1 | // Copyright 2014 The Flutter Authors. All rights reserved. |
2 | // Use of this source code is governed by a BSD-style license that can be |
3 | // found in the LICENSE file. |
4 | |
5 | import 'package:flutter/foundation.dart'; |
6 | import 'package:flutter/rendering.dart'; |
7 | |
8 | import 'framework.dart'; |
9 | |
10 | /// Applies a [ColorFilter] to its child. |
11 | /// |
12 | /// This widget applies a function independently to each pixel of [child]'s |
13 | /// content, according to the [ColorFilter] specified. |
14 | /// Use the [ColorFilter.mode] constructor to apply a [Color] using a [BlendMode]. |
15 | /// Use the [BackdropFilter] widget instead, if the [ColorFilter] |
16 | /// needs to be applied onto the content beneath [child]. |
17 | /// |
18 | /// {@youtube 560 315 https://www.youtube.com/watch?v=F7Cll22Dno8} |
19 | /// |
20 | /// {@tool dartpad} |
21 | /// These two images have two [ColorFilter]s applied with different [BlendMode]s, |
22 | /// one with red color and [BlendMode.modulate] another with a grey color and [BlendMode.saturation]. |
23 | /// |
24 | /// ** See code in examples/api/lib/widgets/color_filter/color_filtered.0.dart ** |
25 | ///{@end-tool} |
26 | /// |
27 | /// See also: |
28 | /// |
29 | /// * [BlendMode], describes how to blend a source image with the destination image. |
30 | /// * [ColorFilter], which describes a function that modify a color to a different color. |
31 | |
32 | @immutable |
33 | class ColorFiltered extends SingleChildRenderObjectWidget { |
34 | /// Creates a widget that applies a [ColorFilter] to its child. |
35 | const ColorFiltered({required this.colorFilter, super.child, super.key}); |
36 | |
37 | /// The color filter to apply to the child of this widget. |
38 | final ColorFilter colorFilter; |
39 | |
40 | @override |
41 | RenderObject createRenderObject(BuildContext context) => _ColorFilterRenderObject(colorFilter); |
42 | |
43 | @override |
44 | void updateRenderObject(BuildContext context, RenderObject renderObject) { |
45 | (renderObject as _ColorFilterRenderObject).colorFilter = colorFilter; |
46 | } |
47 | |
48 | @override |
49 | void debugFillProperties(DiagnosticPropertiesBuilder properties) { |
50 | super.debugFillProperties(properties); |
51 | properties.add(DiagnosticsProperty<ColorFilter>('colorFilter' , colorFilter)); |
52 | } |
53 | } |
54 | |
55 | class _ColorFilterRenderObject extends RenderProxyBox { |
56 | _ColorFilterRenderObject(this._colorFilter); |
57 | |
58 | ColorFilter get colorFilter => _colorFilter; |
59 | ColorFilter _colorFilter; |
60 | set colorFilter(ColorFilter value) { |
61 | if (value != _colorFilter) { |
62 | _colorFilter = value; |
63 | markNeedsPaint(); |
64 | } |
65 | } |
66 | |
67 | @override |
68 | bool get alwaysNeedsCompositing => child != null; |
69 | |
70 | @override |
71 | void paint(PaintingContext context, Offset offset) { |
72 | layer = context.pushColorFilter(offset, colorFilter, super.paint, oldLayer: layer as ColorFilterLayer?); |
73 | assert(() { |
74 | layer!.debugCreator = debugCreator; |
75 | return true; |
76 | }()); |
77 | } |
78 | } |
79 | |