Provided batched input delivery with a BufferedInputRouter

content/browser/renderer_host/input/buffered_input_router.h

Index: content/browser/renderer_host/input/buffered_input_router.h
diff --git a/content/browser/renderer_host/input/buffered_input_router.h b/content/browser/renderer_host/input/buffered_input_router.h
new file mode 100644
index 0000000000000000000000000000000000000000..2c63de2505bd99cd598d8897bd5302f1ce486f82
--- /dev/null
+++ b/content/browser/renderer_host/input/buffered_input_router.h
@@ -0,0 +1,149 @@
+// 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/time/time.h"
+#include "base/timer/timer.h"
+#include "content/browser/renderer_host/input/event_ack_handler.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 content {
+
+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(InputQueueClient),
+      public NON_EXPORTED_BASE(InputRouter),
+      public NON_EXPORTED_BASE(EventAckHandler) {
+ public:
+  BufferedInputRouter(RenderProcessHost* process,
+                      InputRouterClient* client,
+                      int routing_id);
+  virtual ~BufferedInputRouter();
+
+  // InputRouter
+  virtual void Flush() OVERRIDE;
+  virtual bool SendInput(IPC::Message* message) OVERRIDE;
+  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;
+
+  void set_delayed_packet_timeout_ms(const base::TimeDelta& timeout) {
+    delayed_packet_timeout_ms_ = timeout.InMilliseconds();
+  }
+
+private:
+  friend class BufferedInputRouterTest;

[aelias_OOO_until_Jul13, 2013/08/13 06:11:51]

friending can normally be avoided by marking things "protected" and having a
test class derive from it, please give that a try.

+
+  // InputQueueClient
+  virtual void Deliver(const EventPacket& packet) OVERRIDE;

[aelias_OOO_until_Jul13, 2013/08/13 06:11:51]

These are public in the base class so they should be public here too.

[jdduke (slow), 2013/08/13 15:29:48]

Done.

+  virtual void DidFlush() OVERRIDE;
+  virtual void SetNeedsFlush() OVERRIDE;
+
+  // EventAckHandler
+  virtual void OnInputEventAck(const InputEvent& acked_event) OVERRIDE;
+  virtual void OnInputEventAck(const InputEvent& acked_event,
+                               EventInjector* injector) OVERRIDE;
+
+  // IPC::Receiver
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
+  void OnInputEventAck(int64 event_id,
+                       const WebKit::WebInputEvent& web_event,
+                       const ui::LatencyInfo& latency_info,
+                       InputEventAckState acked_result,
+                       bool ack_from_input_queue);
+  void OnEventPacketAck(const EventPacket& acked_packet);
+  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_keyboard_shortcut,
+                      bool has_followup);
+  // 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);
+
+  void StartDelayedPacketMonitorTimeout(base::TimeDelta delay);
+  void StopDelayedPacketMonitorTimeout();
+  void CheckShouldSignalDelayedPacket();
+
+  // Generates a monotonically increasing sequences of id's, starting with 1.
+  int64 NewInputID();

[aelias_OOO_until_Jul13, 2013/08/13 06:11:51]

Call this NextInputID()

[jdduke (slow), 2013/08/13 15:29:48]

Done.

+
+  InputRouterClient* client_;
+  RenderProcessHost* process_;

[aelias_OOO_until_Jul13, 2013/08/13 06:11:51]

All you ever do with this is send IPCs, so store it as an IPC::Sender instead
(likewise take IPC::Sender in the constructor)

[jdduke (slow), 2013/08/13 15:29:48]

Done.

+  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).
+  EventAckHandler::EventInjector* input_queue_override_;
+
+  // Used to assign unique ID's to each InputEvent that is generated.
+  int64 last_input_id_;

[aelias_OOO_until_Jul13, 2013/08/13 06:11:51]

Common idiom is to call this next_input_id_

[jdduke (slow), 2013/08/13 15:29:48]

Done.

+
+  // 0 if there no in-flight EventPacket.
+  int64 in_flight_packet_id_;
+
+  // How long to wait before an in-flight event packet should be dropped.
+  int delayed_packet_timeout_ms_;

[aelias_OOO_until_Jul13, 2013/08/13 06:11:51]

Store this as base::TimeDelta as well.

[jdduke (slow), 2013/08/13 15:29:48]

Done.

+
+  // Time in the future when we should drop the in-flight event packet.
+  base::Time time_when_signal_delayed_packet_;

[aelias_OOO_until_Jul13, 2013/08/13 06:11:51]

Use base::TimeTicks instead.

[jdduke (slow), 2013/08/13 15:29:48]

Done.

+
+  // Check if time_when_signal_delayed_packet_ has past.
+  base::OneShotTimer<BufferedInputRouter> delayed_packet_timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(BufferedInputRouter);
+};
+
+} // namespace content
+
+#endif // CONTENT_BROWSER_INPUT_RENDERER_HOST_BUFFERED_INPUT_ROUTER_H_