This adds in the ability for Chrome to generate windows with snapshots of all...

chrome/browser/chromeos/wm_overview_controller.h

+// Copyright (c) 2010 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_WM_OVERVIEW_CONTROLLER_H_
+#define CHROME_BROWSER_CHROMEOS_WM_OVERVIEW_CONTROLLER_H_
+
+#include <vector>
+
+#include "base/linked_ptr.h"
+#include "base/singleton.h"
+#include "base/timer.h"
+#include "chrome/browser/browser_list.h"
+#include "chrome/browser/chromeos/wm_message_listener.h"
+#include "chrome/common/notification_registrar.h"
+#include "gfx/rect.h"
+
+namespace views {
+class Widget;
+}
+
+class Animation;
+class Browser;
+
+namespace chromeos {
+
+class BrowserListener;
+class WmOverviewSnapshot;
+
+// WmOverviewController is responsible for managing a list of objects
+// that listen to the browsers (BrowserListeners, defined in the
+// source file for this class) for changes, and keep a list of
+// snapshot images in sync with the browser tab contents.
+//
+// As tabs are added/removed from the browsers, the number of snapshot
+// windows changes to match.
+//
+// As obtaining and setting snapshots is expensive we delay setting
+// the snapshot. The delay is controlled by delay_timer_. Once the
+// timer fires another timer is started (configure_timer_). This timer
+// invokes ConfigureNextUnconfiguredCell on the BrowserListener, which
+// obtains and sets the snapshot of the next uncofigured
+// cell. ConfigureNextUnconfiguredCell only configures one cell at a
+// time until they are all configured.
+
+class WmOverviewController : public BrowserList::Observer,
+                             public WmMessageListener::Observer,
+                             public NotificationObserver {
+ public:
+  // This class is a singleton.
+  static WmOverviewController* instance();
+
+  // BrowserList::Observer methods
+  // This is called immediately after a browser is added to the list.
+  void OnBrowserAdded(const Browser* browser) {}
+
+  // This is called immediately before a browser is removed from the list.
+  void OnBrowserRemoving(const Browser* browser);
+  // End BrowserList::Observer methods
+
+  // WmMessageListener::Observer methods
+  // This is called immediately after a browser is added to the list.
+  void ProcessWmMessage(const WmIpc::Message& message,
+                        GdkWindow* window);
+  // End WmMessageListener::Observer methods
+
+  // NotificationObserver methods
+  void Observe(NotificationType type,
+               const NotificationSource& source,
+               const NotificationDetails& details);
+  // End NotificationObserver methods
+
+  // Used by the BrowserListeners to configure their snapshots.
+  const gfx::Rect& monitor_bounds() const { return monitor_bounds_; }
+
+  // Tells the listeners whether or not they're allowed to show
+  // snapshots yet.
+  bool allow_show_snapshots() const { return allow_show_snapshots_; }
+
+  // Starts the delay timer, and once the delay is over, configures
+  // any unconfigured snapshots one at a time until none are left to
+  // be configured.
+  void StartDelayTimer();
+
+ private:
+  friend struct DefaultSingletonTraits<WmOverviewController>;
+
+  // This class is a singleton.
+  WmOverviewController();
+  ~WmOverviewController();
+
+  // Restores tab selections on all browsers to what they were when
+  // Show was last called.  Used when cancelling overview mode.
+  void RestoreTabSelections();
+
+  // Saves the currently selected tabs in the snapshots so that they
+  // can be restored later with RestoreTabSelections.
+  void SaveTabSelections();
+
+  // Show the snapshot windows, saving current tab selections.
+  void Show();
+
+  // Hide the snapshot windows.  When |cancelled| is true, then the
+  // tab selections that were saved when the snapshot windows were
+  // shown are restored.
+  void Hide(bool cancelled);
+
+  // Invoked by delay_timer_. Sets allow_show_snapshots_ to true and starts
+  // configure_timer_.
+  void StartConfiguring();
+
+  // Configure the next unconfigured snapshot window owned by any of
+  // the listeners.
+  void ConfigureNextUnconfiguredSnapshot();
+
+  // Add browser listeners for all existing browsers, reusing any that
+  // were already there.
+  void AddAllBrowsers();
+
+  // This is so we can register for notifications.
+  NotificationRegistrar registrar_;
+
+  // This is a vector of listeners that listen to all the browsers.
+  typedef std::vector<linked_ptr<BrowserListener> > BrowserListenerVector;
+  BrowserListenerVector listeners_;
+
+  // This is the bounds of the monitor we're being displayed on. This
+  // is used to adjust the size of snapshots so they'll fit.
+  gfx::Rect monitor_bounds_;
+
+  // This indicates whether we should actually set the snapshots so we
+  // don't do it when we don't need to. It is initially false, then
+  // set to true by StartConfiguring.
+  bool allow_show_snapshots_;
+
+  // See description above class for details.
+  base::OneShotTimer<WmOverviewController> delay_timer_;
+
+  // See description above class for details.
+  base::RepeatingTimer<WmOverviewController> configure_timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(WmOverviewController);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_WM_OVERVIEW_CONTROLLER_H_