Handle volume keys within Chrome

chrome/browser/chromeos/system_key_event_listener.cc

Index: chrome/browser/chromeos/system_key_event_listener.cc
diff --git a/chrome/browser/chromeos/system_key_event_listener.cc b/chrome/browser/chromeos/system_key_event_listener.cc
index 21f28f2b0a5e697eddbdcc2afab565e396c02b46..f6baaf7593786dd7876fe38acd96ba29024e4e17 100644
--- a/chrome/browser/chromeos/system_key_event_listener.cc
+++ b/chrome/browser/chromeos/system_key_event_listener.cc
@@ -4,9 +4,11 @@
 
 #include "chrome/browser/chromeos/system_key_event_listener.h"
 
+#include <gdk/gdkx.h>
+#include <X11/XF86keysym.h>
+
 #include "chrome/browser/chromeos/audio_handler.h"
 #include "chrome/browser/chromeos/volume_bubble.h"
-#include "cros/chromeos_wm_ipc_enums.h"
 
 namespace chromeos {
 
@@ -23,11 +25,68 @@ SystemKeyEventListener* SystemKeyEventListener::instance() {
 
 SystemKeyEventListener::SystemKeyEventListener()
     : audio_handler_(AudioHandler::instance()) {
-  WmMessageListener::instance()->AddObserver(this);
+  key_volume_mute_ = XKeysymToKeycode(GDK_DISPLAY(), XF86XK_AudioMute);
+  key_volume_down_ = XKeysymToKeycode(GDK_DISPLAY(), XF86XK_AudioLowerVolume);
+  key_volume_up_ = XKeysymToKeycode(GDK_DISPLAY(), XF86XK_AudioRaiseVolume);
+  key_f8_ = XKeysymToKeycode(GDK_DISPLAY(), XK_F8);
+  key_f9_ = XKeysymToKeycode(GDK_DISPLAY(), XK_F9);
+  key_f10_ = XKeysymToKeycode(GDK_DISPLAY(), XK_F10);
+
+  if (key_volume_mute_)
+    GrabKey(key_volume_mute_, 0);
+  if (key_volume_down_)
+    GrabKey(key_volume_down_, 0);
+  if (key_volume_up_)
+    GrabKey(key_volume_up_, 0);
+  GrabKey(key_f8_, 0);
+  GrabKey(key_f9_, 0);
+  GrabKey(key_f10_, 0);
+  gdk_window_add_filter(NULL, GdkEventFilter, this);
 }
 
 SystemKeyEventListener::~SystemKeyEventListener() {
-  WmMessageListener::instance()->RemoveObserver(this);
+  gdk_window_remove_filter(NULL, GdkEventFilter, this);
+}
+
+// static
+GdkFilterReturn SystemKeyEventListener::GdkEventFilter(GdkXEvent* gxevent,
+                                                       GdkEvent* gevent,
+                                                       gpointer data) {
+  SystemKeyEventListener* listener = static_cast<SystemKeyEventListener*>(data);
+  XEvent* xevent = static_cast<XEvent*>(gxevent);
+
+  if (xevent->type == KeyPress) {
+    int32 keycode = xevent->xkey.keycode;
+    if (keycode) {
+      if ((keycode == listener->key_f8_) ||
+          (keycode == listener->key_volume_mute_)) {
+        listener->OnVolumeMute();
+        return GDK_FILTER_REMOVE;
+      } else if ((keycode == listener->key_f9_) ||
+                  keycode == listener->key_volume_down_) {
+        listener->OnVolumeDown();
+        return GDK_FILTER_REMOVE;
+      } else if ((keycode == listener->key_f10_) ||
+                 (keycode == listener->key_volume_up_)) {
+         listener->OnVolumeUp();
+         return GDK_FILTER_REMOVE;
+      }
+    }
+  }
+  return GDK_FILTER_CONTINUE;
+}
+
+void SystemKeyEventListener::GrabKey(int32 key, uint32 mask) {
+  uint32 num_lock_mask = Mod2Mask;
+  uint32 caps_lock_mask = LockMask;
+  Window root = DefaultRootWindow(GDK_DISPLAY());
+  XGrabKey(GDK_DISPLAY(), key, mask, root, True, GrabModeAsync, GrabModeAsync);
+  XGrabKey(GDK_DISPLAY(), key, mask | caps_lock_mask, root, True,
+           GrabModeAsync, GrabModeAsync);
+  XGrabKey(GDK_DISPLAY(), key, mask | num_lock_mask, root, True,
+           GrabModeAsync, GrabModeAsync);
+  XGrabKey(GDK_DISPLAY(), key, mask | caps_lock_mask | num_lock_mask, root,
+           True, GrabModeAsync, GrabModeAsync);
 }
 
 // TODO(davej): Move the ShowVolumeBubble() calls in to AudioHandler so that
@@ -38,40 +97,30 @@ SystemKeyEventListener::~SystemKeyEventListener() {
 // to an AdjustVolumeByPercentOrUnmute() function which can do the steps off
 // of this thread when ShowVolumeBubble() is moved in to AudioHandler.
 
-void SystemKeyEventListener::ProcessWmMessage(const WmIpc::Message& message,
-                                              GdkWindow* window) {
-  if (message.type() != WM_IPC_MESSAGE_CHROME_NOTIFY_SYSKEY_PRESSED)
-    return;
-
-  switch (message.param(0)) {
-    case WM_IPC_SYSTEM_KEY_VOLUME_MUTE:
-      // Always muting (and not toggling) as per final decision on
-      // http://crosbug.com/3751
-      audio_handler_->SetMute(true);
-      VolumeBubble::instance()->ShowVolumeBubble(0);
-      break;
-    case WM_IPC_SYSTEM_KEY_VOLUME_DOWN:
-      if (audio_handler_->IsMute()) {
-        VolumeBubble::instance()->ShowVolumeBubble(0);
-      } else {
-        audio_handler_->AdjustVolumeByPercent(-kStepPercentage);
-        VolumeBubble::instance()->ShowVolumeBubble(
-            audio_handler_->GetVolumePercent());
-      }
-      break;
-    case WM_IPC_SYSTEM_KEY_VOLUME_UP:
-      if (audio_handler_->IsMute())
-        audio_handler_->SetMute(false);
-      else
-        audio_handler_->AdjustVolumeByPercent(kStepPercentage);
-      VolumeBubble::instance()->ShowVolumeBubble(
-          audio_handler_->GetVolumePercent());
-      break;
-    default:
-      DLOG(ERROR) << "SystemKeyEventListener: Unexpected message "
-                  << message.param(0)
-                  << " received";
+void SystemKeyEventListener::OnVolumeMute() {
+  // Always muting (and not toggling) as per final decision on
+  // http://crosbug.com/3751
+  audio_handler_->SetMute(true);
+  VolumeBubble::instance()->ShowVolumeBubble(0);
+}
+
+void SystemKeyEventListener::OnVolumeDown() {
+  if (audio_handler_->IsMute()) {
+    VolumeBubble::instance()->ShowVolumeBubble(0);
+  } else {
+    audio_handler_->AdjustVolumeByPercent(-kStepPercentage);
+    VolumeBubble::instance()->ShowVolumeBubble(
+        audio_handler_->GetVolumePercent());
   }
 }
 
+void SystemKeyEventListener::OnVolumeUp() {
+  if (audio_handler_->IsMute())
+    audio_handler_->SetMute(false);
+  else
+    audio_handler_->AdjustVolumeByPercent(kStepPercentage);
+  VolumeBubble::instance()->ShowVolumeBubble(
+      audio_handler_->GetVolumePercent());
+}
+
 }  // namespace chromeos