Adding key press detection in the browser process.

media/base/user_input_monitor.cc

Index: media/base/user_input_monitor.cc
diff --git a/media/base/user_input_monitor.cc b/media/base/user_input_monitor.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3a8773eb9ae9805d2be386999b7cd0190dbb080f
--- /dev/null
+++ b/media/base/user_input_monitor.cc
@@ -0,0 +1,79 @@
+// Copyright 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.
+
+#include "media/base/user_input_monitor.h"
+
+#include "third_party/skia/include/core/SkPoint.h"
+
+namespace media {
+
+UserInputMonitor::~UserInputMonitor() {
+  DCHECK(!monitoring_mouse_);
+  DCHECK(!monitoring_keyboard_);
+}
+
+void UserInputMonitor::AddMouseListener(MouseEventListener* listener) {
+  base::AutoLock auto_lock(lock_);
+  mouse_listeners_.AddObserver(listener);
+  if (!monitoring_mouse_) {
+    StartMouseMonitoring();
+    monitoring_mouse_ = true;
+    DVLOG(2) << "Started mouse monitoring.";
+  }
+}
+void UserInputMonitor::RemoveMouseListener(MouseEventListener* listener) {
+  base::AutoLock auto_lock(lock_);
+  mouse_listeners_.RemoveObserver(listener);
+  if (mouse_listeners_.size() == 0) {
+    StopMouseMonitoring();
+    monitoring_mouse_ = false;
+    DVLOG(2) << "Stopped mouse monitoring.";
+  }
+}
+void UserInputMonitor::AddKeyStrokeListener(KeyStrokeListener* listener) {
+  base::AutoLock auto_lock(lock_);
+  key_stroke_listeners_.AddObserver(listener);
+  if (!monitoring_keyboard_) {
+    StartKeyboardMonitoring();
+    monitoring_keyboard_ = true;
+    DVLOG(2) << "Started keyboard monitoring.";
+  }
+}
+void UserInputMonitor::RemoveKeyStrokeListener(KeyStrokeListener* listener) {
+  base::AutoLock auto_lock(lock_);
+  key_stroke_listeners_.RemoveObserver(listener);
+  if (key_stroke_listeners_.size() == 0) {
+    StopKeyboardMonitoring();
+    monitoring_keyboard_ = false;
+    DVLOG(2) << "Stopped keyboard monitoring.";
+  }
+}
+
+UserInputMonitor::UserInputMonitor()
+    : monitoring_mouse_(false), monitoring_keyboard_(false) {}
+
+void UserInputMonitor::OnMouseEvent(const SkIPoint& position) {
+  base::AutoLock auto_lock(lock_);
+  FOR_EACH_OBSERVER(
+      MouseEventListener, mouse_listeners_, OnMouseMoved(position));
+}
+
+void UserInputMonitor::OnKeyboardEvent(ui::EventType event,
+                                       ui::KeyboardCode key_code) {
+  base::AutoLock auto_lock(lock_);
+  // Updates the pressed keys and maybe notifies the key_stroke_listeners_.
+  if (event == ui::ET_KEY_PRESSED) {
+    if (pressed_keys_.find(key_code) != pressed_keys_.end())
+      return;
+    pressed_keys_.insert(key_code);
+    DVLOG(6) << "Key stroke detected.";
+    FOR_EACH_OBSERVER(KeyStrokeListener, key_stroke_listeners_, OnKeyStroke());
+  } else {
+    DCHECK_EQ(ui::ET_KEY_RELEASED, event);
+    DCHECK(pressed_keys_.find(key_code) != pressed_keys_.end());
+    pressed_keys_.erase(key_code);
+  }
+}
+
+}  // namespace media