Zoom Extension API (content changes)

content/public/browser/host_zoom_map.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 CONTENT_PUBLIC_BROWSER_HOST_ZOOM_MAP_H_
 #define CONTENT_PUBLIC_BROWSER_HOST_ZOOM_MAP_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 12 matching lines @@
 // Maps hostnames to custom zoom levels.  Written on the UI thread and read on
 // any thread.  One instance per browser context. Must be created on the UI
 // thread, and it'll delete itself on the UI thread as well.
 // Zoom can be defined at three levels: default zoom, zoom for host, and zoom
 // for host with specific scheme. Setting any of the levels leaves settings
 // for other settings intact. Getting the zoom level starts at the most
 // specific setting and progresses to the less specific: first the zoom for the
 // host and scheme pair is checked, secondly the zoom for the host only and
 // lastly default zoom.
 
 class HostZoomMap {

[Fady Samuel, 2014/06/09 15:43:21]

I find this name really confusing, especially with the direction we're going in
with zoom. Could we please call this ZoomManager?

[wjmaclean, 2014/06/09 17:23:29]

I'm OK with that. But, we should then consider the potential for confusion
between ZoomManager and ZoomController. Eventually perhaps the two should merge?
That might be more than we want to put into this CL though.

  public:
   // Enum that indicates what was the scope of zoom level change.
   enum ZoomLevelChangeMode {
     ZOOM_CHANGED_FOR_HOST,            // Zoom level changed for host.
     ZOOM_CHANGED_FOR_SCHEME_AND_HOST, // Zoom level changed for scheme/host
                                       // pair.
     ZOOM_CHANGED_TEMPORARY_ZOOM,      // Temporary zoom change for specific
                                       // renderer, no scheme/host is specified.
   };
 
@@ skipping 27 matching lines @@
   // Here |host| is the host portion of URL, or (in the absence of a host)
   // the complete spec of the URL.
   // Returns the zoom for the specified |scheme| and |host|. See class
   // description for details.
   //
   // This may be called on any thread.
   virtual double GetZoomLevelForHostAndScheme(
       const std::string& scheme,
       const std::string& host) const = 0;
 
+  // Returns true if the specified |scheme| and/or |host| has a zoom level
+  // currently set.
+  //
+  // This may be called on any thread.
+  virtual bool HasZoomLevelInMap(const std::string& scheme,

[Fady Samuel, 2014/06/09 15:43:21]

I'm not a fan of calling this thing a map at all at the content API level. This
class isn't even a map anymore. Please call this function HasZoomLevel.

[wjmaclean, 2014/06/09 17:23:29]

Done.

+                                 const std::string& host) const = 0;
+
   // Returns all non-temporary zoom levels. Can only be called on any thread.
   virtual ZoomLevelVector GetAllZoomLevels() const = 0;
 
   // Here |host| is the host portion of URL, or (in the absence of a host)
   // the complete spec of the URL.
   // Sets the zoom level for the |host| 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.
   // Zoom levels specified for both scheme and host are not affected.
   //
   // This should only be called on the UI thread.
   virtual void SetZoomLevelForHost(const std::string& host, double level) = 0;
 
   // Here |host| is the host portion of URL, or (in the absence of a host)
   // the complete spec of the URL.
   // Sets the zoom level for the |scheme|/|host| pair to |level|. No values
   // will be erased during this operation, and this value will not be stored in
   // the preferences.
   //
   // This should only be called on the UI thread.
   virtual void SetZoomLevelForHostAndScheme(const std::string& scheme,
                                             const std::string& host,
                                             double level) = 0;
 
+  // Sets the temporary zoom level that's only valid for the lifetime of this
+  // WebContents.
+  //
+  // This should only be called on the UI thread.
+  virtual void SetTemporaryZoomLevel(int render_process_id,
+                                     int render_view_id,
+                                     const std::string& host,
+                                     double level,
+                                     bool send_level_to_view) =0;

[Fady Samuel, 2014/06/09 15:43:21]

This last parameter is really confusing at an API level. I wouldn't know how to
use it without looking at the code in chrome.

I feel that we need two methods here:

1. To update the bookkeeping.
2. Set the zoom level according to the bookkeeping.

I'm not yet sure what the best naming is here but this 

[wjmaclean, 2014/06/09 17:23:29]

Ok, I can look into separating this.

One consideration is that this is used because the HostZoomMap doesn't know
anything about the zoom modes, manual vs. isolated. If we merge ZoomController
and HostZoomMap then it will, but in the short term the sender of messages needs
to know who should get one (isolated) and who shouldn't (manual). Perhaps this
should be stored in the temporary zoom settings, and we'll rename the parameter
here ('bool send_level_to_view' becomes 'enum mode {manual, isolated}'?)

[wjmaclean, 2014/06/10 13:20:09]

Done.

+
+  // Erases the temporary zoom level stored for this WebContents.
+  //
+  // This should only be called on the UI thread.
+  virtual void EraseTemporaryZoomLevel(int render_process_id,

[Fady Samuel, 2014/06/09 15:43:21]

name: ClearTemporaryZoomLevel

[wjmaclean, 2014/06/09 17:23:29]

Done.

+                                       int render_view_id) = 0;
+
   // Get/Set the default zoom level for pages that don't override it.
   virtual double GetDefaultZoomLevel() const = 0;
   virtual void SetDefaultZoomLevel(double level) = 0;;
 
   typedef base::Callback<void(const ZoomLevelChange&)> ZoomLevelChangedCallback;
   typedef base::CallbackList<void(const ZoomLevelChange&)>::Subscription
-      Subscription;
+  Subscription;
   // Add and remove zoom level changed callbacks.
   virtual scoped_ptr<Subscription> AddZoomLevelChangedCallback(
       const ZoomLevelChangedCallback& callback) = 0;
 
  protected:
   virtual ~HostZoomMap() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_HOST_ZOOM_MAP_H_