The function gtk_drag_source_set() specifies a set of target types for a drag operation on a widget.
void gtk_drag_source_set( GtkWidget *widget,
GdkModifierType start_button_mask,
const GtkTargetEntry *targets,
gint n_targets,
GdkDragAction actions );The parameters signify the following:
widget specifies the drag source widget
start_button_mask specifies a bitmask of buttons that can start the drag (e.g. GDK_BUTTON1_MASK)
targets specifies a table of target data types the drag will support
n_targets specifies the number of targets above
actions specifies a bitmask of possible actions for a drag from this window
The targets parameter is an array of the following structure:
struct GtkTargetEntry {
gchar *target;
guint flags;
guint info;
};The fields specify a string representing the drag type, optional flags and application assigned integer identifier.
If a widget is no longer required to act as a source for drag-and-drop operations, the function gtk_drag_source_unset() can be used to remove a set of drag-and-drop target types.
void gtk_drag_source_unset( GtkWidget *widget );
The source widget is sent the following signals during a drag-and-drop operation.
Table 18-1. Source widget signals
| drag_begin | void (*drag_begin)(GtkWidget *widget, GdkDragContext *dc, gpointer data) |
| drag_motion | gboolean (*drag_motion)(GtkWidget *widget, GdkDragContext *dc, gint x, gint y, guint t, gpointer data) |
| drag_data_get | void (*drag_data_get)(GtkWidget *widget, GdkDragContext *dc, GtkSelectionData *selection_data, guint info, guint t, gpointer data) |
| drag_data_delete | void (*drag_data_delete)(GtkWidget *widget, GdkDragContext *dc, gpointer data) |
| drag_drop | gboolean (*drag_drop)(GtkWidget *widget, GdkDragContext *dc, gint x, gint y, guint t, gpointer data) |
| drag_end | void (*drag_end)(GtkWidget *widget, GdkDragContext *dc, gpointer data) |
gtk_drag_dest_set() specifies that this widget can receive drops and specifies what types of drops it can receive.
gtk_drag_dest_unset() specifies that the widget can no longer receive drops.
void gtk_drag_dest_set( GtkWidget *widget,
GtkDestDefaults flags,
const GtkTargetEntry *targets,
gint n_targets,
GdkDragAction actions );
void gtk_drag_dest_unset( GtkWidget *widget );The destination widget is sent the following signals during a drag-and-drop operation.