ash: Add RootWindowHostFactory class.

ui/aura/root_window.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 UI_AURA_ROOT_WINDOW_H_
 #define UI_AURA_ROOT_WINDOW_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 30 matching lines @@
 class LayerAnimationSequence;
 class MouseEvent;
 class ScrollEvent;
 class TouchEvent;
 class ViewProp;
 }
 
 namespace aura {
 
 class RootWindow;
+class RootWindowDelegate;
 class RootWindowHost;
 class RootWindowObserver;
 
 // RootWindow is responsible for hosting a set of windows.
 class AURA_EXPORT RootWindow : public ui::CompositorDelegate,
                                public ui::CompositorObserver,
                                public Window,
                                public ui::EventDispatcherDelegate,
                                public ui::GestureEventHelper,
                                public ui::LayerAnimationObserver,
                                public aura::client::CaptureDelegate,
                                public aura::RootWindowHostDelegate {
  public:
   struct AURA_EXPORT CreateParams {
     // CreateParams with initial_bounds and default host.
     CreateParams(const gfx::Rect& initial_bounds);
     ~CreateParams() {}
 
     gfx::Rect initial_bounds;
 
-    // A host to use in place of the default one that RootWindow will create.
+    // RootWindow delegate. Can be used to create a host to use in place of the
+    // default one that RootWindow will create.
     // NULL by default.
-    RootWindowHost* host;
+    RootWindowDelegate* delegate;

[Ben Goodger (Google), 2012/12/11 01:14:02]

Why can't you just set host to the value you want?

This breaks desktop aura btw, which sets this field to something else in several
places in the code.

As an aside, I'd really like to see aura not have any of the RootWindowHost
impls. It's turned out that all of them are very implementation specific.

A very basic RootWindowHost interface should live in aura (much more simple than
what's there now), and nothing more. Ash would create its own kind, and
views/desktop-aura/chrome another.

[reveman, 2012/12/11 07:23:30]

OK, I like this. We don't need RootWindowDelegate. That was really just so we
could implement this cleanly without having an ash specific RootWindowHost.

Knowing that we want to move RootWindowHost impls to ash this patch can be made
simpler.

   };
 
   explicit RootWindow(const CreateParams& params);
   virtual ~RootWindow();
 
   // Returns the RootWindowHost for the specified accelerated widget, or NULL
   // if there is none associated.
   static RootWindow* GetForAcceleratedWidget(gfx::AcceleratedWidget widget);
 
   ui::Compositor* compositor() { return compositor_.get(); }
@@ skipping 260 matching lines @@
   gfx::Rect GetInitialHostWindowBounds() const;
 
   // Posts a task to send synthesized mouse move event if there
   // is no a pending task.
   void PostMouseMoveEventAfterWindowChange();
 
   // Creates and dispatches synthesized mouse move event using the
   // current mouse location.
   void SynthesizeMouseMoveEvent();
 
+  scoped_ptr<RootWindowDelegate> delegate_;
+
   scoped_ptr<ui::Compositor> compositor_;
 
   scoped_ptr<RootWindowHost> host_;
 
   // Used to schedule painting.
   base::WeakPtrFactory<RootWindow> schedule_paint_factory_;
 
   // Use to post mouse move event.
   base::WeakPtrFactory<RootWindow> event_factory_;
 
@@ skipping 31 matching lines @@
   base::WeakPtrFactory<RootWindow> held_mouse_event_factory_;
 
   scoped_ptr<ui::ViewProp> prop_;
 
   DISALLOW_COPY_AND_ASSIGN(RootWindow);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_ROOT_WINDOW_H_