Provided batched input delivery with a BufferedInputRouter

content/browser/renderer_host/input/buffered_input_router.h

+// Copyright (c) 2013 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 CONTENT_BROWSER_INPUT_RENDERER_HOST_BUFFERED_INPUT_ROUTER_H_
+#define CONTENT_BROWSER_INPUT_RENDERER_HOST_BUFFERED_INPUT_ROUTER_H_
+
+#include <map>
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
+#include "content/browser/renderer_host/input/browser_input_event.h"
+#include "content/browser/renderer_host/input/input_queue.h"
+#include "content/browser/renderer_host/input/input_queue_client.h"
+#include "content/browser/renderer_host/input/input_router.h"
+
+namespace IPC {
+class Sender;
+}
+
+namespace content {
+
+class InputAckHandler;
+class RenderProcessHost;
+class RenderWidgetHostImpl;
+
+// Batches input events into EventPackets using a general input queue. Packets
+// are sent the renderer on |Flush()|, called in response to flush requests.
+class CONTENT_EXPORT BufferedInputRouter
+    : public NON_EXPORTED_BASE(BrowserInputEventClient),
+      public NON_EXPORTED_BASE(InputQueueClient),
+      public NON_EXPORTED_BASE(InputRouter) {
+ public:
+  // |sender|, |client| and |ack_handler| must outlive the BufferedInputRouter.
+  BufferedInputRouter(IPC::Sender* sender,
+                      InputRouterClient* client,
+                      InputAckHandler* ack_handler,
+                      int routing_id);
+  virtual ~BufferedInputRouter();
+
+  // InputRouter
+  virtual void Flush() OVERRIDE;
+  virtual bool SendInput(scoped_ptr<IPC::Message> message) OVERRIDE;
+
+  // Certain unhandled input event acks may create follow-up events, e.g.,
+  // TouchEvent -> GestureEvent.  If these follow-up events are sent to the
+  // router synchronously from the original event's |OnDispatched()| ack, they
+  // will be inserted into the current input flush stream.
+  virtual void SendMouseEvent(
+      const MouseEventWithLatencyInfo& mouse_event) OVERRIDE;
+  virtual void SendWheelEvent(
+      const MouseWheelEventWithLatencyInfo& wheel_event) OVERRIDE;
+  virtual void SendKeyboardEvent(const NativeWebKeyboardEvent& key_event,
+                                 const ui::LatencyInfo& latency_info) OVERRIDE;
+  virtual void SendGestureEvent(
+      const GestureEventWithLatencyInfo& gesture_event) OVERRIDE;
+  virtual void SendTouchEvent(
+      const TouchEventWithLatencyInfo& touch_event) OVERRIDE;
+  virtual void SendMouseEventImmediately(
+      const MouseEventWithLatencyInfo& mouse_event) OVERRIDE;
+  virtual void SendTouchEventImmediately(
+      const TouchEventWithLatencyInfo& touch_event) OVERRIDE;
+  virtual void SendGestureEventImmediately(
+      const GestureEventWithLatencyInfo& gesture_event) OVERRIDE;
+  virtual const NativeWebKeyboardEvent* GetLastKeyboardEvent() const OVERRIDE;
+  virtual bool ShouldForwardTouchEvent() const OVERRIDE;
+  virtual bool ShouldForwardGestureEvent(
+      const GestureEventWithLatencyInfo& gesture_event) const OVERRIDE;
+  virtual bool HasQueuedGestureEvents() const OVERRIDE;
+
+  // InputQueueClient
+  virtual void Deliver(const EventPacket& packet) OVERRIDE;
+  virtual void DidFinishFlush() OVERRIDE;
+  virtual void SetNeedsFlush() OVERRIDE;
+
+  // BrowserInputEventClient
+  virtual void OnDispatched(const BrowserInputEvent& event,
+                            InputEventDisposition disposition) OVERRIDE;
+  // Events delivered to the router within the scope of
+  // |OnDispatched()| will be added to |followup|.
+  virtual void OnDispatched(const BrowserInputEvent& event,
+                            InputEventDisposition disposition,
+                            ScopedVector<BrowserInputEvent>* followup) OVERRIDE;
+
+  // IPC::Receiver
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
+ protected:
+  void OnWebInputEventAck(int64 event_id,
+                          const WebKit::WebInputEvent& web_event,
+                          const ui::LatencyInfo& latency_info,
+                          InputEventAckState acked_result,
+                          bool ack_from_input_queue);
+  void OnEventPacketAck(int64 packet_id,
+                        const InputEventDispositions& dispositions);
+  void OnHasTouchEventHandlers(bool has_handlers);
+
+  // Returns the non-zero ID associated with the |InputEvent| added to the
+  // |input_queue_|. If the event was dropped or filtered, returns 0.
+  int64 QueueWebEvent(const WebKit::WebInputEvent& web_event,
+                      const ui::LatencyInfo& latency_info,
+                      bool is_key_shortcut);
+  // Used by |QueueWebEvent()|; returns true if an event was filtered and should
+  // not be added to the |input_queue_|.
+  bool FilterWebEvent(const WebKit::WebInputEvent& web_event,
+                      const ui::LatencyInfo& latency_info);
+
+  // Generates a monotonically increasing sequences of id's, starting with 1.
+  int64 NextInputID();
+
+  const InputQueue* input_queue() const { return input_queue_.get(); }
+
+ private:
+  InputRouterClient* client_;
+  InputAckHandler* ack_handler_;
+  IPC::Sender* sender_;
+  int routing_id_;
+
+  scoped_ptr<InputQueue> input_queue_;
+
+  // TODO(jdduke): Remove when we can properly serialize NativeWebKeyboardEvent.
+  // Alternatively, attach WebInputEvents to InputEvents but don't serialize.
+  typedef std::map<int64, NativeWebKeyboardEvent> KeyMap;
+  KeyMap queued_key_map_;
+
+  // Necessary for |HasQueuedGestureEvents()|.
+  int queued_gesture_count_;
+
+  // Necessary for |ShouldForwardTouchEvent()|.
+  bool has_touch_handler_;
+  int queued_touch_count_;
+
+  // This is non-NULL ONLY in the scope of OnInputEventAck(event, injector).
+  ScopedVector<BrowserInputEvent>* input_queue_override_;
+
+  // Used to assign unique ID's to each InputEvent that is generated.
+  int64 next_input_id_;
+
+  // 0 if there no in-flight EventPacket.
+  int64 in_flight_packet_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(BufferedInputRouter);
+};
+
+} // namespace content
+
+#endif // CONTENT_BROWSER_INPUT_RENDERER_HOST_BUFFERED_INPUT_ROUTER_H_