy];
+        final RenderBox child = _children[xy];
         if (child != null)
           rowHeight = math.max(rowHeight, child.getMaxIntrinsicHeight(widths[x]));
       }
@@ -892,7 +892,7 @@ class RenderTable extends RenderBox {
   Iterable<RenderBox> column(int x) sync* {
     for (int y = 0; y < rows; y += 1) {
       final int xy = x + y * columns;
-      RenderBox child = _children[xy];
+      final RenderBox child = _children[xy];
       if (child != null)
         yield child;
     }
@@ -906,7 +906,7 @@ class RenderTable extends RenderBox {
     final int start = y * columns;
     final int end = (y + 1) * columns;
     for (int xy = start; xy < end; xy += 1) {
-      RenderBox child = _children[xy];
+      final RenderBox child = _children[xy];
       if (child != null)
         yield child;
     }
@@ -933,8 +933,8 @@ class RenderTable extends RenderBox {
     double unflexedTableWidth = 0.0; // sum of the maxIntrinsicWidths of any column that has null flex
     double totalFlex = 0.0;
     for (int x = 0; x < columns; x += 1) {
-      TableColumnWidth columnWidth = _columnWidths[x] ?? defaultColumnWidth;
+      final TableColumnWidth columnWidth = _columnWidths[x] ?? defaultColumnWidth;
-      Iterable<RenderBox> columnCells = column(x);
+      final Iterable<RenderBox> columnCells = column(x);
       // apply ideal width (maxIntrinsicWidth)
       final double maxIntrinsicWidth = columnWidth.maxIntrinsicWidth(columnCells, constraints.maxWidth);
       assert(maxIntrinsicWidth.isFinite);
@@ -948,7 +948,7 @@ class RenderTable extends RenderBox {
       minWidths[x] = minIntrinsicWidth;
       assert(maxIntrinsicWidth >= minIntrinsicWidth);
       // collect flex information while we're at it
-      double flex = columnWidth.flex(columnCells);
+      final double flex = columnWidth.flex(columnCells);
       if (flex != null) {
         assert(flex.isFinite);
         assert(flex > 0.0);
@@ -1058,7 +1058,7 @@ class RenderTable extends RenderBox {
           final double delta = deficit / availableColumns;
           int newAvailableColumns = 0;
           for (int x = 0; x < columns; x += 1) {
-            double availableDelta = widths[x] - minWidths[x];
+            final double availableDelta = widths[x] - minWidths[x];
             if (availableDelta > 0.0) {
               if (availableDelta <= delta) {
                 // shrank to minimum
@@ -1122,12 +1122,12 @@ class RenderTable extends RenderBox {
       bool haveBaseline = false;
       double beforeBaselineDistance = 0.0;
       double afterBaselineDistance = 0.0;
-      List<double> baselines = new List<double>(columns);
+      final List<double> baselines = new List<double>(columns);
       for (int x = 0; x < columns; x += 1) {
         final int xy = x + y * columns;
-        RenderBox child = _children[xy];
+        final RenderBox child = _children[xy];
         if (child != null) {
-          TableCellParentData childParentData = child.parentData;
+          final TableCellParentData childParentData = child.parentData;
           assert(childParentData != null);
           childParentData.x = x;
           childParentData.y = y;
@@ -1135,7 +1135,7 @@ class RenderTable extends RenderBox {
             case TableCellVerticalAlignment.baseline:
               assert(textBaseline != null);
               child.layout(new BoxConstraints.tightFor(width: widths[x]), parentUsesSize: true);
-              double childBaseline = child.getDistanceToBaseline(textBaseline, onlyReal: true);
+              final double childBaseline = child.getDistanceToBaseline(textBaseline, onlyReal: true);
               if (childBaseline != null) {
                 beforeBaselineDistance = math.max(beforeBaselineDistance, childBaseline);
                 afterBaselineDistance = math.max(afterBaselineDistance, child.size.height - childBaseline);
@@ -1164,7 +1164,7 @@ class RenderTable extends RenderBox {
       }
       for (int x = 0; x < columns; x += 1) {
         final int xy = x + y * columns;
-        RenderBox child = _children[xy];
+        final RenderBox child = _children[xy];
         if (child != null) {
           final TableCellParentData childParentData = child.parentData;
           switch (childParentData.verticalAlignment ?? defaultVerticalAlignment) {
@@ -1199,10 +1199,10 @@ class RenderTable extends RenderBox {
   bool hitTestChildren(HitTestResult result, { Point position }) {
     assert(_children.length == rows * columns);
     for (int index = _children.length - 1; index >= 0; index -= 1) {
-      RenderBox child = _children[index];
+      final RenderBox child = _children[index];
       if (child != null) {
         final BoxParentData childParentData = child.parentData;
-        Point transformed = new Point(position.x - childParentData.offset.dx,
+        final Point transformed = new Point(position.x - childParentData.offset.dx,
                                       position.y - childParentData.offset.dy);
         if (child.hitTest(result, position: transformed))
           return true;
@@ -1234,22 +1234,22 @@ class RenderTable extends RenderBox {
       }
     }
     for (int index = 0; index < _children.length; index += 1) {
-      RenderBox child = _children[index];
+      final RenderBox child = _children[index];
       if (child != null) {
         final BoxParentData childParentData = child.parentData;
         context.paintChild(child, childParentData.offset + offset);
       }
     }
     canvas = context.canvas;
-    Rect bounds = offset & size;
+    final Rect bounds = offset & size;
     if (border != null) {
       switch (border.verticalInside.style) {
         case BorderStyle.solid:
-          Paint paint = new Paint()
+          final Paint paint = new Paint()
             ..color = border.verticalInside.color
             ..strokeWidth = border.verticalInside.width
             ..style = PaintingStyle.stroke;
-          Path path = new Path();
+          final Path path = new Path();
           for (int x = 1; x < columns; x += 1) {
             path.moveTo(bounds.left + _columnLefts[x], bounds.top);
             path.lineTo(bounds.left + _columnLefts[x], bounds.bottom);
@@ -1260,11 +1260,11 @@ class RenderTable extends RenderBox {
       }
       switch (border.horizontalInside.style) {
         case BorderStyle.solid:
-          Paint paint = new Paint()
+          final Paint paint = new Paint()
             ..color = border.horizontalInside.color
             ..strokeWidth = border.horizontalInside.width
             ..style = PaintingStyle.stroke;
-          Path path = new Path();
+          final Path path = new Path();
           for (int y = 1; y < rows; y += 1) {
             path.moveTo(bounds.left, bounds.top + _rowTops[y]);
             path.lineTo(bounds.right, bounds.top + _rowTops[y]);
@@ -1292,16 +1292,16 @@ class RenderTable extends RenderBox {
 
   @override
   String debugDescribeChildren(String prefix) {
-    StringBuffer result = new StringBuffer();
+    final StringBuffer result = new StringBuffer();
     result.writeln('$prefix \u2502');
-    int lastIndex = _children.length - 1;
+    final int lastIndex = _children.length - 1;
     if (lastIndex < 0) {
       result.writeln('$prefix \u2514\u2500table is empty');
     } else {
       for (int y = 0; y < rows; y += 1) {
         for (int x = 0; x < columns; x += 1) {
           final int xy = x + y * columns;
-          RenderBox child = _children[xy];
+          final RenderBox child = _children[xy];
           if (child != null) {
             if (xy < lastIndex) {
               result.write('${child.toStringDeep("$prefix \u251C\u2500child ($x, $y): ", "$prefix \u2502")}');

packages/flutter/lib/src/rendering/view.dart

@@ -148,9 +148,9 @@ class RenderView extends RenderObject with RenderObjectWithChildMixin<RenderBox>
   void compositeFrame() {
     Timeline.startSync('Compositing');
     try {
-      ui.SceneBuilder builder = new ui.SceneBuilder();
+      final ui.SceneBuilder builder = new ui.SceneBuilder();
       layer.addToScene(builder, Offset.zero);
-      ui.Scene scene = builder.build();
+      final ui.Scene scene = builder.build();
       ui.window.render(scene);
       scene.dispose();
       assert(() {

packages/flutter/lib/src/rendering/viewport.dart

@@ -675,7 +675,7 @@ class RenderViewport extends RenderViewportBase<SliverPhysicalContainerParentDat
 
     if (leadingNegativeChild != null) {
       // negative scroll offsets
-      double result = layoutOneSide(
+      final double result = layoutOneSide(
         leadingNegativeChild,
         math.max(mainAxisExtent, centerOffset) - mainAxisExtent,
         0.0,

packages/flutter/lib/src/scheduler/binding.dart

@@ -182,7 +182,7 @@ abstract class SchedulerBinding extends BindingBase {
   /// millisecond), so as to not cause the regular frame callbacks to
   /// get delayed.
   void scheduleTask(VoidCallback task, Priority priority) {
-    bool isFirstTask = _taskQueue.isEmpty;
+    final bool isFirstTask = _taskQueue.isEmpty;
     _taskQueue.add(new _TaskEntry(task, priority.value));
     if (isFirstTask)
       _ensureEventLoopCallback();
@@ -209,7 +209,7 @@ abstract class SchedulerBinding extends BindingBase {
   void _runTasks() {
     if (_taskQueue.isEmpty)
       return;
-    _TaskEntry entry = _taskQueue.first;
+    final _TaskEntry entry = _taskQueue.first;
     // TODO(floitsch): for now we only expose the priority. It might
     // be interesting to provide more info (like, how long the task
     // ran the last time, or how long is left in this frame).
@@ -354,7 +354,7 @@ abstract class SchedulerBinding extends BindingBase {
               );
             }
             for (int id in callbacks.keys) {
-              _FrameCallbackEntry entry = callbacks[id];
+              final _FrameCallbackEntry entry = callbacks[id];
               information.writeln('── callback $id ──');
               FlutterError.defaultStackFilter(entry.debugStack.toString().trimRight().split('\n')).forEach(information.writeln);
             }
@@ -533,7 +533,7 @@ abstract class SchedulerBinding extends BindingBase {
   /// These mechanisms together combine to ensure that the durations we give
   /// during frame callbacks are monotonically increasing.
   Duration _adjustForEpoch(Duration rawTimeStamp) {
-    Duration rawDurationSinceEpoch = _firstRawTimeStampInEpoch == null ? Duration.ZERO : rawTimeStamp - _firstRawTimeStampInEpoch;
+    final Duration rawDurationSinceEpoch = _firstRawTimeStampInEpoch == null ? Duration.ZERO : rawTimeStamp - _firstRawTimeStampInEpoch;
     return new Duration(microseconds: (rawDurationSinceEpoch.inMicroseconds / timeDilation).round() + _epochStart.inMicroseconds);
   }
 
@@ -584,7 +584,7 @@ abstract class SchedulerBinding extends BindingBase {
     assert(() {
       _debugFrameNumber += 1;
       if (debugPrintBeginFrameBanner || debugPrintEndFrameBanner) {
-        StringBuffer frameTimeStampDescription = new StringBuffer();
+        final StringBuffer frameTimeStampDescription = new StringBuffer();
         if (rawTimeStamp != null) {
           _debugDescribeTimeStamp(_currentFrameTimeStamp, frameTimeStampDescription);
         } else {
@@ -612,7 +612,7 @@ abstract class SchedulerBinding extends BindingBase {
 
       // POST-FRAME CALLBACKS
       _schedulerPhase = SchedulerPhase.postFrameCallbacks;
-      List<FrameCallback> localPostFrameCallbacks =
+      final List<FrameCallback> localPostFrameCallbacks =
           new List<FrameCallback>.from(_postFrameCallbacks);
       _postFrameCallbacks.clear();
       for (FrameCallback callback in localPostFrameCallbacks)
@@ -636,7 +636,7 @@ abstract class SchedulerBinding extends BindingBase {
   void _invokeTransientFrameCallbacks(Duration timeStamp) {
     Timeline.startSync('Animate');
     assert(schedulerPhase == SchedulerPhase.transientCallbacks);
-    Map<int, _FrameCallbackEntry> callbacks = _transientCallbacks;
+    final Map<int, _FrameCallbackEntry> callbacks = _transientCallbacks;
     _transientCallbacks = new Map<int, _FrameCallbackEntry>();
     callbacks.forEach((int id, _FrameCallbackEntry callbackEntry) {
       if (!_removedIds.contains(id))
@@ -656,7 +656,7 @@ abstract class SchedulerBinding extends BindingBase {
     if (timeStamp.inSeconds > 0)
       buffer.write('${timeStamp.inSeconds - timeStamp.inMinutes * Duration.SECONDS_PER_MINUTE}s ');
     buffer.write('${timeStamp.inMilliseconds - timeStamp.inSeconds * Duration.MILLISECONDS_PER_SECOND}');
-    int microseconds = timeStamp.inMicroseconds - timeStamp.inMilliseconds * Duration.MICROSECONDS_PER_MILLISECOND;
+    final int microseconds = timeStamp.inMicroseconds - timeStamp.inMilliseconds * Duration.MICROSECONDS_PER_MILLISECOND;
     if (microseconds > 0)
       buffer.write('.${microseconds.toString().padLeft(3, "0")}');
     buffer.write('ms');

packages/flutter/lib/src/scheduler/ticker.dart

@@ -164,7 +164,7 @@ class Ticker {
     // We take the _completer into a local variable so that isTicking is false
     // when we actually complete the future (isTicking uses _completer to
     // determine its state).
-    Completer<Null> localCompleter = _completer;
+    final Completer<Null> localCompleter = _completer;
     _completer = null;
     _startTime = null;
     assert(!isActive);

packages/flutter/lib/src/services/asset_bundle.dart

@@ -92,7 +92,7 @@ class NetworkAssetBundle extends AssetBundle {
 
   @override
   Future<ByteData> load(String key) async {
-    http.Response response = await http.get(_urlFromKey(key));
+    final http.Response response = await http.get(_urlFromKey(key));
     if (response.statusCode == 200)
       return null;
     return response.bodyBytes.buffer.asByteData();
@@ -100,7 +100,7 @@ class NetworkAssetBundle extends AssetBundle {
 
   @override
   Future<String> loadString(String key, { bool cache: true }) async {
-    http.Response response = await http.get(_urlFromKey(key));
+    final http.Response response = await http.get(_urlFromKey(key));
     return response.statusCode == 200 ? response.body : null;
   }
 
@@ -199,7 +199,7 @@ abstract class CachingAssetBundle extends AssetBundle {
 class PlatformAssetBundle extends CachingAssetBundle {
   @override
   Future<ByteData> load(String key) {
-    Uint8List encoded = UTF8.encoder.convert(key);
+    final Uint8List encoded = UTF8.encoder.convert(key);
     return PlatformMessages.sendBinary('flutter/assets', encoded.buffer.asByteData());
   }
 }

packages/flutter/lib/src/services/clipboard.dart

@@ -50,7 +50,7 @@ class Clipboard {
   /// Returns a future which completes to null if the data could not be
   /// obtained, and to a [ClipboardData] object if it could.
   static Future<ClipboardData> getData(String format) async {
-    Map<String, dynamic> result = await PlatformMessages.invokeMethod(
+    final Map<String, dynamic> result = await PlatformMessages.invokeMethod(
       _kChannelName,
       'Clipboard.getData',
       <String>[format]

packages/flutter/lib/src/services/image_decoder.dart

@@ -12,7 +12,7 @@ import 'dart:ui' as ui show Image, decodeImageFromList;
 /// the returned [Future] resolves to the decoded image. Otherwise, the [Future]
 /// resolves to [null].
 Future<ui.Image> decodeImageFromList(Uint8List list) {
-  Completer<ui.Image> completer = new Completer<ui.Image>();
+  final Completer<ui.Image> completer = new Completer<ui.Image>();
   ui.decodeImageFromList(list, (ui.Image image) {
     completer.complete(image);
   });

packages/flutter/lib/src/services/image_provider.dart

@@ -92,7 +92,7 @@ class ImageConfiguration {
 
   @override
   String toString() {
-    StringBuffer result = new StringBuffer();
+    final StringBuffer result = new StringBuffer();
     result.write('ImageConfiguration(');
     bool hasArguments = false;
     if (bundle != null) {
@@ -340,7 +340,7 @@ class NetworkImage extends ImageProvider<NetworkImage> {
     if (response == null || response.statusCode != 200)
       return null;
 
-    Uint8List bytes = response.bodyBytes;
+    final Uint8List bytes = response.bodyBytes;
     if (bytes.lengthInBytes == 0)
       return null;
 
@@ -402,7 +402,7 @@ class FileImage extends ImageProvider<FileImage> {
   Future<ImageInfo> _loadAsync(FileImage key) async {
     assert(key == this);
 
-    Uint8List bytes = await file.readAsBytes();
+    final Uint8List bytes = await file.readAsBytes();
     if (bytes.lengthInBytes == 0)
       return null;
 

packages/flutter/lib/src/services/image_resolution.dart

@@ -163,8 +163,8 @@ class AssetImage extends AssetBundleImageProvider {
   String _findNearest(SplayTreeMap<double, String> candidates, double value) {
     if (candidates.containsKey(value))
       return candidates[value];
-    double lower = candidates.lastKeyBefore(value);
+    final double lower = candidates.lastKeyBefore(value);
-    double upper = candidates.firstKeyAfter(value);
+    final double upper = candidates.firstKeyAfter(value);
     if (lower == null)
       return candidates[upper];
     if (upper == null)
@@ -178,7 +178,7 @@ class AssetImage extends AssetBundleImageProvider {
   static final RegExp _extractRatioRegExp = new RegExp(r"/?(\d+(\.\d*)?)x/");
 
   double _parseScale(String key) {
-    Match match = _extractRatioRegExp.firstMatch(key);
+    final Match match = _extractRatioRegExp.firstMatch(key);
     if (match != null && match.groupCount > 0)
       return double.parse(match.group(1));
     return _naturalResolution;

packages/flutter/lib/src/services/image_stream.dart

@@ -122,7 +122,7 @@ class ImageStream {
 
   @override
   String toString() {
-    StringBuffer result = new StringBuffer();
+    final StringBuffer result = new StringBuffer();
     result.write('$runtimeType(');
     if (_completer == null) {
       result.write('unresolved; ');
@@ -181,7 +181,7 @@ class ImageStreamCompleter {
     _current = image;
     if (_listeners.isEmpty)
       return;
-    List<ImageListener> localListeners = new List<ImageListener>.from(_listeners);
+    final List<ImageListener> localListeners = new List<ImageListener>.from(_listeners);
     for (ImageListener listener in localListeners) {
       try {
         listener(image, false);

packages/flutter/lib/src/services/path_provider.dart

@@ -24,7 +24,7 @@ class PathProvider {
   ///
   /// On Android, this uses the `getCacheDir` API on the context.
   static Future<Directory> getTemporaryDirectory() async {
-    Map<String, dynamic> result = await PlatformMessages.invokeMethod(
+    final Map<String, dynamic> result = await PlatformMessages.invokeMethod(
         _kChannelName, 'PathProvider.getTemporaryDirectory');
     if (result == null)
       return null;
@@ -39,7 +39,7 @@ class PathProvider {
   ///
   /// On Android, this returns the AppData directory.
   static Future<Directory> getApplicationDocumentsDirectory() async {
-    Map<String, dynamic> result = await PlatformMessages.invokeMethod(
+    final Map<String, dynamic> result = await PlatformMessages.invokeMethod(
         _kChannelName, 'PathProvider.getApplicationDocumentsDirectory');
     if (result == null)
       return null;