mus: Implement interwindow drag and drop

services/ui/ws/event_dispatcher.h

 // Copyright 2015 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_EVENT_DISPATCHER_H_
 #define SERVICES_UI_WS_EVENT_DISPATCHER_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <memory>
 #include <utility>
 
 #include "base/macros.h"
 #include "services/ui/common/types.h"
 #include "services/ui/public/interfaces/event_matcher.mojom.h"
 #include "services/ui/ws/modal_window_controller.h"
 #include "services/ui/ws/server_window_observer.h"
 #include "ui/gfx/geometry/rect_f.h"
 
 namespace ui {
 class Event;
 class KeyEvent;
 class LocatedEvent;
 
 namespace ws {
 
 class Accelerator;
+class DragController;
+class DragSource;
 class EventDispatcherDelegate;
 class ServerWindow;
+class WindowTree;
 
 namespace test {
 class EventDispatcherTestApi;
 }
 
 // Handles dispatching events to the right location as well as updating focus.
 class EventDispatcher : public ServerWindowObserver {
  public:
   enum class AcceleratorMatchPhase {
     // Both pre and post should be considered.
@@ skipping 27 matching lines @@
   // Setting capture can fail if the window is blocked by a modal window
   // (indicated by returning |false|).
   bool SetCaptureWindow(ServerWindow* capture_window,
                         ClientSpecificId client_id);
 
   // Id of the client that capture events are sent to.
   ClientSpecificId capture_window_client_id() const {
     return capture_window_client_id_;
   }
 
+  void SetDragDropSourceWindow(
+      DragSource* drag_source,
+      ServerWindow* window,
+      int32_t drag_pointer,
+      mojo::Map<mojo::String, mojo::Array<uint8_t>> mime_data,
+      uint32_t drag_operations);
+  void EndDragDrop();
+
   // Adds a system modal window. The window remains modal to system until it is
   // destroyed. There can exist multiple system modal windows, in which case the
   // one that is visible and added most recently or shown most recently would be
   // the active one.
   void AddSystemModalWindow(ServerWindow* window);
 
   // Checks if |modal_window| is a visible modal window that blocks current
   // capture window and if that's the case, releases the capture.
   void ReleaseCaptureBlockedByModalWindow(const ServerWindow* modal_window);
 
@@ skipping 109 matching lines @@
   void ObserveWindow(ServerWindow* winodw);
   void UnobserveWindow(ServerWindow* winodw);
 
   // Returns an Accelerator bound to the specified code/flags, and of the
   // matching |phase|. Otherwise returns null.
   Accelerator* FindAccelerator(const ui::KeyEvent& event,
                                const ui::mojom::AcceleratorPhase phase);
 
   ServerWindow* FindDeepestVisibleWindowForEvents(gfx::Point* location);
 
+  // Clears the implicit captures in |pointer_targets_|, with the exception of
+  // |window|. |window| may be null.
+  void CancelImplicitCaptureExcept(ServerWindow* window);
+
   // ServerWindowObserver:
   void OnWillChangeWindowHierarchy(ServerWindow* window,
                                    ServerWindow* new_parent,
                                    ServerWindow* old_parent) override;
   void OnWindowVisibilityChanged(ServerWindow* window) override;
   void OnWindowDestroyed(ServerWindow* window) override;
 
   EventDispatcherDelegate* delegate_;
 
   ServerWindow* capture_window_;
   ClientSpecificId capture_window_client_id_;
 
+  std::unique_ptr<DragController> drag_controller_;
+
   ModalWindowController modal_window_controller_;
 
   bool mouse_button_down_;
   ServerWindow* mouse_cursor_source_window_;
   bool mouse_cursor_in_non_client_area_;
 
   // The on screen location of the mouse pointer. This can be outside the
   // bounds of |mouse_cursor_source_window_|, which can capture the cursor.
   gfx::Point mouse_pointer_last_location_;
 
@@ skipping 15 matching lines @@
       AcceleratorMatchPhase::ANY;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(EventDispatcher);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_EVENT_DISPATCHER_H_