Adds ability to render omnibox as a view above the page.

chrome/browser/ui/views/frame/contents_container.cc

 // Copyright (c) 2011 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 "chrome/browser/ui/views/frame/contents_container.h"
 
 #include "base/logging.h"
+#include "ui/views/layout/fill_layout.h"
 
 using content::WebContents;
 
+class ContentsContainer::HeaderView : public views::View {
+ public:
+  HeaderView();
+
+  bool should_show() { return child_count() && child_at(0)->visible(); }

[Peter Kasting, 2012/06/22 20:33:22]

Nit: const

+
+ protected:
+  // views::View overrides:
+  virtual void ChildPreferredSizeChanged(views::View* child) OVERRIDE;
+
+ private:
+  bool child_visibile_;

[Peter Kasting, 2012/06/22 20:33:22]

Nit: Maybe call this child_was_visible_ and add some comments about it?

+
+  DISALLOW_COPY_AND_ASSIGN(HeaderView);
+};
+
+ContentsContainer::HeaderView::HeaderView() : child_visibile_(false) {}
+
+void ContentsContainer::HeaderView::ChildPreferredSizeChanged(
+    views::View* child) {
+  if (parent() && (child->visible() || child_visibile_))
+    parent()->Layout();
+  child_visibile_ = child->visible();
+}
+
 // static
 const char ContentsContainer::kViewClassName[] =
     "browser/ui/views/frame/ContentsContainer";
 
 ContentsContainer::ContentsContainer(views::View* active)
-    : active_(active),
+    : header_(new HeaderView()),
+      active_(active),
       preview_(NULL),
       preview_web_contents_(NULL),
       active_top_margin_(0) {
   AddChildView(active_);
+  header_->SetLayoutManager(new views::FillLayout);
+  AddChildView(header_);
 }
 
 ContentsContainer::~ContentsContainer() {
 }
 
+views::View* ContentsContainer::header() { return header_; }
+
 void ContentsContainer::MakePreviewContentsActiveContents() {
   DCHECK(preview_);
 
   active_ = preview_;
   preview_ = NULL;
   preview_web_contents_ = NULL;
   Layout();
 }
 
 void ContentsContainer::SetPreview(views::View* preview,
@@ skipping 21 matching lines @@
   InvalidateLayout();
 }
 
 gfx::Rect ContentsContainer::GetPreviewBounds() {
   gfx::Point screen_loc;
   ConvertPointToScreen(this, &screen_loc);
   return gfx::Rect(screen_loc, size());
 }
 
 void ContentsContainer::Layout() {
-  // The active view always gets the full bounds.
-  active_->SetBounds(0, active_top_margin_, width(),
-                     std::max(0, height() - active_top_margin_));
+  int content_y = active_top_margin_;
+  int content_height = std::max(0, height() - content_y);
+  if (header_->should_show()) {
+    gfx::Size header_pref = header_->GetPreferredSize();
+    int header_height = std::min(content_height, header_pref.height());
+    content_height -= header_height;
+    header_->SetBounds(0, content_y, width(), header_height);
+    content_y += header_height;
+  } else {
+    header_->SetBoundsRect(gfx::Rect());
+  }
+  active_->SetBounds(0, content_y, width(), content_height);
 
   if (preview_)
     preview_->SetBounds(0, 0, width(), height());
 
   // Need to invoke views::View in case any views whose bounds didn't change
   // still need a layout.
   views::View::Layout();
 }
 
 std::string ContentsContainer::GetClassName() const {
   return kViewClassName;
 }