mus: Implement interwindow drag and drop

services/ui/public/cpp/window_tree_client.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_PUBLIC_CPP_WINDOW_TREE_CLIENT_H_
 #define SERVICES_UI_PUBLIC_CPP_WINDOW_TREE_CLIENT_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 90 matching lines @@
                  const gfx::Rect& bounds);
   void SetCapture(Window* window);
   void ReleaseCapture(Window* window);
   void SetClientArea(Id window_id,
                      const gfx::Insets& client_area,
                      const std::vector<gfx::Rect>& additional_client_areas);
   void SetHitTestMask(Id window_id, const gfx::Rect& mask);
   void ClearHitTestMask(Id window_id);
   void SetFocus(Window* window);
   void SetCanFocus(Id window_id, bool can_focus);
+  void SetCanAcceptDrops(Id window_id, bool can_accept_drops);
   void SetCanAcceptEvents(Id window_id, bool can_accept_events);
   void SetPredefinedCursor(Id window_id, ui::mojom::Cursor cursor_id);
   void SetVisible(Window* window, bool visible);
   void SetOpacity(Window* window, float opacity);
   void SetProperty(Window* window,
                    const std::string& name,
                    mojo::Array<uint8_t> data);
   void SetWindowTextInputState(Id window_id, mojo::TextInputStatePtr state);
   void SetImeVisibility(Id window_id,
                         bool visible,
@@ skipping 47 matching lines @@
   // Returns the current location of the mouse on screen. Note: this method may
   // race the asynchronous initialization; but in that case we return (0, 0).
   gfx::Point GetCursorScreenPoint();
 
   // See description in window_tree.mojom. When an existing pointer watcher is
   // updated or cleared then any future events from the server for that watcher
   // will be ignored.
   void StartPointerWatcher(bool want_moves);
   void StopPointerWatcher();
 
+  void PerformDragDrop(
+      Window* window,
+      int drag_pointer,
+      const std::map<std::string, std::vector<uint8_t>>& drag_data,
+      int drag_operation,
+      const gfx::Point& cursor_location,
+      const SkBitmap& bitmap,
+      const base::Callback<void(bool)>& callback);
+
   // Performs a window move. |callback| will be asynchronously called with the
   // whether the move loop completed successfully.
   void PerformWindowMove(Window* window,
                          ui::mojom::MoveLoopSource source,
                          const gfx::Point& cursor_location,
                          const base::Callback<void(bool)>& callback);
 
   // Cancels a in progress window move. (If no window is currently being moved,
   // does nothing.)
   void CancelWindowMove(Window* window);
@@ skipping 12 matching lines @@
 #if !defined(NDEBUG)
   std::string GetDebugWindowHierarchy() const;
   void BuildDebugInfo(const std::string& depth,
                       Window* window,
                       std::string* result) const;
 #endif
 
  private:
   friend class WindowTreeClientPrivate;
 
+  struct CurrentDragState;
+
   enum class NewWindowType {
     CHILD,
     TOP_LEVEL,
   };
 
   using IdToWindowMap = std::map<Id, Window*>;
 
   // TODO(sky): this assumes change_ids never wrap, which is a bad assumption.
   using InFlightMap = std::map<uint32_t, std::unique_ptr<InFlightChange>>;
 
@@ skipping 81 matching lines @@
                                      mojo::Array<uint8_t> new_data) override;
   void OnWindowInputEvent(uint32_t event_id,
                           Id window_id,
                           std::unique_ptr<ui::Event> event,
                           bool matches_pointer_watcher) override;
   void OnPointerEventObserved(std::unique_ptr<ui::Event> event,
                               uint32_t window_id) override;
   void OnWindowFocused(Id focused_window_id) override;
   void OnWindowPredefinedCursorChanged(Id window_id,
                                        mojom::Cursor cursor) override;
+  void OnDragDropStart(
+      mojo::Map<mojo::String, mojo::Array<uint8_t>> mime_data) override;
+  void OnDragEnter(Id window_id,
+                   uint32_t event_flags,
+                   const gfx::Point& position,
+                   uint32_t effect_bitmask,
+                   const OnDragEnterCallback& callback) override;
+  void OnDragOver(Id window_id,
+                  uint32_t event_flags,
+                  const gfx::Point& position,
+                  uint32_t effect_bitmask,
+                  const OnDragOverCallback& callback) override;
+  void OnDragLeave(Id window_id) override;
+  void OnCompleteDrop(Id window_id,
+                      uint32_t event_flags,
+                      const gfx::Point& position,
+                      uint32_t effect_bitmask,
+                      const OnCompleteDropCallback& callback) override;
+  void OnDragDropDone() override;
   void OnChangeCompleted(uint32_t change_id, bool success) override;
   void RequestClose(uint32_t window_id) override;
   void GetWindowManager(
       mojo::AssociatedInterfaceRequest<WindowManager> internal) override;
 
   // Overridden from WindowManager:
   void OnConnect(ClientSpecificId client_id) override;
   void WmNewDisplayAdded(const display::Display& display,
                          mojom::WindowDataPtr root_data,
                          bool parent_drawn) override;
@@ skipping 85 matching lines @@
 
   std::unique_ptr<mojo::AssociatedBinding<mojom::WindowManager>>
       window_manager_internal_;
   mojom::WindowManagerClientAssociatedPtr window_manager_internal_client_;
 
   bool has_pointer_watcher_ = false;
 
   // The current change id for the client.
   uint32_t current_move_loop_change_ = 0u;
 
+  // Callback executed when a move loop initiated by PerformWindowMove() is
+  // completed.
+  base::Callback<void(bool)> on_current_move_finished_;
+
   // The current change id for the window manager.
   uint32_t current_wm_move_loop_change_ = 0u;
   Id current_wm_move_loop_window_id_ = 0u;
 
-  // Callback executed when a move loop initiated by PerformWindowMove() is
-  // completed.
-  base::Callback<void(bool)> on_current_move_finished_;
+  // State related to being the initiator of a drag started with
+  // PerformDragDrop().
+  std::unique_ptr<CurrentDragState> current_drag_state_;
+
+  // The mus server sends the mime drag data once per connection; we cache this
+  // and are responsible for sending it to all of our windows.
+  mojo::Map<mojo::String, mojo::Array<uint8_t>> mime_drag_data_;
+
+  // A set of window ids for windows that we received an OnDragEnter() message
+  // for. We maintain this set so we know who to send OnDragFinish() messages
+  // at the end of the drag.
+  std::set<Id> drag_entered_windows_;
 
   base::WeakPtrFactory<WindowTreeClient> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeClient);
 };
 
 }  // namespace ui
 
 #endif  // SERVICES_UI_PUBLIC_CPP_WINDOW_TREE_CLIENT_H_