Merge pull request #1819 from Hixie/new-enabled-approach

Use the presence of handler to determine 'enabled'

examples/stocks/lib/stock_home.dart

@@ -91,7 +91,6 @@ class StockHomeState extends State<StockHome> {
                 actions: <Widget>[
                   new FlatButton(
                     child: new Text('USE IT'),
-                    enabled: false,
                     onPressed: () {
                       config.navigator.pop(false);
                     }

examples/widgets/card_collection.dart

@@ -42,6 +42,7 @@ class CardCollectionState extends State<CardCollection> {
   bool _snapToCenter = false;
   bool _fixedSizeCards = false;
   bool _sunshine = false;
+  bool _varyFontSizes = false;
   InvalidatorCallback _invalidator;
   Size _cardCollectionSize = new Size(200.0, 200.0);
 
@@ -127,6 +128,7 @@ class CardCollectionState extends State<CardCollection> {
           buildDrawerCheckbox("Snap fling scrolls to center", _snapToCenter, _toggleSnapToCenter),
           buildDrawerCheckbox("Fixed size cards", _fixedSizeCards, _toggleFixedSizeCards),
           buildDrawerCheckbox("Let the sun shine", _sunshine, _toggleSunshine),
+          buildDrawerCheckbox("Vary font sizes", _varyFontSizes, _toggleVaryFontSizes, enabled: !_editable),
           new DrawerDivider(),
           buildDrawerColorRadioItem("Deep Purple", Colors.deepPurple, _primaryColor, _selectColor),
           buildDrawerColorRadioItem("Green", Colors.green, _primaryColor, _selectColor),
@@ -181,6 +183,12 @@ class CardCollectionState extends State<CardCollection> {
     });
   }
 
+  void _toggleVaryFontSizes() {
+    setState(() {
+      _varyFontSizes = !_varyFontSizes;
+    });
+  }
+
   void _selectColor(Map<int, Color> selection) {
     setState(() {
       _primaryColor = selection;
@@ -199,12 +207,15 @@ class CardCollectionState extends State<CardCollection> {
     });
   }
 
-  Widget buildDrawerCheckbox(String label, bool value, void callback()) {
+  Widget buildDrawerCheckbox(String label, bool value, void callback(), { bool enabled: true }) {
     return new DrawerItem(
-      onPressed: callback,
+      onPressed: enabled ? callback : null,
       child: new Row(<Widget>[
         new Flexible(child: new Text(label)),
-        new Checkbox(value: value, onChanged: (_) { callback(); })
+        new Checkbox(
+          value: value,
+          onChanged: enabled ? (_) { callback(); } : null
+        )
       ])
     );
   }
@@ -218,8 +229,7 @@ class CardCollectionState extends State<CardCollection> {
         new Radio<Map<int, Color>>(
           value: itemValue,
           groupValue: currentValue,
-          enabled: enabled,
-          onChanged: onChanged
+          onChanged: enabled ? onChanged : null
         )
       ])
     );
@@ -234,8 +244,7 @@ class CardCollectionState extends State<CardCollection> {
         new Radio<DismissDirection>(
           value: itemValue,
           groupValue: currentValue,
-          enabled: enabled,
-          onChanged: onChanged
+          onChanged: enabled ? onChanged : null
         )
       ])
     );
@@ -250,8 +259,7 @@ class CardCollectionState extends State<CardCollection> {
         new Radio<TextStyle>(
           value: itemValue,
           groupValue: currentValue,
-          enabled: enabled,
-          onChanged: onChanged
+          onChanged: enabled ? onChanged : null
         )
       ])
     );
@@ -292,7 +300,9 @@ class CardCollectionState extends State<CardCollection> {
               )
             )
           : new DefaultTextStyle(
-              style: DefaultTextStyle.of(context).merge(cardLabelStyle).merge(_textStyle),
+              style: DefaultTextStyle.of(context).merge(cardLabelStyle).merge(_textStyle).copyWith(
+                fontSize: _varyFontSizes ? 5.0 + _cardModels.length.toDouble() : null
+              ),
               child: new Column(<Widget>[
                   new Text(cardModel.label)
                 ],

examples/widgets/container.dart

@@ -26,9 +26,7 @@ class ContainerApp extends StatelessComponent {
               onPressed: () => print("Hello World")
             ),
             new RaisedButton(
-              child: new Text('DISABLED'),
-              onPressed: () => print("Hello World"),
-              enabled: false
+              child: new Text('DISABLED')
             )
           ])
         ),

examples/widgets/sector.dart

@@ -73,7 +73,6 @@ class SectorAppState extends State<SectorApp> {
           padding: new EdgeDims.symmetric(horizontal: 8.0, vertical: 25.0),
           child: new Row(<Widget>[
               new RaisedButton(
-                enabled: _enabledAdd,
                 child: new IntrinsicWidth(
                   child: new Row(<Widget>[
                     new Container(
@@ -84,10 +83,9 @@ class SectorAppState extends State<SectorApp> {
                     new Text('ADD SECTOR'),
                   ])
                 ),
-                onPressed: addSector
+                onPressed: _enabledAdd ? addSector : null
               ),
               new RaisedButton(
-                enabled: _enabledRemove,
                 child: new IntrinsicWidth(
                   child: new Row(<Widget>[
                     new Container(
@@ -98,7 +96,7 @@ class SectorAppState extends State<SectorApp> {
                     new Text('REMOVE SECTOR'),
                   ])
                 ),
-                onPressed: removeSector
+                onPressed: _enabledRemove ? removeSector : null
               )
             ],
             justifyContent: FlexJustifyContent.spaceAround

packages/flutter/lib/src/material/checkbox.dart

@@ -7,11 +7,10 @@ import 'dart:ui' as ui;
 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
+import 'colors.dart';
 import 'theme.dart';
 
 const double _kMidpoint = 0.5;
-const Color _kLightUncheckedColor = const Color(0x8A000000);
-const Color _kDarkUncheckedColor = const Color(0xB2FFFFFF);
 const double _kEdgeSize = 18.0;
 const double _kEdgeRadius = 1.0;
 const double _kStrokeWidth = 2.0;
@@ -30,21 +29,37 @@ class Checkbox extends StatelessComponent {
   ///
   /// * `value` determines whether the checkbox is checked.
   /// * `onChanged` is called whenever the state of the checkbox should change.
-  const Checkbox({Key key, this.value, this.onChanged}) : super(key: key);
+  const Checkbox({
+    Key key,
+    this.value,
+    this.onChanged
+  }) : super(key: key);
 
   final bool value;
   final ValueChanged<bool> onChanged;
 
+  bool get enabled => onChanged != null;
+
   Widget build(BuildContext context) {
     ThemeData themeData = Theme.of(context);
-    Color uncheckedColor = themeData.brightness == ThemeBrightness.light
-        ? _kLightUncheckedColor
-        : _kDarkUncheckedColor;
+    if (enabled) {
+      Color uncheckedColor = themeData.brightness == ThemeBrightness.light
+          ? Colors.black54
+          : Colors.white70;
+      return new _CheckboxWrapper(
+        value: value,
+        onChanged: onChanged,
+        uncheckedColor: uncheckedColor,
+        accentColor: themeData.accentColor
+      );
+    }
+    Color disabledColor = themeData.brightness == ThemeBrightness.light
+        ? Colors.black26
+        : Colors.white30;
     return new _CheckboxWrapper(
       value: value,
-      onChanged: onChanged,
-      uncheckedColor: uncheckedColor,
-      accentColor: themeData.accentColor
+      uncheckedColor: disabledColor,
+      accentColor: disabledColor
     );
   }
 }

packages/flutter/lib/src/material/flat_button.dart

@@ -12,11 +12,9 @@ class FlatButton extends MaterialButton {
   FlatButton({
     Key key,
     Widget child,
-    bool enabled: true,
     GestureTapCallback onPressed
   }) : super(key: key,
              child: child,
-             enabled: enabled,
              onPressed: onPressed);
 
   _FlatButtonState createState() => new _FlatButtonState();

packages/flutter/lib/src/material/material_button.dart

@@ -36,18 +36,16 @@ abstract class MaterialButton extends StatefulComponent {
   MaterialButton({
     Key key,
     this.child,
-    this.enabled: true,
     this.textColor,
     this.onPressed
-  }) : super(key: key) {
-    assert(enabled != null);
-  }
+  }) : super(key: key);
 
   final Widget child;
-  final bool enabled;
   final ButtonColor textColor;
   final GestureTapCallback onPressed;
 
+  bool get enabled => onPressed != null;
+
   void debugFillDescription(List<String> description) {
     super.debugFillDescription(description);
     if (!enabled)

packages/flutter/lib/src/material/radio.dart

@@ -12,19 +12,17 @@ import 'theme.dart';
 class Radio<T> extends StatelessComponent {
   Radio({
     Key key,
-    this.enabled,
     this.value,
     this.groupValue,
     this.onChanged
-  }) : super(key: key) {
-    assert(onChanged != null);
-  }
+  }) : super(key: key);
 
-  final bool enabled;
   final T value;
   final T groupValue;
   final ValueChanged<T> onChanged;
 
+  bool get enabled => onChanged != null;
+
   Color _getColor(BuildContext context) {
     ThemeData themeData = Theme.of(context);
     if (!enabled)

packages/flutter/lib/src/material/raised_button.dart

@@ -12,14 +12,10 @@ class RaisedButton extends MaterialButton {
   RaisedButton({
     Key key,
     Widget child,
-    bool enabled: true,
     GestureTapCallback onPressed
   }) : super(key: key,
              child: child,
-             enabled: enabled,
-             onPressed: onPressed) {
-    assert(enabled != null);
-  }
+             onPressed: onPressed);
 
   _RaisedButtonState createState() => new _RaisedButtonState();
 }

packages/flutter/lib/src/rendering/toggleable.dart

@@ -19,10 +19,12 @@ const Duration _kToggleDuration = const Duration(milliseconds: 200);
 // ValueChanged on a tap gesture and driving a changed animation. Subclasses are
 // responsible for painting.
 abstract class RenderToggleable extends RenderConstrainedBox {
-  RenderToggleable({bool value, Size size, ValueChanged<bool> onChanged})
-      : _value = value,
-        _onChanged = onChanged,
-        super(additionalConstraints: new BoxConstraints.tight(size)) {
+  RenderToggleable({
+    bool value,
+    Size size,
+    this.onChanged
+  }) : _value = value,
+       super(additionalConstraints: new BoxConstraints.tight(size)) {
     _performance = new ValuePerformance<double>(
       variable: new AnimatedValue<double>(0.0, end: 1.0, curve: Curves.easeIn, reverseCurve: Curves.easeOut),
       duration: _kToggleDuration,
@@ -30,16 +32,22 @@ abstract class RenderToggleable extends RenderConstrainedBox {
     )..addListener(markNeedsPaint);
   }
 
+  bool get value => _value;
+  bool _value;
+  void set value(bool value) {
+    if (value == _value)
+      return;
+    _value = value;
+    performance.play(value ? AnimationDirection.forward : AnimationDirection.reverse);
+  }
+
+  ValueChanged<bool> onChanged;
+
   ValuePerformance<double> get performance => _performance;
   ValuePerformance<double> _performance;
 
   double get position => _performance.value;
 
-  void handleEvent(InputEvent event, BoxHitTestEntry entry) {
-    if (event.type == 'pointerdown')
-      _tap.addPointer(event);
-  }
-
   TapGestureRecognizer _tap;
 
   void attach() {
@@ -56,23 +64,13 @@ abstract class RenderToggleable extends RenderConstrainedBox {
     super.detach();
   }
 
-  void _handleTap() {
-    if (_onChanged != null)
-      _onChanged(!_value);
-  }
-
-  bool get value => _value;
-  bool _value;
-  void set value(bool value) {
-    if (value == _value)
-      return;
-    _value = value;
-    performance.play(value ? AnimationDirection.forward : AnimationDirection.reverse);
+  void handleEvent(InputEvent event, BoxHitTestEntry entry) {
+    if (event.type == 'pointerdown' && onChanged != null)
+      _tap.addPointer(event);
   }
 
-  ValueChanged<bool> get onChanged => _onChanged;
-  ValueChanged<bool> _onChanged;
-  void set onChanged(ValueChanged<bool> onChanged) {
-    _onChanged = onChanged;
+  void _handleTap() {
+    if (onChanged != null)
+      onChanged(!_value);
   }
 }