Chromium plumbing for Device Orientation.

chrome/browser/device_orientation/dispatcher_host.cc

+// Copyright (c) 2010 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 "chrome/browser/device_orientation/dispatcher_host.h"
+
+#include "base/scoped_ptr.h"
+#include "chrome/browser/chrome_thread.h"
+#include "chrome/browser/device_orientation/orientation.h"
+#include "chrome/browser/device_orientation/provider.h"
+#include "chrome/browser/renderer_host/render_view_host.h"
+#include "chrome/browser/renderer_host/render_view_host_notification_task.h"
+#include "chrome/common/chrome_switches.h"
+#include "chrome/common/render_messages.h"
+#include "ipc/ipc_message.h"
+
+namespace device_orientation {
+
+DispatcherHost::DispatcherHost(int process_id)
+    : process_id_(process_id) {
+}
+
+DispatcherHost::~DispatcherHost() {
+  if (provider_)
+    provider_->RemoveObserver(this);
+}
+
+bool DispatcherHost::OnMessageReceived(const IPC::Message& msg,
+                                       bool* msg_was_ok) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP_EX(DispatcherHost, msg, *msg_was_ok)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_DeviceOrientation_StartUpdating,
+                        OnStartUpdating)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_DeviceOrientation_StopUpdating,
+                        OnStopUpdating)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void DispatcherHost::OnOrientationUpdate(const Orientation& orientation) {
+  ViewMsg_DeviceOrientationUpdated_Params params;
+  params.can_provide_alpha = orientation.can_provide_alpha_;
+  params.alpha = orientation.alpha_;
+  params.can_provide_beta = orientation.can_provide_beta_;
+  params.beta = orientation.beta_;
+  params.can_provide_gamma = orientation.can_provide_gamma_;
+  params.gamma = orientation.gamma_;
+
+  typedef std::set<int>::const_iterator Iterator;
+  for (Iterator i = render_view_ids_.begin(), e = render_view_ids_.end();
+       i != e; ++i) {
+    IPC::Message* message = new ViewMsg_DeviceOrientationUpdated(*i, params);
+    CallRenderViewHost(process_id_, *i, &RenderViewHost::Send, message);
+  }
+}
+
+void DispatcherHost::OnStartUpdating(int render_view_id) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
+
+  render_view_ids_.insert(render_view_id);
+  if (render_view_ids_.size() == 1) {
+    DCHECK(!provider_);
+    provider_ = Provider::GetInstance();
+    provider_->AddObserver(this);
+  }
+}
+
+void DispatcherHost::OnStopUpdating(int render_view_id) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
+
+  render_view_ids_.erase(render_view_id);
+  if (render_view_ids_.empty()) {
+    provider_->RemoveObserver(this);
+    provider_ = NULL;
+  }
+}
+
+}  // namespace device_orientation