Tracks changes to zoom icon and zoom percentage. Notifies browser window if the icon should be chan…

chrome/browser/ui/zoom/zoom_observer.h

+// 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.
+
+#ifndef CHROME_BROWSER_UI_ZOOM_ZOOM_OBSERVER_H_
+#define CHROME_BROWSER_UI_ZOOM_ZOOM_OBSERVER_H_
+#pragma once
+
+#include "chrome/browser/ui/zoom/zoom_controller.h"
+
+class TabContentsWrapper;
+
+// Interface for objects that wish to be notified of changes in ZoomController.
+class ZoomObserver {
+ public:
+  // Notification that the Omnibox zoom icon should change.
+  virtual void OnZoomIconChanged(TabContentsWrapper* source,
+                                 ZoomController::ZoomIconState state) = 0;
+
+  // Notification that the zoom percentage has changed.
+  virtual void OnZoomChanged(TabContentsWrapper* source,
+                             int zoom_percent,
+                             bool can_show_bubble) = 0;
+
+ protected:
+  virtual ~ZoomObserver() {}
+};
+
+#endif  // CHROME_BROWSER_UI_ZOOM_ZOOM_OBSERVER_H_