Changes view manager to report visibility and drawn state

mojo/services/view_manager/server_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/services/view_manager/server_view.h"
 
 #include "mojo/services/view_manager/server_view_delegate.h"
 
 namespace mojo {
 namespace service {
@@ skipping 19 matching lines @@
   DCHECK(child != this);
   DCHECK(!child->Contains(this));
   if (child->parent() == this) {
     if (children_.size() == 1)
       return;  // Already in the right position.
     Reorder(child, children_.back(), ORDER_DIRECTION_ABOVE);
     return;
   }
 
   const ServerView* old_parent = child->parent();
+  child->delegate_->OnWillChangeViewHierarchy(child, this, old_parent);
   if (child->parent())
     child->parent()->RemoveImpl(child);
 
   child->parent_ = this;
   children_.push_back(child);
   child->delegate_->OnViewHierarchyChanged(child, this, old_parent);
 }
 
 void ServerView::Remove(ServerView* child) {
   // We assume validation checks happened else where.
   DCHECK(child);
   DCHECK(child != this);
   DCHECK(child->parent() == this);
 
+  child->delegate_->OnWillChangeViewHierarchy(child, NULL, this);
   RemoveImpl(child);
   child->delegate_->OnViewHierarchyChanged(child, NULL, this);
 }
 
 void ServerView::Reorder(ServerView* child,
                          ServerView* relative,
                          OrderDirection direction) {
   // We assume validation checks happened else where.
   DCHECK(child);
   DCHECK(child->parent() == this);
@@ skipping 43 matching lines @@
     if (parent == this)
       return true;
   }
   return false;
 }
 
 void ServerView::SetVisible(bool value) {
   if (visible_ == value)
     return;
 
+  delegate_->OnWillChangeViewVisibility(this);
   visible_ = value;
-  // TODO(sky): notification, including repaint.
+}
+
+bool ServerView::IsDrawn(const ServerView* root) const {
+  if (!root->visible_)
+    return false;
+  const ServerView* view = this;
+  while (view && view != root && view->visible_)
+    view = view->parent_;
+  return view == root;
 }
 
 void ServerView::SetBitmap(const SkBitmap& bitmap) {
   bitmap_ = bitmap;
   delegate_->OnViewBitmapChanged(this);
 }
 
 void ServerView::RemoveImpl(ServerView* view) {
   view->parent_ = NULL;
   children_.erase(std::find(children_.begin(), children_.end(), view));
 }
 
 }  // namespace service
 }  // namespace mojo