Implement Regular Windows for the win32 framework + add an example application for regular windows #173715
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This pull request introduces support for regular windows on the Win32 platform, along with a comprehensive example application to demonstrate the new multi-windowing API. The changes include a new _window_win32.dart file with the platform-specific implementation using FFI, modifications to _window.dart to integrate the new platform, and a full example project. The implementation is well-structured, using a WindowingOwner pattern and providing a clean interface for creating and managing windows. The example app is a great addition for understanding the API usage.
I have a few minor suggestions to improve code clarity and consistency, mainly around removing unnecessary async keywords in the example app and ensuring consistency with BoxConstraints in the framework code. Overall, this is a solid contribution that significantly expands Flutter's desktop capabilities.
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| onPressed: () async { | ||
| controller.controller.destroy(); | ||
| }, |
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The async keyword is unnecessary here as controller.controller.destroy() is a synchronous method and is not awaited. Removing it improves code clarity.1
onPressed: () {
controller.controller.destroy();
},
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| onPressed: () async { | ||
| final RegularWindowController regular = controller | ||
| .controller as RegularWindowController; | ||
| regular.setFullscreen(!regular.isFullscreen); | ||
| }, |
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The async keyword is not needed here because regular.setFullscreen() is synchronous and not awaited. Removing it makes the code cleaner.1
onPressed: () {
final RegularWindowController regular = controller
.controller as RegularWindowController;
regular.setFullscreen(!regular.isFullscreen);
},
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| onPressed: () async { | ||
| final UniqueKey key = UniqueKey(); | ||
| windowManagerModel.add( | ||
| KeyedWindowController( | ||
| key: key, | ||
| controller: RegularWindowController( | ||
| delegate: CallbackRegularWindowControllerDelegate( | ||
| onDestroyed: () => windowManagerModel.remove(key), | ||
| ), | ||
| title: "Regular", | ||
| preferredSize: windowSettings.regularSize, | ||
| ), | ||
| ), | ||
| ); | ||
| }, |
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The async keyword is unnecessary in this onPressed callback since no asynchronous operations are being awaited. Removing it simplifies the code and improves readability.1
onPressed: () {
final UniqueKey key = UniqueKey();
windowManagerModel.add(
KeyedWindowController(
key: key,
controller: RegularWindowController(
delegate: CallbackRegularWindowControllerDelegate(
onDestroyed: () => windowManagerModel.remove(key),
),
title: "Regular",
preferredSize: windowSettings.regularSize,
),
),
);
},
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| void from(BoxConstraints? constraints) { | ||
| hasConstraints = constraints != null; | ||
| minWidth = constraints?.minWidth ?? 0; | ||
| minHeight = constraints?.minHeight ?? 0; | ||
| maxWidth = constraints?.maxWidth ?? double.maxFinite; | ||
| maxHeight = constraints?.maxHeight ?? double.maxFinite; | ||
| } |
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The BoxConstraints class uses double.infinity to represent unconstrained dimensions. This implementation uses double.maxFinite instead. While double.maxFinite is a very large number, using double.infinity would be more consistent with BoxConstraints and better represent an unconstrained value. If double.infinity cannot be passed over FFI, this should be documented with a comment.1
void from(BoxConstraints? constraints) {
hasConstraints = constraints != null;
minWidth = constraints?.minWidth ?? 0;
minHeight = constraints?.minHeight ?? 0;
maxWidth = constraints?.maxWidth ?? double.infinity;
maxHeight = constraints?.maxHeight ?? double.infinity;
}
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@mattkae What do you think of this? This suggestion seems nice, but I don't mind either ways.
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Same. Could be nice as long as it doesn't make the FFI transition a pain.
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…example application for regular windows (flutter/flutter#173715)
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Roll Flutter from 6cc976ec26d3 to 96fe3b3df509 (32 revisions) flutter/flutter@6cc976e...96fe3b3 2025-09-29 engine-flutter-autoroll@skia.org Roll Packages from 389c678 to 34eec78 (6 revisions) (flutter/flutter#176205) 2025-09-29 engine-flutter-autoroll@skia.org Roll Skia from 9b2b942d1eb1 to bb3b6bd4be0d (4 revisions) (flutter/flutter#176201) 2025-09-29 bkonyi@google.com [ Widget Preview ] Improve IDE integration support (flutter/flutter#176114) 2025-09-29 robert.ancell@canonical.com Fix name of driver file (flutter/flutter#176186) 2025-09-29 engine-flutter-autoroll@skia.org Roll Skia from beb673968802 to 9b2b942d1eb1 (3 revisions) (flutter/flutter#176190) 2025-09-28 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from 0Z45OXT_Wb8aWI3a0... to 8zjcJic_DtvB2Bo2x... (flutter/flutter#176158) 2025-09-28 flar@google.com Revert "[Impeller] Optimize scale translate rectangle transforms" (flutter/flutter#176161) 2025-09-27 engine-flutter-autoroll@skia.org Roll Skia from 2e5da5c0a9cd to beb673968802 (1 revision) (flutter/flutter#176145) 2025-09-27 flar@google.com [Impeller] Optimize scale translate rectangle transforms (flutter/flutter#176123) 2025-09-27 engine-flutter-autoroll@skia.org Roll Skia from d8422aaf8f89 to 2e5da5c0a9cd (2 revisions) (flutter/flutter#176141) 2025-09-27 mdebbar@google.com [web] Remove mention of non-existent `canvaskit_lock.yaml` (flutter/flutter#176108) 2025-09-27 engine-flutter-autoroll@skia.org Roll Skia from 96b73f61fe61 to d8422aaf8f89 (2 revisions) (flutter/flutter#176118) 2025-09-27 sokolovskyi.konstantin@gmail.com [a11y] Add `expanded` flag support to Android. (flutter/flutter#174981) 2025-09-26 ahmedsameha1@gmail.com Make sure that a DesktopTextSelectionToolbar doesn't crash in 0x0 env… (flutter/flutter#173928) 2025-09-26 engine-flutter-autoroll@skia.org Roll Dart SDK from 899c7340cc4c to af31d2637b6b (11 revisions) (flutter/flutter#176056) 2025-09-26 1063596+reidbaker@users.noreply.github.com Update java version ranges with the top end limitation for java pre 17 (flutter/flutter#176049) 2025-09-26 1063596+reidbaker@users.noreply.github.com Add warn java evaluation to android_workflow (flutter/flutter#176097) 2025-09-26 katelovett@google.com Removes type annotations in templates (flutter/flutter#176106) 2025-09-26 fluttergithubbot@gmail.com Marks Linux_pixel_7pro static_path_stroke_tessellation_perf__timeline_summary to be unflaky (flutter/flutter#175917) 2025-09-26 1063596+reidbaker@users.noreply.github.com Add kotlin/kgp 2.2.* evaluation criteria. (flutter/flutter#176094) 2025-09-26 32538273+ValentinVignal@users.noreply.github.com Migrate to `WidgetStateMouseCursor` (flutter/flutter#175981) 2025-09-26 engine-flutter-autoroll@skia.org Roll Packages from 117bf63 to 389c678 (4 revisions) (flutter/flutter#176092) 2025-09-26 34871572+gmackall@users.noreply.github.com Fix link to .gclient setup instructions (flutter/flutter#176046) 2025-09-26 matt.kosarek@canonical.com Implement Regular Windows for the win32 framework + add an example application for regular windows (flutter/flutter#173715) 2025-09-26 engine-flutter-autoroll@skia.org Roll Skia from 5d99c3fc7c83 to 96b73f61fe61 (3 revisions) (flutter/flutter#176075) 2025-09-26 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from naeytagBIBEpKgZNZ... to 0Z45OXT_Wb8aWI3a0... (flutter/flutter#176068) 2025-09-26 100504385+AlsoShantanuBorkar@users.noreply.github.com Add itemClipBehavior property for CarouselView's children (flutter/flutter#175324) 2025-09-26 engine-flutter-autoroll@skia.org Roll Skia from 55436d87e414 to 5d99c3fc7c83 (4 revisions) (flutter/flutter#176060) 2025-09-26 flar@google.com Revert "[Impeller] Optimize scale translate rectangle transforms" (flutter/flutter#176061) 2025-09-25 98614782+auto-submit[bot]@users.noreply.github.com Reverts "Reapply "Update the AccessibilityPlugin::Announce method to account f… (#174365)" (flutter/flutter#176059) 2025-09-25 ahmedsameha1@gmail.com Make sure that a CupertinoDesktopTextSelectionToolbarButton doesn't c… (flutter/flutter#173894) 2025-09-25 mohellebiabdessalem@gmail.com Improve code quality in `SensitiveContentPluginTest.java` (flutter/flutter#175721) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC stuartmorgan@google.com on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md ...
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…plication for regular windows (flutter#173715) ## What's new? - Implement and test `_window_win32.dart`, the Win32 implementation of `_window.dart` 🎉 - Wrote a bunch of tests in `window_win32_test.dart` which uses a mock API barrier to mock the native Win32 layer - Update `BaseWindowController` to extend `ChangeNotifier` and use it to inform the `WindowScope` of when things change - Made `RegularWindowController.empty()` a non-internal constructor, as it is needed by implementations - Added a _large_ example application for windowing where users can test out different windowing concepts and see how they work! To test, simply run the tests or try out the example app! ## 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.
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Example app is giving below error flutter run
Launching lib\main.dart on Windows in debug mode...
Building Windows application... 9.1s
✓ Built build\windows\x64\runner\Debug\multiple_windows.exe
[ERROR:flutter/runtime/dart_vm_initializer.cc(40)] Unhandled Exception: 'package:flutter/src/widgets/binding.dart': Failed assertion: line 1752 pos 12: '_child != null': is not true.
#0 _AssertionError._doThrowNew (dart:core-patch/errors_patch.dart:67:4)
#1 _AssertionError._throwNew (dart:core-patch/errors_patch.dart:49:5)
#2 RootElement.mount (package:flutter/src/widgets/binding.dart:1752:12)
#3 RootWidget.attach.<anonymous closure> (package:flutter/src/widgets/binding.dart:1704:18)
#4 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:3101:19)
#5 RootWidget.attach (package:flutter/src/widgets/binding.dart:1703:13)
#6 WidgetsBinding.attachToBuildOwner (package:flutter/src/widgets/binding.dart:1379:27)
#7 WidgetsBinding.attachRootWidget (package:flutter/src/widgets/binding.dart:1364:5)
#8 WidgetsBinding.scheduleAttachRootWidget.<anonymous closure> (package:flutter/src/widgets/binding.dart:1350:7)
#9 Timer._createTimer.<anonymous closure> (dart:async-patch/timer_patch.dart:18:15)
#10 _Timer._runTimers (dart:isolate-patch/timer_impl.dart:423:19)
#11 _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:454:5)
#12 _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:193:12)
Syncing files to device Windows... 101ms |
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You will have to run this against the locally built engine and pass the feature. Did you do |
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…example application for regular windows (flutter/flutter#173715)
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What's new?
_window_win32.dart, the Win32 implementation of_window.dart🎉window_win32_test.dartwhich uses a mock API barrier to mock the native Win32 layerBaseWindowControllerto extendChangeNotifierand use it to inform theWindowScopeof when things changeRegularWindowController.empty()a non-internal constructor, as it is needed by implementationsTo test, simply run the tests or try out the example app!
Pre-launch Checklist
///).