[gtk+] Example for setting default action in gtk_drag_dest_set

[Robin Stocker <robinst src gnome org>]

commit 26e2c7f398e9376df4e67ca2d712b38a220b88f5
Author: Robin Stocker <robin nibor org>
Date:   Sun Nov 8 01:27:05 2009 +0100

    Example for setting default action in gtk_drag_dest_set

 gtk/gtkdnd.c |   22 ++++++++++++++++++++++
 1 files changed, 22 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkdnd.c b/gtk/gtkdnd.c
index 8bbb4d2..c3a95d8 100644
--- a/gtk/gtkdnd.c
+++ b/gtk/gtkdnd.c
@@ -1239,6 +1239,28 @@ gtk_drag_dest_set_internal (GtkWidget       *widget,
  * and invokations of gtk_drag_finish() in #GtkWidget:drag-data-received.
  * Especially the later is dramatic, when your own #GtkWidget:drag-motion
  * handler calls gtk_drag_get_data() to inspect the dragged data.
+ *
+ * There's no way to set a default action here, you can use the
+ * #GtkWidget:drag-motion callback for that. Here's an example which selects
+ * the action to use depending on whether the control key is pressed or not:
+ * |[
+ * static void
+ * drag_motion (GtkWidget *widget,
+ *              GdkDragContext *context,
+ *              gint x,
+ *              gint y,
+ *              guint time)
+ * {
+ *   GdkModifierType mask;
+ *
+ *   gdk_window_get_pointer (gtk_widget_get_window (widget),
+ *                           NULL, NULL, &mask);
+ *   if (mask & GDK_CONTROL_MASK)
+ *     gdk_drag_status (context, GDK_ACTION_COPY, time);
+ *   else
+ *     gdk_drag_status (context, GDK_ACTION_MOVE, time);
+ * }
+ * ]|
  */
 void
 gtk_drag_dest_set (GtkWidget            *widget,