Input event filtering and compositor thread setup.

content/renderer/gpu/input_event_filter.cc

Index: content/renderer/gpu/input_event_filter.cc
===================================================================
--- content/renderer/gpu/input_event_filter.cc	(revision 0)
+++ content/renderer/gpu/input_event_filter.cc	(revision 0)
@@ -0,0 +1,145 @@
+// Copyright (c) 2011 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.
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "content/common/view_messages.h"
+#include "content/renderer/gpu/input_event_filter.h"
+
+using WebKit::WebInputEvent;
+
+InputEventFilter::InputEventFilter(IPC::Channel::Listener* main_listener,
+                                   base::MessageLoopProxy* target_loop,
+                                   const Handler& handler)
+    : main_loop_(base::MessageLoopProxy::current()),
+      main_listener_(main_listener),
+      sender_(NULL),
+      target_loop_(target_loop),
+      handler_(handler) {
+  DCHECK(target_loop_);
+  DCHECK(!handler_.is_null());
+}
+
+void InputEventFilter::AddRoute(int routing_id) {
+  base::AutoLock locked(routes_lock_);
+  routes_.insert(routing_id);
+}
+
+void InputEventFilter::RemoveRoute(int routing_id) {
+  base::AutoLock locked(routes_lock_);
+  routes_.erase(routing_id);
+}
+
+void InputEventFilter::DidHandleInputEvent() {
+  DCHECK(target_loop_->BelongsToCurrentThread());
+
+  bool processed = true;
+  SendACK(messages_.front(), processed);
+  messages_.pop();
+}
+
+void InputEventFilter::DidNotHandleInputEvent(bool send_to_widget) {
+  DCHECK(target_loop_->BelongsToCurrentThread());
+
+  if (send_to_widget) {
+    // Forward to the renderer thread, and dispatch the message there.
+    main_loop_->PostTask(
+        FROM_HERE,
+        base::Bind(&InputEventFilter::ForwardToMainListener,
+                   this, messages_.front()));
+  } else {
+    bool processed = false;
+    SendACK(messages_.front(), processed);
+  }
+  messages_.pop();
+}
+
+void InputEventFilter::OnFilterAdded(IPC::Channel* channel) {
+  io_loop_ = base::MessageLoopProxy::current();
+  sender_ = channel;
+}
+
+void InputEventFilter::OnFilterRemoved() {
+  sender_ = NULL;
+}
+
+void InputEventFilter::OnChannelClosing() {
+  sender_ = NULL;
+}
+
+bool InputEventFilter::OnMessageReceived(const IPC::Message& message) {
+  if (message.type() != ViewMsg_HandleInputEvent::ID)
+    return false;
+
+  {
+    base::AutoLock locked(routes_lock_);
+    if (routes_.find(message.routing_id()) == routes_.end())
+      return false;
+  }
+
+  const WebInputEvent* event = CrackMessage(message);
+  if (event->type == WebInputEvent::Undefined)
+    return false;
+
+  target_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&InputEventFilter::ForwardToHandler, this, message));
+  return true;
+}
+
+// static
+const WebInputEvent* InputEventFilter::CrackMessage(
+    const IPC::Message& message) {
+  DCHECK(message.type() == ViewMsg_HandleInputEvent::ID);
+
+  void* iter = NULL;
+  const char* data;
+  int data_length;
+  if (!message.ReadData(&iter, &data, &data_length))
+    return NULL;
+
+  return reinterpret_cast<const WebInputEvent*>(data);
+}
+
+InputEventFilter::~InputEventFilter() {
+}
+
+void InputEventFilter::ForwardToMainListener(const IPC::Message& message) {
+  main_listener_->OnMessageReceived(message);
+}
+
+void InputEventFilter::ForwardToHandler(const IPC::Message& message) {
+  DCHECK(target_loop_->BelongsToCurrentThread());
+
+  // Save this message for later, in case we need to bounce it back up to the
+  // main listener.
+  //
+  // TODO(darin): Change RenderWidgetHost to always require an ACK before
+  // sending the next input event.  This way we can nuke this queue.
+  //
+  messages_.push(message);
+
+  handler_.Run(message.routing_id(), CrackMessage(message));
+}
+
+void InputEventFilter::SendACK(const IPC::Message& message, bool processed) {
+  DCHECK(target_loop_->BelongsToCurrentThread());
+
+  io_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&InputEventFilter::SendACKOnIOThread, this,
+                 message.routing_id(), CrackMessage(message)->type, processed));
+}
+
+void InputEventFilter::SendACKOnIOThread(int routing_id,
+                                         WebInputEvent::Type event_type,
+                                         bool processed) {
+  DCHECK(io_loop_->BelongsToCurrentThread());
+
+  if (!sender_)
+    return;  // Filter was removed.
+
+  sender_->Send(
+      new ViewHostMsg_HandleInputEvent_ACK(routing_id, event_type, processed));
+}