From bc0d3289cb2cb6bcef303b5f99e6fa1aa3cf9fab Mon Sep 17 00:00:00 2001 From: Nick Sparks Date: Fri, 2 May 2025 16:34:04 -0700 Subject: [PATCH] InputDecorator - animate between transparent hoverColor and hoverColor (#168244) As described in https://github.com/flutter/flutter/issues/155169, TextFields with hoverColor set can have an issue where they flicker as the mouse enters and exits their bounds. _BorderContainerState uses a 15ms animation to transition between non-hovered and hovered states. Part of this animation is a ColorTween between Colors.transparent and a given hoverColor. Critically, Colors.transparent is transparent black. On high refresh rate displays (any display with faster than 60z), this can result in a frame being rendered where the TextField fill color is a dark, semi-transparent version of hoverColor. The immediate solution to this is to animate between hoverColor and a hoverColor with alpha 0. Before: https://github.com/user-attachments/assets/01d62c6a-015d-4dc7-9897-7c3a75ca8aa0 After: https://github.com/user-attachments/assets/ff51a5b2-ba4a-4508-a111-4c915d31ac46 Fixes https://github.com/flutter/flutter/issues/155169 ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md --------- Co-authored-by: Nick Sparks <6109599+nsparks@users.noreply.github.com> --- .../lib/src/material/input_decorator.dart | 7 +++++-- .../test/material/input_decorator_test.dart | 17 +++++++++++++++++ 2 files changed, 22 insertions(+), 2 deletions(-) diff --git a/packages/flutter/lib/src/material/input_decorator.dart b/packages/flutter/lib/src/material/input_decorator.dart index bcf68c1edc9..b65ed44d04e 100644 --- a/packages/flutter/lib/src/material/input_decorator.dart +++ b/packages/flutter/lib/src/material/input_decorator.dart @@ -218,7 +218,9 @@ class _BorderContainerState extends State<_BorderContainer> with TickerProviderS ); _border = _InputBorderTween(begin: widget.border, end: widget.border); _hoverAnimation = CurvedAnimation(parent: _hoverColorController, curve: Curves.linear); - _hoverColorTween = ColorTween(begin: Colors.transparent, end: widget.hoverColor); + + // Animate between transparent [widget.hoverColor] and [widget.hoverColor]. + _hoverColorTween = ColorTween(begin: widget.hoverColor.withAlpha(0), end: widget.hoverColor); } @override @@ -240,7 +242,8 @@ class _BorderContainerState extends State<_BorderContainer> with TickerProviderS ..forward(); } if (widget.hoverColor != oldWidget.hoverColor) { - _hoverColorTween = ColorTween(begin: Colors.transparent, end: widget.hoverColor); + // Animate between transparent [widget.hoverColor] and [widget.hoverColor]. + _hoverColorTween = ColorTween(begin: widget.hoverColor.withAlpha(0), end: widget.hoverColor); } if (widget.isHovering != oldWidget.isHovering) { if (widget.isHovering) { diff --git a/packages/flutter/test/material/input_decorator_test.dart b/packages/flutter/test/material/input_decorator_test.dart index 6b2ff3824b5..49da3d42029 100644 --- a/packages/flutter/test/material/input_decorator_test.dart +++ b/packages/flutter/test/material/input_decorator_test.dart @@ -238,6 +238,14 @@ Rect getContainerRect(WidgetTester tester) { return box.paintBounds; } +Animation _getHoverAnimation(WidgetTester tester) { + final CustomPaint customPaint = tester.widget(findBorderPainter()); + final dynamic /*_InputBorderPainter*/ inputBorderPainter = customPaint.foregroundPainter; + // ignore: avoid_dynamic_calls + final Animation animation = inputBorderPainter.hoverAnimation as Animation; + return animation; +} + InputBorder? getBorder(WidgetTester tester) { if (!tester.any(findBorderPainter())) { return null; @@ -13361,6 +13369,15 @@ void main() { await tester.pump(const Duration(milliseconds: 15)); expect(getContainerColor(tester), isSameColorAs(fillColor)); + // Test that for high refresh rate displays, the color mid-animation is somewhere between + // the fill color and the hover color. + await pumpDecorator(hovering: true); + expect(getContainerColor(tester), isSameColorAs(fillColor)); + await tester.pump(const Duration(milliseconds: 6)); + final Color midHoverColor = + Color.lerp(hoverColor.withAlpha(0), hoverColor, _getHoverAnimation(tester).value)!; + expect(getContainerColor(tester), isSameColorAs(Color.alphaBlend(midHoverColor, fillColor))); + await pumpDecorator(hovering: false, enabled: false); expect(getContainerColor(tester), isSameColorAs(disabledColor)); await tester.pump(const Duration(seconds: 10));