Promotes remaining global window manager state into WindowManagerState

components/mus/ws/display_manager.h

 // Copyright 2016 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 COMPONENTS_MUS_WS_DISPLAY_MANAGER_H_
 #define COMPONENTS_MUS_WS_DISPLAY_MANAGER_H_
 
 #include <map>
 #include <memory>
 #include <set>
 
 #include "base/macros.h"
 #include "components/mus/ws/ids.h"
 #include "components/mus/ws/user_id.h"
+#include "components/mus/ws/user_id_tracker_observer.h"
 
 namespace mus {
 namespace ws {
 
 class Display;
 class DisplayManagerDelegate;
 class ServerWindow;
 class UserDisplayManager;
-class WindowManagerState;
+class UserIdTracker;
+class WindowManagerDisplayRoot;
 
-struct WindowManagerAndDisplay {
-  WindowManagerAndDisplay() : window_manager_state(nullptr), display(nullptr) {}
-
-  WindowManagerState* window_manager_state;
-  Display* display;
-};
-
-struct WindowManagerAndDisplayConst {
-  WindowManagerAndDisplayConst()
-      : window_manager_state(nullptr), display(nullptr) {}
-  const WindowManagerState* window_manager_state;
-  const Display* display;
-};
-
-class DisplayManager {
+// DisplayManager manages the set of Displays. DisplayManager distinguishes
+// between displays that do yet have an accelerated widget (pending), vs
+// those that do.
+class DisplayManager : public UserIdTrackerObserver {
  public:
-  explicit DisplayManager(DisplayManagerDelegate* delegate);
-  ~DisplayManager();
+  DisplayManager(DisplayManagerDelegate* delegate,
+                 UserIdTracker* user_id_tracker);
+  ~DisplayManager() override;
 
   // Returns the UserDisplayManager for |user_id|. DisplayManager owns the
   // return value.
   UserDisplayManager* GetUserDisplayManager(const UserId& user_id);
 
   // Adds/removes a Display. DisplayManager owns the Displays.
   // TODO(sky): make add take a scoped_ptr.
   void AddDisplay(Display* display);
   void DestroyDisplay(Display* display);
   void DestroyAllDisplays();
   const std::set<Display*>& displays() { return displays_; }
   std::set<const Display*> displays() const;
 
   // Notifies when something about the Display changes.
   void OnDisplayUpdate(Display* display);
 
   // Returns the Display that contains |window|, or null if |window| is not
   // attached to a display.
   Display* GetDisplayContaining(ServerWindow* window);
   const Display* GetDisplayContaining(const ServerWindow* window) const;
 
-  WindowManagerAndDisplayConst GetWindowManagerAndDisplay(
+  const WindowManagerDisplayRoot* GetWindowManagerDisplayRoot(
       const ServerWindow* window) const;
-  WindowManagerAndDisplay GetWindowManagerAndDisplay(
+  // TODO(sky): constness here is wrong! fix!
+  WindowManagerDisplayRoot* GetWindowManagerDisplayRoot(
       const ServerWindow* window);
 
   bool has_displays() const { return !displays_.empty(); }
   bool has_active_or_pending_displays() const {
     return !displays_.empty() || !pending_displays_.empty();
   }
 
   // Returns the id for the next root window (both for the root of a Display
   // as well as the root of WindowManagers).
   WindowId GetAndAdvanceNextRootId();
 
   uint32_t GetAndAdvanceNextDisplayId();
 
   // Called when the AcceleratedWidget is available for |display|.
   void OnDisplayAcceleratedWidgetAvailable(Display* display);
 
  private:
+  // UserIdTrackerObserver:
+  void OnActiveUserIdChanged(const UserId& previously_active_id,
+                             const UserId& active_id) override;
+
   DisplayManagerDelegate* delegate_;
+  UserIdTracker* user_id_tracker_;
 
   // Displays are initially added to |pending_displays_|. When the display is
   // initialized it is moved to |displays_|. WindowServer owns the Displays.
   std::set<Display*> pending_displays_;
   std::set<Display*> displays_;
 
   std::map<UserId, std::unique_ptr<UserDisplayManager>> user_display_managers_;
 
   // ID to use for next root node.
   ClientSpecificId next_root_id_;
 
   uint32_t next_display_id_;
 
   DISALLOW_COPY_AND_ASSIGN(DisplayManager);
 };
 
 }  // namespace ws
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_WS_DISPLAY_MANAGER_H_