Merge pull request #436 from jamesr/event_disposition

Teach event system about disposition and make 'consumed' disposition …

packages/flutter/example/demo_launcher/lib/main.dart

@@ -18,7 +18,7 @@ AssetBundle _initBundle() {
 
 final AssetBundle _bundle = _initBundle();
 
-void launch(String relativeUrl, String bundle) {
+EventDisposition launch(String relativeUrl, String bundle) {
   // TODO(eseidel): This is a hack to keep non-skyx examples working for now:
   Uri productionBase = Uri.parse(
     'https://domokit.github.io/example/demo_launcher/lib/main.dart');
@@ -42,6 +42,7 @@ void launch(String relativeUrl, String bundle) {
   }
 
   activity.startActivity(intent);
+  return EventDisposition.processed;
 }
 
 class SkyDemo {

packages/flutter/example/fitness/lib/feed.dart

@@ -82,11 +82,12 @@ class FeedFragment extends StatefulComponent {
 
   bool _isShowingSnackBar = false;
 
-  void _handleFitnessModeChange(FitnessMode value) {
+  EventDisposition _handleFitnessModeChange(FitnessMode value) {
     setState(() {
       _fitnessMode = value;
       _drawerShowing = false;
     });
+    return EventDisposition.processed;
   }
 
   Drawer buildDrawer() {
@@ -137,9 +138,10 @@ class FeedFragment extends StatefulComponent {
     });
   }
 
-  void _handleShowSettings() {
+  EventDisposition _handleShowSettings() {
     navigator.pop();
     navigator.pushNamed('/settings');
+    return EventDisposition.processed;
   }
 
   // TODO(jackson): We should be localizing

packages/flutter/example/fitness/lib/meal.dart

@@ -56,9 +56,10 @@ class MealFragment extends StatefulComponent {
 
   String _description = "";
 
-  void _handleSave() {
+  EventDisposition _handleSave() {
     onCreated(new Meal(when: new DateTime.now(), description: _description));
     navigator.pop();
+    return EventDisposition.processed;
   }
 
   Widget buildToolBar() {

packages/flutter/example/fitness/lib/measurement.dart

@@ -60,7 +60,7 @@ class MeasurementFragment extends StatefulComponent {
   String _weight = "";
   String _errorMessage = null;
 
-  void _handleSave() {
+  EventDisposition _handleSave() {
     double parsedWeight;
     try {
       parsedWeight = double.parse(_weight);
@@ -68,10 +68,11 @@ class MeasurementFragment extends StatefulComponent {
       setState(() {
         _errorMessage = "Save failed";
       });
-      return;
+      return EventDisposition.processed;
     }
     onCreated(new Measurement(when: new DateTime.now(), weight: parsedWeight));
     navigator.pop();
+    return EventDisposition.processed;
   }
 
   Widget buildToolBar() {

packages/flutter/example/game/lib/sprite_box.dart

@@ -174,9 +174,9 @@ class SpriteBox extends RenderBox {
     }
   }
 
-  void handleEvent(Event event, _SpriteBoxHitTestEntry entry) {
+  EventDisposition handleEvent(Event event, _SpriteBoxHitTestEntry entry) {
     if (!attached)
-      return;
+      return EventDisposition.ignored;
 
     if (event is PointerEvent) {
 
@@ -225,6 +225,7 @@ class SpriteBox extends RenderBox {
         }
       }
     }
+    return EventDisposition.ignored;
   }
 
   bool hitTest(HitTestResult result, { Point position }) {

packages/flutter/example/mine_digger/lib/main.dart

@@ -208,10 +208,11 @@ class MineDiggerApp extends App {
     );
   }
 
-  void handleToolbarPointerDown(sky.PointerEvent event) {
+  EventDisposition handleToolbarPointerDown(sky.PointerEvent event) {
     setState(() {
       resetGame();
     });
+    return EventDisposition.processed;
   }
 
   // User action. The user uncovers the cell which can cause losing the game.

packages/flutter/example/rendering/flex.dart

@@ -37,11 +37,15 @@ class RenderSolidColor extends RenderDecoratedBox {
     size = constraints.constrain(desiredSize);
   }
 
-  void handleEvent(sky.Event event, BoxHitTestEntry entry) {
-    if (event.type == 'pointerdown')
+  EventDisposition handleEvent(sky.Event event, BoxHitTestEntry entry) {
+    if (event.type == 'pointerdown') {
       decoration = new BoxDecoration(backgroundColor: const sky.Color(0xFFFF0000));
-    else if (event.type == 'pointerup')
+      return EventDisposition.processed;
+    } else if (event.type == 'pointerup') {
       decoration = new BoxDecoration(backgroundColor: backgroundColor);
+      return EventDisposition.processed;
+    }
+    return super.handleEvent(event, entry);
   }
 }
 

packages/flutter/example/rendering/sector_layout.dart

@@ -517,11 +517,15 @@ class RenderSolidColor extends RenderDecoratedSector {
     deltaTheta = constraints.constrainDeltaTheta(desiredDeltaTheta);
   }
 
-  void handleEvent(sky.Event event, HitTestEntry entry) {
-    if (event.type == 'pointerdown')
+  EventDisposition handleEvent(sky.Event event, HitTestEntry entry) {
+    if (event.type == 'pointerdown') {
       decoration = new BoxDecoration(backgroundColor: const Color(0xFFFF0000));
-    else if (event.type == 'pointerup')
+      return EventDisposition.processed;
+    } else if (event.type == 'pointerup') {
       decoration = new BoxDecoration(backgroundColor: backgroundColor);
+      return EventDisposition.processed;
+    }
+    return EventDisposition.ignored;
   }
 }
 

packages/flutter/example/rendering/solid_color_box.dart

@@ -42,10 +42,14 @@ class RenderSolidColorBox extends RenderDecoratedBox {
     size = constraints.constrain(desiredSize);
   }
 
-  void handleEvent(sky.Event event, BoxHitTestEntry entry) {
-    if (event.type == 'pointerdown')
+  EventDisposition handleEvent(sky.Event event, BoxHitTestEntry entry) {
+    if (event.type == 'pointerdown') {
       decoration = new BoxDecoration(backgroundColor: const Color(0xFFFF0000));
-    else if (event.type == 'pointerup')
+      return EventDisposition.processed;
+    } else if (event.type == 'pointerup') {
       decoration = new BoxDecoration(backgroundColor: backgroundColor);
+      return EventDisposition.processed;
+    }
+    return EventDisposition.ignored;
   }
 }

packages/flutter/example/rendering/touch_demo.dart

@@ -43,7 +43,7 @@ class RenderTouchDemo extends RenderBox {
 
   RenderTouchDemo();
 
-  void handleEvent(sky.Event event, BoxHitTestEntry entry) {
+  EventDisposition handleEvent(sky.Event event, BoxHitTestEntry entry) {
     if (event is sky.PointerEvent) {
       switch (event.type) {
         case 'pointerdown':
@@ -60,8 +60,10 @@ class RenderTouchDemo extends RenderBox {
           dots[event.pointer].update(event);
           break;
       }
+      markNeedsPaint();
+      return EventDisposition.processed;
     }
-    markNeedsPaint();
+    return EventDisposition.processed;
   }
 
   void performLayout() {

packages/flutter/example/stocks/lib/stock_home.dart

@@ -103,12 +103,13 @@ class StockHome extends StatefulComponent {
     });
   }
 
-  void _handleStockModeChange(StockMode value) {
+  EventDisposition _handleStockModeChange(StockMode value) {
     setState(() {
       stockMode = value;
     });
     if (modeUpdater != null)
       modeUpdater(value);
+    return EventDisposition.processed;
   }
 
   Drawer buildDrawer() {
@@ -156,9 +157,10 @@ class StockHome extends StatefulComponent {
     );
   }
 
-  void _handleShowSettings() {
+  EventDisposition _handleShowSettings() {
     navigator.pop();
     navigator.pushNamed('/settings');
+    return EventDisposition.processed;
   }
 
   Widget buildToolBar() {

packages/flutter/example/stocks/lib/stock_settings.dart

@@ -39,7 +39,7 @@ class StockSettings extends StatefulComponent {
     sendUpdates();
   }
 
-  void _confirmOptimismChange() {
+  EventDisposition _confirmOptimismChange() {
     switch (optimism) {
       case StockMode.optimistic:
         _handleOptimismChanged(false);
@@ -70,6 +70,7 @@ class StockSettings extends StatefulComponent {
         }).then(_handleOptimismChanged);
         break;
     }
+    return EventDisposition.processed;
   }
 
   void sendUpdates() {

packages/flutter/example/widgets/piano.dart

@@ -26,17 +26,19 @@ class Key {
   final String soundUrl;
   MediaPlayerProxy player;
 
-  void down() {
+  EventDisposition down() {
     if (player == null)
-      return;
+      return EventDisposition.ignored;
     player.ptr.seekTo(0);
     player.ptr.start();
+    return EventDisposition.processed;
   }
 
-  void up() {
+  EventDisposition up() {
     if (player == null)
-      return;
+      return EventDisposition.ignored;
     player.ptr.pause();
+    return EventDisposition.processed;
   }
 }
 

packages/flutter/example/widgets/styled_text.dart

@@ -71,10 +71,11 @@ HAL: This mission is too important for me to allow you to jeopardize it.''';
     );
   }
 
-  void toggleToTextFunction(_) {
+  EventDisposition toggleToTextFunction(_) {
     setState(() {
       toText = (toText == toPlainText) ? toStyledText : toPlainText;
     });
+    return EventDisposition.processed;
   }
 
   Widget build() {

packages/flutter/lib/base/hit_test.dart

@@ -4,8 +4,14 @@
 
 import 'dart:sky' as sky;
 
+enum EventDisposition {
+  ignored,
+  processed,
+  consumed,
+}
+
 abstract class HitTestTarget {
-  void handleEvent(sky.Event event, HitTestEntry entry);
+  EventDisposition handleEvent(sky.Event event, HitTestEntry entry);
 }
 
 class HitTestEntry {

packages/flutter/lib/editing/input.dart

@@ -107,7 +107,7 @@ class Input extends StatefulComponent {
     );
   }
 
-  void focus(_) {
+  EventDisposition focus(_) {
     if (Focus.at(this)) {
       assert(_keyboardHandle.attached);
       _keyboardHandle.showByRequest();
@@ -115,6 +115,7 @@ class Input extends StatefulComponent {
       Focus.moveTo(this);
       // we'll get told to rebuild and we'll take care of the keyboard then
     }
+    return EventDisposition.processed;
   }
 
   void didUnmount() {

packages/flutter/lib/rendering/flex.dart

@@ -7,6 +7,8 @@ import 'dart:math' as math;
 import 'package:sky/rendering/box.dart';
 import 'package:sky/rendering/object.dart';
 
+export 'package:sky/rendering/object.dart' show EventDisposition;
+
 class FlexBoxParentData extends BoxParentData with ContainerParentDataMixin<RenderBox> {
   int flex;
 

packages/flutter/lib/rendering/object.dart

@@ -12,7 +12,7 @@ import 'package:sky/base/node.dart';
 import 'package:sky/base/scheduler.dart' as scheduler;
 
 export 'dart:sky' show Point, Offset, Size, Rect, Color, Paint, Path;
-export 'package:sky/base/hit_test.dart' show HitTestTarget, HitTestEntry, HitTestResult;
+export 'package:sky/base/hit_test.dart' show EventDisposition, HitTestTarget, HitTestEntry, HitTestResult;
 
 class ParentData {
   void detach() {
@@ -415,9 +415,10 @@ abstract class RenderObject extends AbstractNode implements HitTestTarget {
 
   // EVENTS
 
-  void handleEvent(sky.Event event, HitTestEntry entry) {
+  EventDisposition handleEvent(sky.Event event, HitTestEntry entry) {
     // override this if you have a client, to hand it to the client
     // override this if you want to do anything with the event
+    return EventDisposition.ignored;
   }
 
 

packages/flutter/lib/rendering/sky_binding.dart

@@ -109,7 +109,7 @@ class SkyBinding {
     return state;
   }
 
-  void _handlePointerEvent(sky.PointerEvent event) {
+  EventDisposition _handlePointerEvent(sky.PointerEvent event) {
     Point position = new Point(event.x, event.y);
 
     PointerState state = _getOrCreateStateForPointer(event, position);
@@ -123,13 +123,20 @@ class SkyBinding {
     event.dy = position.y - state.lastPosition.y;
     state.lastPosition = position;
 
-    dispatchEvent(event, state.result);
+    return dispatchEvent(event, state.result);
   }
 
-  void dispatchEvent(sky.Event event, HitTestResult result) {
+  EventDisposition dispatchEvent(sky.Event event, HitTestResult result) {
     assert(result != null);
-    for (HitTestEntry entry in result.path.reversed)
-      entry.target.handleEvent(event, entry);
+    EventDisposition disposition = EventDisposition.ignored;
+    for (HitTestEntry entry in result.path.reversed) {
+      EventDisposition entryDisposition = entry.target.handleEvent(event, entry);
+      if (entryDisposition == EventDisposition.consumed)
+        return EventDisposition.consumed;
+      else if (entryDisposition == EventDisposition.processed)
+        disposition = EventDisposition.processed;
+    }
+    return disposition;
   }
 
   String toString() => 'Render Tree:\n${_renderView}';

packages/flutter/lib/widgets/basic.dart

@@ -19,6 +19,7 @@ import 'package:sky/rendering/stack.dart';
 import 'package:sky/widgets/default_text_style.dart';
 import 'package:sky/widgets/widget.dart';
 
+export 'package:sky/base/hit_test.dart' show EventDisposition;
 export 'package:sky/rendering/box.dart' show BackgroundImage, BoxConstraints, BoxDecoration, Border, BorderSide, EdgeDims;
 export 'package:sky/rendering/flex.dart' show FlexDirection, FlexJustifyContent, FlexAlignItems;
 export 'package:sky/rendering/object.dart' show Point, Offset, Size, Rect, Color, Paint, Path;

packages/flutter/lib/widgets/button_base.dart

@@ -14,20 +14,23 @@ abstract class ButtonBase extends StatefulComponent {
     highlight = source.highlight;
   }
 
-  void _handlePointerDown(_) {
+  EventDisposition _handlePointerDown(_) {
     setState(() {
       highlight = true;
     });
+    return EventDisposition.processed;
   }
-  void _handlePointerUp(_) {
+  EventDisposition _handlePointerUp(_) {
     setState(() {
       highlight = false;
     });
+    return EventDisposition.processed;
   }
-  void _handlePointerCancel(_) {
+  EventDisposition _handlePointerCancel(_) {
     setState(() {
       highlight = false;
     });
+    return EventDisposition.processed;
   }
 
   Widget build() {

packages/flutter/lib/widgets/dismissable.dart

@@ -99,15 +99,16 @@ class Dismissable extends StatefulComponent {
       _maybeCallOnResized();
   }
 
-  void _handlePointerDown(sky.PointerEvent event) {
+  EventDisposition _handlePointerDown(sky.PointerEvent event) {
     _dragUnderway = true;
     _dragX = 0.0;
     _fadePerformance.progress = 0.0;
+    return EventDisposition.processed;
   }
 
-  void _handlePointerMove(sky.PointerEvent event) {
+  EventDisposition _handlePointerMove(sky.PointerEvent event) {
     if (!_isActive)
-      return;
+      return EventDisposition.ignored;
 
     double oldDragX = _dragX;
     _dragX += event.dx;
@@ -115,17 +116,19 @@ class Dismissable extends StatefulComponent {
       setState(() {}); // Rebuild to update the new drag endpoint.
     if (!_fadePerformance.isAnimating)
       _fadePerformance.progress = _dragX.abs() / (_size.width * _kDismissCardThreshold);
+    return EventDisposition.processed;
   }
 
-  void _handlePointerUpOrCancel(_) {
+  EventDisposition _handlePointerUpOrCancel(_) {
     if (!_isActive)
-      return;
+      return EventDisposition.ignored;
 
     _dragUnderway = false;
     if (_fadePerformance.isCompleted)
       _startResizePerformance();
     else if (!_fadePerformance.isAnimating)
       _fadePerformance.reverse();
+    return EventDisposition.processed;
   }
 
   bool _isHorizontalFlingGesture(sky.GestureEvent event) {
@@ -134,15 +137,16 @@ class Dismissable extends StatefulComponent {
     return vx - vy > _kMinFlingVelocityDelta && vx > _kMinFlingVelocity;
   }
 
-  void _handleFlingStart(sky.GestureEvent event) {
+  EventDisposition _handleFlingStart(sky.GestureEvent event) {
     if (!_isActive)
-      return;
+      return EventDisposition.ignored;
 
     if (_isHorizontalFlingGesture(event)) {
       _dragUnderway = false;
       _dragX = event.velocityX.sign;
       _fadePerformance.fling(Direction.forward, velocity: event.velocityX.abs() * _kFlingVelocityScale);
     }
+    return EventDisposition.processed;
   }
 
   void _handleSizeChanged(Size newSize) {

packages/flutter/lib/widgets/drawer.dart

@@ -139,33 +139,48 @@ class Drawer extends StatefulComponent {
 
   void _settle() { _isMostlyClosed ? _performance.reverse() : _performance.play(); }
 
-  void handleMaskTap(_) { _performance.reverse(); }
+  EventDisposition handleMaskTap(_) {
+    _performance.reverse();
+    return EventDisposition.consumed;
+  }
 
   // TODO(mpcomplete): Figure out how to generalize these handlers on a
   // "PannableThingy" interface.
-  void handlePointerDown(_) { _performance.stop(); }
+  EventDisposition handlePointerDown(_) {
+    _performance.stop();
+    return EventDisposition.processed;
+ }
 
-  void handlePointerMove(sky.PointerEvent event) {
+  EventDisposition handlePointerMove(sky.PointerEvent event) {
     if (_performance.isAnimating)
-      return;
+      return EventDisposition.ignored;
     _performance.progress += event.dx / _kWidth;
+    return EventDisposition.processed;
   }
 
-  void handlePointerUp(_) {
-    if (!_performance.isAnimating)
+  EventDisposition handlePointerUp(_) {
+    if (!_performance.isAnimating) {
       _settle();
+      return EventDisposition.processed;
+    }
+    return EventDisposition.ignored;
   }
 
-  void handlePointerCancel(_) {
-    if (!_performance.isAnimating)
+  EventDisposition handlePointerCancel(_) {
+    if (!_performance.isAnimating) {
       _settle();
+      return EventDisposition.processed;
+    }
+    return EventDisposition.ignored;
   }
 
-  void handleFlingStart(event) {
+  EventDisposition handleFlingStart(event) {
     if (event.velocityX.abs() >= _kMinFlingVelocity) {
       _performance.fling(
           event.velocityX < 0.0 ? Direction.reverse : Direction.forward,
           velocity: event.velocityX.abs() * _kFlingVelocityScale);
+      return EventDisposition.processed;
     }
+    return EventDisposition.ignored;
   }
 }

packages/flutter/lib/widgets/drawer_item.dart

@@ -14,13 +14,15 @@ import 'package:sky/widgets/ink_well.dart';
 import 'package:sky/widgets/theme.dart';
 import 'package:sky/widgets/widget.dart';
 
+typedef EventDisposition OnPressedFunction();
+
 class DrawerItem extends ButtonBase {
   DrawerItem({ Key key, this.icon, this.children, this.onPressed, this.selected: false })
     : super(key: key);
 
   String icon;
   List<Widget> children;
-  Function onPressed;
+  OnPressedFunction onPressed;
   bool selected;
 
   void syncFields(DrawerItem source) {
@@ -82,7 +84,8 @@ class DrawerItem extends ButtonBase {
     return new Listener(
       onGestureTap: (_) {
         if (onPressed != null)
-          onPressed();
+          return onPressed();
+        return EventDisposition.ignored;
       },
       child: new Container(
         height: 48.0,

packages/flutter/lib/widgets/ink_well.dart

@@ -84,17 +84,18 @@ class RenderInkWell extends RenderProxyBox {
 
   final List<InkSplash> _splashes = new List<InkSplash>();
 
-  void handleEvent(sky.Event event, BoxHitTestEntry entry) {
+  EventDisposition handleEvent(sky.Event event, BoxHitTestEntry entry) {
     if (event is sky.GestureEvent) {
       switch (event.type) {
         case 'gesturetapdown':
           _startSplash(event.primaryPointer, entry.localPosition);
-          break;
+          return EventDisposition.processed;
         case 'gesturetap':
           _confirmSplash(event.primaryPointer);
-          break;
+          return EventDisposition.processed;
       }
     }
+    return EventDisposition.ignored;
   }
 
   void _startSplash(int pointer, Point position) {

packages/flutter/lib/widgets/radio.dart

@@ -68,12 +68,13 @@ class Radio extends ButtonBase {
           }
         )
       ),
-      onGestureTap: _handleClick
+      onGestureTap: _handleTap
     );
   }
 
-  void _handleClick(_) {
+  EventDisposition _handleTap(_) {
     onChanged(value);
+    return EventDisposition.consumed;
   }
 
 }

packages/flutter/lib/widgets/scrollable.dart

@@ -181,20 +181,23 @@ abstract class Scrollable extends StatefulComponent {
     scrollTo(value);
   }
 
-  void _handlePointerDown(_) {
+  EventDisposition _handlePointerDown(_) {
     _stopToEndAnimation();
     _stopToOffsetAnimation();
+    return EventDisposition.processed;
   }
 
-  void _handleScrollUpdate(sky.GestureEvent event) {
+  EventDisposition _handleScrollUpdate(sky.GestureEvent event) {
     scrollBy(direction == ScrollDirection.horizontal ? event.dx : -event.dy);
+    return EventDisposition.processed;
   }
 
-  void _handleFlingStart(sky.GestureEvent event) {
+  EventDisposition _handleFlingStart(sky.GestureEvent event) {
     double eventVelocity = direction == ScrollDirection.horizontal
       ? -event.velocityX
       : -event.velocityY;
     _startToEndAnimation(velocity: _velocityForFlingGesture(eventVelocity));
+    return EventDisposition.processed;
   }
 
   void _maybeSettleScrollOffset() {
@@ -202,13 +205,20 @@ abstract class Scrollable extends StatefulComponent {
       settleScrollOffset();
   }
 
-  void _handlePointerUpOrCancel(_) { _maybeSettleScrollOffset(); }
+  EventDisposition _handlePointerUpOrCancel(_) {
+    _maybeSettleScrollOffset();
+    return EventDisposition.processed;
+  }
 
-  void _handleFlingCancel(sky.GestureEvent event) { _maybeSettleScrollOffset(); }
+  EventDisposition _handleFlingCancel(sky.GestureEvent event) {
+    _maybeSettleScrollOffset();
+    return EventDisposition.processed;
+  }
 
 
-  void _handleWheel(sky.WheelEvent event) {
+  EventDisposition _handleWheel(sky.WheelEvent event) {
     scrollBy(-event.offsetY);
+    return EventDisposition.processed;
   }
 }
 

packages/flutter/lib/widgets/switch.dart

@@ -80,9 +80,12 @@ class _RenderSwitch extends RenderConstrainedBox {
       ..addListener(markNeedsPaint);
   }
 
-  void handleEvent(sky.Event event, BoxHitTestEntry entry) {
-    if (event is sky.GestureEvent &&
-        event.type == 'gesturetap') _onChanged(!_value);
+  EventDisposition handleEvent(sky.Event event, BoxHitTestEntry entry) {
+    if (event is sky.GestureEvent && event.type == 'gesturetap') {
+      _onChanged(!_value);
+      return EventDisposition.consumed;
+    }
+    return EventDisposition.ignored;
   }
 
   bool _value;

packages/flutter/lib/widgets/tabs.dart

@@ -475,7 +475,7 @@ class TabBar extends Scrollable {
       .clamp(scrollBehavior.minScrollOffset, scrollBehavior.maxScrollOffset);
   }
 
-  void _handleTap(int tabIndex) {
+  EventDisposition _handleTap(int tabIndex) {
     if (tabIndex != selectedIndex) {
       if (_tabWidths != null) {
         if (isScrollable)
@@ -484,7 +484,9 @@ class TabBar extends Scrollable {
       }
       if (onChanged != null)
         onChanged(tabIndex);
+      return EventDisposition.processed;
     }
+    return EventDisposition.ignored;
   }
 
   Widget _toTab(TabLabel label, int tabIndex) {

packages/flutter/lib/widgets/toggleable.dart

@@ -57,8 +57,9 @@ abstract class Toggleable extends AnimatedComponent {
     super.syncFields(source);
   }
 
-  void _handleClick(sky.Event e) {
+  EventDisposition _handleClick(sky.Event e) {
     onChanged(!value);
+    return EventDisposition.consumed;
   }
 
   // Override these to draw yourself

packages/flutter/lib/widgets/widget.dart

@@ -13,6 +13,7 @@ import 'package:sky/rendering/box.dart';
 import 'package:sky/rendering/object.dart';
 import 'package:sky/rendering/sky_binding.dart';
 
+export 'package:sky/base/hit_test.dart' show EventDisposition;
 export 'package:sky/rendering/box.dart' show BoxConstraints, BoxDecoration, Border, BorderSide, EdgeDims;
 export 'package:sky/rendering/flex.dart' show FlexDirection;
 export 'package:sky/rendering/object.dart' show Point, Offset, Size, Rect, Color, Paint, Path;
@@ -446,9 +447,9 @@ abstract class Inherited extends TagNode {
 
 }
 
-typedef void GestureEventListener(sky.GestureEvent e);
-typedef void PointerEventListener(sky.PointerEvent e);
-typedef void EventListener(sky.Event e);
+typedef EventDisposition GestureEventListener(sky.GestureEvent e);
+typedef EventDisposition PointerEventListener(sky.PointerEvent e);
+typedef EventDisposition EventListener(sky.Event e);
 
 class Listener extends TagNode  {
 
@@ -529,11 +530,12 @@ class Listener extends TagNode  {
     return listeners;
   }
 
-  void _handleEvent(sky.Event e) {
+  EventDisposition _handleEvent(sky.Event e) {
     EventListener listener = listeners[e.type];
     if (listener != null) {
-      listener(e);
+      return listener(e);
     }
+    return EventDisposition.ignored;
   }
 
 }
@@ -1169,20 +1171,29 @@ class WidgetSkyBinding extends SkyBinding {
     assert(SkyBinding.instance is WidgetSkyBinding);
   }
 
-  void dispatchEvent(sky.Event event, HitTestResult result) {
+  EventDisposition dispatchEvent(sky.Event event, HitTestResult result) {
     assert(SkyBinding.instance == this);
-    super.dispatchEvent(event, result);
+    EventDisposition disposition = super.dispatchEvent(event, result);
+    if (disposition == EventDisposition.consumed)
+      return EventDisposition.consumed;
     for (HitTestEntry entry in result.path.reversed) {
       Widget target = RenderObjectWrapper._getMounted(entry.target);
       if (target == null)
         continue;
       RenderObject targetRoot = target.root;
       while (target != null && target.root == targetRoot) {
-        if (target is Listener)
-          target._handleEvent(event);
+        if (target is Listener) {
+          EventDisposition targetDisposition = target._handleEvent(event);
+          if (targetDisposition == EventDisposition.consumed) {
+            return targetDisposition;
+          } else if (targetDisposition == EventDisposition.processed) {
+            disposition = EventDisposition.processed;
+          }
+        }
         target = target._parent;
       }
     }
+    return disposition;
   }
 
   void beginFrame(double timeStamp) {