gtk.drop_target

[gtk.drop_target.DropTarget] is an event controller to receive Drag-and-Drop operations.

The most basic way to use a [gtk.drop_target.DropTarget] to receive drops on a widget is to create it via [gtk.drop_target.DropTarget.new_], passing in the GType of the data you want to receive and connect to the [gtk.drop_target.DropTarget.drop] signal to receive the data:

static gboolean
on_drop (GtkDropTarget *target,
        const GValue  *value,
        double         x,
        double         y,
        gpointer       data)
{
 MyWidget *self = data;

 // Call the appropriate setter depending on the type of data
 // that we received
 if (G_VALUE_HOLDS (value, G_TYPE_FILE))
   my_widget_set_file (self, g_value_get_object (value));
 else if (G_VALUE_HOLDS (value, GDK_TYPE_PIXBUF))
   my_widget_set_pixbuf (self, g_value_get_object (value));
 else
   return FALSE;

 return TRUE;
}

static void
my_widget_init (MyWidget *self)
{
 GtkDropTarget *target =
   gtk_drop_target_new (G_TYPE_INVALID, GDK_ACTION_COPY);

 // This widget accepts two types of drop types: GFile objects
 // and GdkPixbuf objects
 gtk_drop_target_set_gtypes (target, (GType [2]) {
   G_TYPE_FILE,
   GDK_TYPE_PIXBUF,
 }, 2);

 g_signal_connect (target, "drop", G_CALLBACK (on_drop), self);
 gtk_widget_add_controller (GTK_WIDGET (self), GTK_EVENT_CONTROLLER (target));
}

[gtk.drop_target.DropTarget] supports more options, such as:

• rejecting potential drops via the [gtk.drop_target.DropTarget.accept] signal

and the [gtk.drop_target.DropTarget.reject] function to let other drop targets handle the drop

• tracking an ongoing drag operation before the drop via the

[gtk.drop_target.DropTarget.enter], [gtk.drop_target.DropTarget.motion] and [gtk.drop_target.DropTarget.leave] signals

• configuring how to receive data by setting the

[gtk.drop_target.DropTarget.preload] property and listening for its availability via the [gtk.drop_target.DropTarget.value] property

However, [gtk.drop_target.DropTarget] is ultimately modeled in a synchronous way and only supports data transferred via GType. If you want full control over an ongoing drop, the [gtk.drop_target_async.DropTargetAsync] object gives you this ability.

While a pointer is dragged over the drop target's widget and the drop has not been rejected, that widget will receive the [gtk.types.StateFlags.DropActive] state, which can be used to style the widget.

If you are not interested in receiving the drop, but just want to update UI state during a Drag-and-Drop operation (e.g. switching tabs), you can use [gtk.drop_controller_motion.DropControllerMotion].

Fluent builder for [gtk.drop_target.DropTarget]