Provided batched input delivery with a BufferedInputRouter

content/browser/renderer_host/input/browser_input_event.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_RENDERER_HOST_INPUT_BROWSER_INPUT_EVENT_H_
+#define CONTENT_BROWSER_RENDERER_HOST_INPUT_BROWSER_INPUT_EVENT_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_vector.h"
+#include "content/common/input/input_event.h"
+#include "content/common/input/input_event_disposition.h"
+
+namespace content {
+
+class BrowserInputEvent;
+
+// Provides customized dispatch response for BrowserInputEvents.
+class BrowserInputEventClient {
+ public:
+  virtual ~BrowserInputEventClient() {}
+
+  virtual void OnDispatched(const BrowserInputEvent& event,
+                            InputEventDisposition disposition) {}
+
+  // Called if the event went unconsumed and can create followup events. Any
+  // events added to |followup| by the client will be inserted into the
+  // current input event stream. |followup| will never be NULL.
+  virtual void OnDispatched(const BrowserInputEvent& event,
+                            InputEventDisposition disposition,
+                            ScopedVector<BrowserInputEvent>* followup) {}
+};
+
+// Augmented InputEvent allowing customized dispatch response in the browser.
+class CONTENT_EXPORT BrowserInputEvent : public InputEvent {
+ public:
+  // |client| is assumed to be non-NULL.
+  static scoped_ptr<BrowserInputEvent> Create(
+      int64 id,
+      scoped_ptr<InputEvent::Payload> payload,
+      BrowserInputEventClient* client);
+
+  template <typename PayloadType>
+  static scoped_ptr<BrowserInputEvent> Create(int64 id,
+                                              scoped_ptr<PayloadType> payload,
+                                              BrowserInputEventClient* client) {
+    return Create(id, payload.template PassAs<InputEvent::Payload>(), client);
+  }
+
+  virtual ~BrowserInputEvent();
+
+  // |followup_events| must not be NULL, and will only be modified if the
+  // event went unconsumed and can create followup events.
+  void OnDispatched(InputEventDisposition disposition,
+                    ScopedVector<BrowserInputEvent>* followup_events);
+
+ protected:
+  explicit BrowserInputEvent(BrowserInputEventClient* client);
+
+  bool CanCreateFollowupEvents() const;
+
+ private:
+  BrowserInputEventClient* client_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_BROWSER_INPUT_EVENT_H_