[gnome-settings-daemon] common: Add code to grab a mouse button on a device

[Bastien Nocera <hadess src gnome org>]

commit 5693e1bedd4624a60acf4b811041340602e5a5a6
Author: Bastien Nocera <hadess hadess net>
Date:   Mon Feb 13 18:14:27 2012 +0000

    common: Add code to grab a mouse button on a device
    
    So we can capture all the mouse button events from the pad device.

 plugins/common/gsd-keygrab.c |   56 ++++++++++++++++++++++++++++++++++++++++++
 plugins/common/gsd-keygrab.h |    4 +++
 2 files changed, 60 insertions(+), 0 deletions(-)
---
diff --git a/plugins/common/gsd-keygrab.c b/plugins/common/gsd-keygrab.c
index ace44cd..755cc24 100644
--- a/plugins/common/gsd-keygrab.c
+++ b/plugins/common/gsd-keygrab.c
@@ -366,3 +366,59 @@ free_key (Key *key)
 	g_free (key->keycodes);
 	g_free (key);
 }
+
+static void
+grab_button_real (int        deviceid,
+		  gboolean   grab,
+		  GdkWindow *root)
+{
+	XIGrabModifiers mods;
+
+	mods.modifiers = XIAnyModifier;
+
+	if (grab) {
+		XIEventMask evmask;
+		unsigned char mask[(XI_LASTEVENT + 7)/8];
+
+		memset (mask, 0, sizeof (mask));
+		XISetMask (mask, XI_ButtonRelease);
+
+		evmask.deviceid = deviceid;
+		evmask.mask_len = sizeof (mask);
+		evmask.mask = mask;
+
+		XIGrabButton (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()),
+			      deviceid,
+			      XIAnyButton,
+			      GDK_WINDOW_XID (root),
+			      None,
+			      GrabModeAsync,
+			      GrabModeAsync,
+			      False,
+			      &evmask,
+			      1,
+			      &mods);
+	} else {
+		XIUngrabButton (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()),
+				deviceid,
+				XIAnyButton,
+		                GDK_WINDOW_XID (root),
+				1, &mods);
+	}
+}
+
+void
+grab_button (int      deviceid,
+	     gboolean grab,
+	     GSList  *screens)
+{
+        GSList *l;
+
+        for (l = screens; l; l = l->next) {
+                GdkScreen *screen = l->data;
+
+		grab_button_real (deviceid,
+				  grab,
+				  gdk_screen_get_root_window (screen));
+        }
+}
diff --git a/plugins/common/gsd-keygrab.h b/plugins/common/gsd-keygrab.h
index 8e92dd2..e450072 100644
--- a/plugins/common/gsd-keygrab.h
+++ b/plugins/common/gsd-keygrab.h
@@ -46,6 +46,10 @@ gboolean        key_uses_keycode (const Key *key,
 Key *           parse_key        (const char    *str);
 void            free_key         (Key           *key);
 
+void            grab_button      (int      deviceid,
+                                  gboolean grab,
+                                  GSList  *screens);
+
 G_END_DECLS
 
 #endif /* __GSD_COMMON_KEYGRAB_H */