Add a basic InkWell implementation

sky/sdk/lib/framework/components2/ink_well.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import '../animation/animated_value.dart';
+import '../animation/curves.dart';
 import '../fn2.dart';
+import '../rendering/box.dart';
 import '../rendering/flex.dart';
+import '../rendering/object.dart';
+import '../theme/view_configuration.dart' as config;
+import 'dart:async';
 import 'dart:collection';
+import 'dart:math' as math;
 import 'dart:sky' as sky;
-// import 'ink_splash.dart';
-import 'scrollable.dart';
 
-class InkWell extends Component implements ScrollClient {
+const int _kSplashInitialOpacity = 0x80;
+const double _kSplashInitialSize = 0.0;
+const double _kSplashConfirmedDuration = 350.0;
+const double _kSplashUnconfirmedDuration = config.kDefaultLongPressTimeout;
+const double _kSplashInitialDelay = 0.0; // we could delay initially in case the user scrolls
+
+double _getSplashTargetSize(Size bounds, Point position) {
+  return 2.0 * math.max(math.max(position.x, bounds.width - position.x),
+                        math.max(position.y, bounds.height - position.y));
+}
+
+class InkSplash {
+  final int pointer;
+  final Point position;
+  final RenderInkWell well;
+
+  double _targetRadius;
+  AnimatedValue _radius;
+
+  InkSplash(this.pointer, this.position, this.well) {
+    _targetRadius = _getSplashTargetSize(well.size, position);
+    _radius = new AnimatedValue(_kSplashInitialSize, onChange: _handleRadiusChange);
+    _radius.animateTo(_targetRadius, _kSplashUnconfirmedDuration,
+                      curve: easeOut, initialDelay: _kSplashInitialDelay);
+  }
+
+  void confirm() {
+    double fractionRemaining = (_targetRadius - _radius.value) / _targetRadius;
+    double duration = fractionRemaining * _kSplashConfirmedDuration;
+    if (duration <= 0.0)
+      return;
+    _radius.animateTo(_targetRadius, duration, curve: easeOut);
+  }
+
+  void _handleRadiusChange() {
+    if (_radius.value == _targetRadius)
+      well._splashes.remove(this);
+    well.markNeedsPaint();
+  }
+
+  void paint(RenderObjectDisplayList canvas) {
+    int opacity = (_kSplashInitialOpacity * (1.0 - (_radius.value / _targetRadius))).floor();
+    sky.Paint paint = new sky.Paint()..color = new sky.Color(opacity << 24);
+    canvas.drawCircle(position.x, position.y, _radius.value, paint);
+  }
+}
+
+class RenderInkWell extends RenderProxyBox {
+  final List<InkSplash> _splashes = new List<InkSplash>();
+
+  RenderInkWell({ RenderBox child }) : super(child);
+
+  void handleEvent(sky.Event event) {
+    switch (event.type) {
+      case 'gesturetapdown':
+        // TODO(abarth): We should position the splash at the location of the tap.
+        _startSplash(event.primaryPointer, new Point(size.width / 2.0, size.height / 2.0));
+        break;
+      case 'gesturetap':
+        _confirmSplash(event.primaryPointer);
+        break;
+    }
+  }
+
+  void _startSplash(int pointer, Point position) {
+    _splashes.add(new InkSplash(pointer, position, this));
+    markNeedsPaint();
+  }
+
+  void _confirmSplash(int pointer) {
+    _splashes.where((splash) => splash.pointer == pointer)
+             .forEach((splash) { splash.confirm(); });
+    markNeedsPaint();
+  }
+
+  void paint(RenderObjectDisplayList canvas) {
+    if (!_splashes.isEmpty) {
+      canvas.save();
+      canvas.clipRect(new Rect.fromSize(size));
+      for (InkSplash splash in _splashes)
+        splash.paint(canvas);
+      canvas.restore();
+    }
+    super.paint(canvas);
+  }
+}
+
+class InkWellWrapper extends OneChildRenderObjectWrapper {
+  RenderInkWell root;
+
+  InkWellWrapper({ UINode child, Object key })
+    : super(child: child, key: key);
+
+  RenderInkWell createNode() => new RenderInkWell();
+}
+
+class InkWell extends Component {
+  List<UINode> children;
 
   InkWell({ Object key, this.children }) : super(key: key);
 
-  // static final Style _containmentStyleHack = new Style('''
-  //   align-items: center;
-  //   transform: translateX(0);''');
-
-  // LinkedHashSet<SplashController> _splashes;
-
-  List<UINode> children;
-
-  // InkWell({ Object key, this.inlineStyle, this.children })
-  //     : super(key: key) {
-  //   onDidUnmount(() {
-  //     _cancelSplashes(null);
-  //   });
-  // }
-
   UINode build() {
-    return new FlexContainer(
-      direction: FlexDirection.horizontal,
-      justifyContent: FlexJustifyContent.center,
-      children: children);
-    // List<UINode> childrenIncludingSplashes = [];
-
-    // if (_splashes != null) {
-    //   childrenIncludingSplashes.addAll(
-    //       _splashes.map((s) => new InkSplash(s.onStyleChanged)));
-    // }
-
-    // if (children != null)
-    //   childrenIncludingSplashes.addAll(children);
-
-    // return new EventListenerNode(
-    //   new FlexContainer(
-    //     direction: FlexDirection.horizontal,
-    //     style: _containmentStyleHack,
-    //     inlineStyle: inlineStyle,
-    //     children: childrenIncludingSplashes),
-    //   onGestureTapDown: _startSplash,
-    //   onGestureTap: _confirmSplash
-    // );
+    return new InkWellWrapper(
+      child: new FlexContainer(
+        direction: FlexDirection.horizontal,
+        justifyContent: FlexJustifyContent.center,
+        children: children
+      )
+    );
   }
-
-  // void _startSplash(sky.GestureEvent event) {
-  //   setState(() {
-  //     if (_splashes == null)
-  //       _splashes = new LinkedHashSet<SplashController>();
-  //     var splash;
-  //     var root = getRoot();
-  //     splash = new SplashController(root.rect, event.x, event.y,
-  //                                   pointer: event.primaryPointer,
-  //                                   onDone: () { _splashDone(splash); });
-  //     _splashes.add(splash);
-  //     UINode node = parent;
-  //     while (node != null) {
-  //       if (node is Scrollable)
-  //         node.registerScrollClient(this);
-  //       node = node.parent;
-  //     }
-  //   });
-  // }
-
-  bool ancestorScrolled(Scrollable ancestor) {
-  //   _abortSplashes();
-    return false;
-  }
-
-  // void handleRemoved() {
-  //   UINode node = parent;
-  //   while (node != null) {
-  //     if (node is Scrollable)
-  //       node.unregisterScrollClient(this);
-  //     node = node.parent;
-  //   }
-  //   super.handleRemoved();
-  // }
-
-  // void _confirmSplash(sky.GestureEvent event) {
-  //   if (_splashes == null)
-  //     return;
-  //   _splashes.where((splash) => splash.pointer == event.primaryPointer)
-  //            .forEach((splash) { splash.confirm(); });
-  // }
-
-  // void _abortSplashes() {
-  //   if (_splashes == null)
-  //     return;
-  //   setState(() {
-  //     _splashes.forEach((s) { s.abort(); });
-  //   });
-  // }
-
-  // void _cancelSplashes(sky.Event event) {
-  //   if (_splashes == null)
-  //     return;
-  //   setState(() {
-  //     var splashes = _splashes;
-  //     _splashes = null;
-  //     splashes.forEach((s) { s.cancel(); });
-  //   });
-  // }
-
-  // void _splashDone(SplashController splash) {
-  //   if (_splashes == null)
-  //     return;
-  //   setState(() {
-  //     _splashes.remove(splash);
-  //     if (_splashes.length == 0)
-  //       _splashes = null;
-  //   });
-  // }
-
 }