Preliminary interactive layout of window manager's demo_launcher

mojo/examples/html_viewer/html_document_view.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/examples/html_viewer/html_document_view.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/thread_task_runner_handle.h"
@@ skipping 62 matching lines @@
   return false;
 }
 
 }  // namespace
 
 HTMLDocumentView::HTMLDocumentView(ServiceProvider* service_provider,
                                    view_manager::ViewManager* view_manager)
     : view_manager_(view_manager),
       view_(view_manager::View::Create(view_manager_)),
       web_view_(NULL),
+      root_(NULL),
       repaint_pending_(false),
       navigator_host_(service_provider),
       weak_factory_(this) {
   view_->AddObserver(this);
 }
 
 HTMLDocumentView::~HTMLDocumentView() {
   view_->RemoveObserver(this);
-
   if (web_view_)
     web_view_->close();
+  if (root_)
+    root_->RemoveObserver(this);
 }
 
 void HTMLDocumentView::AttachToNode(view_manager::Node* node) {
-  node->SetActiveView(view_);
+  root_ = node;
+  root_->SetActiveView(view_);
   view_->SetColor(SK_ColorCYAN);  // Dummy background color.
 
   web_view_ = blink::WebView::create(this);
   ConfigureSettings(web_view_->settings());
   web_view_->setMainFrame(blink::WebLocalFrame::create(this));
+  web_view_->resize(root_->bounds().size());
 
-  web_view_->resize(gfx::Size(node->bounds().size()));
+  root_->AddObserver(this);
 }
 
 void HTMLDocumentView::Load(URLResponsePtr response) {
   DCHECK(web_view_);
 
   GURL url(response->url);
 
   WebURLRequestExtraData* extra_data = new WebURLRequestExtraData;
   extra_data->synthetic_response = response.Pass();
 
@@ skipping 62 matching lines @@
 
 void HTMLDocumentView::OnViewInputEvent(view_manager::View* view,
                                         const EventPtr& event) {
   scoped_ptr<blink::WebInputEvent> web_event =
       TypeConverter<EventPtr, scoped_ptr<blink::WebInputEvent> >::ConvertTo(
           event);
   if (web_event)
     web_view_->handleInputEvent(*web_event);
 }
 
+// Overridden from NodeObserver:

[sky, 2014/07/15 00:07:49]

Style guide says not to duplicate comments like this in the definition.

[hansmuller, 2014/07/15 00:27:43]

Done.

+void HTMLDocumentView::OnNodeBoundsChanged(view_manager::Node* node,
+                                           const gfx::Rect& old_bounds,
+                                           const gfx::Rect& new_bounds) {
+  DCHECK_EQ(node, root_);
+  web_view_->resize(node->bounds().size());
+}
+
+// Overridden from NodeObserver:
+void HTMLDocumentView::OnNodeDestroying(view_manager::Node* node) {
+  DCHECK_EQ(node, root_);
+  node->RemoveObserver(this);

[sky, 2014/07/15 00:07:49]

Shouldn't you set root_ to NULL here too? This comment applies to similar
overrides.

[hansmuller, 2014/07/15 00:27:43]

That implies that other NodeObserver methods can't rely on root_ once the
OnNodeDestroying method has run. They don't know but they could. Why set root_
to NULL here?

[sky, 2014/07/15 04:08:37]

By adding this override you're saying root_ may be destroyed before this. If
that happens you'll crash on 94 because root_ will not be NULL yet root_ has
been deleted.

+}
+
 void HTMLDocumentView::Repaint() {
   repaint_pending_ = false;
 
   web_view_->animate(0.0);
   web_view_->layout();
 
   int width = web_view_->size().width;
   int height = web_view_->size().height;
 
   skia::RefPtr<SkCanvas> canvas = skia::AdoptRef(SkCanvas::NewRaster(
       SkImageInfo::MakeN32(width, height, kOpaque_SkAlphaType)));
 
   web_view_->paint(canvas.get(), gfx::Rect(0, 0, width, height));
 
   view_->SetContents(canvas->getDevice()->accessBitmap(false));
 }
 
 }  // namespace examples
 }  // namespace mojo