Make event-targeting asynchronous in window server.

services/ui/ws/window_manager_state.h

 // Copyright 2016 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_MANAGER_STATE_H_
 #define SERVICES_UI_WS_WINDOW_MANAGER_STATE_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 135 matching lines @@
   struct QueuedEvent {
     QueuedEvent();
     ~QueuedEvent();
 
     std::unique_ptr<Event> event;
     std::unique_ptr<ProcessedEventTarget> processed_target;
     int64_t display_id;
   };
 
   // Tracks state associated with an event being dispatched to a client.
-  struct InFlightEventDetails {
-    InFlightEventDetails(WindowManagerState* window_manager_state,
-                         WindowTree* tree,
-                         int64_t display_id,
-                         const Event& event,
-                         EventDispatchPhase phase);
-    ~InFlightEventDetails();
+  struct InFlightEventDispatchDetails {
+    InFlightEventDispatchDetails(WindowManagerState* window_manager_state,
+                                 WindowTree* tree,
+                                 int64_t display_id,
+                                 const Event& event,
+                                 EventDispatchPhase phase);
+    ~InFlightEventDispatchDetails();
 
     base::OneShotTimer timer;
     WindowTree* tree;
     int64_t display_id;
     std::unique_ptr<Event> event;
     EventDispatchPhase phase;
     base::WeakPtr<Accelerator> post_target_accelerator;
     // Used for callbacks/timer specific to processing |event|.
     base::WeakPtrFactory<WindowManagerState> weak_factory;
   };
@@ skipping 33 matching lines @@
 
   // Implemenation of processing an event with a match phase of all. This
   // handles debug accelerators and forwards to EventDispatcher.
   void ProcessEventImpl(const Event& event, int64_t display_id);
 
   // Schedules an event to be processed later.
   void QueueEvent(const Event& event,
                   std::unique_ptr<ProcessedEventTarget> processed_event_target,
                   int64_t display_id);
 
-  // Processes the next valid event in |event_queue_|. If the event has already
-  // been processed it is dispatched, otherwise the event is passed to the
-  // EventDispatcher for processing.
-  void ProcessNextEventFromQueue();
-
   // Dispatches the event to the appropriate client and starts the ack timer.
   void DispatchInputEventToWindowImpl(ServerWindow* target,
                                       ClientSpecificId client_id,
                                       const Event& event,
                                       base::WeakPtr<Accelerator> accelerator);
 
   // Registers accelerators used internally for debugging.
   void AddDebugAccelerators();
 
   // Finds the debug accelerator for |event| and if one is found calls
@@ skipping 18 matching lines @@
   void SetNativeCapture(ServerWindow* window) override;
   void ReleaseNativeCapture() override;
   void UpdateNativeCursorFromDispatcher() override;
   void OnCaptureChanged(ServerWindow* new_capture,
                         ServerWindow* old_capture) override;
   void OnMouseCursorLocationChanged(const gfx::Point& point) override;
   void DispatchInputEventToWindow(ServerWindow* target,
                                   ClientSpecificId client_id,
                                   const Event& event,
                                   Accelerator* accelerator) override;
+  // Processes the next valid event in |event_queue_|. If the event has already
+  // been processed it is dispatched, otherwise the event is passed to the
+  // EventDispatcher for processing.
+  void ProcessNextEventFromQueue() override;
   ClientSpecificId GetEventTargetClientId(const ServerWindow* window,
                                           bool in_nonclient_area) override;
   ServerWindow* GetRootWindowContaining(gfx::Point* location) override;
   void OnEventTargetNotFound(const Event& event) override;
 
   // ServerWindowObserver:
   void OnWindowEmbeddedAppDisconnected(ServerWindow* window) override;
 
   // The single WindowTree this WindowManagerState is associated with.
   // |window_tree_| owns this.
   WindowTree* window_tree_;
 
   // Set to true the first time SetFrameDecorationValues() is called.
   bool got_frame_decoration_values_ = false;
   mojom::FrameDecorationValuesPtr frame_decoration_values_;
 
+  // Events can go into this queue if there's a hit-test in flight in
+  // EventDispatcher or if we are actively dispatching an event.
   std::queue<std::unique_ptr<QueuedEvent>> event_queue_;
 
   std::vector<DebugAccelerator> debug_accelerators_;
 
   // If non-null we're actively waiting for a response from a client for an
   // event.
-  std::unique_ptr<InFlightEventDetails> in_flight_event_details_;
+  std::unique_ptr<InFlightEventDispatchDetails>
+      in_flight_event_dispatch_details_;
 
   EventDispatcher event_dispatcher_;
 
   // PlatformDisplay that currently has capture.
   PlatformDisplay* platform_display_with_capture_ = nullptr;
 
   // All the active WindowManagerDisplayRoots.
   WindowManagerDisplayRoots window_manager_display_roots_;
 
   // Id of the display the current event being processed originated from.
   int64_t event_processing_display_id_ = 0;
 
   // Set of WindowManagerDisplayRoots corresponding to Displays that have been
   // destroyed. WindowManagerDisplayRoots are not destroyed immediately when
   // the Display is destroyed to allow the client to destroy the window when it
   // wants to. Once the client destroys the window WindowManagerDisplayRoots is
   // destroyed.
   WindowManagerDisplayRoots orphaned_window_manager_display_roots_;
 
   // All state regarding what the current cursor is.
   CursorState cursor_state_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowManagerState);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_WINDOW_MANAGER_STATE_H_