From bde56f4b5c619f4af70ef1f23ef14a64feb73b00 Mon Sep 17 00:00:00 2001
From: Hixie <github.com@spam.hixie.ch>
Date: Thu, 23 Jul 2015 10:55:00 -0700
Subject: [PATCH] Track global keys globally. Assert that there are no
 duplicates. Export GlobalKey from basic.dart, so that people don't have to
 import widgets.dart just for that. Fix the "initialFocus" feature which
 actually didn't work.

---
 sky/sdk/lib/editing/input.dart  |  2 +-
 sky/sdk/lib/widgets/basic.dart  |  2 +-
 sky/sdk/lib/widgets/focus.dart  |  4 ++--
 sky/sdk/lib/widgets/widget.dart | 37 +++++++++++++++++++++++++++++++--
 4 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/sky/sdk/lib/editing/input.dart b/sky/sdk/lib/editing/input.dart
index 91eb5e316b72d..0f0e3e5217488 100644
--- a/sky/sdk/lib/editing/input.dart
+++ b/sky/sdk/lib/editing/input.dart
@@ -19,7 +19,7 @@ const EdgeDims _kTextfieldPadding = const EdgeDims.symmetric(vertical: 8.0);
 class Input extends StatefulComponent {
 
   Input({
-    Key key,
+    GlobalKey key,
     this.placeholder,
     this.onChanged
   }): super(key: key);
diff --git a/sky/sdk/lib/widgets/basic.dart b/sky/sdk/lib/widgets/basic.dart
index 5e7ba5dee04b7..f7df35c8f5aa8 100644
--- a/sky/sdk/lib/widgets/basic.dart
+++ b/sky/sdk/lib/widgets/basic.dart
@@ -22,7 +22,7 @@ import 'package:sky/widgets/widget.dart';
 export 'package:sky/rendering/box.dart' show BackgroundImage, BoxConstraints, BoxDecoration, Border, BorderSide, EdgeDims;
 export 'package:sky/rendering/flex.dart' show FlexDirection, FlexJustifyContent, FlexAlignItems;
 export 'package:sky/rendering/object.dart' show Point, Offset, Size, Rect, Color, Paint, Path;
-export 'package:sky/widgets/widget.dart' show Key, Widget, Component, StatefulComponent, App, runApp, Listener, ParentDataNode;
+export 'package:sky/widgets/widget.dart' show Key, GlobalKey, Widget, Component, StatefulComponent, App, runApp, Listener, ParentDataNode;
 
 
 // PAINTING NODES
diff --git a/sky/sdk/lib/widgets/focus.dart b/sky/sdk/lib/widgets/focus.dart
index 5abb6fd1b4377..c50d434d622fc 100644
--- a/sky/sdk/lib/widgets/focus.dart
+++ b/sky/sdk/lib/widgets/focus.dart
@@ -14,11 +14,11 @@ class Focus extends Inherited {
 
   Focus({
     GlobalKey key,
-    GlobalKey initialFocus,
+    this.initialFocus,
     Widget child
   }) : super(key: key, child: child);
 
-  GlobalKey initialFocus;
+  final GlobalKey initialFocus;
 
   GlobalKey _currentlyFocusedKey;
   GlobalKey get currentlyFocusedKey {
diff --git a/sky/sdk/lib/widgets/widget.dart b/sky/sdk/lib/widgets/widget.dart
index 83b04d002a4ac..a7de0ca712bd5 100644
--- a/sky/sdk/lib/widgets/widget.dart
+++ b/sky/sdk/lib/widgets/widget.dart
@@ -140,13 +140,46 @@ abstract class Widget {
       _notifyingMountStatus = false;
       sky.tracing.end("Widget._notifyMountStatusChanged");
     }
+    assert(_debugDuplicateGlobalKeys.isEmpty);
   }
 
+  static final Map<GlobalKey, Widget> _globalKeys = new Map<GlobalKey, Widget>();
+  static final Map<GlobalKey, int> _debugDuplicateGlobalKeys = new Map<GlobalKey, int>();
+
   /// Override this function to learn when this [Widget] enters the widget tree.
-  void didMount() { }
+  void didMount() {
+    if (key is GlobalKey) {
+      assert(() {
+        if (_globalKeys.containsKey(key)) {
+          int oldCount = _debugDuplicateGlobalKeys.putIfAbsent(key, () => 1);
+          assert(oldCount >= 1);
+          _debugDuplicateGlobalKeys[key] = oldCount + 1;
+        }
+        return true;
+      });
+      _globalKeys[key] = this;
+    }
+  }
 
   /// Override this function to learn when this [Widget] leaves the widget tree.
-  void didUnmount() { }
+  void didUnmount() {
+    if (key is GlobalKey) {
+      assert(() {
+        if (_globalKeys.containsKey(key) && _debugDuplicateGlobalKeys.containsKey(key)) {
+          int oldCount = _debugDuplicateGlobalKeys[key];
+          assert(oldCount >= 2);
+          if (oldCount == 2) {
+            _debugDuplicateGlobalKeys.remove(key);
+          } else {
+            _debugDuplicateGlobalKeys[key] = oldCount - 1;
+          }
+        }
+        return true;
+      });
+      if (_globalKeys[key] == this)
+        _globalKeys.remove(key);
+    }
+  }
 
   RenderObject _root;