[gnome-control-center] mouse: show enable trackpad slider button even if mouse is not present.

[Srinivasa Ragavan <sragavan src gnome org>]

commit d855a80bf60e43978fedd4737ff9941b969ae10c
Author: Srinivasa Ragavan <srinivasa ragavan venkateswaran intel com>
Date:   Wed Jul 10 18:42:07 2013 +0530

    mouse: show enable trackpad slider button even if mouse is not present.
    
    On touchscreen machine, if the trackpad was previously disabled using mouse
    which isn't present now, there is no way to enable it. It now shows the slider
    when trackpad is disable or if mouse/touchscreen is present.
    
    Fixes bug #703946

 panels/mouse/gnome-mouse-properties.c |   26 ++++++++++++++++++++++++--
 1 files changed, 24 insertions(+), 2 deletions(-)
---
diff --git a/panels/mouse/gnome-mouse-properties.c b/panels/mouse/gnome-mouse-properties.c
index 6c41997..1a10ecf 100644
--- a/panels/mouse/gnome-mouse-properties.c
+++ b/panels/mouse/gnome-mouse-properties.c
@@ -165,6 +165,26 @@ pointer_speed_scale_event (GtkRange *scale, CcMousePropertiesPrivate *d)
        g_settings_set_int (settings, "motion-threshold", value);
 }
 
+static gboolean
+show_touchpad_enabling_switch (GSettings *touchpad_settings)
+{
+       gboolean enabled;
+
+       if (!touchpad_is_present())
+               return FALSE;
+
+       /* Lets show the button when the mouse/touchscreen is present */
+       if (mouse_is_present() || touchscreen_is_present())
+               return TRUE;
+       
+       /* Lets also show when touch pad is disabled. */
+       enabled = g_settings_get_boolean (touchpad_settings,  "touchpad-enabled");
+       if (!enabled)
+               return TRUE;
+       
+       return FALSE;
+}
+
 /* Set up the property editors in the dialog. */
 static void
 setup_dialog (CcMousePropertiesPrivate *d)
@@ -200,7 +220,8 @@ setup_dialog (CcMousePropertiesPrivate *d)
        /* Trackpad page */
        touchpad_present = touchpad_is_present ();
        gtk_widget_set_visible (WID ("touchpad_vbox"), touchpad_present);
-       gtk_widget_set_visible (WID ("touchpad_enabled_switch"), mouse_present);
+       gtk_widget_set_visible (WID ("touchpad_enabled_switch"), 
+                               show_touchpad_enabling_switch (touchpad_settings));
 
        g_settings_bind (d->touchpad_settings, "touchpad-enabled",
                         WID ("touchpad_enabled_switch"), "active",
@@ -281,7 +302,8 @@ device_changed (GdkDeviceManager *device_manager,
 
        present = mouse_is_present ();
        gtk_widget_set_visible (WID ("mouse_vbox"), present);
-       gtk_widget_set_visible (WID ("touchpad_enabled_switch"), present);
+       gtk_widget_set_visible (WID ("touchpad_enabled_switch"), 
+                               show_touchpad_enabling_switch (touchpad_settings));
 }