Zoom Extension API (work in progress)

chrome/browser/ui/zoom/zoom_controller.h

Index: chrome/browser/ui/zoom/zoom_controller.h
diff --git a/chrome/browser/ui/zoom/zoom_controller.h b/chrome/browser/ui/zoom/zoom_controller.h
index 3c427a716d6956b4603ee54f1d1fe67dd4780985..29b8fbabfca53367a145464a5ce362f164392e3a 100644
--- a/chrome/browser/ui/zoom/zoom_controller.h
+++ b/chrome/browser/ui/zoom/zoom_controller.h
@@ -5,12 +5,15 @@
 #ifndef CHROME_BROWSER_UI_ZOOM_ZOOM_CONTROLLER_H_
 #define CHROME_BROWSER_UI_ZOOM_ZOOM_CONTROLLER_H_
 
+#include <queue>
+
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/prefs/pref_member.h"
 #include "content/public/browser/host_zoom_map.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
+#include "extensions/common/extension.h"
 
 class ZoomObserver;
 
@@ -18,7 +21,28 @@ namespace content {
 class WebContents;
 }
 
-// Per-tab class to manage the Omnibox zoom icon.
+// Defines how zoom changes are handled.
+// |kZoomModeDefault| results in default zoom behavior, i.e. zoom changes are
+//     handled automatically and on a per-origin basis, meaning that other
+//     tabs navigated to the same origin will also zoom.
+// |kZoomModeIsolated| results in zoom changes being handled automatically,
+//     but on a per-tab basis. Tabs in this zoom mode will not be affected by
+//     zoom changes in other tabs, and vice versa.
+// |kZoomModeManual| overrides the automatic handling of zoom changes. The
+//     |onZoomChange| event will still be dispatched, but the page will not
+//     actually be zoomed. These zoom changes can be handled manually by
+//     listening for the |onZoomChange| event. Zooming in this mode is also on
+//     a per-tab basis.
+// |kZoomModeDisabled| disables all zooming in this tab. The tab will revert
+//     to default (100%) zoom, and all attempted zoom changes will be ignored.
+enum ZoomMode {
+  kZoomModeDefault,
+  kZoomModeIsolated,
+  kZoomModeManual,
+  kZoomModeDisabled,
+};
+
+// Per-tab class to manage zoom changes and the Omnibox zoom icon.
 class ZoomController : public content::WebContentsObserver,
                        public content::WebContentsUserData<ZoomController> {
  public:
@@ -26,14 +50,32 @@ class ZoomController : public content::WebContentsObserver,
 
   int zoom_percent() const { return zoom_percent_; }
 
+  ZoomMode zoom_mode() const { return zoom_mode_; }
+
   // Convenience method to quickly check if the tab's at default zoom.
   bool IsAtDefaultZoom() const;
 
   // Returns which image should be loaded for the current zoom level.
   int GetResourceForZoomLevel() const;
 
+  const extensions::Extension* last_extension() const;
+
   void set_observer(ZoomObserver* observer) { observer_ = observer; }
 
+  // Sets the zoom level through WebContents::SetZoomLevel(). Returns a boolean
+  // flag indicating success (true) or failure (false).
+  bool SetZoomLevel(double zoom_level);
+
+  // Sets the zoom level through WebContents::SetZoomLevel(), and attributes the
+  // zoom to |extension|. Returns a boolean flag indicating success (true) or
+  // failure (false).
+  bool SetZoomLevelByExtension(
+      double zoom_level,
+      scoped_refptr<const extensions::Extension> extension);
+
+  // Sets the zoom mode, which defines zoom behavior (see enum ZoomMode).
+  void SetZoomMode(ZoomMode zoom_mode);
+
   // content::WebContentsObserver overrides:
   virtual void DidNavigateMainFrame(
       const content::LoadCommittedDetails& details,
@@ -51,13 +93,26 @@ class ZoomController : public content::WebContentsObserver,
   // meaning the change should apply to ~all sites. If it is not empty, the
   // change only affects sites with the given host.
   void UpdateState(const std::string& host);
+  void UpdateState(const std::string& host, bool is_temporary_zoom);
+
+  // This function serves as a callback that will be called after a zoom
+  // change has completed that is initiated from SetZoomLevelByExtension().
+  void ZoomCallback(scoped_refptr<const extensions::Extension> extension,
+                    const base::Callback<void(void)>& callback);
 
   // The current zoom percentage.
   int zoom_percent_;
 
+  // The current zoom mode.
+  ZoomMode zoom_mode_;
+
   // Used to access the default zoom level preference.
   DoublePrefMember default_zoom_level_;
 
+  // Keeps track of the extension (if any) that initiated the last zoom change
+  // that took effect.
+  scoped_refptr<const extensions::Extension> last_extension_;
+
   // Observer receiving notifications on state changes.
   ZoomObserver* observer_;
 
@@ -65,6 +120,10 @@ class ZoomController : public content::WebContentsObserver,
 
   scoped_ptr<content::HostZoomMap::Subscription> zoom_subscription_;
 
+  // Keeps track of extensions that initiated zoom changes so that they can be
+  // attributed when the zoom changes complete.
+  std::queue<scoped_refptr<const extensions::Extension> > extensions_;
+
   DISALLOW_COPY_AND_ASSIGN(ZoomController);
 };