Fix #721 Dialogs should appear in place rather than animating in from bottom

packages/flutter/lib/widgets/dialog.dart

@@ -4,6 +4,8 @@
 
 import 'dart:async';
 
+import 'package:sky/animation/animated_value.dart';
+import 'package:sky/animation/curves.dart';
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/widgets/basic.dart';
 import 'package:sky/widgets/default_text_style.dart';
@@ -12,6 +14,7 @@ import 'package:sky/widgets/material.dart';
 import 'package:sky/widgets/navigator.dart';
 import 'package:sky/widgets/scrollable.dart';
 import 'package:sky/widgets/theme.dart';
+import 'package:sky/widgets/transitions.dart';
 
 typedef Widget DialogBuilder(Navigator navigator);
 
@@ -107,6 +110,47 @@ class Dialog extends Component {
   }
 }
 
+class DialogRoute extends RouteBase {
+  DialogRoute({ this.completer, this.builder });
+
+  final Completer completer;
+  final RouteBuilder builder;
+
+  Widget build(Navigator navigator, RouteBase route) => builder(navigator, route);
+  bool get isOpaque => false;
+
+  void popState([dynamic result]) {
+    completer.complete(result);
+  }
+
+  TransitionBase buildTransition({ Key key }) => new DialogTransition(key: key);
+}
+
+const Duration _kTransitionDuration = const Duration(milliseconds: 150);
+class DialogTransition extends TransitionBase {
+  DialogTransition({
+    Key key,
+    Widget child,
+    Direction direction,
+    Function onDismissed,
+    Function onCompleted
+  }): super(key: key,
+            child: child,
+            duration: _kTransitionDuration,
+            direction: direction,
+            onDismissed: onDismissed,
+            onCompleted: onCompleted);
+
+  Widget buildWithChild(Widget child) {
+    return new FadeTransition(
+      performance: performance,
+      direction: direction,
+      opacity: new AnimatedValue<double>(0.0, end: 1.0, curve: easeOut),
+      child: child
+    );
+  }
+}
+
 Future showDialog(Navigator navigator, DialogBuilder builder) {
   Completer completer = new Completer();
   navigator.push(new DialogRoute(

packages/flutter/lib/widgets/navigator.dart

@@ -2,8 +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 'package:sky/animation/animated_value.dart';
 import 'package:sky/animation/animation_performance.dart';
 import 'package:sky/animation/curves.dart';
@@ -17,6 +15,7 @@ abstract class RouteBase {
   Widget build(Navigator navigator, RouteBase route);
   bool get isOpaque;
   void popState([dynamic result]) { assert(result == null); }
+  TransitionBase buildTransition({ Key key });
 }
 
 class Route extends RouteBase {
@@ -27,20 +26,7 @@ class Route extends RouteBase {
 
   Widget build(Navigator navigator, RouteBase route) => builder(navigator, route);
   bool get isOpaque => true;
-}
-
-class DialogRoute extends RouteBase {
-  DialogRoute({ this.completer, this.builder });
-
-  final Completer completer;
-  final RouteBuilder builder;
-
-  Widget build(Navigator navigator, RouteBase route) => builder(navigator, route);
-  bool get isOpaque => false;
-
-  void popState([dynamic result]) {
-    completer.complete(result);
-  }
+  TransitionBase buildTransition({ Key key }) => new SlideUpFadeTransition(key: key);
 }
 
 class RouteState extends RouteBase {
@@ -58,32 +44,30 @@ class RouteState extends RouteBase {
     if (callback != null)
       callback(this);
   }
+
+  TransitionBase buildTransition({ Key key }) {
+    // Custom state routes shouldn't be asked to construct a transition
+    assert(false);
+    return null;
+  }
 }
 
 // TODO(jackson): Refactor this into its own file
-// and support multiple transition types
 const Duration _kTransitionDuration = const Duration(milliseconds: 150);
 const Point _kTransitionStartPoint = const Point(0.0, 75.0);
-class Transition extends TransitionBase {
-  Transition({
+class SlideUpFadeTransition extends TransitionBase {
+  SlideUpFadeTransition({
     Key key,
     Widget child,
     Direction direction,
     Function onDismissed,
-    Function onCompleted,
-    this.interactive
+    Function onCompleted
   }): super(key: key,
             child: child,
             duration: _kTransitionDuration,
             direction: direction,
             onDismissed: onDismissed,
             onCompleted: onCompleted);
-  bool interactive;
-
-  void syncFields(Transition source) {
-    interactive = source.interactive;
-    super.syncFields(source);
-  }
 
   Widget buildWithChild(Widget child) {
     // TODO(jackson): Hit testing should ignore transform
@@ -201,22 +185,19 @@ class Navigator extends StatefulComponent {
       }
       if (child == null)
         continue;
-      Transition transition = new Transition(
-        key: new Key.fromObjectIdentity(historyEntry),
-        child: child,
-        direction: (i <= state.historyIndex) ? Direction.forward : Direction.reverse,
-        interactive: (i == state.historyIndex),
-        onDismissed: () {
+      TransitionBase transition = historyEntry.route.buildTransition(key: new Key.fromObjectIdentity(historyEntry))
+        ..child = child
+        ..direction = (i <= state.historyIndex) ? Direction.forward : Direction.reverse
+        ..onDismissed = () {
           setState(() {
             state.history.remove(historyEntry);
           });
-        },
-        onCompleted: () {
+        }
+        ..onCompleted = () {
           setState(() {
             historyEntry.fullyOpaque = historyEntry.route.isOpaque;
           });
-        }
-      );
+        };
       visibleRoutes.add(transition);
     }
     return new Focus(child: new Stack(visibleRoutes));

packages/flutter/lib/widgets/transitions.dart

@@ -8,6 +8,8 @@ import 'package:sky/animation/animated_value.dart';
 import 'package:sky/widgets/basic.dart';
 import 'package:vector_math/vector_math.dart';
 
+export 'package:sky/animation/direction.dart' show Direction;
+
 dynamic _maybe(AnimatedValue x) => x != null ? x.value : null;
 
 // A helper class to anchor widgets to one another. Pass an instance of this to