1779 lines
66 KiB
Dart
1779 lines
66 KiB
Dart
// Copyright 2014 The Flutter Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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import 'dart:math';
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import 'package:flutter/foundation.dart';
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import 'package:flutter/gestures.dart';
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import 'package:flutter/rendering.dart';
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import 'package:flutter/scheduler.dart';
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import 'package:flutter/services.dart';
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import 'package:vector_math/vector_math_64.dart';
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import 'actions.dart';
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import 'basic.dart';
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import 'debug.dart';
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import 'focus_manager.dart';
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import 'focus_scope.dart';
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import 'framework.dart';
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import 'gesture_detector.dart';
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import 'magnifier.dart';
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import 'media_query.dart';
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import 'overlay.dart';
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import 'platform_selectable_region_context_menu.dart';
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import 'selection_container.dart';
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import 'text_editing_intents.dart';
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import 'text_selection.dart';
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// Examples can assume:
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// FocusNode _focusNode = FocusNode();
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// late GlobalKey key;
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const Set<PointerDeviceKind> _kLongPressSelectionDevices = <PointerDeviceKind>{
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PointerDeviceKind.touch,
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PointerDeviceKind.stylus,
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PointerDeviceKind.invertedStylus,
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};
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/// A widget that introduces an area for user selections.
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///
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/// Flutter widgets are not selectable by default. Wrapping a widget subtree
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/// with a [SelectableRegion] widget enables selection within that subtree (for
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/// example, [Text] widgets automatically look for selectable regions to enable
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/// selection). The wrapped subtree can be selected by users using mouse or
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/// touch gestures, e.g. users can select widgets by holding the mouse
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/// left-click and dragging across widgets, or they can use long press gestures
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/// to select words on touch devices.
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///
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/// A [SelectableRegion] widget requires configuration; in particular specific
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/// [selectionControls] must be provided.
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///
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/// The [SelectionArea] widget from the [material] library configures a
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/// [SelectableRegion] in a platform-specific manner (e.g. using a Material
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/// toolbar on Android, a Cupertino toolbar on iOS), and it may therefore be
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/// simpler to use that widget rather than using [SelectableRegion] directly.
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///
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/// ## An overview of the selection system.
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///
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/// Every [Selectable] under the [SelectableRegion] can be selected. They form a
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/// selection tree structure to handle the selection.
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///
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/// The [SelectableRegion] is a wrapper over [SelectionContainer]. It listens to
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/// user gestures and sends corresponding [SelectionEvent]s to the
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/// [SelectionContainer] it creates.
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///
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/// A [SelectionContainer] is a single [Selectable] that handles
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/// [SelectionEvent]s on behalf of child [Selectable]s in the subtree. It
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/// creates a [SelectionRegistrarScope] with its [SelectionContainer.delegate]
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/// to collect child [Selectable]s and sends the [SelectionEvent]s it receives
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/// from the parent [SelectionRegistrar] to the appropriate child [Selectable]s.
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/// It creates an abstraction for the parent [SelectionRegistrar] as if it is
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/// interacting with a single [Selectable].
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///
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/// The [SelectionContainer] created by [SelectableRegion] is the root node of a
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/// selection tree. Each non-leaf node in the tree is a [SelectionContainer],
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/// and the leaf node is a leaf widget whose render object implements
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/// [Selectable]. They are connected through [SelectionRegistrarScope]s created
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/// by [SelectionContainer]s.
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///
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/// Both [SelectionContainer]s and the leaf [Selectable]s need to register
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/// themselves to the [SelectionRegistrar] from the
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/// [SelectionContainer.maybeOf] if they want to participate in the
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/// selection.
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///
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/// An example selection tree will look like:
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///
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/// {@tool snippet}
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///
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/// ```dart
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/// MaterialApp(
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/// home: SelectableRegion(
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/// selectionControls: materialTextSelectionControls,
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/// focusNode: _focusNode, // initialized to FocusNode()
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/// child: Scaffold(
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/// appBar: AppBar(title: const Text('Flutter Code Sample')),
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/// body: ListView(
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/// children: const <Widget>[
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/// Text('Item 0', style: TextStyle(fontSize: 50.0)),
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/// Text('Item 1', style: TextStyle(fontSize: 50.0)),
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/// ],
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/// ),
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/// ),
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/// ),
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/// )
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/// ```
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/// {@end-tool}
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///
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///
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/// SelectionContainer
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/// (SelectableRegion)
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/// / \
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/// / \
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/// / \
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/// Selectable \
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/// ("Flutter Code Sample") \
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/// \
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/// SelectionContainer
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/// (ListView)
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/// / \
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/// / \
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/// / \
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/// Selectable Selectable
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/// ("Item 0") ("Item 1")
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///
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///
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/// ## Making a widget selectable
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///
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/// Some leaf widgets, such as [Text], have all of the selection logic wired up
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/// automatically and can be selected as long as they are under a
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/// [SelectableRegion].
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///
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/// To make a custom selectable widget, its render object needs to mix in
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/// [Selectable] and implement the required APIs to handle [SelectionEvent]s
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/// as well as paint appropriate selection highlights.
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///
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/// The render object also needs to register itself to a [SelectionRegistrar].
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/// For the most cases, one can use [SelectionRegistrant] to auto-register
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/// itself with the register returned from [SelectionContainer.maybeOf] as
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/// seen in the example below.
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///
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/// {@tool dartpad}
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/// This sample demonstrates how to create an adapter widget that makes any
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/// child widget selectable.
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///
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/// ** See code in examples/api/lib/material/selection_area/custom_selectable.dart **
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/// {@end-tool}
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///
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/// ## Complex layout
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///
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/// By default, the screen order is used as the selection order. If a group of
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/// [Selectable]s needs to select differently, consider wrapping them with a
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/// [SelectionContainer] to customize its selection behavior.
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///
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/// {@tool dartpad}
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/// This sample demonstrates how to create a [SelectionContainer] that only
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/// allows selecting everything or nothing with no partial selection.
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///
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/// ** See code in examples/api/lib/material/selection_area/custom_container.dart **
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/// {@end-tool}
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///
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/// In the case where a group of widgets should be excluded from selection under
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/// a [SelectableRegion], consider wrapping that group of widgets using
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/// [SelectionContainer.disabled].
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///
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/// {@tool dartpad}
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/// This sample demonstrates how to disable selection for a Text in a Column.
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///
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/// ** See code in examples/api/lib/material/selection_area/disable_partial_selection.dart **
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/// {@end-tool}
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///
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/// To create a separate selection system from its parent selection area,
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/// wrap part of the subtree with another [SelectableRegion]. The selection of the
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/// child selection area can not extend past its subtree, and the selection of
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/// the parent selection area can not extend inside the child selection area.
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///
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/// ## Tests
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///
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/// In a test, a region can be selected either by faking drag events (e.g. using
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/// [WidgetTester.dragFrom]) or by sending intents to a widget inside the region
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/// that has been given a [GlobalKey], e.g.:
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///
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/// ```dart
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/// Actions.invoke(key.currentContext!, const SelectAllTextIntent(SelectionChangedCause.keyboard));
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/// ```
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///
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/// See also:
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/// * [SelectionArea], which creates a [SelectableRegion] with
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/// platform-adaptive selection controls.
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/// * [SelectionHandler], which contains APIs to handle selection events from the
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/// [SelectableRegion].
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/// * [Selectable], which provides API to participate in the selection system.
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/// * [SelectionRegistrar], which [Selectable] needs to subscribe to receive
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/// selection events.
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/// * [SelectionContainer], which collects selectable widgets in the subtree
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/// and provides api to dispatch selection event to the collected widget.
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class SelectableRegion extends StatefulWidget {
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/// Create a new [SelectableRegion] widget.
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///
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/// The [selectionControls] are used for building the selection handles and
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/// toolbar for mobile devices.
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const SelectableRegion({
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super.key,
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required this.focusNode,
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required this.selectionControls,
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required this.child,
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this.magnifierConfiguration = TextMagnifierConfiguration.disabled,
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});
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/// {@macro flutter.widgets.magnifier.TextMagnifierConfiguration.intro}
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///
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/// {@macro flutter.widgets.magnifier.intro}
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///
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/// By default, [SelectableRegion]'s [TextMagnifierConfiguration] is disabled.
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///
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/// {@macro flutter.widgets.magnifier.TextMagnifierConfiguration.details}
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final TextMagnifierConfiguration magnifierConfiguration;
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/// {@macro flutter.widgets.Focus.focusNode}
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final FocusNode focusNode;
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/// The child widget this selection area applies to.
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///
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/// {@macro flutter.widgets.ProxyWidget.child}
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final Widget child;
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/// The delegate to build the selection handles and toolbar for mobile
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/// devices.
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///
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/// The [emptyTextSelectionControls] global variable provides a default
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/// [TextSelectionControls] implementation with no controls.
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final TextSelectionControls selectionControls;
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@override
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State<StatefulWidget> createState() => _SelectableRegionState();
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}
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class _SelectableRegionState extends State<SelectableRegion> with TextSelectionDelegate implements SelectionRegistrar {
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late final Map<Type, Action<Intent>> _actions = <Type, Action<Intent>>{
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SelectAllTextIntent: _makeOverridable(_SelectAllAction(this)),
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CopySelectionTextIntent: _makeOverridable(_CopySelectionAction(this)),
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};
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final Map<Type, GestureRecognizerFactory> _gestureRecognizers = <Type, GestureRecognizerFactory>{};
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SelectionOverlay? _selectionOverlay;
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final LayerLink _startHandleLayerLink = LayerLink();
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final LayerLink _endHandleLayerLink = LayerLink();
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final LayerLink _toolbarLayerLink = LayerLink();
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final _SelectableRegionContainerDelegate _selectionDelegate = _SelectableRegionContainerDelegate();
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// there should only ever be one selectable, which is the SelectionContainer.
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Selectable? _selectable;
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bool get _hasSelectionOverlayGeometry => _selectionDelegate.value.startSelectionPoint != null
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|| _selectionDelegate.value.endSelectionPoint != null;
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Orientation? _lastOrientation;
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@override
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void initState() {
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super.initState();
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widget.focusNode.addListener(_handleFocusChanged);
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_initMouseGestureRecognizer();
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_initTouchGestureRecognizer();
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// Taps and right clicks.
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_gestureRecognizers[TapGestureRecognizer] = GestureRecognizerFactoryWithHandlers<TapGestureRecognizer>(
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() => TapGestureRecognizer(debugOwner: this),
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(TapGestureRecognizer instance) {
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instance.onTap = _clearSelection;
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instance.onSecondaryTapDown = _handleRightClickDown;
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},
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);
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}
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@override
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void didChangeDependencies() {
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super.didChangeDependencies();
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switch (defaultTargetPlatform) {
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case TargetPlatform.android:
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case TargetPlatform.iOS:
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break;
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case TargetPlatform.fuchsia:
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case TargetPlatform.linux:
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case TargetPlatform.macOS:
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case TargetPlatform.windows:
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return;
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}
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// Hide the text selection toolbar on mobile when orientation changes.
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final Orientation orientation = MediaQuery.of(context).orientation;
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if (_lastOrientation == null) {
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_lastOrientation = orientation;
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return;
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}
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if (orientation != _lastOrientation) {
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_lastOrientation = orientation;
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hideToolbar(defaultTargetPlatform == TargetPlatform.android);
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}
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}
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@override
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void didUpdateWidget(SelectableRegion oldWidget) {
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super.didUpdateWidget(oldWidget);
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if (widget.focusNode != oldWidget.focusNode) {
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oldWidget.focusNode.removeListener(_handleFocusChanged);
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widget.focusNode.addListener(_handleFocusChanged);
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if (widget.focusNode.hasFocus != oldWidget.focusNode.hasFocus) {
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_handleFocusChanged();
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}
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}
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}
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Action<T> _makeOverridable<T extends Intent>(Action<T> defaultAction) {
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return Action<T>.overridable(context: context, defaultAction: defaultAction);
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}
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void _handleFocusChanged() {
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if (!widget.focusNode.hasFocus) {
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if (kIsWeb) {
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PlatformSelectableRegionContextMenu.detach(_selectionDelegate);
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}
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_clearSelection();
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}
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if (kIsWeb) {
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PlatformSelectableRegionContextMenu.attach(_selectionDelegate);
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}
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}
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void _updateSelectionStatus() {
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final TextSelection selection;
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final SelectionGeometry geometry = _selectionDelegate.value;
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switch(geometry.status) {
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case SelectionStatus.uncollapsed:
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case SelectionStatus.collapsed:
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selection = const TextSelection(baseOffset: 0, extentOffset: 1);
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break;
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case SelectionStatus.none:
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selection = const TextSelection.collapsed(offset: 1);
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break;
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}
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textEditingValue = TextEditingValue(text: '__', selection: selection);
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if (_hasSelectionOverlayGeometry) {
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_updateSelectionOverlay();
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} else {
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_selectionOverlay?.dispose();
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_selectionOverlay = null;
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}
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}
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// gestures.
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void _initMouseGestureRecognizer() {
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_gestureRecognizers[PanGestureRecognizer] = GestureRecognizerFactoryWithHandlers<PanGestureRecognizer>(
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() => PanGestureRecognizer(debugOwner:this, supportedDevices: <PointerDeviceKind>{ PointerDeviceKind.mouse }),
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(PanGestureRecognizer instance) {
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instance
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..onDown = _startNewMouseSelectionGesture
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..onStart = _handleMouseDragStart
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..onUpdate = _handleMouseDragUpdate
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..onEnd = _handleMouseDragEnd
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..onCancel = _clearSelection
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..dragStartBehavior = DragStartBehavior.down;
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},
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);
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}
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void _initTouchGestureRecognizer() {
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_gestureRecognizers[LongPressGestureRecognizer] = GestureRecognizerFactoryWithHandlers<LongPressGestureRecognizer>(
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() => LongPressGestureRecognizer(debugOwner: this, supportedDevices: _kLongPressSelectionDevices),
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(LongPressGestureRecognizer instance) {
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instance
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..onLongPressStart = _handleTouchLongPressStart
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..onLongPressMoveUpdate = _handleTouchLongPressMoveUpdate
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..onLongPressEnd = _handleTouchLongPressEnd
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..onLongPressCancel = _clearSelection;
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},
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);
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}
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void _startNewMouseSelectionGesture(DragDownDetails details) {
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widget.focusNode.requestFocus();
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hideToolbar();
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_clearSelection();
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}
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void _handleMouseDragStart(DragStartDetails details) {
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_selectStartTo(offset: details.globalPosition);
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}
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void _handleMouseDragUpdate(DragUpdateDetails details) {
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_selectEndTo(offset: details.globalPosition, continuous: true);
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}
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void _handleMouseDragEnd(DragEndDetails details) {
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_finalizeSelection();
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}
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void _handleTouchLongPressStart(LongPressStartDetails details) {
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widget.focusNode.requestFocus();
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_selectWordAt(offset: details.globalPosition);
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_showToolbar();
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_showHandles();
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}
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void _handleTouchLongPressMoveUpdate(LongPressMoveUpdateDetails details) {
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_selectEndTo(offset: details.globalPosition);
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}
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void _handleTouchLongPressEnd(LongPressEndDetails details) {
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_finalizeSelection();
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}
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void _handleRightClickDown(TapDownDetails details) {
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widget.focusNode.requestFocus();
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_selectWordAt(offset: details.globalPosition);
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_showHandles();
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_showToolbar(location: details.globalPosition);
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}
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// Selection update helper methods.
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Offset? _selectionEndPosition;
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bool get _userDraggingSelectionEnd => _selectionEndPosition != null;
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bool _scheduledSelectionEndEdgeUpdate = false;
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/// Sends end [SelectionEdgeUpdateEvent] to the selectable subtree.
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///
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/// If the selectable subtree returns a [SelectionResult.pending], this method
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/// continues to send [SelectionEdgeUpdateEvent]s every frame until the result
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/// is not pending or users end their gestures.
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void _triggerSelectionEndEdgeUpdate() {
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// This method can be called when the drag is not in progress. This can
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// happen if the the child scrollable returns SelectionResult.pending, and
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// the selection area scheduled a selection update for the next frame, but
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// the drag is lifted before the scheduled selection update is run.
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if (_scheduledSelectionEndEdgeUpdate || !_userDraggingSelectionEnd) {
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return;
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}
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if (_selectable?.dispatchSelectionEvent(
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SelectionEdgeUpdateEvent.forEnd(globalPosition: _selectionEndPosition!)) == SelectionResult.pending) {
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_scheduledSelectionEndEdgeUpdate = true;
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SchedulerBinding.instance.addPostFrameCallback((Duration timeStamp) {
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if (!_scheduledSelectionEndEdgeUpdate) {
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return;
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}
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_scheduledSelectionEndEdgeUpdate = false;
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_triggerSelectionEndEdgeUpdate();
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});
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return;
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}
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}
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void _onAnyDragEnd(DragEndDetails details) {
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_selectionOverlay!.hideMagnifier(shouldShowToolbar: true);
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_stopSelectionEndEdgeUpdate();
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}
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void _stopSelectionEndEdgeUpdate() {
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_scheduledSelectionEndEdgeUpdate = false;
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_selectionEndPosition = null;
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}
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Offset? _selectionStartPosition;
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bool get _userDraggingSelectionStart => _selectionStartPosition != null;
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bool _scheduledSelectionStartEdgeUpdate = false;
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/// Sends start [SelectionEdgeUpdateEvent] to the selectable subtree.
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///
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/// If the selectable subtree returns a [SelectionResult.pending], this method
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/// continues to send [SelectionEdgeUpdateEvent]s every frame until the result
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/// is not pending or users end their gestures.
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void _triggerSelectionStartEdgeUpdate() {
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// This method can be called when the drag is not in progress. This can
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// happen if the the child scrollable returns SelectionResult.pending, and
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// the selection area scheduled a selection update for the next frame, but
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// the drag is lifted before the scheduled selection update is run.
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if (_scheduledSelectionStartEdgeUpdate || !_userDraggingSelectionStart) {
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return;
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}
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if (_selectable?.dispatchSelectionEvent(
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SelectionEdgeUpdateEvent.forStart(globalPosition: _selectionStartPosition!)) == SelectionResult.pending) {
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_scheduledSelectionStartEdgeUpdate = true;
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SchedulerBinding.instance.addPostFrameCallback((Duration timeStamp) {
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if (!_scheduledSelectionStartEdgeUpdate) {
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return;
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}
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_scheduledSelectionStartEdgeUpdate = false;
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_triggerSelectionStartEdgeUpdate();
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});
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return;
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}
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}
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void _stopSelectionStartEdgeUpdate() {
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_scheduledSelectionStartEdgeUpdate = false;
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_selectionEndPosition = null;
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}
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// SelectionOverlay helper methods.
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late Offset _selectionStartHandleDragPosition;
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late Offset _selectionEndHandleDragPosition;
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late List<TextSelectionPoint> points;
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void _handleSelectionStartHandleDragStart(DragStartDetails details) {
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assert(_selectionDelegate.value.startSelectionPoint != null);
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final Offset localPosition = _selectionDelegate.value.startSelectionPoint!.localPosition;
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final Matrix4 globalTransform = _selectable!.getTransformTo(null);
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_selectionStartHandleDragPosition = MatrixUtils.transformPoint(globalTransform, localPosition);
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|
|
_selectionOverlay!.showMagnifier(_buildInfoForMagnifier(
|
|
details.globalPosition,
|
|
_selectionDelegate.value.startSelectionPoint!,
|
|
));
|
|
}
|
|
|
|
void _handleSelectionStartHandleDragUpdate(DragUpdateDetails details) {
|
|
_selectionStartHandleDragPosition = _selectionStartHandleDragPosition + details.delta;
|
|
// The value corresponds to the paint origin of the selection handle.
|
|
// Offset it to the center of the line to make it feel more natural.
|
|
_selectionStartPosition = _selectionStartHandleDragPosition - Offset(0, _selectionDelegate.value.startSelectionPoint!.lineHeight / 2);
|
|
_triggerSelectionStartEdgeUpdate();
|
|
|
|
_selectionOverlay!.updateMagnifier(_buildInfoForMagnifier(
|
|
details.globalPosition,
|
|
_selectionDelegate.value.startSelectionPoint!,
|
|
));
|
|
}
|
|
|
|
void _handleSelectionEndHandleDragStart(DragStartDetails details) {
|
|
assert(_selectionDelegate.value.endSelectionPoint != null);
|
|
final Offset localPosition = _selectionDelegate.value.endSelectionPoint!.localPosition;
|
|
final Matrix4 globalTransform = _selectable!.getTransformTo(null);
|
|
_selectionEndHandleDragPosition = MatrixUtils.transformPoint(globalTransform, localPosition);
|
|
|
|
_selectionOverlay!.showMagnifier(_buildInfoForMagnifier(
|
|
details.globalPosition,
|
|
_selectionDelegate.value.endSelectionPoint!,
|
|
));
|
|
}
|
|
|
|
void _handleSelectionEndHandleDragUpdate(DragUpdateDetails details) {
|
|
_selectionEndHandleDragPosition = _selectionEndHandleDragPosition + details.delta;
|
|
// The value corresponds to the paint origin of the selection handle.
|
|
// Offset it to the center of the line to make it feel more natural.
|
|
_selectionEndPosition = _selectionEndHandleDragPosition - Offset(0, _selectionDelegate.value.endSelectionPoint!.lineHeight / 2);
|
|
_triggerSelectionEndEdgeUpdate();
|
|
|
|
_selectionOverlay!.updateMagnifier(_buildInfoForMagnifier(
|
|
details.globalPosition,
|
|
_selectionDelegate.value.endSelectionPoint!,
|
|
));
|
|
}
|
|
|
|
MagnifierOverlayInfoBearer _buildInfoForMagnifier(Offset globalGesturePosition, SelectionPoint selectionPoint) {
|
|
final Vector3 globalTransform = _selectable!.getTransformTo(null).getTranslation();
|
|
final Offset globalTransformAsOffset = Offset(globalTransform.x, globalTransform.y);
|
|
final Offset globalSelectionPointPosition = selectionPoint.localPosition + globalTransformAsOffset;
|
|
final Rect caretRect = Rect.fromLTWH(
|
|
globalSelectionPointPosition.dx,
|
|
globalSelectionPointPosition.dy - selectionPoint.lineHeight,
|
|
0,
|
|
selectionPoint.lineHeight
|
|
);
|
|
|
|
return MagnifierOverlayInfoBearer(
|
|
globalGesturePosition: globalGesturePosition,
|
|
caretRect: caretRect,
|
|
fieldBounds: globalTransformAsOffset & _selectable!.size,
|
|
currentLineBoundaries: globalTransformAsOffset & _selectable!.size,
|
|
);
|
|
}
|
|
|
|
void _createSelectionOverlay() {
|
|
assert(_hasSelectionOverlayGeometry);
|
|
if (_selectionOverlay != null) {
|
|
return;
|
|
}
|
|
final SelectionPoint? start = _selectionDelegate.value.startSelectionPoint;
|
|
final SelectionPoint? end = _selectionDelegate.value.endSelectionPoint;
|
|
final Offset startLocalPosition = start?.localPosition ?? end!.localPosition;
|
|
final Offset endLocalPosition = end?.localPosition ?? start!.localPosition;
|
|
if (startLocalPosition.dy > endLocalPosition.dy) {
|
|
points = <TextSelectionPoint>[
|
|
TextSelectionPoint(endLocalPosition, TextDirection.ltr),
|
|
TextSelectionPoint(startLocalPosition, TextDirection.ltr),
|
|
];
|
|
} else {
|
|
points = <TextSelectionPoint>[
|
|
TextSelectionPoint(startLocalPosition, TextDirection.ltr),
|
|
TextSelectionPoint(endLocalPosition, TextDirection.ltr),
|
|
];
|
|
}
|
|
_selectionOverlay = SelectionOverlay(
|
|
context: context,
|
|
debugRequiredFor: widget,
|
|
startHandleType: start?.handleType ?? TextSelectionHandleType.left,
|
|
lineHeightAtStart: start?.lineHeight ?? end!.lineHeight,
|
|
onStartHandleDragStart: _handleSelectionStartHandleDragStart,
|
|
onStartHandleDragUpdate: _handleSelectionStartHandleDragUpdate,
|
|
onStartHandleDragEnd: _onAnyDragEnd,
|
|
endHandleType: end?.handleType ?? TextSelectionHandleType.right,
|
|
lineHeightAtEnd: end?.lineHeight ?? start!.lineHeight,
|
|
onEndHandleDragStart: _handleSelectionEndHandleDragStart,
|
|
onEndHandleDragUpdate: _handleSelectionEndHandleDragUpdate,
|
|
onEndHandleDragEnd: _onAnyDragEnd,
|
|
selectionEndpoints: points,
|
|
selectionControls: widget.selectionControls,
|
|
selectionDelegate: this,
|
|
clipboardStatus: null,
|
|
startHandleLayerLink: _startHandleLayerLink,
|
|
endHandleLayerLink: _endHandleLayerLink,
|
|
toolbarLayerLink: _toolbarLayerLink,
|
|
magnifierConfiguration: widget.magnifierConfiguration
|
|
);
|
|
}
|
|
|
|
void _updateSelectionOverlay() {
|
|
if (_selectionOverlay == null) {
|
|
return;
|
|
}
|
|
assert(_hasSelectionOverlayGeometry);
|
|
final SelectionPoint? start = _selectionDelegate.value.startSelectionPoint;
|
|
final SelectionPoint? end = _selectionDelegate.value.endSelectionPoint;
|
|
late List<TextSelectionPoint> points;
|
|
final Offset startLocalPosition = start?.localPosition ?? end!.localPosition;
|
|
final Offset endLocalPosition = end?.localPosition ?? start!.localPosition;
|
|
if (startLocalPosition.dy > endLocalPosition.dy) {
|
|
points = <TextSelectionPoint>[
|
|
TextSelectionPoint(endLocalPosition, TextDirection.ltr),
|
|
TextSelectionPoint(startLocalPosition, TextDirection.ltr),
|
|
];
|
|
} else {
|
|
points = <TextSelectionPoint>[
|
|
TextSelectionPoint(startLocalPosition, TextDirection.ltr),
|
|
TextSelectionPoint(endLocalPosition, TextDirection.ltr),
|
|
];
|
|
}
|
|
_selectionOverlay!
|
|
..startHandleType = start?.handleType ?? TextSelectionHandleType.left
|
|
..lineHeightAtStart = start?.lineHeight ?? end!.lineHeight
|
|
..endHandleType = end?.handleType ?? TextSelectionHandleType.right
|
|
..lineHeightAtEnd = end?.lineHeight ?? start!.lineHeight
|
|
..selectionEndpoints = points;
|
|
}
|
|
|
|
/// Shows the selection handles.
|
|
///
|
|
/// Returns true if the handles are shown, false if the handles can't be
|
|
/// shown.
|
|
bool _showHandles() {
|
|
if (_selectionOverlay != null) {
|
|
_selectionOverlay!.showHandles();
|
|
return true;
|
|
}
|
|
|
|
if (!_hasSelectionOverlayGeometry) {
|
|
return false;
|
|
}
|
|
|
|
_createSelectionOverlay();
|
|
_selectionOverlay!.showHandles();
|
|
return true;
|
|
}
|
|
|
|
/// Shows the text selection toolbar.
|
|
///
|
|
/// If the parameter `location` is set, the toolbar will be shown at the
|
|
/// location. Otherwise, the toolbar location will be calculated based on the
|
|
/// handles' locations. The `location` is in the coordinates system of the
|
|
/// [Overlay].
|
|
///
|
|
/// Returns true if the toolbar is shown, false if the toolbar can't be shown.
|
|
bool _showToolbar({Offset? location}) {
|
|
if (!_hasSelectionOverlayGeometry && _selectionOverlay == null) {
|
|
return false;
|
|
}
|
|
|
|
// Web is using native dom elements to enable clipboard functionality of the
|
|
// toolbar: copy, paste, select, cut. It might also provide additional
|
|
// functionality depending on the browser (such as translate). Due to this
|
|
// we should not show a Flutter toolbar for the editable text elements.
|
|
if (kIsWeb) {
|
|
return false;
|
|
}
|
|
|
|
if (_selectionOverlay == null) {
|
|
_createSelectionOverlay();
|
|
}
|
|
|
|
_selectionOverlay!.toolbarLocation = location;
|
|
_selectionOverlay!.showToolbar();
|
|
return true;
|
|
}
|
|
|
|
/// Sets or updates selection end edge to the `offset` location.
|
|
///
|
|
/// A selection always contains a select start edge and selection end edge.
|
|
/// They can be created by calling both [_selectStartTo] and [_selectEndTo], or
|
|
/// use other selection APIs, such as [_selectWordAt] or [selectAll].
|
|
///
|
|
/// This method sets or updates the selection end edge by sending
|
|
/// [SelectionEdgeUpdateEvent]s to the child [Selectable]s.
|
|
///
|
|
/// If `continuous` is set to true and the update causes scrolling, the
|
|
/// method will continue sending the same [SelectionEdgeUpdateEvent]s to the
|
|
/// child [Selectable]s every frame until the scrolling finishes or a
|
|
/// [_finalizeSelection] is called.
|
|
///
|
|
/// The `continuous` argument defaults to false.
|
|
///
|
|
/// The `offset` is in global coordinates.
|
|
///
|
|
/// See also:
|
|
/// * [_selectStartTo], which sets or updates selection start edge.
|
|
/// * [_finalizeSelection], which stops the `continuous` updates.
|
|
/// * [_clearSelection], which clear the ongoing selection.
|
|
/// * [_selectWordAt], which selects a whole word at the location.
|
|
/// * [selectAll], which selects the entire content.
|
|
void _selectEndTo({required Offset offset, bool continuous = false}) {
|
|
if (!continuous) {
|
|
_selectable?.dispatchSelectionEvent(SelectionEdgeUpdateEvent.forEnd(globalPosition: offset));
|
|
return;
|
|
}
|
|
if (_selectionEndPosition != offset) {
|
|
_selectionEndPosition = offset;
|
|
_triggerSelectionEndEdgeUpdate();
|
|
}
|
|
}
|
|
|
|
/// Sets or updates selection start edge to the `offset` location.
|
|
///
|
|
/// A selection always contains a select start edge and selection end edge.
|
|
/// They can be created by calling both [_selectStartTo] and [_selectEndTo], or
|
|
/// use other selection APIs, such as [_selectWordAt] or [selectAll].
|
|
///
|
|
/// This method sets or updates the selection start edge by sending
|
|
/// [SelectionEdgeUpdateEvent]s to the child [Selectable]s.
|
|
///
|
|
/// If `continuous` is set to true and the update causes scrolling, the
|
|
/// method will continue sending the same [SelectionEdgeUpdateEvent]s to the
|
|
/// child [Selectable]s every frame until the scrolling finishes or a
|
|
/// [_finalizeSelection] is called.
|
|
///
|
|
/// The `continuous` argument defaults to false.
|
|
///
|
|
/// The `offset` is in global coordinates.
|
|
///
|
|
/// See also:
|
|
/// * [_selectEndTo], which sets or updates selection end edge.
|
|
/// * [_finalizeSelection], which stops the `continuous` updates.
|
|
/// * [_clearSelection], which clear the ongoing selection.
|
|
/// * [_selectWordAt], which selects a whole word at the location.
|
|
/// * [selectAll], which selects the entire content.
|
|
void _selectStartTo({required Offset offset, bool continuous = false}) {
|
|
if (!continuous) {
|
|
_selectable?.dispatchSelectionEvent(SelectionEdgeUpdateEvent.forStart(globalPosition: offset));
|
|
return;
|
|
}
|
|
if (_selectionStartPosition != offset) {
|
|
_selectionStartPosition = offset;
|
|
_triggerSelectionStartEdgeUpdate();
|
|
}
|
|
}
|
|
|
|
/// Selects a whole word at the `offset` location.
|
|
///
|
|
/// If the whole word is already in the current selection, selection won't
|
|
/// change. One call [_clearSelection] first if the selection needs to be
|
|
/// updated even if the word is already covered by the current selection.
|
|
///
|
|
/// One can also use [_selectEndTo] or [_selectStartTo] to adjust the selection
|
|
/// edges after calling this method.
|
|
///
|
|
/// See also:
|
|
/// * [_selectStartTo], which sets or updates selection start edge.
|
|
/// * [_selectEndTo], which sets or updates selection end edge.
|
|
/// * [_finalizeSelection], which stops the `continuous` updates.
|
|
/// * [_clearSelection], which clear the ongoing selection.
|
|
/// * [selectAll], which selects the entire content.
|
|
void _selectWordAt({required Offset offset}) {
|
|
// There may be other selection ongoing.
|
|
_finalizeSelection();
|
|
_selectable?.dispatchSelectionEvent(SelectWordSelectionEvent(globalPosition: offset));
|
|
}
|
|
|
|
/// Stops any ongoing selection updates.
|
|
///
|
|
/// This method is different from [_clearSelection] that it does not remove
|
|
/// the current selection. It only stops the continuous updates.
|
|
///
|
|
/// A continuous update can happen as result of calling [_selectStartTo] or
|
|
/// [_selectEndTo] with `continuous` sets to true which causes a [Selectable]
|
|
/// to scroll. Calling this method will stop the update as well as the
|
|
/// scrolling.
|
|
void _finalizeSelection() {
|
|
_stopSelectionEndEdgeUpdate();
|
|
_stopSelectionStartEdgeUpdate();
|
|
}
|
|
|
|
/// Removes the ongoing selection.
|
|
void _clearSelection() {
|
|
_finalizeSelection();
|
|
_selectable?.dispatchSelectionEvent(const ClearSelectionEvent());
|
|
}
|
|
|
|
Future<void> _copy() async {
|
|
final SelectedContent? data = _selectable?.getSelectedContent();
|
|
if (data == null) {
|
|
return;
|
|
}
|
|
await Clipboard.setData(ClipboardData(text: data.plainText));
|
|
}
|
|
|
|
// [TextSelectionDelegate] overrides.
|
|
|
|
@override
|
|
bool get cutEnabled => false;
|
|
|
|
@override
|
|
bool get pasteEnabled => false;
|
|
|
|
@override
|
|
void hideToolbar([bool hideHandles = true]) {
|
|
_selectionOverlay?.hideToolbar();
|
|
if (hideHandles) {
|
|
_selectionOverlay?.hideHandles();
|
|
}
|
|
}
|
|
|
|
@override
|
|
void selectAll([SelectionChangedCause? cause]) {
|
|
_clearSelection();
|
|
_selectable?.dispatchSelectionEvent(const SelectAllSelectionEvent());
|
|
if (cause == SelectionChangedCause.toolbar) {
|
|
_showToolbar();
|
|
_showHandles();
|
|
}
|
|
}
|
|
|
|
@override
|
|
void copySelection(SelectionChangedCause cause) {
|
|
_copy();
|
|
_clearSelection();
|
|
}
|
|
|
|
// TODO(chunhtai): remove this workaround after decoupling text selection
|
|
// from text editing in TextSelectionDelegate.
|
|
@override
|
|
TextEditingValue textEditingValue = const TextEditingValue(text: '_');
|
|
|
|
@override
|
|
void bringIntoView(TextPosition position) {/* SelectableRegion must be in view at this point. */}
|
|
|
|
@override
|
|
void cutSelection(SelectionChangedCause cause) {
|
|
assert(false);
|
|
}
|
|
|
|
@override
|
|
void userUpdateTextEditingValue(TextEditingValue value, SelectionChangedCause cause) {/* SelectableRegion maintains its own state */}
|
|
|
|
@override
|
|
Future<void> pasteText(SelectionChangedCause cause) async {
|
|
assert(false);
|
|
}
|
|
|
|
// [SelectionRegistrar] override.
|
|
|
|
@override
|
|
void add(Selectable selectable) {
|
|
assert(_selectable == null);
|
|
_selectable = selectable;
|
|
_selectable!.addListener(_updateSelectionStatus);
|
|
_selectable!.pushHandleLayers(_startHandleLayerLink, _endHandleLayerLink);
|
|
}
|
|
|
|
@override
|
|
void remove(Selectable selectable) {
|
|
assert(_selectable == selectable);
|
|
_selectable!.removeListener(_updateSelectionStatus);
|
|
_selectable!.pushHandleLayers(null, null);
|
|
_selectable = null;
|
|
}
|
|
|
|
@override
|
|
void dispose() {
|
|
_selectable?.removeListener(_updateSelectionStatus);
|
|
_selectable?.pushHandleLayers(null, null);
|
|
_selectionDelegate.dispose();
|
|
// In case dispose was triggered before gesture end, remove the magnifier
|
|
// so it doesn't remain stuck in the overlay forever.
|
|
_selectionOverlay?.hideMagnifier(shouldShowToolbar: false);
|
|
_selectionOverlay?.dispose();
|
|
_selectionOverlay = null;
|
|
super.dispose();
|
|
}
|
|
|
|
@override
|
|
Widget build(BuildContext context) {
|
|
assert(debugCheckHasOverlay(context));
|
|
Widget result = SelectionContainer(
|
|
registrar: this,
|
|
delegate: _selectionDelegate,
|
|
child: widget.child,
|
|
);
|
|
if (kIsWeb) {
|
|
result = PlatformSelectableRegionContextMenu(
|
|
child: result,
|
|
);
|
|
}
|
|
return CompositedTransformTarget(
|
|
link: _toolbarLayerLink,
|
|
child: RawGestureDetector(
|
|
gestures: _gestureRecognizers,
|
|
behavior: HitTestBehavior.translucent,
|
|
excludeFromSemantics: true,
|
|
child: Actions(
|
|
actions: _actions,
|
|
child: Focus(
|
|
includeSemantics: false,
|
|
focusNode: widget.focusNode,
|
|
child: result,
|
|
),
|
|
),
|
|
),
|
|
);
|
|
}
|
|
}
|
|
|
|
/// An action that does not override any [Action.overridable] in the subtree.
|
|
///
|
|
/// If this action is invoked by an [Action.overridable], it will immediately
|
|
/// invoke the [Action.overridable] and do nothing else. Otherwise, it will call
|
|
/// [invokeAction].
|
|
abstract class _NonOverrideAction<T extends Intent> extends ContextAction<T> {
|
|
Object? invokeAction(T intent, [BuildContext? context]);
|
|
|
|
@override
|
|
Object? invoke(T intent, [BuildContext? context]) {
|
|
if (callingAction != null) {
|
|
return callingAction!.invoke(intent);
|
|
}
|
|
return invokeAction(intent, context);
|
|
}
|
|
}
|
|
|
|
class _SelectAllAction extends _NonOverrideAction<SelectAllTextIntent> {
|
|
_SelectAllAction(this.state);
|
|
|
|
final _SelectableRegionState state;
|
|
|
|
@override
|
|
void invokeAction(SelectAllTextIntent intent, [BuildContext? context]) {
|
|
state.selectAll(SelectionChangedCause.keyboard);
|
|
}
|
|
}
|
|
|
|
class _CopySelectionAction extends _NonOverrideAction<CopySelectionTextIntent> {
|
|
_CopySelectionAction(this.state);
|
|
|
|
final _SelectableRegionState state;
|
|
|
|
@override
|
|
void invokeAction(CopySelectionTextIntent intent, [BuildContext? context]) {
|
|
state._copy();
|
|
}
|
|
}
|
|
|
|
class _SelectableRegionContainerDelegate extends MultiSelectableSelectionContainerDelegate {
|
|
final Set<Selectable> _hasReceivedStartEvent = <Selectable>{};
|
|
final Set<Selectable> _hasReceivedEndEvent = <Selectable>{};
|
|
|
|
Offset? _lastStartEdgeUpdateGlobalPosition;
|
|
Offset? _lastEndEdgeUpdateGlobalPosition;
|
|
|
|
@override
|
|
void remove(Selectable selectable) {
|
|
_hasReceivedStartEvent.remove(selectable);
|
|
_hasReceivedEndEvent.remove(selectable);
|
|
super.remove(selectable);
|
|
}
|
|
|
|
void _updateLastEdgeEventsFromGeometries() {
|
|
if (currentSelectionStartIndex != -1) {
|
|
final Selectable start = selectables[currentSelectionStartIndex];
|
|
final Offset localStartEdge = start.value.startSelectionPoint!.localPosition +
|
|
Offset(0, - start.value.startSelectionPoint!.lineHeight / 2);
|
|
_lastStartEdgeUpdateGlobalPosition = MatrixUtils.transformPoint(start.getTransformTo(null), localStartEdge);
|
|
}
|
|
if (currentSelectionEndIndex != -1) {
|
|
final Selectable end = selectables[currentSelectionEndIndex];
|
|
final Offset localEndEdge = end.value.endSelectionPoint!.localPosition +
|
|
Offset(0, -end.value.endSelectionPoint!.lineHeight / 2);
|
|
_lastEndEdgeUpdateGlobalPosition = MatrixUtils.transformPoint(end.getTransformTo(null), localEndEdge);
|
|
}
|
|
}
|
|
|
|
@override
|
|
SelectionResult handleSelectAll(SelectAllSelectionEvent event) {
|
|
final SelectionResult result = super.handleSelectAll(event);
|
|
for (final Selectable selectable in selectables) {
|
|
_hasReceivedStartEvent.add(selectable);
|
|
_hasReceivedEndEvent.add(selectable);
|
|
}
|
|
// Synthesize last update event so the edge updates continue to work.
|
|
_updateLastEdgeEventsFromGeometries();
|
|
return result;
|
|
}
|
|
|
|
/// Selects a word in a selectable at the location
|
|
/// [SelectWordSelectionEvent.globalPosition].
|
|
@override
|
|
SelectionResult handleSelectWord(SelectWordSelectionEvent event) {
|
|
final SelectionResult result = super.handleSelectWord(event);
|
|
if (currentSelectionStartIndex != -1) {
|
|
_hasReceivedStartEvent.add(selectables[currentSelectionStartIndex]);
|
|
}
|
|
if (currentSelectionEndIndex != -1) {
|
|
_hasReceivedEndEvent.add(selectables[currentSelectionEndIndex]);
|
|
}
|
|
_updateLastEdgeEventsFromGeometries();
|
|
return result;
|
|
}
|
|
|
|
@override
|
|
SelectionResult handleClearSelection(ClearSelectionEvent event) {
|
|
final SelectionResult result = super.handleClearSelection(event);
|
|
_hasReceivedStartEvent.clear();
|
|
_hasReceivedEndEvent.clear();
|
|
_lastStartEdgeUpdateGlobalPosition = null;
|
|
_lastEndEdgeUpdateGlobalPosition = null;
|
|
return result;
|
|
}
|
|
|
|
@override
|
|
SelectionResult handleSelectionEdgeUpdate(SelectionEdgeUpdateEvent event) {
|
|
if (event.type == SelectionEventType.endEdgeUpdate) {
|
|
_lastEndEdgeUpdateGlobalPosition = event.globalPosition;
|
|
} else {
|
|
_lastStartEdgeUpdateGlobalPosition = event.globalPosition;
|
|
}
|
|
return super.handleSelectionEdgeUpdate(event);
|
|
}
|
|
|
|
@override
|
|
void dispose() {
|
|
_hasReceivedStartEvent.clear();
|
|
_hasReceivedEndEvent.clear();
|
|
super.dispose();
|
|
}
|
|
|
|
@override
|
|
SelectionResult dispatchSelectionEventToChild(Selectable selectable, SelectionEvent event) {
|
|
switch (event.type) {
|
|
case SelectionEventType.startEdgeUpdate:
|
|
_hasReceivedStartEvent.add(selectable);
|
|
ensureChildUpdated(selectable);
|
|
break;
|
|
case SelectionEventType.endEdgeUpdate:
|
|
_hasReceivedEndEvent.add(selectable);
|
|
ensureChildUpdated(selectable);
|
|
break;
|
|
case SelectionEventType.clear:
|
|
_hasReceivedStartEvent.remove(selectable);
|
|
_hasReceivedEndEvent.remove(selectable);
|
|
break;
|
|
case SelectionEventType.selectAll:
|
|
case SelectionEventType.selectWord:
|
|
break;
|
|
}
|
|
return super.dispatchSelectionEventToChild(selectable, event);
|
|
}
|
|
|
|
@override
|
|
void ensureChildUpdated(Selectable selectable) {
|
|
if (_lastEndEdgeUpdateGlobalPosition != null && _hasReceivedEndEvent.add(selectable)) {
|
|
final SelectionEdgeUpdateEvent synthesizedEvent = SelectionEdgeUpdateEvent.forEnd(
|
|
globalPosition: _lastEndEdgeUpdateGlobalPosition!,
|
|
);
|
|
if (currentSelectionEndIndex == -1) {
|
|
handleSelectionEdgeUpdate(synthesizedEvent);
|
|
}
|
|
selectable.dispatchSelectionEvent(synthesizedEvent);
|
|
}
|
|
if (_lastStartEdgeUpdateGlobalPosition != null && _hasReceivedStartEvent.add(selectable)) {
|
|
final SelectionEdgeUpdateEvent synthesizedEvent = SelectionEdgeUpdateEvent.forStart(
|
|
globalPosition: _lastStartEdgeUpdateGlobalPosition!,
|
|
);
|
|
if (currentSelectionStartIndex == -1) {
|
|
handleSelectionEdgeUpdate(synthesizedEvent);
|
|
}
|
|
selectable.dispatchSelectionEvent(synthesizedEvent);
|
|
}
|
|
}
|
|
|
|
@override
|
|
void didChangeSelectables() {
|
|
if (_lastEndEdgeUpdateGlobalPosition != null) {
|
|
handleSelectionEdgeUpdate(
|
|
SelectionEdgeUpdateEvent.forEnd(
|
|
globalPosition: _lastEndEdgeUpdateGlobalPosition!,
|
|
),
|
|
);
|
|
}
|
|
if (_lastStartEdgeUpdateGlobalPosition != null) {
|
|
handleSelectionEdgeUpdate(
|
|
SelectionEdgeUpdateEvent.forStart(
|
|
globalPosition: _lastStartEdgeUpdateGlobalPosition!,
|
|
),
|
|
);
|
|
}
|
|
final Set<Selectable> selectableSet = selectables.toSet();
|
|
_hasReceivedEndEvent.removeWhere((Selectable selectable) => !selectableSet.contains(selectable));
|
|
_hasReceivedStartEvent.removeWhere((Selectable selectable) => !selectableSet.contains(selectable));
|
|
super.didChangeSelectables();
|
|
}
|
|
}
|
|
|
|
/// An abstract base class for updating multiple selectable children.
|
|
///
|
|
/// This class provide basic [SelectionEvent] handling and child [Selectable]
|
|
/// updating. The subclass needs to implement [ensureChildUpdated] to ensure
|
|
/// child [Selectable] is updated properly.
|
|
///
|
|
/// This class optimize the selection update by keeping track of the
|
|
/// [Selectable]s that currently contain the selection edges.
|
|
abstract class MultiSelectableSelectionContainerDelegate extends SelectionContainerDelegate with ChangeNotifier {
|
|
/// Gets the list of selectables this delegate is managing.
|
|
List<Selectable> selectables = <Selectable>[];
|
|
|
|
/// The number of additional pixels added to the selection handle drawable
|
|
/// area.
|
|
///
|
|
/// Selection handles that are outside of the drawable area will be hidden.
|
|
/// That logic prevents handles that get scrolled off the viewport from being
|
|
/// drawn on the screen.
|
|
///
|
|
/// The drawable area = current rectangle of [SelectionContainer] +
|
|
/// _kSelectionHandleDrawableAreaPadding on each side.
|
|
///
|
|
/// This was an eyeballed value to create smooth user experiences.
|
|
static const double _kSelectionHandleDrawableAreaPadding = 5.0;
|
|
|
|
/// The current selectable that contains the selection end edge.
|
|
@protected
|
|
int currentSelectionEndIndex = -1;
|
|
|
|
/// The current selectable that contains the selection start edge.
|
|
@protected
|
|
int currentSelectionStartIndex = -1;
|
|
|
|
LayerLink? _startHandleLayer;
|
|
Selectable? _startHandleLayerOwner;
|
|
LayerLink? _endHandleLayer;
|
|
Selectable? _endHandleLayerOwner;
|
|
|
|
bool _isHandlingSelectionEvent = false;
|
|
bool _scheduledSelectableUpdate = false;
|
|
bool _selectionInProgress = false;
|
|
Set<Selectable> _additions = <Selectable>{};
|
|
|
|
@override
|
|
void add(Selectable selectable) {
|
|
assert(!selectables.contains(selectable));
|
|
_additions.add(selectable);
|
|
_scheduleSelectableUpdate();
|
|
}
|
|
|
|
@override
|
|
void remove(Selectable selectable) {
|
|
if (_additions.remove(selectable)) {
|
|
return;
|
|
}
|
|
_removeSelectable(selectable);
|
|
_scheduleSelectableUpdate();
|
|
}
|
|
|
|
/// Notifies this delegate that layout of the container has changed.
|
|
void layoutDidChange() {
|
|
_updateSelectionGeometry();
|
|
}
|
|
|
|
void _scheduleSelectableUpdate() {
|
|
if (!_scheduledSelectableUpdate) {
|
|
_scheduledSelectableUpdate = true;
|
|
SchedulerBinding.instance.addPostFrameCallback((Duration timeStamp) {
|
|
if (!_scheduledSelectableUpdate) {
|
|
return;
|
|
}
|
|
_scheduledSelectableUpdate = false;
|
|
_updateSelectables();
|
|
});
|
|
}
|
|
}
|
|
|
|
void _updateSelectables() {
|
|
// Remove offScreen selectable.
|
|
if (_additions.isNotEmpty) {
|
|
_flushAdditions();
|
|
}
|
|
didChangeSelectables();
|
|
}
|
|
|
|
void _flushAdditions() {
|
|
final List<Selectable> mergingSelectables = _additions.toList()..sort(compareOrder);
|
|
final List<Selectable> existingSelectables = selectables;
|
|
selectables = <Selectable>[];
|
|
int mergingIndex = 0;
|
|
int existingIndex = 0;
|
|
int selectionStartIndex = currentSelectionStartIndex;
|
|
int selectionEndIndex = currentSelectionEndIndex;
|
|
// Merge two sorted lists.
|
|
while (mergingIndex < mergingSelectables.length || existingIndex < existingSelectables.length) {
|
|
if (mergingIndex >= mergingSelectables.length ||
|
|
(existingIndex < existingSelectables.length &&
|
|
compareOrder(existingSelectables[existingIndex], mergingSelectables[mergingIndex]) < 0)) {
|
|
if (existingIndex == currentSelectionStartIndex) {
|
|
selectionStartIndex = selectables.length;
|
|
}
|
|
if (existingIndex == currentSelectionEndIndex) {
|
|
selectionEndIndex = selectables.length;
|
|
}
|
|
selectables.add(existingSelectables[existingIndex]);
|
|
existingIndex += 1;
|
|
continue;
|
|
}
|
|
|
|
// If the merging selectable falls in the selection range, their selection
|
|
// needs to be updated.
|
|
final Selectable mergingSelectable = mergingSelectables[mergingIndex];
|
|
if (existingIndex < max(currentSelectionStartIndex, currentSelectionEndIndex) &&
|
|
existingIndex > min(currentSelectionStartIndex, currentSelectionEndIndex)) {
|
|
ensureChildUpdated(mergingSelectable);
|
|
}
|
|
mergingSelectable.addListener(_handleSelectableGeometryChange);
|
|
selectables.add(mergingSelectable);
|
|
mergingIndex += 1;
|
|
}
|
|
assert(mergingIndex == mergingSelectables.length &&
|
|
existingIndex == existingSelectables.length &&
|
|
selectables.length == existingIndex + mergingIndex);
|
|
assert(selectionStartIndex >= -1 || selectionStartIndex < selectables.length);
|
|
assert(selectionEndIndex >= -1 || selectionEndIndex < selectables.length);
|
|
// selection indices should not be set to -1 unless they originally were.
|
|
assert((currentSelectionStartIndex == -1) == (selectionStartIndex == -1));
|
|
assert((currentSelectionEndIndex == -1) == (selectionEndIndex == -1));
|
|
currentSelectionEndIndex = selectionEndIndex;
|
|
currentSelectionStartIndex = selectionStartIndex;
|
|
_additions = <Selectable>{};
|
|
}
|
|
|
|
void _removeSelectable(Selectable selectable) {
|
|
assert(selectables.contains(selectable), 'The selectable is not in this registrar.');
|
|
final int index = selectables.indexOf(selectable);
|
|
selectables.removeAt(index);
|
|
if (index <= currentSelectionEndIndex) {
|
|
currentSelectionEndIndex -= 1;
|
|
}
|
|
if (index <= currentSelectionStartIndex) {
|
|
currentSelectionStartIndex -= 1;
|
|
}
|
|
selectable.removeListener(_handleSelectableGeometryChange);
|
|
}
|
|
|
|
/// Called when this delegate finishes updating the selectables.
|
|
@protected
|
|
@mustCallSuper
|
|
void didChangeSelectables() {
|
|
_updateSelectionGeometry();
|
|
}
|
|
|
|
@override
|
|
SelectionGeometry get value => _selectionGeometry;
|
|
SelectionGeometry _selectionGeometry = const SelectionGeometry(
|
|
hasContent: false,
|
|
status: SelectionStatus.none,
|
|
);
|
|
|
|
/// Updates the [value] in this class and notifies listeners if necessary.
|
|
void _updateSelectionGeometry() {
|
|
final SelectionGeometry newValue = getSelectionGeometry();
|
|
if (_selectionGeometry != newValue) {
|
|
_selectionGeometry = newValue;
|
|
notifyListeners();
|
|
}
|
|
_updateHandleLayersAndOwners();
|
|
}
|
|
|
|
/// The compare function this delegate used for determining the selection
|
|
/// order of the selectables.
|
|
///
|
|
/// Defaults to screen order.
|
|
@protected
|
|
Comparator<Selectable> get compareOrder => _compareScreenOrder;
|
|
|
|
int _compareScreenOrder(Selectable a, Selectable b) {
|
|
final Rect rectA = MatrixUtils.transformRect(
|
|
a.getTransformTo(null),
|
|
Rect.fromLTWH(0, 0, a.size.width, a.size.height),
|
|
);
|
|
final Rect rectB = MatrixUtils.transformRect(
|
|
b.getTransformTo(null),
|
|
Rect.fromLTWH(0, 0, b.size.width, b.size.height),
|
|
);
|
|
final int result = _compareVertically(rectA, rectB);
|
|
if (result != 0) {
|
|
return result;
|
|
}
|
|
return _compareHorizontally(rectA, rectB);
|
|
}
|
|
|
|
/// Compares two rectangles in the screen order solely by their vertical
|
|
/// positions.
|
|
///
|
|
/// Returns positive if a is lower, negative if a is higher, 0 if their
|
|
/// order can't be determine solely by their vertical position.
|
|
static int _compareVertically(Rect a, Rect b) {
|
|
if ((a.top - b.top < precisionErrorTolerance && a.bottom - b.bottom > - precisionErrorTolerance) ||
|
|
(b.top - a.top < precisionErrorTolerance && b.bottom - a.bottom > - precisionErrorTolerance)) {
|
|
return 0;
|
|
}
|
|
if ((a.top - b.top).abs() > precisionErrorTolerance) {
|
|
return a.top > b.top ? 1 : -1;
|
|
}
|
|
return a.bottom > b.bottom ? 1 : -1;
|
|
}
|
|
|
|
/// Compares two rectangles in the screen order by their horizontal positions
|
|
/// assuming one of the rectangles enclose the other rect vertically.
|
|
///
|
|
/// Returns positive if a is lower, negative if a is higher.
|
|
static int _compareHorizontally(Rect a, Rect b) {
|
|
if (a.left - b.left < precisionErrorTolerance && a.right - b.right > - precisionErrorTolerance) {
|
|
// a encloses b.
|
|
return -1;
|
|
}
|
|
if (b.left - a.left < precisionErrorTolerance && b.right - a.right > - precisionErrorTolerance) {
|
|
// b encloses a.
|
|
return 1;
|
|
}
|
|
if ((a.left - b.left).abs() > precisionErrorTolerance) {
|
|
return a.left > b.left ? 1 : -1;
|
|
}
|
|
return a.right > b.right ? 1 : -1;
|
|
}
|
|
|
|
void _handleSelectableGeometryChange() {
|
|
// Geometries of selectable children may change multiple times when handling
|
|
// selection events. Ignore these updates since the selection geometry of
|
|
// this delegate will be updated after handling the selection events.
|
|
if (_isHandlingSelectionEvent) {
|
|
return;
|
|
}
|
|
_updateSelectionGeometry();
|
|
}
|
|
|
|
/// Gets the combined selection geometry for child selectables.
|
|
@protected
|
|
SelectionGeometry getSelectionGeometry() {
|
|
if (currentSelectionEndIndex == -1 ||
|
|
currentSelectionStartIndex == -1 ||
|
|
selectables.isEmpty) {
|
|
// There is no valid selection.
|
|
return SelectionGeometry(
|
|
status: SelectionStatus.none,
|
|
hasContent: selectables.isNotEmpty,
|
|
);
|
|
}
|
|
|
|
currentSelectionStartIndex = _adjustSelectionIndexBasedOnSelectionGeometry(
|
|
currentSelectionStartIndex,
|
|
currentSelectionEndIndex,
|
|
);
|
|
currentSelectionEndIndex = _adjustSelectionIndexBasedOnSelectionGeometry(
|
|
currentSelectionEndIndex,
|
|
currentSelectionStartIndex,
|
|
);
|
|
|
|
// Need to find the non-null start selection point.
|
|
SelectionGeometry startGeometry = selectables[currentSelectionStartIndex].value;
|
|
final bool forwardSelection = currentSelectionEndIndex >= currentSelectionStartIndex;
|
|
int startIndexWalker = currentSelectionStartIndex;
|
|
while (startIndexWalker != currentSelectionEndIndex && startGeometry.startSelectionPoint == null) {
|
|
startIndexWalker += forwardSelection ? 1 : -1;
|
|
startGeometry = selectables[startIndexWalker].value;
|
|
}
|
|
|
|
SelectionPoint? startPoint;
|
|
if (startGeometry.startSelectionPoint != null) {
|
|
final Matrix4 startTransform = getTransformFrom(selectables[startIndexWalker]);
|
|
final Offset start = MatrixUtils.transformPoint(startTransform, startGeometry.startSelectionPoint!.localPosition);
|
|
// It can be NaN if it is detached or off-screen.
|
|
if (start.isFinite) {
|
|
startPoint = SelectionPoint(
|
|
localPosition: start,
|
|
lineHeight: startGeometry.startSelectionPoint!.lineHeight,
|
|
handleType: startGeometry.startSelectionPoint!.handleType,
|
|
);
|
|
}
|
|
}
|
|
|
|
// Need to find the non-null end selection point.
|
|
SelectionGeometry endGeometry = selectables[currentSelectionEndIndex].value;
|
|
int endIndexWalker = currentSelectionEndIndex;
|
|
while (endIndexWalker != currentSelectionStartIndex && endGeometry.endSelectionPoint == null) {
|
|
endIndexWalker += forwardSelection ? -1 : 1;
|
|
endGeometry = selectables[endIndexWalker].value;
|
|
}
|
|
SelectionPoint? endPoint;
|
|
if (endGeometry.endSelectionPoint != null) {
|
|
final Matrix4 endTransform = getTransformFrom(selectables[endIndexWalker]);
|
|
final Offset end = MatrixUtils.transformPoint(endTransform, endGeometry.endSelectionPoint!.localPosition);
|
|
// It can be NaN if it is detached or off-screen.
|
|
if (end.isFinite) {
|
|
endPoint = SelectionPoint(
|
|
localPosition: end,
|
|
lineHeight: endGeometry.endSelectionPoint!.lineHeight,
|
|
handleType: endGeometry.endSelectionPoint!.handleType,
|
|
);
|
|
}
|
|
}
|
|
|
|
return SelectionGeometry(
|
|
startSelectionPoint: startPoint,
|
|
endSelectionPoint: endPoint,
|
|
status: startGeometry != endGeometry
|
|
? SelectionStatus.uncollapsed
|
|
: startGeometry.status,
|
|
// Would have at least one selectable child.
|
|
hasContent: true,
|
|
);
|
|
}
|
|
|
|
// The currentSelectionStartIndex or currentSelectionEndIndex may not be
|
|
// the current index that contains selection edges. This can happen if the
|
|
// selection edge is in between two selectables. One of the selectable will
|
|
// have its selection collapsed at the index 0 or contentLength depends on
|
|
// whether the selection is reversed or not. The current selection index can
|
|
// be point to either one.
|
|
//
|
|
// This method adjusts the index to point to selectable with valid selection.
|
|
int _adjustSelectionIndexBasedOnSelectionGeometry(int currentIndex, int towardIndex) {
|
|
final bool forward = towardIndex > currentIndex;
|
|
while (currentIndex != towardIndex &&
|
|
selectables[currentIndex].value.status != SelectionStatus.uncollapsed) {
|
|
currentIndex += forward ? 1 : -1;
|
|
}
|
|
return currentIndex;
|
|
}
|
|
|
|
@override
|
|
void pushHandleLayers(LayerLink? startHandle, LayerLink? endHandle) {
|
|
if (_startHandleLayer == startHandle && _endHandleLayer == endHandle) {
|
|
return;
|
|
}
|
|
_startHandleLayer = startHandle;
|
|
_endHandleLayer = endHandle;
|
|
_updateHandleLayersAndOwners();
|
|
}
|
|
|
|
/// Pushes both handle layers to the selectables that contain selection edges.
|
|
///
|
|
/// This method needs to be called every time the selectables that contain the
|
|
/// selection edges change, i.e. [currentSelectionStartIndex] or
|
|
/// [currentSelectionEndIndex] changes. Otherwise, the handle may be painted
|
|
/// in the wrong place.
|
|
void _updateHandleLayersAndOwners() {
|
|
LayerLink? effectiveStartHandle = _startHandleLayer;
|
|
LayerLink? effectiveEndHandle = _endHandleLayer;
|
|
if (effectiveStartHandle != null || effectiveEndHandle != null) {
|
|
final Rect drawableArea = Rect
|
|
.fromLTWH(0, 0, containerSize.width, containerSize.height)
|
|
.inflate(_kSelectionHandleDrawableAreaPadding);
|
|
final bool hideStartHandle = value.startSelectionPoint == null || !drawableArea.contains(value.startSelectionPoint!.localPosition);
|
|
final bool hideEndHandle = value.endSelectionPoint == null || !drawableArea.contains(value.endSelectionPoint!.localPosition);
|
|
effectiveStartHandle = hideStartHandle ? null : _startHandleLayer;
|
|
effectiveEndHandle = hideEndHandle ? null : _endHandleLayer;
|
|
}
|
|
if (currentSelectionStartIndex == -1 || currentSelectionEndIndex == -1) {
|
|
// No valid selection.
|
|
if (_startHandleLayerOwner != null) {
|
|
_startHandleLayerOwner!.pushHandleLayers(null, null);
|
|
_startHandleLayerOwner = null;
|
|
}
|
|
if (_endHandleLayerOwner != null) {
|
|
_endHandleLayerOwner!.pushHandleLayers(null, null);
|
|
_endHandleLayerOwner = null;
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (selectables[currentSelectionStartIndex] != _startHandleLayerOwner) {
|
|
_startHandleLayerOwner?.pushHandleLayers(null, null);
|
|
}
|
|
if (selectables[currentSelectionEndIndex] != _endHandleLayerOwner) {
|
|
_endHandleLayerOwner?.pushHandleLayers(null, null);
|
|
}
|
|
|
|
_startHandleLayerOwner = selectables[currentSelectionStartIndex];
|
|
|
|
if (currentSelectionStartIndex == currentSelectionEndIndex) {
|
|
// Selection edges is on the same selectable.
|
|
_endHandleLayerOwner = _startHandleLayerOwner;
|
|
_startHandleLayerOwner!.pushHandleLayers(effectiveStartHandle, effectiveEndHandle);
|
|
return;
|
|
}
|
|
|
|
_startHandleLayerOwner!.pushHandleLayers(effectiveStartHandle, null);
|
|
_endHandleLayerOwner = selectables[currentSelectionEndIndex];
|
|
_endHandleLayerOwner!.pushHandleLayers(null, effectiveEndHandle);
|
|
}
|
|
|
|
/// Copies the selected contents of all selectables.
|
|
@override
|
|
SelectedContent? getSelectedContent() {
|
|
final List<SelectedContent> selections = <SelectedContent>[];
|
|
for (final Selectable selectable in selectables) {
|
|
final SelectedContent? data = selectable.getSelectedContent();
|
|
if (data != null) {
|
|
selections.add(data);
|
|
}
|
|
}
|
|
if (selections.isEmpty) {
|
|
return null;
|
|
}
|
|
final StringBuffer buffer = StringBuffer();
|
|
for (final SelectedContent selection in selections) {
|
|
buffer.write(selection.plainText);
|
|
}
|
|
return SelectedContent(
|
|
plainText: buffer.toString(),
|
|
);
|
|
}
|
|
|
|
/// Selects all contents of all selectables.
|
|
@protected
|
|
SelectionResult handleSelectAll(SelectAllSelectionEvent event) {
|
|
for (final Selectable selectable in selectables) {
|
|
dispatchSelectionEventToChild(selectable, event);
|
|
}
|
|
currentSelectionStartIndex = 0;
|
|
currentSelectionEndIndex = selectables.length - 1;
|
|
return SelectionResult.none;
|
|
}
|
|
|
|
/// Selects a word in a selectable at the location
|
|
/// [SelectWordSelectionEvent.globalPosition].
|
|
@protected
|
|
SelectionResult handleSelectWord(SelectWordSelectionEvent event) {
|
|
for (int index = 0; index < selectables.length; index += 1) {
|
|
final Rect localRect = Rect.fromLTWH(0, 0, selectables[index].size.width, selectables[index].size.height);
|
|
final Matrix4 transform = selectables[index].getTransformTo(null);
|
|
final Rect globalRect = MatrixUtils.transformRect(transform, localRect);
|
|
if (globalRect.contains(event.globalPosition)) {
|
|
final SelectionGeometry existingGeometry = selectables[index].value;
|
|
dispatchSelectionEventToChild(selectables[index], event);
|
|
if (selectables[index].value != existingGeometry) {
|
|
// Geometry has changed as a result of select word, need to clear the
|
|
// selection of other selectables to keep selection in sync.
|
|
selectables
|
|
.where((Selectable target) => target != selectables[index])
|
|
.forEach((Selectable target) => dispatchSelectionEventToChild(target, const ClearSelectionEvent()));
|
|
currentSelectionStartIndex = currentSelectionEndIndex = index;
|
|
}
|
|
return SelectionResult.end;
|
|
}
|
|
}
|
|
return SelectionResult.none;
|
|
}
|
|
|
|
/// Removes the selection of all selectables this delegate manages.
|
|
@protected
|
|
SelectionResult handleClearSelection(ClearSelectionEvent event) {
|
|
for (final Selectable selectable in selectables) {
|
|
dispatchSelectionEventToChild(selectable, event);
|
|
}
|
|
currentSelectionEndIndex = -1;
|
|
currentSelectionStartIndex = -1;
|
|
return SelectionResult.none;
|
|
}
|
|
|
|
/// Updates the selection edges.
|
|
@protected
|
|
SelectionResult handleSelectionEdgeUpdate(SelectionEdgeUpdateEvent event) {
|
|
if (event.type == SelectionEventType.endEdgeUpdate) {
|
|
return currentSelectionEndIndex == -1 ? _initSelection(event, isEnd: true) : _adjustSelection(event, isEnd: true);
|
|
}
|
|
return currentSelectionStartIndex == -1 ? _initSelection(event, isEnd: false) : _adjustSelection(event, isEnd: false);
|
|
}
|
|
|
|
@override
|
|
SelectionResult dispatchSelectionEvent(SelectionEvent event) {
|
|
final bool selectionWillbeInProgress = event is! ClearSelectionEvent;
|
|
if (!_selectionInProgress && selectionWillbeInProgress) {
|
|
// Sort the selectable every time a selection start.
|
|
selectables.sort(compareOrder);
|
|
}
|
|
_selectionInProgress = selectionWillbeInProgress;
|
|
_isHandlingSelectionEvent = true;
|
|
late SelectionResult result;
|
|
switch (event.type) {
|
|
case SelectionEventType.startEdgeUpdate:
|
|
case SelectionEventType.endEdgeUpdate:
|
|
result = handleSelectionEdgeUpdate(event as SelectionEdgeUpdateEvent);
|
|
break;
|
|
case SelectionEventType.clear:
|
|
result = handleClearSelection(event as ClearSelectionEvent);
|
|
break;
|
|
case SelectionEventType.selectAll:
|
|
result = handleSelectAll(event as SelectAllSelectionEvent);
|
|
break;
|
|
case SelectionEventType.selectWord:
|
|
result = handleSelectWord(event as SelectWordSelectionEvent);
|
|
break;
|
|
}
|
|
_isHandlingSelectionEvent = false;
|
|
_updateSelectionGeometry();
|
|
return result;
|
|
}
|
|
|
|
@override
|
|
void dispose() {
|
|
for (final Selectable selectable in selectables) {
|
|
selectable.removeListener(_handleSelectableGeometryChange);
|
|
}
|
|
selectables = const <Selectable>[];
|
|
_scheduledSelectableUpdate = false;
|
|
super.dispose();
|
|
}
|
|
|
|
/// Ensures the selectable child has received up to date selection event.
|
|
///
|
|
/// This method is called when a new [Selectable] is added to the delegate,
|
|
/// and its screen location falls into the previous selection.
|
|
///
|
|
/// Subclasses are responsible for updating the selection of this newly added
|
|
/// [Selectable].
|
|
@protected
|
|
void ensureChildUpdated(Selectable selectable);
|
|
|
|
/// Dispatches a selection event to a specific selectable.
|
|
///
|
|
/// Override this method if subclasses need to generate additional events or
|
|
/// treatments prior to sending the selection events.
|
|
@protected
|
|
SelectionResult dispatchSelectionEventToChild(Selectable selectable, SelectionEvent event) {
|
|
return selectable.dispatchSelectionEvent(event);
|
|
}
|
|
|
|
/// Initializes the selection of the selectable children.
|
|
///
|
|
/// The goal is to find the selectable child that contains the selection edge.
|
|
/// Returns [SelectionResult.end] if the selection edge ends on any of the
|
|
/// children. Otherwise, it returns [SelectionResult.previous] if the selection
|
|
/// does not reach any of its children. Returns [SelectionResult.next]
|
|
/// if the selection reaches the end of its children.
|
|
///
|
|
/// Ideally, this method should only be called twice at the beginning of the
|
|
/// drag selection, once for start edge update event, once for end edge update
|
|
/// event.
|
|
SelectionResult _initSelection(SelectionEdgeUpdateEvent event, {required bool isEnd}) {
|
|
assert((isEnd && currentSelectionEndIndex == -1) || (!isEnd && currentSelectionStartIndex == -1));
|
|
int newIndex = -1;
|
|
bool hasFoundEdgeIndex = false;
|
|
SelectionResult? result;
|
|
for (int index = 0; index < selectables.length && !hasFoundEdgeIndex; index += 1) {
|
|
final Selectable child = selectables[index];
|
|
final SelectionResult childResult = dispatchSelectionEventToChild(child, event);
|
|
switch (childResult) {
|
|
case SelectionResult.next:
|
|
case SelectionResult.none:
|
|
newIndex = index;
|
|
break;
|
|
case SelectionResult.end:
|
|
newIndex = index;
|
|
result = SelectionResult.end;
|
|
hasFoundEdgeIndex = true;
|
|
break;
|
|
case SelectionResult.previous:
|
|
hasFoundEdgeIndex = true;
|
|
if (index == 0) {
|
|
newIndex = 0;
|
|
result = SelectionResult.previous;
|
|
}
|
|
result ??= SelectionResult.end;
|
|
break;
|
|
case SelectionResult.pending:
|
|
newIndex = index;
|
|
result = SelectionResult.pending;
|
|
hasFoundEdgeIndex = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (newIndex == -1) {
|
|
assert(selectables.isEmpty);
|
|
return SelectionResult.none;
|
|
}
|
|
if (isEnd) {
|
|
currentSelectionEndIndex = newIndex;
|
|
} else {
|
|
currentSelectionStartIndex = newIndex;
|
|
}
|
|
// The result can only be null if the loop went through the entire list
|
|
// without any of the selection returned end or previous. In this case, the
|
|
// caller of this method needs to find the next selectable in their list.
|
|
return result ?? SelectionResult.next;
|
|
}
|
|
|
|
/// Adjusts the selection based on the drag selection update event if there
|
|
/// is already a selectable child that contains the selection edge.
|
|
///
|
|
/// This method starts by sending the selection event to the current
|
|
/// selectable that contains the selection edge, and finds forward or backward
|
|
/// if that selectable no longer contains the selection edge.
|
|
SelectionResult _adjustSelection(SelectionEdgeUpdateEvent event, {required bool isEnd}) {
|
|
assert(() {
|
|
if (isEnd) {
|
|
assert(currentSelectionEndIndex < selectables.length && currentSelectionEndIndex >= 0);
|
|
return true;
|
|
}
|
|
assert(currentSelectionStartIndex < selectables.length && currentSelectionStartIndex >= 0);
|
|
return true;
|
|
}());
|
|
SelectionResult? finalResult;
|
|
int newIndex = isEnd ? currentSelectionEndIndex : currentSelectionStartIndex;
|
|
bool? forward;
|
|
late SelectionResult currentSelectableResult;
|
|
// This loop sends the selection event to the
|
|
// currentSelectionEndIndex/currentSelectionStartIndex to determine the
|
|
// direction of the search. If the result is `SelectionResult.next`, this
|
|
// loop look backward. Otherwise, it looks forward.
|
|
//
|
|
// The terminate condition are:
|
|
// 1. the selectable returns end, pending, none.
|
|
// 2. the selectable returns previous when looking forward.
|
|
// 2. the selectable returns next when looking backward.
|
|
while (newIndex < selectables.length && newIndex >= 0 && finalResult == null) {
|
|
currentSelectableResult = dispatchSelectionEventToChild(selectables[newIndex], event);
|
|
switch (currentSelectableResult) {
|
|
case SelectionResult.end:
|
|
case SelectionResult.pending:
|
|
case SelectionResult.none:
|
|
finalResult = currentSelectableResult;
|
|
break;
|
|
case SelectionResult.next:
|
|
if (forward == false) {
|
|
newIndex += 1;
|
|
finalResult = SelectionResult.end;
|
|
} else if (newIndex == selectables.length - 1) {
|
|
finalResult = currentSelectableResult;
|
|
} else {
|
|
forward = true;
|
|
newIndex += 1;
|
|
}
|
|
break;
|
|
case SelectionResult.previous:
|
|
if (forward ?? false) {
|
|
newIndex -= 1;
|
|
finalResult = SelectionResult.end;
|
|
} else if (newIndex == 0) {
|
|
finalResult = currentSelectableResult;
|
|
} else {
|
|
forward = false;
|
|
newIndex -= 1;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
if (isEnd) {
|
|
currentSelectionEndIndex = newIndex;
|
|
} else {
|
|
currentSelectionStartIndex = newIndex;
|
|
}
|
|
return finalResult!;
|
|
}
|
|
}
|