mus: Implement Window Server Capture

components/mus/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 COMPONENTS_MUS_WS_EVENT_DISPATCHER_H_
 #define COMPONENTS_MUS_WS_EVENT_DISPATCHER_H_
 
 #include <map>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 15 matching lines @@
 // Handles dispatching events to the right location as well as updating focus.
 class EventDispatcher : public ServerWindowObserver {
  public:
   explicit EventDispatcher(EventDispatcherDelegate* delegate);
   ~EventDispatcher() override;
 
   void set_root(ServerWindow* root) { root_ = root; }
 
   void set_surface_id(cc::SurfaceId surface_id) { surface_id_ = surface_id; }
 
+  ServerWindow* capture_window() { return capture_window_; }
+  const ServerWindow* capture_window() const { return capture_window_; }
+  void SetCaptureWindow(ServerWindow* capture_window);
+
   void AddAccelerator(uint32_t id, mojom::EventMatcherPtr event_matcher);
   void RemoveAccelerator(uint32_t id);
 
   void OnEvent(mojom::EventPtr event);
 
  private:
   // Keeps track of state associated with a pointer down until the
   // corresponding up/cancel.
   struct PointerTarget {
     PointerTarget() : window(nullptr), in_nonclient_area(false) {}
@@ skipping 14 matching lines @@
   // . move (not drag) events go to the deepest window.
   // . when a pointer goes down all events until the corresponding up or
   //   cancel go to the deepest target. For mouse events the up only occurs
   //   when no buttons on the mouse are down.
   void ProcessPointerEvent(mojom::EventPtr event);
 
   // If |target->window| is valid, then passes the event to the delegate.
   void DispatchToPointerTarget(const PointerTarget& target,
                                mojom::EventPtr event);
 
+  // Cancels all implicit capture. This is called when the explicit capture
+  // state changes.
+  void CancelAllPointerEvents();
+
   // Stops sending pointer events to |window|. This does not remove the entry
   // for |window| from |pointer_targets_|, rather it nulls out the window. This
   // way we continue to eat events until the up/cancel is received.
   void CancelPointerEventsToTarget(ServerWindow* window);
 
   // Returns true if we're currently an observer for |window|. We are an
   // observer for a window if any pointer events are targeting it.
   bool IsObservingWindow(ServerWindow* window);
 
   // Looks to see if there is an accelerator bound to the specified code/flags.
   // If there is one, sets |accelerator_id| to the id of the accelerator invoked
   // and returns true. If there is none, returns false so normal key event
   // processing can continue.
   bool FindAccelerator(const mojom::Event& event, uint32_t* accelerator_id);
 
   // 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* root_;
+  ServerWindow* capture_window_;
 
   cc::SurfaceId surface_id_;
 
   using Entry = std::pair<uint32_t, EventMatcher>;
   std::map<uint32_t, EventMatcher> accelerators_;
 
   using PointerIdToTargetMap = std::map<int32_t, PointerTarget>;
   PointerIdToTargetMap pointer_targets_;
 
   DISALLOW_COPY_AND_ASSIGN(EventDispatcher);
 };
 
 }  // namespace ws
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_WS_EVENT_DISPATCHER_H_