Cros Tablet Window management - Split Screen part II

ash/wm/splitview/split_view_controller.h

 // Copyright 2017 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 ASH_WM_SPLITSVIEW_SPLIT_VIEW_CONTROLLER_H_
 #define ASH_WM_SPLITSVIEW_SPLIT_VIEW_CONTROLLER_H_
 
 #include "ash/ash_export.h"
 #include "ash/shell_observer.h"
 #include "ash/wm/window_state_observer.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "ui/aura/window_observer.h"
 #include "ui/wm/public/activation_change_observer.h"
 
 namespace ash {
 
 class SplitViewControllerTest;
 
 // The controller for the split view. It snaps a window to left/right side of
 // the screen. It also observes the two snapped windows and decides when to exit
 // the split view mode.
 class ASH_EXPORT SplitViewController : public aura::WindowObserver,
                                        public ash::wm::WindowStateObserver,
                                        public ::wm::ActivationChangeObserver,
                                        public ShellObserver {
  public:
   enum State { NO_SNAP, LEFT_SNAPPED, RIGHT_SNAPPED, BOTH_SNAPPED };
-  enum SnapPosition { LEFT, RIGHT };
+  enum SnapPosition { NONE, LEFT, RIGHT };
 
   class Observer {
    public:
     // Called when split view state changed from |previous_state| to |state|.
     virtual void OnSplitViewStateChanged(
         SplitViewController::State previous_state,
         SplitViewController::State state) {}
   };
 
   SplitViewController();
@@ skipping 11 matching lines @@
 
   // Returns the default snapped window. It's the window that remains open until
   // the split mode ends. It's decided by |default_snap_position_|. E.g., If
   // |default_snap_position_| equals LEFT, then the default snapped window is
   // |left_window_|. All the other window will open on the right side.
   aura::Window* GetDefaultSnappedWindow();
 
   // Gets the window bounds according to the snap state |snap_state| and the
   // separator position |separator_position_|.
   gfx::Rect GetSnappedWindowBoundsInParent(aura::Window* window,
-                                           State snap_state);
+                                           SnapPosition snap_position);
   gfx::Rect GetSnappedWindowBoundsInScreen(aura::Window* window,
-                                           State snap_state);
+                                           SnapPosition snap_position);
   gfx::Rect GetDisplayWorkAreaBoundsInParent(aura::Window* window);
   gfx::Rect GetDisplayWorkAreaBoundsInScreen(aura::Window* window);
 
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
   // aura::WindowObserver:
   void OnWindowDestroying(aura::Window* window) override;
 
   // ash::wm::WindowStateObserver:
   void OnPostWindowStateTypeChange(ash::wm::WindowState* window_state,
                                    ash::wm::WindowStateType old_type) override;
 
   // wm::ActivationChangeObserver:
   void OnWindowActivated(ActivationReason reason,
                          aura::Window* gained_active,
                          aura::Window* lost_active) override;
 
   // ShellObserver:
   void OnOverviewModeStarting() override;
   void OnOverviewModeEnded() override;
 
   aura::Window* left_window() { return left_window_; }
   aura::Window* right_window() { return right_window_; }
   int divider_position() const { return divider_position_; }
   State state() const { return state_; }
+  SnapPosition default_snap_position() const { return default_snap_position_; }
 
  private:
   friend class SplitViewControllerTest;
 
   // Ends the split view mode.
   void EndSplitView();
 
   // Starts/Stops observing |window|.
   void StartObserving(aura::Window* window);
   void StopObserving(aura::Window* window);
@@ skipping 15 matching lines @@
   // screen coordinates.
   int divider_position_ = -1;
 
   // Current snap state.
   State state_ = NO_SNAP;
 
   // The default snap position. It's decided by the first snapped window. If the
   // first window was snapped left, then |default_snap_position_| equals LEFT,
   // i.e., all the other windows will open snapped on the right side - and vice
   // versa.
-  SnapPosition default_snap_position_ = LEFT;
+  SnapPosition default_snap_position_ = NONE;
 
   base::ObserverList<Observer> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(SplitViewController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_SPLITSVIEW_SPLIT_VIEW_CONTROLLER_H_