Adding edge avoidance, painting tests, general cleanup (#15078)

Fixed the real repaint problem the Slider had (missing addListener), and added tests for it.

Added GlobalKey reparenting test.

Added the ability for the value indicator to slide left and right to avoid falling off the edge of the screen.
It only shifts as much as it can without deforming, but even at large text scales, that is enough to keep the text on the screen.

Updated the formatting on theme_data.dart and others to use longer line length.

Also, removed a color tween that faded the value indicator in as it scaled, since that wasn't to spec.

packages/flutter/lib/src/widgets/icon_theme_data.dart

@@ -34,7 +34,10 @@ class IconThemeData extends Diagnosticable {
   /// the new values.
   IconThemeData copyWith({Color color, double opacity, double size}) {
     return new IconThemeData(
-        color: color ?? this.color, opacity: opacity ?? this.opacity, size: size ?? this.size);
+      color: color ?? this.color,
+      opacity: opacity ?? this.opacity,
+      size: size ?? this.size,
+    );
   }
 
   /// Returns a new icon theme that matches this icon theme but with some values
@@ -43,7 +46,11 @@ class IconThemeData extends Diagnosticable {
   IconThemeData merge(IconThemeData other) {
     if (other == null)
       return this;
-    return copyWith(color: other.color, opacity: other.opacity, size: other.size);
+    return copyWith(
+      color: other.color,
+      opacity: other.opacity,
+      size: other.size,
+    );
   }
 
   /// Whether all the properties of this object are non-null.
@@ -97,11 +104,8 @@ class IconThemeData extends Diagnosticable {
   @override
   void debugFillProperties(DiagnosticPropertiesBuilder description) {
     super.debugFillProperties(description);
-    if (color == null && _opacity == null && size == null) {
-      return;
-    }
-    description.add(new DiagnosticsProperty<Color>('color', color));
-    description.add(new DoubleProperty('opacity', _opacity));
-    description.add(new DoubleProperty('size', size));
+    description.add(new DiagnosticsProperty<Color>('color', color, defaultValue: null));
+    description.add(new DoubleProperty('opacity', opacity, defaultValue: null));
+    description.add(new DoubleProperty('size', size, defaultValue: null));
   }
 }

packages/flutter/test/material/slider_theme_test.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:ui' show window;
+
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -31,14 +33,17 @@ void main() {
     Widget buildSlider(SliderThemeData data) {
       return new Directionality(
         textDirection: TextDirection.ltr,
-        child: new Material(
-          child: new Center(
-            child: new Theme(
-              data: theme,
-              child: const Slider(
-                value: 0.5,
-                label: '0.5',
-                onChanged: null,
+        child: new MediaQuery(
+          data: new MediaQueryData.fromWindow(window),
+          child: new Material(
+            child: new Center(
+              child: new Theme(
+                data: theme,
+                child: const Slider(
+                  value: 0.5,
+                  label: '0.5',
+                  onChanged: null,
+                ),
               ),
             ),
           ),
@@ -50,15 +55,10 @@ void main() {
 
     final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));
 
-    expect(
-        sliderBox,
-        paints
-          ..rect(color: sliderTheme.disabledActiveRailColor)
-          ..rect(color: sliderTheme.disabledInactiveRailColor));
+    expect(sliderBox, paints..rect(color: sliderTheme.disabledActiveRailColor)..rect(color: sliderTheme.disabledInactiveRailColor));
   });
 
-  testWidgets('Slider overrides ThemeData theme if SliderTheme present',
-      (WidgetTester tester) async {
+  testWidgets('Slider overrides ThemeData theme if SliderTheme present', (WidgetTester tester) async {
     final ThemeData theme = new ThemeData(
       platform: TargetPlatform.android,
       primarySwatch: Colors.red,
@@ -72,16 +72,19 @@ void main() {
     Widget buildSlider(SliderThemeData data) {
       return new Directionality(
         textDirection: TextDirection.ltr,
-        child: new Material(
-          child: new Center(
-            child: new Theme(
-              data: theme,
-              child: new SliderTheme(
-                data: customTheme,
-                child: const Slider(
-                  value: 0.5,
-                  label: '0.5',
-                  onChanged: null,
+        child: new MediaQuery(
+          data: new MediaQueryData.fromWindow(window),
+          child: new Material(
+            child: new Center(
+              child: new Theme(
+                data: theme,
+                child: new SliderTheme(
+                  data: customTheme,
+                  child: const Slider(
+                    value: 0.5,
+                    label: '0.5',
+                    onChanged: null,
+                  ),
                 ),
               ),
             ),
@@ -94,20 +97,15 @@ void main() {
 
     final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));
 
-    expect(
-        sliderBox,
-        paints
-          ..rect(color: customTheme.disabledActiveRailColor)
-          ..rect(color: customTheme.disabledInactiveRailColor));
+    expect(sliderBox, paints..rect(color: customTheme.disabledActiveRailColor)..rect(color: customTheme.disabledInactiveRailColor));
   });
 
-  testWidgets('SliderThemeData generates correct opacities for materialDefaults',
-      (WidgetTester tester) async {
+  testWidgets('SliderThemeData generates correct opacities for materialDefaults', (WidgetTester tester) async {
     const Color customColor1 = const Color(0xcafefeed);
     const Color customColor2 = const Color(0xdeadbeef);
     const Color customColor3 = const Color(0xdecaface);
 
-    final SliderThemeData sliderTheme = new SliderThemeData.materialDefaults(
+    final SliderThemeData sliderTheme = new SliderThemeData.fromPrimaryColors(
       primaryColor: customColor1,
       primaryColorDark: customColor2,
       primaryColorLight: customColor3,
@@ -126,18 +124,17 @@ void main() {
     expect(sliderTheme.overlayColor, equals(customColor1.withAlpha(0x29)));
     expect(sliderTheme.valueIndicatorColor, equals(customColor1.withAlpha(0xff)));
     expect(sliderTheme.thumbShape, equals(const isInstanceOf<RoundSliderThumbShape>()));
-    expect(sliderTheme.valueIndicatorShape,
-        equals(const isInstanceOf<PaddleSliderValueIndicatorShape>()));
+    expect(sliderTheme.valueIndicatorShape, equals(const isInstanceOf<PaddleSliderValueIndicatorShape>()));
     expect(sliderTheme.showValueIndicator, equals(ShowValueIndicator.onlyForDiscrete));
   });
 
   testWidgets('SliderThemeData lerps correctly', (WidgetTester tester) async {
-    final SliderThemeData sliderThemeBlack = new SliderThemeData.materialDefaults(
+    final SliderThemeData sliderThemeBlack = new SliderThemeData.fromPrimaryColors(
       primaryColor: Colors.black,
       primaryColorDark: Colors.black,
       primaryColorLight: Colors.black,
     );
-    final SliderThemeData sliderThemeWhite = new SliderThemeData.materialDefaults(
+    final SliderThemeData sliderThemeWhite = new SliderThemeData.fromPrimaryColors(
       primaryColor: Colors.white,
       primaryColorDark: Colors.white,
       primaryColorLight: Colors.white,
@@ -172,15 +169,18 @@ void main() {
       final ValueChanged<double> onChanged = enabled ? (double d) => value = d : null;
       return new Directionality(
         textDirection: TextDirection.ltr,
-        child: new Material(
-          child: new Center(
-            child: new SliderTheme(
-              data: sliderTheme,
-              child: new Slider(
-                value: value,
-                label: '$value',
-                divisions: divisions,
-                onChanged: onChanged,
+        child: new MediaQuery(
+          data: new MediaQueryData.fromWindow(window),
+          child: new Material(
+            child: new Center(
+              child: new SliderTheme(
+                data: sliderTheme,
+                child: new Slider(
+                  value: value,
+                  label: '$value',
+                  divisions: divisions,
+                  onChanged: onChanged,
+                ),
               ),
             ),
           ),
@@ -225,21 +225,27 @@ void main() {
       platform: TargetPlatform.android,
       primarySwatch: Colors.blue,
     );
-    final SliderThemeData sliderTheme = theme.sliderTheme
-        .copyWith(thumbColor: Colors.red.shade500, showValueIndicator: ShowValueIndicator.always);
-    Widget buildApp(String value) {
+    final SliderThemeData sliderTheme = theme.sliderTheme.copyWith(thumbColor: Colors.red.shade500, showValueIndicator: ShowValueIndicator.always);
+    Widget buildApp(String value, {double sliderValue = 0.5}) {
       return new Directionality(
         textDirection: TextDirection.ltr,
-        child: new Material(
-          child: new Center(
-            child: new SliderTheme(
-              data: sliderTheme,
-              child: new Slider(
-                value: 0.5,
-                label: '$value',
-                divisions: 3,
-                onChanged: (double d) {},
-              ),
+        child: new MediaQuery(
+          data: new MediaQueryData.fromWindow(window),
+          child: new Material(
+            child: new Row(
+              children: <Widget>[
+                new Expanded(
+                  child: new SliderTheme(
+                    data: sliderTheme,
+                    child: new Slider(
+                      value: sliderValue,
+                      label: '$value',
+                      divisions: 3,
+                      onChanged: (double d) {},
+                    ),
+                  ),
+                ),
+              ],
             ),
           ),
         ),
@@ -290,5 +296,47 @@ void main() {
             excludes: <Offset>[const Offset(36.1, -40.0), const Offset(-36.1, -40.0)],
           ));
     await gesture.up();
+
+    // Test that it avoids the left edge of the screen.
+    await tester.pumpWidget(buildApp('1000000', sliderValue: 0.0));
+    center = tester.getCenter(find.byType(Slider));
+    gesture = await tester.startGesture(center);
+    await tester.pump();
+    // Wait for value indicator animation to finish.
+    await tester.pump(const Duration(milliseconds: 500));
+    expect(
+        sliderBox,
+        paints
+          ..path(
+            color: sliderTheme.valueIndicatorColor,
+            includes: <Offset>[
+              const Offset(0.0, -40.0),
+              const Offset(98.0, -40.0),
+              const Offset(-16.0, -40.0),
+            ],
+            excludes: <Offset>[const Offset(98.1, -40.0), const Offset(-16.1, -40.0)],
+          ));
+    await gesture.up();
+
+    // Test that it avoids the right edge of the screen.
+    await tester.pumpWidget(buildApp('1000000', sliderValue: 1.0));
+    center = tester.getCenter(find.byType(Slider));
+    gesture = await tester.startGesture(center);
+    await tester.pump();
+    // Wait for value indicator animation to finish.
+    await tester.pump(const Duration(milliseconds: 500));
+    expect(
+        sliderBox,
+        paints
+          ..path(
+            color: sliderTheme.valueIndicatorColor,
+            includes: <Offset>[
+              const Offset(0.0, -40.0),
+              const Offset(16.0, -40.0),
+              const Offset(-98.0, -40.0),
+            ],
+            excludes: <Offset>[const Offset(16.1, -40.0), const Offset(-98.1, -40.0)],
+          ));
+    await gesture.up();
   });
 }

packages/flutter/test/widgets/semantics_debugger_test.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:ui' show window;
+
 import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter/rendering.dart';
@@ -292,13 +294,16 @@ void main() {
         child: new SemanticsDebugger(
           child: new Directionality(
             textDirection: TextDirection.ltr,
-            child: new Material(
-              child: new Center(
-                child: new Slider(
-                  value: value,
-                  onChanged: (double newValue) {
-                    value = newValue;
-                  },
+            child: new MediaQuery(
+              data: new MediaQueryData.fromWindow(window),
+              child: new Material(
+                child: new Center(
+                  child: new Slider(
+                    value: value,
+                    onChanged: (double newValue) {
+                      value = newValue;
+                    },
+                  ),
                 ),
               ),
             ),