Split Screen mode implementation

athena/wm/split_view_controller.h

Index: athena/wm/split_view_controller.h
diff --git a/athena/wm/split_view_controller.h b/athena/wm/split_view_controller.h
index e0652def1b19050b568964926916aee06aac731f..88a77b568d1fbd3bfd2697d966989031a9226966 100644
--- a/athena/wm/split_view_controller.h
+++ b/athena/wm/split_view_controller.h
@@ -6,24 +6,73 @@
 #define ATHENA_WM_SPLIT_VIEW_CONTROLLER_H_
 
 #include "athena/wm/bezel_controller.h"
+#include "athena/wm/public/window_manager_observer.h"
+#include "athena/wm/window_overview_mode.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "ui/compositor/layer_animation_observer.h"
+
+namespace gfx {
+class Transform;
+}
 
 namespace athena {
+class WindowListProvider;
+class WindowManager;
+class WindowOverviewModeDelegate;
 
 // Responsible for entering split view mode, exiting from split view mode, and
 // laying out the windows in split view mode.
-class SplitViewController : public BezelController::ScrollDelegate {
+class SplitViewController : public BezelController::ScrollDelegate,
+                            public WindowManagerObserver {
  public:
-  SplitViewController();
   virtual ~SplitViewController();
+  SplitViewController(aura::Window* container,
+                      WindowListProvider* window_list_provider,
+                      WindowManager* window_manager);
+
+
+  bool IsSplitViewModeActive();
 
  private:
+  enum State {INACTIVE, SCROLLING, ACTIVE};
+
+  void Layout(bool animate);
+
+  void SetWindowTransform(
+      aura::Window* window, const gfx::Transform& transform, bool animate);
+
+  void AnimationCompleted();
+
+  void UpdateSeparatorPositionFromScrollDelta(float delta);
+
+  aura::Window* GetCurrentWindow();
+
   // BezelController::ScrollDelegate overrides.
   virtual void ScrollBegin(BezelController::Bezel bezel, float delta) OVERRIDE;
   virtual void ScrollEnd() OVERRIDE;
   virtual void ScrollUpdate(float delta) OVERRIDE;
   virtual bool CanScroll() OVERRIDE;
 
+  // WindowManagerObserver overrides
+  virtual void OnOverviewModeEnter() OVERRIDE;
+  virtual void OnOverviewModeExit() OVERRIDE;
+
+  base::WeakPtrFactory<SplitViewController> weak_factory_;
+
+  State state_;
+
+  aura::Window* container_;
+  WindowManager* window_manager_;
+  WindowListProvider* window_list_provider_;
+
+  aura::Window* current_window_;
+  aura::Window* left_window_;
+  aura::Window* right_window_;
+  // Position of the separator between left_window_ and right_window_ in
+  // container_ coordinates (along the x axis).
+  int separator_position_;
+
   DISALLOW_COPY_AND_ASSIGN(SplitViewController);
 };