Tab dragging as implemented as a mus API.

components/mus/ws/window_server.h

 // Copyright 2014 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_WINDOW_SERVER_H_
 #define COMPONENTS_MUS_WS_WINDOW_SERVER_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 140 matching lines @@
                                          uint32_t client_change_id);
 
   // Called when a response from the window manager is obtained. Calls to
   // the client that initiated the change with the change id originally
   // supplied by the client.
   void WindowManagerChangeCompleted(uint32_t window_manager_change_id,
                                     bool success);
   void WindowManagerCreatedTopLevelWindow(WindowTree* wm_tree,
                                           uint32_t window_manager_change_id,
                                           const ServerWindow* window);
+  void WindowManagerCompletedMoveLoop(uint32_t window_manager_change_id,
+                                      const ServerWindow* window,
+                                      bool completed);
 
   // Called when we get an unexpected message from the WindowManager.
   // TODO(sky): decide what we want to do here.
   void WindowManagerSentBogusMessage() {}
 
   // These functions trivially delegate to all WindowTrees, which in
   // term notify their clients.
   void ProcessWindowBoundsChanged(const ServerWindow* window,
                                   const gfx::Rect& old_bounds,
                                   const gfx::Rect& new_bounds);
@@ skipping 18 matching lines @@
   // Sends an |event| to all WindowTrees belonging to |user_id| that might be
   // observing events. Skips |ignore_tree| if it is non-null.
   void SendToEventObservers(const ui::Event& event,
                             const UserId& user_id,
                             WindowTree* ignore_tree);
 
   // Sets a callback to be called whenever a ServerWindow is scheduled for
   // a [re]paint. This should only be called in a test configuration.
   void SetPaintCallback(const base::Callback<void(ServerWindow*)>& callback);
 
+  void StartMoveLoop(uint32_t change_id,
+                     ServerWindow* window,
+                     WindowTree* initiator,
+                     const gfx::Rect& revert_bounds);
+  void EndMoveLoop();
+  uint32_t GetCurrentMoveLoopChangeId();
+  ServerWindow* GetCurrentMoveLoopWindow();
+  WindowTree* GetCurrentMoveLoopInitiator();
+  gfx::Rect GetCurrentMoveLoopRevertBounds();
+  bool in_move_loop() { return !!current_move_loop_.get(); }

[sky, 2016/06/29 00:04:09]

nit: const

+
  private:
+  struct CurrentMoveLoopState;
   friend class Operation;
 
   using WindowTreeMap =
       std::map<ClientSpecificId, std::unique_ptr<WindowTree>>;
   using UserActivityMonitorMap =
       std::map<UserId, std::unique_ptr<UserActivityMonitor>>;
 
   struct InFlightWindowManagerChange {
     // Identifies the client that initiated the change.
     ClientSpecificId client_id;
@@ skipping 94 matching lines @@
   WindowServerDelegate* delegate_;
 
   // State for rendering into a Surface.
   scoped_refptr<mus::SurfacesState> surfaces_state_;
 
   // ID to use for next WindowTree.
   ClientSpecificId next_client_id_;
 
   std::unique_ptr<DisplayManager> display_manager_;
 
+  std::unique_ptr<CurrentMoveLoopState> current_move_loop_;
+
   // Set of WindowTrees.
   WindowTreeMap tree_map_;
 
   // If non-null then we're processing a client operation. The Operation is
   // not owned by us (it's created on the stack by WindowTree).
   Operation* current_operation_;
 
   bool in_destructor_;
 
   // Maps from window manager change id to the client that initiated the
   // request.
   InFlightWindowManagerChangeMap in_flight_wm_change_map_;
 
   // Next id supplied to the window manager.
   uint32_t next_wm_change_id_;
 
   base::Callback<void(ServerWindow*)> window_paint_callback_;
 
   UserActivityMonitorMap activity_monitor_map_;
 
   WindowManagerWindowTreeFactorySet window_manager_window_tree_factory_set_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowServer);
 };
 
 }  // namespace ws
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_WS_WINDOW_SERVER_H_