mus: Fix activation cycle direction.

components/mus/ws/focus_controller.h

Index: components/mus/ws/focus_controller.h
diff --git a/components/mus/ws/focus_controller.h b/components/mus/ws/focus_controller.h
index a86c86e3912ad44114cf3ee65ff1b1ecdcecf8bd..105f35c994d6ebee59ad6508d1d68f8e3ce58a93 100644
--- a/components/mus/ws/focus_controller.h
+++ b/components/mus/ws/focus_controller.h
@@ -9,6 +9,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "components/mus/ws/server_window_drawn_tracker_observer.h"
+#include "components/mus/ws/server_window_observer.h"
 
 namespace mus {
 
@@ -18,6 +19,7 @@ class FocusControllerDelegate;
 class FocusControllerObserver;
 class ServerWindow;
 class ServerWindowDrawnTracker;
+struct WindowId;
 
 // Describes the source of the change.
 enum class FocusControllerChangeSource {
@@ -27,7 +29,8 @@ enum class FocusControllerChangeSource {
 
 // Tracks the focused window. Focus is moved to another window when the drawn
 // state of the focused window changes.
-class FocusController : public ServerWindowDrawnTrackerObserver {
+class FocusController : public ServerWindowDrawnTrackerObserver,
+                        public ServerWindowObserver {
  public:
   FocusController(FocusControllerDelegate* delegate, ServerWindow* root);
   ~FocusController() override;
@@ -44,7 +47,13 @@ class FocusController : public ServerWindowDrawnTrackerObserver {
   void RemoveObserver(FocusControllerObserver* observer);
 
  private:
-  void SetActiveWindow(ServerWindow* window);
+  enum class ActivationChangeReason {
+    UNKNONW,
+    CYCLE,  // Activation changed because of ActivateNextWindow().
+    FOCUS,  // Focus change required a different window to be activated.
+    DRAWN_STATE_CHANGED,  // Active window was hidden or destroyed.
+  };
+  void SetActiveWindow(ServerWindow* window, ActivationChangeReason reason);
 
   // Returns whether |window| can be focused or activated.
   bool CanBeFocused(ServerWindow* window) const;
@@ -58,6 +67,8 @@ class FocusController : public ServerWindowDrawnTrackerObserver {
   void SetFocusedWindowImpl(FocusControllerChangeSource change_source,
                             ServerWindow* window);
 
+  void ClearCycleWindows();
+
   // ServerWindowDrawnTrackerObserver:
   void OnDrawnStateWillChange(ServerWindow* ancestor,
                               ServerWindow* window,
@@ -66,11 +77,18 @@ class FocusController : public ServerWindowDrawnTrackerObserver {
                            ServerWindow* window,
                            bool is_drawn) override;
 
+  // ServerWindowObserver:
+  void OnWillDestroyWindow(ServerWindow* window) override;
+
   FocusControllerDelegate* delegate_;
 
   ServerWindow* root_;
   ServerWindow* focused_window_;
   ServerWindow* active_window_;
+  // Tracks what caused |active_window_| to be activated.
+  ActivationChangeReason activation_reason_;
+
+  std::vector<ServerWindow*> cycle_windows_;

[sky, 2016/01/06 21:02:39]

It's not obvious what this is, or how it changes based on the name (nor do I
think you could come up with a name that would convey it). Please add a
description.

[sadrul, 2016/01/08 20:40:26]

Done.

 
   base::ObserverList<FocusControllerObserver> observers_;