Adding key press detection in the browser process.

media/base/user_input_monitor.cc

+// 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() {}
+
+void UserInputMonitor::AddMouseListener(MouseEventListener* listener) {
+  mouse_listeners_.AddObserver(listener);
+  if (mouse_listeners_.size() == 1)
+    StartMonitorMouse();
+}
+void UserInputMonitor::RemoveMouseListener(MouseEventListener* listener) {
+  mouse_listeners_.RemoveObserver(listener);
+  if (mouse_listeners_.size() == 0)
+    StopMonitorMouse();
+}
+void UserInputMonitor::AddRawKeyboardListener(
+    RawKeyboardEventListener* listener) {
+  keyboard_listeners_.AddObserver(listener);
+  if (keyboard_listeners_.size() == 1 && key_press_listeners_.size() == 0)

[DaleCurtis, 2013/08/10 00:13:12]

It'd be clearer to just track this through two bools set by their respective
functions; i.e., if (!monitoring_keyboard_) ... if (!monitoring_mouse_) etc.

+    StartMonitorKeyboard();
+}
+void UserInputMonitor::RemoveRawKeyboardListener(
+    RawKeyboardEventListener* listener) {
+  keyboard_listeners_.RemoveObserver(listener);
+  if (keyboard_listeners_.size() == 0 && key_press_listeners_.size() == 0)
+    StopMonitorKeyboard();
+}
+void UserInputMonitor::AddKeyPressListener(KeyPressListener* listener) {
+  key_press_listeners_.AddObserver(listener);
+  if (keyboard_listeners_.size() == 0 && key_press_listeners_.size() == 1)
+    StartMonitorKeyboard();
+}
+void UserInputMonitor::RemoveKeyPressListener(KeyPressListener* listener) {
+  key_press_listeners_.RemoveObserver(listener);
+  if (keyboard_listeners_.size() == 0 && key_press_listeners_.size() == 0)
+    StopMonitorKeyboard();
+}
+
+UserInputMonitor::UserInputMonitor() {}
+
+void UserInputMonitor::OnMouseEvent(const SkIPoint& position) {
+  FOR_EACH_OBSERVER(
+      MouseEventListener, mouse_listeners_, OnMouseMoved(position));
+}
+
+void UserInputMonitor::OnKeyboardEvent(ui::EventType event,
+                                       ui::KeyboardCode key_code) {
+  FOR_EACH_OBSERVER(RawKeyboardEventListener,
+                    keyboard_listeners_,
+                    OnKeyboardEvent(event, key_code));
+
+  // Updates the pressed keys and maybe notifies the key_press_listeners_.
+  if (event == ui::ET_KEY_PRESSED) {
+    if (pressed_keys_.find(key_code) != pressed_keys_.end())
+      return;
+    pressed_keys_.insert(key_code);
+    FOR_EACH_OBSERVER(KeyPressListener, key_press_listeners_, OnKeyPressed());
+  } else {
+    DCHECK_EQ(ui::ET_KEY_RELEASED, event);
+    DCHECK(pressed_keys_.find(key_code) != pressed_keys_.end());
+    pressed_keys_.erase(key_code);
+  }
+}
+
+}  // namespace media