Create Content API around HostZoomMap.

content/browser/host_zoom_map.h

-// 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.
-
-// Maps hostnames to custom zoom levels.  Written on the UI thread and read on
-// any thread.  One instance per browser context.
-
-#ifndef CONTENT_BROWSER_HOST_ZOOM_MAP_H_
-#define CONTENT_BROWSER_HOST_ZOOM_MAP_H_
-#pragma once
-
-#include <map>
-#include <string>
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/memory/ref_counted.h"
-#include "base/message_loop_helpers.h"
-#include "base/synchronization/lock.h"
-#include "content/common/content_export.h"
-#include "content/public/browser/browser_thread.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
-
-// HostZoomMap needs to be deleted on the UI thread because it listens
-// to notifications on there (and holds a NotificationRegistrar).
-class CONTENT_EXPORT HostZoomMap
-    : public content::NotificationObserver,
-      public base::RefCountedThreadSafe<
-          HostZoomMap, content::BrowserThread::DeleteOnUIThread> {
- public:
-  HostZoomMap();
-
-  // Copy the zoom levels from the given map. Can only be called on the UI
-  // thread.
-  void CopyFrom(HostZoomMap* copy);
-
-  // Returns the zoom level for the host or spec for a given url. The zoom
-  // level is determined by the host portion of the URL, or (in the absence of
-  // a host) the complete spec of the URL. In most cases, there is no custom
-  // zoom level, and this returns the user's default zoom level.  Otherwise,
-  // returns the saved zoom level, which may be positive (to zoom in) or
-  // negative (to zoom out).
-  //
-  // This may be called on any thread.
-  double GetZoomLevel(const std::string& host) const;
-
-  // Sets the zoom level for the host or spec for a given url to |level|.  If
-  // the level matches the current default zoom level, the host is erased
-  // from the saved preferences; otherwise the new value is written out.
-  //
-  // This should only be called on the UI thread.
-  void SetZoomLevel(std::string host, double level);
-
-  // Returns the temporary zoom level that's only valid for the lifetime of
-  // the given tab (i.e. isn't saved and doesn't affect other tabs) if it
-  // exists, the default zoom level otherwise.
-  //
-  // This may be called on any thread.
-  double GetTemporaryZoomLevel(int render_process_id,
-                               int render_view_id) const;
-
-  // Sets the temporary zoom level that's only valid for the lifetime of this
-  // tab.
-  //
-  // This should only be called on the UI thread.
-  void SetTemporaryZoomLevel(int render_process_id,
-                             int render_view_id,
-                             double level);
-
-  // content::NotificationObserver implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
-
-  double default_zoom_level() const { return default_zoom_level_; }
-  void set_default_zoom_level(double level) { default_zoom_level_ = level; }
-
- private:
-  friend class base::RefCountedThreadSafe<
-      HostZoomMap, content::BrowserThread::DeleteOnUIThread>;
-  friend struct content::BrowserThread::DeleteOnThread<
-      content::BrowserThread::UI>;
-  friend class base::DeleteHelper<HostZoomMap>;
-
-  typedef std::map<std::string, double> HostZoomLevels;
-
-  virtual ~HostZoomMap();
-
-  // Copy of the pref data, so that we can read it on the IO thread.
-  HostZoomLevels host_zoom_levels_;
-  double default_zoom_level_;
-
-  struct TemporaryZoomLevel {
-    int render_process_id;
-    int render_view_id;
-    double zoom_level;
-  };
-
-  // Don't expect more than a couple of tabs that are using a temporary zoom
-  // level, so vector is fine for now.
-  std::vector<TemporaryZoomLevel> temporary_zoom_levels_;
-
-  // Used around accesses to |host_zoom_levels_|, |default_zoom_level_| and
-  // |temporary_zoom_levels_| to guarantee thread safety.
-  mutable base::Lock lock_;
-
-  content::NotificationRegistrar registrar_;
-
-  DISALLOW_COPY_AND_ASSIGN(HostZoomMap);
-};
-
-#endif  // CONTENT_BROWSER_HOST_ZOOM_MAP_H_