aura-mus: add a drag representation image.

services/ui/ws/window_tree.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 SERVICES_UI_WS_WINDOW_TREE_H_
 #define SERVICES_UI_WS_WINDOW_TREE_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <memory>
 #include <queue>
 #include <set>
 #include <string>
 #include <unordered_map>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
 #include "cc/ipc/surface_id.mojom.h"
 #include "mojo/public/cpp/bindings/associated_binding.h"
 #include "services/ui/public/interfaces/window_tree.mojom.h"
 #include "services/ui/ws/access_policy_delegate.h"
 #include "services/ui/ws/drag_source.h"
 #include "services/ui/ws/drag_target_connection.h"
 #include "services/ui/ws/ids.h"
 #include "services/ui/ws/user_id.h"
 #include "services/ui/ws/window_tree_binding.h"
 
@@ skipping 335 matching lines @@
 
   void DispatchInputEventImpl(ServerWindow* target, const ui::Event& event);
 
   // Returns true if the client has a pointer watcher and this event matches.
   bool EventMatchesPointerWatcher(const ui::Event& event) const;
 
   // Calls OnChangeCompleted() on the client.
   void NotifyChangeCompleted(uint32_t change_id,
                              mojom::WindowManagerErrorCode error_code);
 
+  // Callback for when WmMoveDragImage completes. This sends off the next
+  // queued move under the image if the mouse had further moves while we were
+  // waiting for the last move to be acknowledged.
+  void OnWmMoveDragImageCompleted();
+
   // WindowTree:
   void NewWindow(uint32_t change_id,
                  Id transport_window_id,
                  const base::Optional<
                      std::unordered_map<std::string, std::vector<uint8_t>>>&
                      transport_properties) override;
   void NewTopLevelWindow(
       uint32_t change_id,
       Id transport_window_id,
       const std::unordered_map<std::string, std::vector<uint8_t>>&
@@ skipping 68 matching lines @@
   void StackAbove(uint32_t change_id, Id above_id, Id below_id) override;
   void StackAtTop(uint32_t change_id, Id window_id) override;
   void GetWindowManagerClient(
       mojo::AssociatedInterfaceRequest<mojom::WindowManagerClient> internal)
       override;
   void GetCursorLocationMemory(const GetCursorLocationMemoryCallback& callback)
       override;
   void PerformDragDrop(
       uint32_t change_id,
       Id source_window_id,
+      const gfx::Point& screen_location,
       const std::unordered_map<std::string, std::vector<uint8_t>>& drag_data,
-      uint32_t drag_operation) override;
+      const SkBitmap& drag_image,
+      const gfx::Vector2d& drag_image_offset,
+      uint32_t drag_operation,
+      ui::mojom::DragEventSource source) override;
   void CancelDragDrop(Id window_id) override;
   void PerformWindowMove(uint32_t change_id,
                          Id window_id,
                          ui::mojom::MoveLoopSource source,
                          const gfx::Point& cursor) override;
   void CancelWindowMove(Id window_id) override;
 
   // mojom::WindowManagerClient:
   void AddAccelerators(std::vector<mojom::WmAcceleratorPtr> accelerators,
                        const AddAcceleratorsCallback& callback) override;
@@ skipping 18 matching lines @@
 
   // AccessPolicyDelegate:
   bool HasRootForAccessPolicy(const ServerWindow* window) const override;
   bool IsWindowKnownForAccessPolicy(const ServerWindow* window) const override;
   bool IsWindowRootOfAnotherTreeForAccessPolicy(
       const ServerWindow* window) const override;
   bool IsWindowCreatedByWindowManager(
       const ServerWindow* window) const override;
 
   // DragSource:
+  void OnDragContinued(const gfx::Point& location) override;
   void OnDragCompleted(bool success, uint32_t action_taken) override;
   ServerWindow* GetWindowById(const WindowId& id) override;
   DragTargetConnection* GetDragTargetForWindow(
       const ServerWindow* window) override;
 
   // DragTargetConnection:
   void PerformOnDragDropStart(
       const std::unordered_map<std::string, std::vector<uint8_t>>& mime_data)
       override;
   void PerformOnDragEnter(
@@ skipping 66 matching lines @@
 
   std::unique_ptr<mojo::AssociatedBinding<mojom::WindowManagerClient>>
       window_manager_internal_client_binding_;
   mojom::WindowManager* window_manager_internal_;
   std::unique_ptr<WindowManagerState> window_manager_state_;
 
   std::unique_ptr<WaitingForTopLevelWindowInfo>
       waiting_for_top_level_window_info_;
   bool embedder_intercepts_events_ = false;
 
+  // Whether we're waiting for an ack from a WmMoveDragImage message.

[sky, 2017/03/23 00:05:36]

Similar to WindowManager please put the state related to a drag into it's own
struct.

[Elliot Glaysher, 2017/03/23 19:58:44]

Done. But I left the weak_factory_ in WindowTree (and renamed) as I'm unsure if
its safe to have a factory to an object in another one. I can't think of a
reason this would be so, but...

+  bool waiting_for_move_drag_ack_ = false;
+
+  // Whether we've queued a move to |queued_cursor_location_| when we get an
+  // ack from WmMoveDragImage.
+  bool has_queued_drag_window_move_ = false;
+
+  // When |has_queued_drag_window_move_| is true, this is a location which
+  // should be sent to the window manager as soon as it acked the last one.
+  gfx::Point queued_cursor_location_;
+
+  base::WeakPtrFactory<WindowTree> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(WindowTree);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_WINDOW_TREE_H_