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Remove extracted luminance calculations from Material (#12718)

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* remove extracted methods

* lint
This commit is contained in:
xster 2017-11-03 06:14:40 -07:00 committed by GitHub
parent 35bb855c0d
commit 015c738318
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 2 additions and 14 deletions
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16
packages/flutter/lib/src/material/theme_data.dart
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@ -2,7 +2,6 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'dart:math' as math;
import 'dart:ui' show Color, hashValues;
import 'package:flutter/foundation.dart';
@ -497,24 +496,13 @@ class ThemeData {
);
}
// See <https://www.w3.org/TR/WCAG20/#relativeluminancedef>
static double _linearizeColorComponent(double component) {
if (component <= 0.03928)
return component / 12.92;
return math.pow((component + 0.055) / 1.055, 2.4);
}
/// Determines whether the given [Color] is [Brightness.light] or
/// [Brightness.dark].
///
/// This compares the luminosity of the given color to a threshold value that
/// matches the material design specification.
static Brightness estimateBrightnessForColor(Color color) {
// See <https://www.w3.org/TR/WCAG20/#relativeluminancedef>
final double R = _linearizeColorComponent(color.red / 0xFF);
final double G = _linearizeColorComponent(color.green / 0xFF);
final double B = _linearizeColorComponent(color.blue / 0xFF);
final double L = 0.2126 * R + 0.7152 * G + 0.0722 * B;
final double relativeLuminance = color.computeLuminance();
// See <https://www.w3.org/TR/WCAG20/#contrast-ratiodef>
// The spec says to use kThreshold=0.0525, but Material Design appears to bias
@ -523,7 +511,7 @@ class ThemeData {
// Design spec shows for its color palette on
// <https://material.io/guidelines/style/color.html#color-color-palette>.
const double kThreshold = 0.15;
if ((L + 0.05) * (L + 0.05) > kThreshold )
if ((relativeLuminance + 0.05) * (relativeLuminance + 0.05) > kThreshold )
return Brightness.light;
return Brightness.dark;
}