athena: Introduce ActivityView.

athena/activity/public/activity_view_model.h

 // Copyright 2014 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 ATHENA_ACTIVITY_PUBLIC_ACTIVITY_VIEW_MODEL_H_
 #define ATHENA_ACTIVITY_PUBLIC_ACTIVITY_VIEW_MODEL_H_
 
 #include "athena/athena_export.h"
 #include "base/strings/string16.h"
 
 typedef unsigned int SkColor;
 
 namespace gfx {
 class ImageSkia;
 }
 
 namespace views {
 class View;
 class Widget;
 }
 
 namespace athena {
 
+class ActivityView;
+
 // The view model for the representation of the activity.
 class ATHENA_EXPORT ActivityViewModel {
  public:
   virtual ~ActivityViewModel() {}
 
   // Called after the view model is attached to the widget/window tree and
   // before it gets registered to the ActivityManager and the ResourceManager.
   // At this time the Activity can also be moved to a different place in the
   // Activity history.
   virtual void Init() = 0;
 
   // Returns a color most representative of this activity.
   virtual SkColor GetRepresentativeColor() const = 0;
 
   // Returns a title for the activity.
   virtual base::string16 GetTitle() const = 0;
 
   // Returns an icon for the activity.
   virtual gfx::ImageSkia GetIcon() const = 0;
 
+  // Sets the ActivityView for the model to update. The model does not take
+  // ownership of the view.
+  virtual void SetActivityView(ActivityView* view) = 0;
+
   // True if the activity wants to use Widget's frame, or false if the activity
   // draws its own frame.
   virtual bool UsesFrame() const = 0;
 
   // Returns the contents view which might be nullptr if the activity is not
   // loaded. Note that the caller should not hold on to the view since it can
   // be deleted by the resource manager.
   virtual views::View* GetContentsView() = 0;
 
   // Returns an image which can be used to represent the activity in e.g. the
   // overview mode. The returned image can have no size if either a view exists
   // or the activity has not yet been loaded or ever been presented. In that
   // case GetRepresentativeColor() should be used to clear the preview area.
   // Note that since the image gets created upon request, and the
   // ActivityViewModel will hold no reference to the returned image data. As
   // such it is advisable to hold on to the image as long as needed instead of
   // calling this function frequently since it will cause time to generate.
   virtual gfx::ImageSkia GetOverviewModeImage() = 0;
 
   // Prepares the contents view for overview.
   virtual void PrepareContentsForOverview() = 0;
 
   // Undoes any changes done by PrepareContentsForOverview().
   virtual void ResetContentsView() = 0;
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_ACTIVITY_PUBLIC_ACTIVITY_VIEW_MODEL_H_