From 603f589ba3ff25a4bfb733e88e6ae81310ab81a0 Mon Sep 17 00:00:00 2001
From: Adam Barth <abarth@chromium.org>
Date: Tue, 21 Jul 2015 14:38:44 -0700
Subject: [PATCH] Images don't appears in VariableHeightScrollables

When we build widgets during layout we weren't notifying those widgets that
they were mounted. Now we notify mount status changes when exiting build phases
inside layout.

Fixes #176
---
 .../widgets/variable_height_scrollable.dart   |  2 ++
 sky/sdk/lib/widgets/widget.dart               | 20 ++++++++++---------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/sky/sdk/lib/widgets/variable_height_scrollable.dart b/sky/sdk/lib/widgets/variable_height_scrollable.dart
index 7799d913b22..66f060f85df 100644
--- a/sky/sdk/lib/widgets/variable_height_scrollable.dart
+++ b/sky/sdk/lib/widgets/variable_height_scrollable.dart
@@ -8,6 +8,8 @@ import 'package:sky/widgets/block_viewport.dart';
 import 'package:sky/widgets/scrollable.dart';
 import 'package:sky/widgets/widget.dart';
 
+export 'package:sky/widgets/block_viewport.dart' show BlockViewportLayoutState;
+
 class VariableHeightScrollable extends Scrollable {
   VariableHeightScrollable({
     String key,
diff --git a/sky/sdk/lib/widgets/widget.dart b/sky/sdk/lib/widgets/widget.dart
index 637f39084f0..6f96239056c 100644
--- a/sky/sdk/lib/widgets/widget.dart
+++ b/sky/sdk/lib/widgets/widget.dart
@@ -6,7 +6,6 @@ import 'dart:async';
 import 'dart:collection';
 import 'dart:sky' as sky;
 
-import 'package:sky/base/debug.dart';
 import 'package:sky/base/hit_test.dart';
 import 'package:sky/mojo/activity.dart' as activity;
 import 'package:sky/rendering/box.dart';
@@ -600,17 +599,20 @@ int _inLayoutCallbackBuilder = 0;
 
 class LayoutCallbackBuilderHandle { bool _active = true; }
 LayoutCallbackBuilderHandle enterLayoutCallbackBuilder() {
-  if (!inDebugBuild)
-    return null;
-  _inLayoutCallbackBuilder += 1;
+  assert(() {
+    _inLayoutCallbackBuilder += 1;
+    return true;
+  });
   return new LayoutCallbackBuilderHandle();
 }
 void exitLayoutCallbackBuilder(LayoutCallbackBuilderHandle handle) {
-  if (!inDebugBuild)
-    return;
-  assert(handle._active);
-  handle._active = false;
-  _inLayoutCallbackBuilder -= 1;
+  assert(() {
+    assert(handle._active);
+    handle._active = false;
+    _inLayoutCallbackBuilder -= 1;
+    return true;
+  });
+  Widget._notifyMountStatusChanged();
 }
 
 List<int> _debugFrameTimes = <int>[];