mouse: Move "has touchpad" function to common

So it can be reused. This also fixes a memory leak in the function.
We were leaking the device list

Taken from GSD commit: f6dcba4e954f3e910854f3c92fb69b157683267d
From: Bastien Nocera <[email protected]>

3 files changed, 149 insertions, 2 deletions

diff --git a/plugins/common/Makefile.am b/plugins/common/Makefile.am
index 3733a90..4cd30d8 100644
--- a/plugins/common/Makefile.am
+++ b/plugins/common/Makefile.am
@@ -6,6 +6,8 @@ libcommon_la_SOURCES = \
 	eggaccelerators.h	\
 	msd-keygrab.c		\
 	msd-keygrab.h		\
+	msd-input-helper.c	\
+	msd-input-helper.h	\
 	msd-osd-window.c	\
 	msd-osd-window.h
 
@@ -14,10 +16,12 @@ libcommon_la_CPPFLAGS = \
 
 libcommon_la_CFLAGS = \
 	$(SETTINGS_PLUGIN_CFLAGS)	\
+	$(XINPUT_CFLAGS)		\
 	$(AM_CFLAGS)
 
 libcommon_la_LDFLAGS = \
-	$(MSD_PLUGIN_LDFLAGS) $(X11_LIBS)
+	$(MSD_PLUGIN_LDFLAGS) $(XINPUT_LIBS) $(X11_LIBS)
 
 libcommon_la_LIBADD  = \
-	$(SETTINGS_PLUGIN_LIBS)
+	$(SETTINGS_PLUGIN_LIBS)		\
+	$(XINPUT_LIBS)
diff --git a/plugins/common/msd-input-helper.c b/plugins/common/msd-input-helper.c
new file mode 100644
index 0000000..5043e35
--- /dev/null
+++ b/plugins/common/msd-input-helper.c
@@ -0,0 +1,108 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
+ *
+ * Copyright (C) 2010 Bastien Nocera <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#include "config.h"
+
+#include <gdk/gdk.h>
+#include <gdk/gdkx.h>
+
+#include <sys/types.h>
+#include <X11/Xatom.h>
+
+#include "msd-input-helper.h"
+
+static gboolean
+supports_xinput_devices (void)
+{
+        gint op_code, event, error;
+
+        return XQueryExtension (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()),
+                                "XInputExtension",
+                                &op_code,
+                                &event,
+                                &error);
+}
+
+XDevice*
+device_is_touchpad (XDeviceInfo deviceinfo)
+{
+        XDevice *device;
+        Atom realtype, prop;
+        int realformat;
+        unsigned long nitems, bytes_after;
+        unsigned char *data;
+
+        if (deviceinfo.type != XInternAtom (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()), XI_TOUCHPAD, False))
+                return NULL;
+
+        prop = XInternAtom (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()), "Synaptics Off", False);
+        if (!prop)
+                return NULL;
+
+        gdk_error_trap_push ();
+        device = XOpenDevice (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()), deviceinfo.id);
+        if (gdk_error_trap_pop () || (device == NULL))
+                return NULL;
+
+        gdk_error_trap_push ();
+        if ((XGetDeviceProperty (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()), device, prop, 0, 1, False,
+                                XA_INTEGER, &realtype, &realformat, &nitems,
+                                &bytes_after, &data) == Success) && (realtype != None)) {
+                gdk_error_trap_pop ();
+                XFree (data);
+                return device;
+        }
+        gdk_error_trap_pop ();
+
+        XCloseDevice (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()), device);
+        return NULL;
+}
+
+gboolean
+touchpad_is_present (void)
+{
+        XDeviceInfo *device_info;
+        gint n_devices;
+        guint i;
+        gboolean retval;
+
+        if (supports_xinput_devices () == FALSE)
+                return TRUE;
+
+        retval = FALSE;
+
+        device_info = XListInputDevices (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()), &n_devices);
+        if (device_info == NULL)
+                return FALSE;
+
+        for (i = 0; i < n_devices; i++) {
+                XDevice *device;
+
+                device = device_is_touchpad (device_info[i]);
+                if (device != NULL) {
+                        retval = TRUE;
+                        break;
+                }
+        }
+        if (device_info != NULL)
+                XFreeDeviceList (device_info);
+
+        return retval;
+}
diff --git a/plugins/common/msd-input-helper.h b/plugins/common/msd-input-helper.h
new file mode 100644
index 0000000..2a971ae
--- /dev/null
+++ b/plugins/common/msd-input-helper.h
@@ -0,0 +1,35 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
+ *
+ * Copyright (C) 2010 Bastien Nocera <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __MSD_INPUT_HELPER_H
+#define __MSD_INPUT_HELPER_H
+
+G_BEGIN_DECLS
+
+#include <glib.h>
+
+#include <X11/extensions/XInput.h>
+#include <X11/extensions/XIproto.h>
+
+XDevice * device_is_touchpad  (XDeviceInfo deviceinfo);
+gboolean  touchpad_is_present (void);
+
+G_END_DECLS
+
+#endif /* __MSD_INPUT_HELPER_H */