| 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 | /// @docImport 'package:flutter/widgets.dart'; |
| 6 | library; |
| 7 | |
| 8 | import 'package:flutter/foundation.dart'; |
| 9 | import 'package:flutter/gestures.dart'; |
| 10 | import 'package:flutter/scheduler.dart'; |
| 11 | import 'package:flutter/semantics.dart'; |
| 12 | import 'package:flutter/services.dart'; |
| 13 | |
| 14 | import 'box.dart'; |
| 15 | import 'layer.dart'; |
| 16 | import 'object.dart'; |
| 17 | |
| 18 | /// How an embedded platform view behave during hit tests. |
| 19 | enum PlatformViewHitTestBehavior { |
| 20 | /// Opaque targets can be hit by hit tests, causing them to both receive |
| 21 | /// events within their bounds and prevent targets visually behind them from |
| 22 | /// also receiving events. |
| 23 | opaque, |
| 24 | |
| 25 | /// Translucent targets both receive events within their bounds and permit |
| 26 | /// targets visually behind them to also receive events. |
| 27 | translucent, |
| 28 | |
| 29 | /// Transparent targets don't receive events within their bounds and permit |
| 30 | /// targets visually behind them to receive events. |
| 31 | transparent, |
| 32 | } |
| 33 | |
| 34 | enum _PlatformViewState { uninitialized, resizing, ready } |
| 35 | |
| 36 | bool _factoryTypesSetEquals<T>(Set<Factory<T>>? a, Set<Factory<T>>? b) { |
| 37 | if (a == b) { |
| 38 | return true; |
| 39 | } |
| 40 | if (a == null || b == null) { |
| 41 | return false; |
| 42 | } |
| 43 | return setEquals(_factoriesTypeSet(a), _factoriesTypeSet(b)); |
| 44 | } |
| 45 | |
| 46 | Set<Type> _factoriesTypeSet<T>(Set<Factory<T>> factories) { |
| 47 | return factories.map<Type>((Factory<T> factory) => factory.type).toSet(); |
| 48 | } |
| 49 | |
| 50 | /// A render object for an Android view. |
| 51 | /// |
| 52 | /// Requires Android API level 23 or greater. |
| 53 | /// |
| 54 | /// [RenderAndroidView] is responsible for sizing, displaying and passing touch events to an |
| 55 | /// Android [View](https://developer.android.com/reference/android/view/View). |
| 56 | /// |
| 57 | /// {@template flutter.rendering.RenderAndroidView.layout} |
| 58 | /// The render object's layout behavior is to fill all available space, the parent of this object must |
| 59 | /// provide bounded layout constraints. |
| 60 | /// {@endtemplate} |
| 61 | /// |
| 62 | /// {@template flutter.rendering.RenderAndroidView.gestures} |
| 63 | /// The render object participates in Flutter's gesture arenas, and dispatches touch events to the |
| 64 | /// platform view iff it won the arena. Specific gestures that should be dispatched to the platform |
| 65 | /// view can be specified with factories in the `gestureRecognizers` constructor parameter or |
| 66 | /// by calling `updateGestureRecognizers`. If the set of gesture recognizers is empty, the gesture |
| 67 | /// will be dispatched to the platform view iff it was not claimed by any other gesture recognizer. |
| 68 | /// {@endtemplate} |
| 69 | /// |
| 70 | /// See also: |
| 71 | /// |
| 72 | /// * [AndroidView] which is a widget that is used to show an Android view. |
| 73 | /// * [PlatformViewsService] which is a service for controlling platform views. |
| 74 | class RenderAndroidView extends PlatformViewRenderBox { |
| 75 | /// Creates a render object for an Android view. |
| 76 | RenderAndroidView({ |
| 77 | required AndroidViewController viewController, |
| 78 | required PlatformViewHitTestBehavior hitTestBehavior, |
| 79 | required Set<Factory<OneSequenceGestureRecognizer>> gestureRecognizers, |
| 80 | Clip clipBehavior = Clip.hardEdge, |
| 81 | }) : _viewController = viewController, |
| 82 | _clipBehavior = clipBehavior, |
| 83 | super( |
| 84 | controller: viewController, |
| 85 | hitTestBehavior: hitTestBehavior, |
| 86 | gestureRecognizers: gestureRecognizers, |
| 87 | ) { |
| 88 | _viewController.pointTransformer = (Offset offset) => globalToLocal(offset); |
| 89 | updateGestureRecognizers(gestureRecognizers); |
| 90 | _viewController.addOnPlatformViewCreatedListener(_onPlatformViewCreated); |
| 91 | this.hitTestBehavior = hitTestBehavior; |
| 92 | _setOffset(); |
| 93 | } |
| 94 | |
| 95 | _PlatformViewState _state = _PlatformViewState.uninitialized; |
| 96 | |
| 97 | Size? _currentTextureSize; |
| 98 | |
| 99 | bool _isDisposed = false; |
| 100 | |
| 101 | /// The Android view controller for the Android view associated with this render object. |
| 102 | @override |
| 103 | AndroidViewController get controller => _viewController; |
| 104 | |
| 105 | AndroidViewController _viewController; |
| 106 | |
| 107 | /// Sets a new Android view controller. |
| 108 | @override |
| 109 | set controller(AndroidViewController controller) { |
| 110 | assert(!_isDisposed); |
| 111 | if (_viewController == controller) { |
| 112 | return; |
| 113 | } |
| 114 | _viewController.removeOnPlatformViewCreatedListener(_onPlatformViewCreated); |
| 115 | super.controller = controller; |
| 116 | _viewController = controller; |
| 117 | _viewController.pointTransformer = (Offset offset) => globalToLocal(offset); |
| 118 | _sizePlatformView(); |
| 119 | if (_viewController.isCreated) { |
| 120 | markNeedsSemanticsUpdate(); |
| 121 | } |
| 122 | _viewController.addOnPlatformViewCreatedListener(_onPlatformViewCreated); |
| 123 | } |
| 124 | |
| 125 | /// {@macro flutter.material.Material.clipBehavior} |
| 126 | /// |
| 127 | /// Defaults to [Clip.hardEdge]. |
| 128 | Clip get clipBehavior => _clipBehavior; |
| 129 | Clip _clipBehavior = Clip.hardEdge; |
| 130 | set clipBehavior(Clip value) { |
| 131 | if (value != _clipBehavior) { |
| 132 | _clipBehavior = value; |
| 133 | markNeedsPaint(); |
| 134 | markNeedsSemanticsUpdate(); |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | void _onPlatformViewCreated(int id) { |
| 139 | assert(!_isDisposed); |
| 140 | markNeedsSemanticsUpdate(); |
| 141 | } |
| 142 | |
| 143 | @override |
| 144 | bool get sizedByParent => true; |
| 145 | |
| 146 | @override |
| 147 | bool get alwaysNeedsCompositing => true; |
| 148 | |
| 149 | @override |
| 150 | bool get isRepaintBoundary => true; |
| 151 | |
| 152 | @override |
| 153 | @protected |
| 154 | Size computeDryLayout(covariant BoxConstraints constraints) { |
| 155 | return constraints.biggest; |
| 156 | } |
| 157 | |
| 158 | @override |
| 159 | void performResize() { |
| 160 | super.performResize(); |
| 161 | _sizePlatformView(); |
| 162 | } |
| 163 | |
| 164 | Future<void> _sizePlatformView() async { |
| 165 | // Android virtual displays cannot have a zero size. |
| 166 | // Trying to size it to 0 crashes the app, which was happening when starting the app |
| 167 | // with a locked screen (see: https://github.com/flutter/flutter/issues/20456). |
| 168 | if (_state == _PlatformViewState.resizing || size.isEmpty) { |
| 169 | return; |
| 170 | } |
| 171 | |
| 172 | _state = _PlatformViewState.resizing; |
| 173 | markNeedsPaint(); |
| 174 | |
| 175 | Size targetSize; |
| 176 | do { |
| 177 | targetSize = size; |
| 178 | _currentTextureSize = await _viewController.setSize(targetSize); |
| 179 | if (_isDisposed) { |
| 180 | return; |
| 181 | } |
| 182 | // We've resized the platform view to targetSize, but it is possible that |
| 183 | // while we were resizing the render object's size was changed again. |
| 184 | // In that case we will resize the platform view again. |
| 185 | } while (size != targetSize); |
| 186 | |
| 187 | _state = _PlatformViewState.ready; |
| 188 | markNeedsPaint(); |
| 189 | } |
| 190 | |
| 191 | // Sets the offset of the underlying platform view on the platform side. |
| 192 | // |
| 193 | // This allows the Android native view to draw the a11y highlights in the same |
| 194 | // location on the screen as the platform view widget in the Flutter framework. |
| 195 | // |
| 196 | // It also allows platform code to obtain the correct position of the Android |
| 197 | // native view on the screen. |
| 198 | void _setOffset() { |
| 199 | SchedulerBinding.instance.addPostFrameCallback((_) async { |
| 200 | if (!_isDisposed) { |
| 201 | if (attached) { |
| 202 | await _viewController.setOffset(localToGlobal(Offset.zero)); |
| 203 | } |
| 204 | // Schedule a new post frame callback. |
| 205 | _setOffset(); |
| 206 | } |
| 207 | }, debugLabel: 'RenderAndroidView.setOffset' ); |
| 208 | } |
| 209 | |
| 210 | @override |
| 211 | void paint(PaintingContext context, Offset offset) { |
| 212 | if (_viewController.textureId == null || _currentTextureSize == null) { |
| 213 | return; |
| 214 | } |
| 215 | |
| 216 | // As resizing the Android view happens asynchronously we don't know exactly when is a |
| 217 | // texture frame with the new size is ready for consumption. |
| 218 | // TextureLayer is unaware of the texture frame's size and always maps it to the |
| 219 | // specified rect. If the rect we provide has a different size from the current texture frame's |
| 220 | // size the texture frame will be scaled. |
| 221 | // To prevent unwanted scaling artifacts while resizing, clip the texture. |
| 222 | // This guarantees that the size of the texture frame we're painting is always |
| 223 | // _currentAndroidTextureSize. |
| 224 | final bool isTextureLargerThanWidget = |
| 225 | _currentTextureSize!.width > size.width || _currentTextureSize!.height > size.height; |
| 226 | if (isTextureLargerThanWidget && clipBehavior != Clip.none) { |
| 227 | _clipRectLayer.layer = context.pushClipRect( |
| 228 | true, |
| 229 | offset, |
| 230 | offset & size, |
| 231 | _paintTexture, |
| 232 | clipBehavior: clipBehavior, |
| 233 | oldLayer: _clipRectLayer.layer, |
| 234 | ); |
| 235 | return; |
| 236 | } |
| 237 | _clipRectLayer.layer = null; |
| 238 | _paintTexture(context, offset); |
| 239 | } |
| 240 | |
| 241 | final LayerHandle<ClipRectLayer> _clipRectLayer = LayerHandle<ClipRectLayer>(); |
| 242 | |
| 243 | @override |
| 244 | void dispose() { |
| 245 | _isDisposed = true; |
| 246 | _clipRectLayer.layer = null; |
| 247 | _viewController.removeOnPlatformViewCreatedListener(_onPlatformViewCreated); |
| 248 | super.dispose(); |
| 249 | } |
| 250 | |
| 251 | void _paintTexture(PaintingContext context, Offset offset) { |
| 252 | if (_currentTextureSize == null) { |
| 253 | return; |
| 254 | } |
| 255 | |
| 256 | context.addLayer( |
| 257 | TextureLayer(rect: offset & _currentTextureSize!, textureId: _viewController.textureId!), |
| 258 | ); |
| 259 | } |
| 260 | |
| 261 | @override |
| 262 | void describeSemanticsConfiguration(SemanticsConfiguration config) { |
| 263 | // Don't call the super implementation since `platformViewId` should |
| 264 | // be set only when the platform view is created, but the concept of |
| 265 | // a "created" platform view belongs to this subclass. |
| 266 | config.isSemanticBoundary = true; |
| 267 | |
| 268 | if (_viewController.isCreated) { |
| 269 | config.platformViewId = _viewController.viewId; |
| 270 | } |
| 271 | } |
| 272 | } |
| 273 | |
| 274 | /// Common render-layer functionality for iOS and macOS platform views. |
| 275 | /// |
| 276 | /// Provides the basic rendering logic for iOS and macOS platformviews. |
| 277 | /// Subclasses shall override handleEvent in order to execute custom event logic. |
| 278 | /// T represents the class of the view controller for the corresponding widget. |
| 279 | abstract class RenderDarwinPlatformView<T extends DarwinPlatformViewController> extends RenderBox { |
| 280 | /// Creates a render object for a platform view. |
| 281 | RenderDarwinPlatformView({ |
| 282 | required T viewController, |
| 283 | required this.hitTestBehavior, |
| 284 | required Set<Factory<OneSequenceGestureRecognizer>> gestureRecognizers, |
| 285 | }) : _viewController = viewController { |
| 286 | updateGestureRecognizers(gestureRecognizers); |
| 287 | } |
| 288 | |
| 289 | /// The unique identifier of the platform view controlled by this controller. |
| 290 | T get viewController => _viewController; |
| 291 | T _viewController; |
| 292 | set viewController(T value) { |
| 293 | if (_viewController == value) { |
| 294 | return; |
| 295 | } |
| 296 | final bool needsSemanticsUpdate = _viewController.id != value.id; |
| 297 | _viewController = value; |
| 298 | markNeedsPaint(); |
| 299 | if (needsSemanticsUpdate) { |
| 300 | markNeedsSemanticsUpdate(); |
| 301 | } |
| 302 | } |
| 303 | |
| 304 | /// How to behave during hit testing. |
| 305 | // The implicit setter is enough here as changing this value will just affect |
| 306 | // any newly arriving events there's nothing we need to invalidate. |
| 307 | PlatformViewHitTestBehavior hitTestBehavior; |
| 308 | |
| 309 | @override |
| 310 | bool get sizedByParent => true; |
| 311 | |
| 312 | @override |
| 313 | bool get alwaysNeedsCompositing => true; |
| 314 | |
| 315 | @override |
| 316 | bool get isRepaintBoundary => true; |
| 317 | |
| 318 | PointerEvent? _lastPointerDownEvent; |
| 319 | |
| 320 | _UiKitViewGestureRecognizer? _gestureRecognizer; |
| 321 | |
| 322 | @override |
| 323 | @protected |
| 324 | Size computeDryLayout(covariant BoxConstraints constraints) { |
| 325 | return constraints.biggest; |
| 326 | } |
| 327 | |
| 328 | @override |
| 329 | void paint(PaintingContext context, Offset offset) { |
| 330 | context.addLayer(PlatformViewLayer(rect: offset & size, viewId: _viewController.id)); |
| 331 | } |
| 332 | |
| 333 | @override |
| 334 | bool hitTest(BoxHitTestResult result, {Offset? position}) { |
| 335 | if (hitTestBehavior == PlatformViewHitTestBehavior.transparent || !size.contains(position!)) { |
| 336 | return false; |
| 337 | } |
| 338 | result.add(BoxHitTestEntry(this, position)); |
| 339 | return hitTestBehavior == PlatformViewHitTestBehavior.opaque; |
| 340 | } |
| 341 | |
| 342 | @override |
| 343 | bool hitTestSelf(Offset position) => hitTestBehavior != PlatformViewHitTestBehavior.transparent; |
| 344 | |
| 345 | // This is registered as a global PointerRoute while the render object is attached. |
| 346 | void _handleGlobalPointerEvent(PointerEvent event) { |
| 347 | if (event is! PointerDownEvent) { |
| 348 | return; |
| 349 | } |
| 350 | if (!(Offset.zero & size).contains(globalToLocal(event.position))) { |
| 351 | return; |
| 352 | } |
| 353 | if ((event.original ?? event) != _lastPointerDownEvent) { |
| 354 | // The pointer event is in the bounds of this render box, but we didn't get it in handleEvent. |
| 355 | // This means that the pointer event was absorbed by a different render object. |
| 356 | // Since on the platform side the FlutterTouchIntercepting view is seeing all events that are |
| 357 | // within its bounds we need to tell it to reject the current touch sequence. |
| 358 | _viewController.rejectGesture(); |
| 359 | } |
| 360 | _lastPointerDownEvent = null; |
| 361 | } |
| 362 | |
| 363 | @override |
| 364 | void describeSemanticsConfiguration(SemanticsConfiguration config) { |
| 365 | super.describeSemanticsConfiguration(config); |
| 366 | config.isSemanticBoundary = true; |
| 367 | config.platformViewId = _viewController.id; |
| 368 | } |
| 369 | |
| 370 | @override |
| 371 | void attach(PipelineOwner owner) { |
| 372 | super.attach(owner); |
| 373 | GestureBinding.instance.pointerRouter.addGlobalRoute(_handleGlobalPointerEvent); |
| 374 | } |
| 375 | |
| 376 | @override |
| 377 | void detach() { |
| 378 | GestureBinding.instance.pointerRouter.removeGlobalRoute(_handleGlobalPointerEvent); |
| 379 | super.detach(); |
| 380 | } |
| 381 | |
| 382 | /// {@macro flutter.rendering.PlatformViewRenderBox.updateGestureRecognizers} |
| 383 | void updateGestureRecognizers(Set<Factory<OneSequenceGestureRecognizer>> gestureRecognizers); |
| 384 | } |
| 385 | |
| 386 | /// A render object for an iOS UIKit UIView. |
| 387 | /// |
| 388 | /// [RenderUiKitView] is responsible for sizing and displaying an iOS |
| 389 | /// [UIView](https://developer.apple.com/documentation/uikit/uiview). |
| 390 | /// |
| 391 | /// UIViews are added as subviews of the FlutterView and are composited by Quartz. |
| 392 | /// |
| 393 | /// The viewController is typically generated by [PlatformViewsRegistry.getNextPlatformViewId], the UIView |
| 394 | /// must have been created by calling [PlatformViewsService.initUiKitView]. |
| 395 | /// |
| 396 | /// {@macro flutter.rendering.RenderAndroidView.layout} |
| 397 | /// |
| 398 | /// {@macro flutter.rendering.RenderAndroidView.gestures} |
| 399 | /// |
| 400 | /// See also: |
| 401 | /// |
| 402 | /// * [UiKitView], which is a widget that is used to show a UIView. |
| 403 | /// * [PlatformViewsService], which is a service for controlling platform views. |
| 404 | class RenderUiKitView extends RenderDarwinPlatformView<UiKitViewController> { |
| 405 | /// Creates a render object for an iOS UIView. |
| 406 | RenderUiKitView({ |
| 407 | required super.viewController, |
| 408 | required super.hitTestBehavior, |
| 409 | required super.gestureRecognizers, |
| 410 | }); |
| 411 | |
| 412 | /// {@macro flutter.rendering.PlatformViewRenderBox.updateGestureRecognizers} |
| 413 | @override |
| 414 | void updateGestureRecognizers(Set<Factory<OneSequenceGestureRecognizer>> gestureRecognizers) { |
| 415 | assert( |
| 416 | _factoriesTypeSet(gestureRecognizers).length == gestureRecognizers.length, |
| 417 | 'There were multiple gesture recognizer factories for the same type, there must only be a single ' |
| 418 | 'gesture recognizer factory for each gesture recognizer type.' , |
| 419 | ); |
| 420 | if (_factoryTypesSetEquals( |
| 421 | gestureRecognizers, |
| 422 | _gestureRecognizer?.gestureRecognizerFactories, |
| 423 | )) { |
| 424 | return; |
| 425 | } |
| 426 | _gestureRecognizer?.dispose(); |
| 427 | _gestureRecognizer = _UiKitViewGestureRecognizer(viewController, gestureRecognizers); |
| 428 | } |
| 429 | |
| 430 | @override |
| 431 | void handleEvent(PointerEvent event, HitTestEntry entry) { |
| 432 | if (event is! PointerDownEvent) { |
| 433 | return; |
| 434 | } |
| 435 | _gestureRecognizer!.addPointer(event); |
| 436 | _lastPointerDownEvent = event.original ?? event; |
| 437 | } |
| 438 | |
| 439 | @override |
| 440 | void detach() { |
| 441 | _gestureRecognizer!.reset(); |
| 442 | super.detach(); |
| 443 | } |
| 444 | |
| 445 | @override |
| 446 | void dispose() { |
| 447 | _gestureRecognizer?.dispose(); |
| 448 | super.dispose(); |
| 449 | } |
| 450 | } |
| 451 | |
| 452 | /// A render object for a macOS platform view. |
| 453 | class RenderAppKitView extends RenderDarwinPlatformView<AppKitViewController> { |
| 454 | /// Creates a render object for a macOS AppKitView. |
| 455 | RenderAppKitView({ |
| 456 | required super.viewController, |
| 457 | required super.hitTestBehavior, |
| 458 | required super.gestureRecognizers, |
| 459 | }); |
| 460 | |
| 461 | // TODO(schectman): Add gesture functionality to macOS platform view when implemented. |
| 462 | // https://github.com/flutter/flutter/issues/128519 |
| 463 | // This method will need to behave the same as the same-named method for RenderUiKitView, |
| 464 | // but use a _AppKitViewGestureRecognizer or equivalent, whose constructor shall accept an |
| 465 | // AppKitViewController. |
| 466 | @override |
| 467 | void updateGestureRecognizers(Set<Factory<OneSequenceGestureRecognizer>> gestureRecognizers) {} |
| 468 | } |
| 469 | |
| 470 | // This recognizer constructs gesture recognizers from a set of gesture recognizer factories |
| 471 | // it was give, adds all of them to a gesture arena team with the _UiKitViewGestureRecognizer |
| 472 | // as the team captain. |
| 473 | // When the team wins a gesture the recognizer notifies the engine that it should release |
| 474 | // the touch sequence to the embedded UIView. |
| 475 | class _UiKitViewGestureRecognizer extends OneSequenceGestureRecognizer { |
| 476 | _UiKitViewGestureRecognizer(this.controller, this.gestureRecognizerFactories) { |
| 477 | team = GestureArenaTeam()..captain = this; |
| 478 | _gestureRecognizers = gestureRecognizerFactories.map(( |
| 479 | Factory<OneSequenceGestureRecognizer> recognizerFactory, |
| 480 | ) { |
| 481 | final OneSequenceGestureRecognizer gestureRecognizer = recognizerFactory.constructor(); |
| 482 | gestureRecognizer.team = team; |
| 483 | // The below gesture recognizers requires at least one non-empty callback to |
| 484 | // compete in the gesture arena. |
| 485 | // https://github.com/flutter/flutter/issues/35394#issuecomment-562285087 |
| 486 | if (gestureRecognizer is LongPressGestureRecognizer) { |
| 487 | gestureRecognizer.onLongPress ??= () {}; |
| 488 | } else if (gestureRecognizer is DragGestureRecognizer) { |
| 489 | gestureRecognizer.onDown ??= (_) {}; |
| 490 | } else if (gestureRecognizer is TapGestureRecognizer) { |
| 491 | gestureRecognizer.onTapDown ??= (_) {}; |
| 492 | } |
| 493 | return gestureRecognizer; |
| 494 | }).toSet(); |
| 495 | } |
| 496 | |
| 497 | // We use OneSequenceGestureRecognizers as they support gesture arena teams. |
| 498 | // TODO(amirh): get a list of GestureRecognizers here. |
| 499 | // https://github.com/flutter/flutter/issues/20953 |
| 500 | final Set<Factory<OneSequenceGestureRecognizer>> gestureRecognizerFactories; |
| 501 | late Set<OneSequenceGestureRecognizer> _gestureRecognizers; |
| 502 | |
| 503 | final UiKitViewController controller; |
| 504 | |
| 505 | @override |
| 506 | void addAllowedPointer(PointerDownEvent event) { |
| 507 | super.addAllowedPointer(event); |
| 508 | for (final OneSequenceGestureRecognizer recognizer in _gestureRecognizers) { |
| 509 | recognizer.addPointer(event); |
| 510 | } |
| 511 | } |
| 512 | |
| 513 | @override |
| 514 | String get debugDescription => 'UIKit view' ; |
| 515 | |
| 516 | @override |
| 517 | void didStopTrackingLastPointer(int pointer) {} |
| 518 | |
| 519 | @override |
| 520 | void handleEvent(PointerEvent event) { |
| 521 | stopTrackingIfPointerNoLongerDown(event); |
| 522 | } |
| 523 | |
| 524 | @override |
| 525 | void acceptGesture(int pointer) { |
| 526 | controller.acceptGesture(); |
| 527 | } |
| 528 | |
| 529 | @override |
| 530 | void rejectGesture(int pointer) { |
| 531 | controller.rejectGesture(); |
| 532 | } |
| 533 | |
| 534 | void reset() { |
| 535 | resolve(GestureDisposition.rejected); |
| 536 | } |
| 537 | } |
| 538 | |
| 539 | typedef _HandlePointerEvent = Future<void> Function(PointerEvent event); |
| 540 | |
| 541 | // This recognizer constructs gesture recognizers from a set of gesture recognizer factories |
| 542 | // it was give, adds all of them to a gesture arena team with the _PlatformViewGestureRecognizer |
| 543 | // as the team captain. |
| 544 | // As long as the gesture arena is unresolved, the recognizer caches all pointer events. |
| 545 | // When the team wins, the recognizer sends all the cached pointer events to `_handlePointerEvent`, and |
| 546 | // sets itself to a "forwarding mode" where it will forward any new pointer event to `_handlePointerEvent`. |
| 547 | class _PlatformViewGestureRecognizer extends OneSequenceGestureRecognizer { |
| 548 | _PlatformViewGestureRecognizer( |
| 549 | _HandlePointerEvent handlePointerEvent, |
| 550 | this.gestureRecognizerFactories, |
| 551 | ) { |
| 552 | team = GestureArenaTeam()..captain = this; |
| 553 | _gestureRecognizers = gestureRecognizerFactories.map(( |
| 554 | Factory<OneSequenceGestureRecognizer> recognizerFactory, |
| 555 | ) { |
| 556 | final OneSequenceGestureRecognizer gestureRecognizer = recognizerFactory.constructor(); |
| 557 | gestureRecognizer.team = team; |
| 558 | // The below gesture recognizers requires at least one non-empty callback to |
| 559 | // compete in the gesture arena. |
| 560 | // https://github.com/flutter/flutter/issues/35394#issuecomment-562285087 |
| 561 | if (gestureRecognizer is LongPressGestureRecognizer) { |
| 562 | gestureRecognizer.onLongPress ??= () {}; |
| 563 | } else if (gestureRecognizer is DragGestureRecognizer) { |
| 564 | gestureRecognizer.onDown ??= (_) {}; |
| 565 | } else if (gestureRecognizer is TapGestureRecognizer) { |
| 566 | gestureRecognizer.onTapDown ??= (_) {}; |
| 567 | } |
| 568 | return gestureRecognizer; |
| 569 | }).toSet(); |
| 570 | _handlePointerEvent = handlePointerEvent; |
| 571 | } |
| 572 | |
| 573 | late _HandlePointerEvent _handlePointerEvent; |
| 574 | |
| 575 | // Maps a pointer to a list of its cached pointer events. |
| 576 | // Before the arena for a pointer is resolved all events are cached here, if we win the arena |
| 577 | // the cached events are dispatched to `_handlePointerEvent`, if we lose the arena we clear the cache for |
| 578 | // the pointer. |
| 579 | final Map<int, List<PointerEvent>> cachedEvents = <int, List<PointerEvent>>{}; |
| 580 | |
| 581 | // Pointer for which we have already won the arena, events for pointers in this set are |
| 582 | // immediately dispatched to `_handlePointerEvent`. |
| 583 | final Set<int> forwardedPointers = <int>{}; |
| 584 | |
| 585 | // We use OneSequenceGestureRecognizers as they support gesture arena teams. |
| 586 | // TODO(amirh): get a list of GestureRecognizers here. |
| 587 | // https://github.com/flutter/flutter/issues/20953 |
| 588 | final Set<Factory<OneSequenceGestureRecognizer>> gestureRecognizerFactories; |
| 589 | late Set<OneSequenceGestureRecognizer> _gestureRecognizers; |
| 590 | |
| 591 | @override |
| 592 | void addAllowedPointer(PointerDownEvent event) { |
| 593 | super.addAllowedPointer(event); |
| 594 | for (final OneSequenceGestureRecognizer recognizer in _gestureRecognizers) { |
| 595 | recognizer.addPointer(event); |
| 596 | } |
| 597 | } |
| 598 | |
| 599 | @override |
| 600 | String get debugDescription => 'Platform view' ; |
| 601 | |
| 602 | @override |
| 603 | void didStopTrackingLastPointer(int pointer) {} |
| 604 | |
| 605 | @override |
| 606 | void handleEvent(PointerEvent event) { |
| 607 | if (!forwardedPointers.contains(event.pointer)) { |
| 608 | _cacheEvent(event); |
| 609 | } else { |
| 610 | _handlePointerEvent(event); |
| 611 | } |
| 612 | stopTrackingIfPointerNoLongerDown(event); |
| 613 | } |
| 614 | |
| 615 | @override |
| 616 | void acceptGesture(int pointer) { |
| 617 | _flushPointerCache(pointer); |
| 618 | forwardedPointers.add(pointer); |
| 619 | } |
| 620 | |
| 621 | @override |
| 622 | void rejectGesture(int pointer) { |
| 623 | stopTrackingPointer(pointer); |
| 624 | cachedEvents.remove(pointer); |
| 625 | } |
| 626 | |
| 627 | void _cacheEvent(PointerEvent event) { |
| 628 | if (!cachedEvents.containsKey(event.pointer)) { |
| 629 | cachedEvents[event.pointer] = <PointerEvent>[]; |
| 630 | } |
| 631 | cachedEvents[event.pointer]!.add(event); |
| 632 | } |
| 633 | |
| 634 | void _flushPointerCache(int pointer) { |
| 635 | cachedEvents.remove(pointer)?.forEach(_handlePointerEvent); |
| 636 | } |
| 637 | |
| 638 | @override |
| 639 | void stopTrackingPointer(int pointer) { |
| 640 | super.stopTrackingPointer(pointer); |
| 641 | forwardedPointers.remove(pointer); |
| 642 | } |
| 643 | |
| 644 | void reset() { |
| 645 | forwardedPointers.forEach(super.stopTrackingPointer); |
| 646 | forwardedPointers.clear(); |
| 647 | cachedEvents.keys.forEach(super.stopTrackingPointer); |
| 648 | cachedEvents.clear(); |
| 649 | resolve(GestureDisposition.rejected); |
| 650 | } |
| 651 | } |
| 652 | |
| 653 | /// A render object for embedding a platform view. |
| 654 | /// |
| 655 | /// [PlatformViewRenderBox] presents a platform view by adding a [PlatformViewLayer] layer, |
| 656 | /// integrates it with the gesture arenas system and adds relevant semantic nodes to the semantics tree. |
| 657 | class PlatformViewRenderBox extends RenderBox with _PlatformViewGestureMixin { |
| 658 | /// Creating a render object for a [PlatformViewSurface]. |
| 659 | PlatformViewRenderBox({ |
| 660 | required PlatformViewController controller, |
| 661 | required PlatformViewHitTestBehavior hitTestBehavior, |
| 662 | required Set<Factory<OneSequenceGestureRecognizer>> gestureRecognizers, |
| 663 | }) : assert(controller.viewId > -1), |
| 664 | _controller = controller { |
| 665 | this.hitTestBehavior = hitTestBehavior; |
| 666 | updateGestureRecognizers(gestureRecognizers); |
| 667 | } |
| 668 | |
| 669 | /// The controller for this render object. |
| 670 | PlatformViewController get controller => _controller; |
| 671 | PlatformViewController _controller; |
| 672 | |
| 673 | /// Setting this value to a new value will result in a repaint. |
| 674 | set controller(covariant PlatformViewController controller) { |
| 675 | assert(controller.viewId > -1); |
| 676 | |
| 677 | if (_controller == controller) { |
| 678 | return; |
| 679 | } |
| 680 | final bool needsSemanticsUpdate = _controller.viewId != controller.viewId; |
| 681 | _controller = controller; |
| 682 | markNeedsPaint(); |
| 683 | if (needsSemanticsUpdate) { |
| 684 | markNeedsSemanticsUpdate(); |
| 685 | } |
| 686 | } |
| 687 | |
| 688 | /// {@template flutter.rendering.PlatformViewRenderBox.updateGestureRecognizers} |
| 689 | /// Updates which gestures should be forwarded to the platform view. |
| 690 | /// |
| 691 | /// Gesture recognizers created by factories in this set participate in the gesture arena for each |
| 692 | /// pointer that was put down on the render box. If any of the recognizers on this list wins the |
| 693 | /// gesture arena, the entire pointer event sequence starting from the pointer down event |
| 694 | /// will be dispatched to the Android view. |
| 695 | /// |
| 696 | /// The `gestureRecognizers` property must not contain more than one factory with the same [Factory.type]. |
| 697 | /// |
| 698 | /// Setting a new set of gesture recognizer factories with the same [Factory.type]s as the current |
| 699 | /// set has no effect, because the factories' constructors would have already been called with the previous set. |
| 700 | /// {@endtemplate} |
| 701 | /// |
| 702 | /// Any active gesture arena the `PlatformView` participates in is rejected when the |
| 703 | /// set of gesture recognizers is changed. |
| 704 | void updateGestureRecognizers(Set<Factory<OneSequenceGestureRecognizer>> gestureRecognizers) { |
| 705 | _updateGestureRecognizersWithCallBack(gestureRecognizers, _controller.dispatchPointerEvent); |
| 706 | } |
| 707 | |
| 708 | @override |
| 709 | bool get sizedByParent => true; |
| 710 | |
| 711 | @override |
| 712 | bool get alwaysNeedsCompositing => true; |
| 713 | |
| 714 | @override |
| 715 | bool get isRepaintBoundary => true; |
| 716 | |
| 717 | @override |
| 718 | @protected |
| 719 | Size computeDryLayout(covariant BoxConstraints constraints) { |
| 720 | return constraints.biggest; |
| 721 | } |
| 722 | |
| 723 | @override |
| 724 | void paint(PaintingContext context, Offset offset) { |
| 725 | context.addLayer(PlatformViewLayer(rect: offset & size, viewId: _controller.viewId)); |
| 726 | } |
| 727 | |
| 728 | @override |
| 729 | void describeSemanticsConfiguration(SemanticsConfiguration config) { |
| 730 | super.describeSemanticsConfiguration(config); |
| 731 | config.isSemanticBoundary = true; |
| 732 | config.platformViewId = _controller.viewId; |
| 733 | } |
| 734 | } |
| 735 | |
| 736 | /// The Mixin handling the pointer events and gestures of a platform view render box. |
| 737 | mixin _PlatformViewGestureMixin on RenderBox implements MouseTrackerAnnotation { |
| 738 | /// How to behave during hit testing. |
| 739 | // Changing _hitTestBehavior might affect which objects are considered hovered over. |
| 740 | set hitTestBehavior(PlatformViewHitTestBehavior value) { |
| 741 | if (value != _hitTestBehavior) { |
| 742 | _hitTestBehavior = value; |
| 743 | if (owner != null) { |
| 744 | markNeedsPaint(); |
| 745 | } |
| 746 | } |
| 747 | } |
| 748 | |
| 749 | PlatformViewHitTestBehavior? _hitTestBehavior; |
| 750 | |
| 751 | _HandlePointerEvent? _handlePointerEvent; |
| 752 | |
| 753 | /// {@macro flutter.rendering.PlatformViewRenderBox.updateGestureRecognizers} |
| 754 | /// |
| 755 | /// Any active gesture arena the `PlatformView` participates in is rejected when the |
| 756 | /// set of gesture recognizers is changed. |
| 757 | void _updateGestureRecognizersWithCallBack( |
| 758 | Set<Factory<OneSequenceGestureRecognizer>> gestureRecognizers, |
| 759 | _HandlePointerEvent handlePointerEvent, |
| 760 | ) { |
| 761 | assert( |
| 762 | _factoriesTypeSet(gestureRecognizers).length == gestureRecognizers.length, |
| 763 | 'There were multiple gesture recognizer factories for the same type, there must only be a single ' |
| 764 | 'gesture recognizer factory for each gesture recognizer type.' , |
| 765 | ); |
| 766 | if (_factoryTypesSetEquals( |
| 767 | gestureRecognizers, |
| 768 | _gestureRecognizer?.gestureRecognizerFactories, |
| 769 | )) { |
| 770 | return; |
| 771 | } |
| 772 | _gestureRecognizer?.dispose(); |
| 773 | _gestureRecognizer = _PlatformViewGestureRecognizer(handlePointerEvent, gestureRecognizers); |
| 774 | _handlePointerEvent = handlePointerEvent; |
| 775 | } |
| 776 | |
| 777 | _PlatformViewGestureRecognizer? _gestureRecognizer; |
| 778 | |
| 779 | @override |
| 780 | bool hitTest(BoxHitTestResult result, {required Offset position}) { |
| 781 | if (_hitTestBehavior == PlatformViewHitTestBehavior.transparent || !size.contains(position)) { |
| 782 | return false; |
| 783 | } |
| 784 | result.add(BoxHitTestEntry(this, position)); |
| 785 | return _hitTestBehavior == PlatformViewHitTestBehavior.opaque; |
| 786 | } |
| 787 | |
| 788 | @override |
| 789 | bool hitTestSelf(Offset position) => _hitTestBehavior != PlatformViewHitTestBehavior.transparent; |
| 790 | |
| 791 | @override |
| 792 | PointerEnterEventListener? get onEnter => null; |
| 793 | |
| 794 | @override |
| 795 | PointerExitEventListener? get onExit => null; |
| 796 | |
| 797 | @override |
| 798 | MouseCursor get cursor => MouseCursor.uncontrolled; |
| 799 | |
| 800 | @override |
| 801 | bool get validForMouseTracker => true; |
| 802 | |
| 803 | @override |
| 804 | void handleEvent(PointerEvent event, HitTestEntry entry) { |
| 805 | if (event is PointerDownEvent) { |
| 806 | _gestureRecognizer!.addPointer(event); |
| 807 | } |
| 808 | if (event is PointerHoverEvent) { |
| 809 | _handlePointerEvent?.call(event); |
| 810 | } |
| 811 | } |
| 812 | |
| 813 | @override |
| 814 | void detach() { |
| 815 | _gestureRecognizer!.reset(); |
| 816 | super.detach(); |
| 817 | } |
| 818 | |
| 819 | @override |
| 820 | void dispose() { |
| 821 | _gestureRecognizer?.dispose(); |
| 822 | super.dispose(); |
| 823 | } |
| 824 | } |
| 825 | |