[gtk+/multitouch: 69/124] gtk, range: Have slider jump to the pointer coordinates on touch devices

[Carlos Garnacho <carlosg src gnome org>]

commit 17c133e8c39210db96c3c3f6c0261e1fc67affbc
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Jan 5 00:21:36 2012 +0100

    gtk,range: Have slider jump to the pointer coordinates on touch devices
    
    This widget is too narrow to make touch interaction tricky enough, so
    don't add the penalty of having the slider run farther from the touch
    coordinates if it happens to miss the slider.

 gtk/gtkrange.c |   17 +++++++++++------
 1 files changed, 11 insertions(+), 6 deletions(-)
---
diff --git a/gtk/gtkrange.c b/gtk/gtkrange.c
index b40d1a2..627d3f3 100644
--- a/gtk/gtkrange.c
+++ b/gtk/gtkrange.c
@@ -2525,7 +2525,8 @@ gtk_range_button_press (GtkWidget      *widget,
 {
   GtkRange *range = GTK_RANGE (widget);
   GtkRangePrivate *priv = range->priv;
-  GdkDevice *device;
+  GdkDevice *device, *source_device;
+  GdkInputSource source;
 
   if (!gtk_widget_has_focus (widget))
     gtk_widget_grab_focus (widget);
@@ -2535,13 +2536,17 @@ gtk_range_button_press (GtkWidget      *widget,
     return FALSE;
 
   device = gdk_event_get_device ((GdkEvent *) event);
+  source_device = gdk_event_get_source_device ((GdkEvent *) event);
+  source = gdk_device_get_source (source_device);
+
   priv->mouse_x = event->x;
   priv->mouse_y = event->y;
 
   if (gtk_range_update_mouse_location (range))
     gtk_widget_queue_draw (widget);
 
-  if (priv->mouse_location == MOUSE_TROUGH  &&
+  if (source != GDK_SOURCE_TOUCH &&
+      priv->mouse_location == MOUSE_TROUGH &&
       event->button == 1)
     {
       /* button 1 steps by page increment, as with button 2 on a stepper
@@ -2590,17 +2595,17 @@ gtk_range_button_press (GtkWidget      *widget,
       return TRUE;
     }
   else if ((priv->mouse_location == MOUSE_TROUGH &&
-            event->button == 2) ||
+            (source == GDK_SOURCE_TOUCH || event->button == 2)) ||
            priv->mouse_location == MOUSE_SLIDER)
     {
       gboolean need_value_update = FALSE;
 
       /* Any button can be used to drag the slider, but you can start
        * dragging the slider with a trough click using button 2;
-       * On button 2 press, we warp the slider to mouse position,
-       * then begin the slider drag.
+       * On button 2 press and touch devices, we warp the slider to
+       * mouse position, then begin the slider drag.
        */
-      if (event->button == 2)
+      if (event->button == 2 || source == GDK_SOURCE_TOUCH)
         {
           gdouble slider_low_value, slider_high_value, new_value;