Makes workspace 2 show an alternate background (system background)

ash/wm/workspace/system_background_controller.cc

+// Copyright (c) 2012 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 "ash/wm/workspace/system_background_controller.h"
+
+#include "ash/shell_window_ids.h"
+#include "ui/aura/root_window.h"
+#include "ui/gfx/canvas.h"
+#include "ui/views/widget/widget.h"
+#include "ui/views/widget/widget_delegate.h"
+
+namespace ash {
+namespace internal {
+
+// View implementation responsible for rendering the background.
+class SystemBackgroundController::View : public views::WidgetDelegateView {
+ public:
+  explicit View(SystemBackgroundController* controller);
+  virtual ~View();
+
+  // Closes the hosting widget.
+  void Close();
+
+  // WidgetDelegate overrides:
+  virtual views::View* GetContentsView() OVERRIDE;
+
+  // View overrides:
+  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+
+ private:
+  SystemBackgroundController* controller_;
+
+  DISALLOW_COPY_AND_ASSIGN(View);
+};
+
+SystemBackgroundController::View::View(SystemBackgroundController* controller)
+    : controller_(controller) {
+}
+
+SystemBackgroundController::View::~View() {
+  if (controller_)
+    controller_->view_ = NULL;
+}
+
+void SystemBackgroundController::View::Close() {
+  controller_ = NULL;
+  GetWidget()->Close();
+}
+
+views::View* SystemBackgroundController::View::GetContentsView() {
+  return this;
+}
+
+void SystemBackgroundController::View::OnPaint(gfx::Canvas* canvas) {
+  // TODO: get image!
+  canvas->DrawColor(SK_ColorRED);
+}
+
+SystemBackgroundController::SystemBackgroundController(aura::RootWindow* root)
+    : ALLOW_THIS_IN_INITIALIZER_LIST(view_(new View(this))) {
+  views::Widget* widget = new views::Widget;
+  views::Widget::InitParams params(
+      views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
+  params.delegate = view_;
+  params.parent = root->GetChildById(kShellWindowId_SystemBackgroundContainer);
+  widget->Init(params);
+  widget->SetBounds(params.parent->bounds());
+  widget->Show();
+  widget->GetNativeView()->SetName("SystemBackground");
+}
+
+SystemBackgroundController::~SystemBackgroundController() {
+  if (view_)
+    view_->Close();
+}
+
+}  // namespace internal
+}  // namespace ash