Sets the calling widget as a drag-and-drop destination. flags is one of four GtkDestDefaults values which define how the widget reacts when the drag is over the widget.

The targets parameter defines a list with all data types which can be dropped over the widget. The parameter is an array of arrays of size three:

$targets = array(
//array( target, flags, info),
  array( 'text/plain', GTK_TARGET_SAME_APP, 0),
  array( 'text/uri-list', 0, 1)
);

The flags of the targets determine from which widget the drag has to come from:

info allows you to pass a number to the function connected to the "drag-data-received" signal. This is useful when e.g. allowing multiple image types to be dropped, as well as some other non-image types: All image types could be assigned "1" as info parameter, all other types "2" or so. In the drag received function could pass the necessary data to a image open function by checking if the info parameter is "1", without having to compare the mime type.

define('TYPE_IMAGE', 1);
define('TYPE_PDF'  , 2);
define('TYPE_OTHER', 3);
$targets = array(
 array( 'image/jpg' , 0, TYPE_IMAGE),
 array( 'image/jpeg', 0, TYPE_IMAGE),
 array( 'image/gif' , 0, TYPE_IMAGE),
 array( 'image/png' , 0, TYPE_IMAGE),
 array( 'application/pdf', 0, TYPE_PDF),
 array( 'text/plain'     , 0, TYPE_OTHER)
);

$list->drag_dest_set(GTK_DEST_DEFAULT_ALL, $targets, GDK_ACTION_COPY | GDK_ACTION_MOVE);
$list->connect('drag-data-received', 'dnd_drag_data_received');

function dnd_drag_data_received( $widget, $context, $x, $y, $data, $info, $time)
{
    if( $info == TYPE_IMAGE) { handle_image( $data); return; }
    //do different things with pdf and other type here
}

See also: drag_dest_unset()