Remove PopupMenuController

Rather than using a controller, the PopupMenu now takes input via its
constructor. I'm not 100% happy with PopupMenuStatusChangedCallback, but we can
continue to iterate.

Also, fix the positioning of the menu to be correct.

R=jackson@google.com

Review URL: https://codereview.chromium.org/1234063003 .

sdk/example/stocks/lib/stock_home.dart

@@ -100,22 +100,25 @@ class StockHome extends AnimatedComponent {
     });
   }
 
-  PopupMenuController _menuController;
+  bool _menuShowing = false;
+  PopupMenuStatus _menuStatus = PopupMenuStatus.inactive;
 
   void _handleMenuShow() {
     setState(() {
-      _menuController = new PopupMenuController();
-      _menuController.open();
+      _menuShowing = true;
+      _menuStatus = PopupMenuStatus.active;
     });
   }
 
   void _handleMenuHide() {
     setState(() {
-      _menuController.close().then((_) {
-        setState(() {
-          _menuController = null;
-        });
-      });
+      _menuShowing = false;
+    });
+  }
+
+  void _handleMenuStatusChanged(PopupMenuStatus status) {
+    setState(() {
+      _menuStatus = status;
     });
   }
 
@@ -303,11 +306,12 @@ class StockHome extends AnimatedComponent {
   }
 
   void addMenuToOverlays(List<Widget> overlays) {
-    if (_menuController == null)
+    if (_menuStatus == PopupMenuStatus.inactive)
       return;
     overlays.add(new ModalOverlay(
       children: [new StockMenu(
-        controller: _menuController,
+        showing: _menuShowing,
+        onStatusChanged: _handleMenuStatusChanged,
         autorefresh: _autorefresh,
         onAutorefreshChanged: _handleAutorefreshChanged
       )],

sdk/example/stocks/lib/stock_menu.dart

@@ -2,21 +2,25 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:sky' as sky;
+
 import 'package:sky/widgets/checkbox.dart';
 import 'package:sky/widgets/popup_menu.dart';
 import 'package:sky/widgets/basic.dart';
-import 'package:sky/theme/view_configuration.dart';
 
-class StockMenu extends Component {
+export 'package:sky/widgets/popup_menu.dart' show PopupMenuStatus;
 
+class StockMenu extends Component {
   StockMenu({
     String key,
-    this.controller,
+    this.showing,
+    this.onStatusChanged,
     this.autorefresh: false,
     this.onAutorefreshChanged
   }) : super(key: key);
 
-  final PopupMenuController controller;
+  bool showing;
+  PopupMenuStatusChangedCallback onStatusChanged;
   final bool autorefresh;
   final ValueChanged onAutorefreshChanged;
 
@@ -28,16 +32,17 @@ class StockMenu extends Component {
 
     return new Positioned(
       child: new PopupMenu(
-        controller: controller,
         items: [
           new Text('Add stock'),
           new Text('Remove stock'),
           new Flex([new Flexible(child: new Text('Autorefresh')), checkbox]),
         ],
-        level: 4
+        level: 4,
+        showing: showing,
+        onStatusChanged: onStatusChanged
       ),
-      right: 0.0,
-      top: 0.0 + kStatusBarHeight
+      right: sky.view.paddingRight,
+      top: sky.view.paddingTop
     );
   }
 }

sdk/lib/widgets/popup_menu.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:async';
 import 'dart:math' as math;
 import 'dart:sky' as sky;
 
@@ -25,103 +24,98 @@ const double _kMenuMaxWidth = 5.0 * _kMenuWidthStep;
 const double _kMenuHorizontalPadding = 16.0;
 const double _kMenuVerticalPadding = 8.0;
 
-enum MenuState { closed, opening, open, closing }
-
-class PopupMenuController {
+enum PopupMenuStatus {
+  active,
+  inactive,
+}
 
-  PopupMenuController() {
-    position = new AnimatedType<double>(0.0, end: 1.0);
-    performance = new AnimationPerformance()
-      ..variable = position
-      ..addListener(_updateState);
-  }
+typedef void PopupMenuStatusChangedCallback(PopupMenuStatus status);
 
-  AnimatedType<double> position;
-  AnimationPerformance performance;
+class PopupMenu extends AnimatedComponent {
 
-  MenuState _state = MenuState.closed;
-  MenuState get state => _state;
+  PopupMenu({
+    String key,
+    this.showing,
+    this.onStatusChanged,
+    this.items,
+    this.level
+  }) : super(key: key);
 
-  bool get canReact => (_state == MenuState.opening) || (_state == MenuState.open);
+  bool showing;
+  PopupMenuStatusChangedCallback onStatusChanged;
+  List<PopupMenuItem> items;
+  int level;
 
-  void _updateState() {
-    if (position.value == 0.0) {
-      _state = MenuState.closed;
-      if (_closeCompleter != null)
-        _closeCompleter.complete();
-      return;
-    }
+  AnimatedType<double> _position;
+  AnimationPerformance _performance;
 
-    if (position.value == 1.0)
-      _state = MenuState.open;
+  void initState() {
+    _position = new AnimatedType<double>(0.0, end: 1.0);
+    _performance = new AnimationPerformance()
+      ..variable = _position
+      ..addListener(_checkForStateChanged);
+    watch(_performance);
+    _updateBoxPainter();
+    if (showing)
+      _open();
   }
 
-  Completer _closeCompleter;
-  Timer _closeTimer;
-
-  void open() {
-    if (_state != MenuState.closed)
-      return;
-    if (_closeTimer != null) {
-      _closeTimer.cancel();
-      _closeTimer = null;
+  void syncFields(PopupMenu source) {
+    if (showing != source.showing) {
+      showing = source.showing;
+      if (showing)
+        _open();
+      else
+        _close();
     }
-    _closeCompleter = null;
-    _state = MenuState.opening;
-    performance..duration = _kMenuOpenDuration
-               ..play();
-  }
-
-  Future close() {
-    if (_state == MenuState.closing || _state == MenuState.closed)
-      return _closeCompleter.future;
-
-    _state = MenuState.closing;
-    assert(_closeCompleter == null);
-    _closeCompleter = new Completer();
-    performance.duration = _kMenuCloseDuration;
-
-    assert(_closeTimer == null);
-    _closeTimer = new Timer(_kMenuCloseDelay, performance.reverse);
-
-    return _closeCompleter.future;
+    onStatusChanged = source.onStatusChanged;
+    if (level != source.level) {
+      level = source.level;
+      _updateBoxPainter();
+    }
+    items = source.items;
+    super.syncFields(source);
   }
-}
-
-class PopupMenu extends AnimatedComponent {
-
-  PopupMenu({ String key, this.controller, this.items, this.level })
-      : super(key: key);
 
-  PopupMenuController controller;
-  List<PopupMenuItem> items;
-  int level;
-
-  void initState() {
+  void _updateBoxPainter() {
     _painter = new BoxPainter(new BoxDecoration(
       backgroundColor: Grey[50],
       borderRadius: 2.0,
       boxShadow: shadows[level]));
-    watch(controller.performance);
   }
 
-  void syncFields(PopupMenu source) {
-    controller = source.controller;
-    items = source.items;
-    level = source.level;
-    super.syncFields(source);
+  PopupMenuStatus get _status => _position.value != 0.0 ? PopupMenuStatus.active : PopupMenuStatus.inactive;
+
+  PopupMenuStatus _lastStatus;
+  void _checkForStateChanged() {
+    PopupMenuStatus status = _status;
+    if (_lastStatus != null && status != _lastStatus && onStatusChanged != null)
+      onStatusChanged(status);
+    _lastStatus = status;
+  }
+
+  void _open() {
+    _performance
+      ..duration = _kMenuOpenDuration
+      ..play();
+  }
+
+  void _close() {
+    _performance
+      ..duration = _kMenuCloseDuration
+      ..reverse();
   }
 
   BoxPainter _painter;
 
   double _opacityFor(int i) {
-    assert(controller.position.value != null);
-    if (controller.position.value == null || controller.position.value == 1.0)
+    assert(_position.value != null);
+    if (_position.value == null || _position.value == 1.0)
       return 1.0;
     double unit = 1.0 / items.length;
     double duration = 1.5 * unit;
     double start = i * unit;
-    return math.max(0.0, math.min(1.0, (controller.position.value - start) / duration));
+    return math.max(0.0, math.min(1.0, (_position.value - start) / duration));
   }
 
   Widget build() {
@@ -132,13 +126,13 @@ class PopupMenu extends AnimatedComponent {
     }));
 
     return new Opacity(
-      opacity: math.min(1.0, controller.position.value * 3.0),
+      opacity: math.min(1.0, _position.value * 3.0),
       child: new Container(
         margin: new EdgeDims.all(_kMenuMargin),
         child: new CustomPaint(
           callback: (sky.Canvas canvas, Size size) {
-            double width = math.min(size.width, size.width * (0.5 + controller.position.value * 2.0));
-            double height = math.min(size.height, size.height * controller.position.value * 1.5);
+            double width = math.min(size.width, size.width * (0.5 + _position.value * 2.0));
+            double height = math.min(size.height, size.height * _position.value * 1.5);
             _painter.paint(canvas, new Rect.fromLTRB(size.width - width, 0.0, width, height));
           },
           child: new ConstrainedBox(