GTK+ 3 Reference Manual: Drag and Drop

Drag and Drop

Drag and Drop — Functions for controlling drag and drop handling

Functions

void	gtk_drag_dest_set ()
void	gtk_drag_dest_set_proxy ()
void	gtk_drag_dest_unset ()
GdkAtom	gtk_drag_dest_find_target ()
GtkTargetList *	gtk_drag_dest_get_target_list ()
void	gtk_drag_dest_set_target_list ()
void	gtk_drag_dest_add_text_targets ()
void	gtk_drag_dest_add_image_targets ()
void	gtk_drag_dest_add_uri_targets ()
void	gtk_drag_dest_set_track_motion ()
gboolean	gtk_drag_dest_get_track_motion ()
void	gtk_drag_finish ()
void	gtk_drag_get_data ()
GtkWidget *	gtk_drag_get_source_widget ()
void	gtk_drag_highlight ()
void	gtk_drag_unhighlight ()
GdkDragContext *	gtk_drag_begin ()
GdkDragContext *	gtk_drag_begin_with_coordinates ()
void	gtk_drag_set_icon_widget ()
void	gtk_drag_set_icon_pixbuf ()
void	gtk_drag_set_icon_stock ()
void	gtk_drag_set_icon_surface ()
void	gtk_drag_set_icon_name ()
void	gtk_drag_set_icon_gicon ()
void	gtk_drag_set_icon_default ()
gboolean	gtk_drag_check_threshold ()
void	gtk_drag_source_set ()
void	gtk_drag_source_set_icon_pixbuf ()
void	gtk_drag_source_set_icon_stock ()
void	gtk_drag_source_set_icon_name ()
void	gtk_drag_source_set_icon_gicon ()
void	gtk_drag_source_unset ()
void	gtk_drag_source_set_target_list ()
GtkTargetList *	gtk_drag_source_get_target_list ()
void	gtk_drag_source_add_text_targets ()
void	gtk_drag_source_add_image_targets ()
void	gtk_drag_source_add_uri_targets ()

Types and Values

enum	GtkDestDefaults
enum	GtkTargetFlags

Includes

#include <gtk/gtk.h>

Description

GTK+ has a rich set of functions for doing inter-process communication via the drag-and-drop metaphor.

As well as the functions listed here, applications may need to use some facilities provided for Selections. Also, the Drag and Drop API makes use of signals in the GtkWidget class.

Functions

gtk_drag_dest_set ()

void
gtk_drag_dest_set (GtkWidget *widget,
                   GtkDestDefaults flags,
                   const GtkTargetEntry *targets,
                   gint n_targets,
                   GdkDragAction actions);

Parameters

widget	a GtkWidget
flags	which types of default drag behavior to use
targets	a pointer to an array of GtkTargetEntrys indicating the drop types that this `widget` will accept, or `NULL`. Later you can access the list with `gtk_drag_dest_get_target_list()` and `gtk_drag_dest_find_target()`.	[allow-none][array length=n_targets]
n_targets	the number of entries in `targets`
actions	a bitmask of possible actions for a drop onto this `widget` .

gtk_drag_dest_set_proxy ()

void
gtk_drag_dest_set_proxy (GtkWidget *widget,
                         GdkWindow *proxy_window,
                         GdkDragProtocol protocol,
                         gboolean use_coordinates);

Parameters

widget	a GtkWidget
proxy_window	the window to which to forward drag events
protocol	the drag protocol which the `proxy_window` accepts (You can use `gdk_drag_get_protocol()` to determine this)
use_coordinates	If `TRUE`, send the same coordinates to the destination, because it is an embedded subwindow.

gtk_drag_dest_unset ()

void
gtk_drag_dest_unset (GtkWidget *widget);

Parameters

widget

a GtkWidget

gtk_drag_dest_find_target ()

GdkAtom
gtk_drag_dest_find_target (GtkWidget *widget,
                           GdkDragContext *context,
                           GtkTargetList *target_list);

Parameters

widget	drag destination widget
context	drag context
target_list	list of droppable targets, or `NULL` to use gtk_drag_dest_get_target_list (`widget` ).	[allow-none]

gtk_drag_dest_get_target_list ()

GtkTargetList *
gtk_drag_dest_get_target_list (GtkWidget *widget);

Parameters

widget

a GtkWidget

gtk_drag_dest_set_target_list ()

void
gtk_drag_dest_set_target_list (GtkWidget *widget,
                               GtkTargetList *target_list);

Parameters

widget	a GtkWidget that’s a drag destination
target_list	list of droppable targets, or `NULL` for none.	[allow-none]

gtk_drag_dest_add_text_targets ()

void
gtk_drag_dest_add_text_targets (GtkWidget *widget);

Parameters

widget

a GtkWidget that’s a drag destination

Since 2.6

gtk_drag_dest_add_image_targets ()

void
gtk_drag_dest_add_image_targets (GtkWidget *widget);

Parameters

widget

a GtkWidget that’s a drag destination

Since 2.6

gtk_drag_dest_add_uri_targets ()

void
gtk_drag_dest_add_uri_targets (GtkWidget *widget);

Parameters

widget

a GtkWidget that’s a drag destination

Since 2.6

gtk_drag_dest_set_track_motion ()

void
gtk_drag_dest_set_track_motion (GtkWidget *widget,
                                gboolean track_motion);

Parameters

widget	a GtkWidget that’s a drag destination
track_motion	whether to accept all targets

Since 2.10

gtk_drag_dest_get_track_motion ()

gboolean
gtk_drag_dest_get_track_motion (GtkWidget *widget);

Parameters

widget

a GtkWidget that’s a drag destination

Since 2.10

gtk_drag_finish ()

void
gtk_drag_finish (GdkDragContext *context,
                 gboolean success,
                 gboolean del,
                 guint32 time_);

Parameters

context	the drag context.
success	a flag indicating whether the drop was successful
del	a flag indicating whether the source should delete the original data. (This should be `TRUE` for a move)
time_	the timestamp from the “drag-drop” signal.

gtk_drag_get_data ()

void
gtk_drag_get_data (GtkWidget *widget,
                   GdkDragContext *context,
                   GdkAtom target,
                   guint32 time_);

Parameters

widget	the widget that will receive the “drag-data-received” signal.
context	the drag context
target	the target (form of the data) to retrieve.
time_	a timestamp for retrieving the data. This will generally be the time received in a “drag-motion”" or “drag-drop”" signal.

gtk_drag_get_source_widget ()

GtkWidget *
gtk_drag_get_source_widget (GdkDragContext *context);

Parameters

context

a (destination side) drag context

gtk_drag_highlight ()

void
gtk_drag_highlight (GtkWidget *widget);

Parameters

widget

a widget to highlight

gtk_drag_unhighlight ()

void
gtk_drag_unhighlight (GtkWidget *widget);

Parameters

widget

a widget to remove the highlight from.

gtk_drag_begin ()

GdkDragContext *
gtk_drag_begin (GtkWidget *widget,
                GtkTargetList *targets,
                GdkDragAction actions,
                gint button,
                GdkEvent *event);

gtk_drag_begin has been deprecated since version 3.10 and should not be used in newly-written code.

Use gtk_drag_begin_with_coordinates() instead.

Parameters

widget	the source widget.
targets	The targets (data formats) in which the source can provide the data.
actions	A bitmask of the allowed drag actions for this drag.
button	The button the user clicked to start the drag.
event	The event that triggered the start of the drag.

gtk_drag_begin_with_coordinates ()

GdkDragContext *
gtk_drag_begin_with_coordinates (GtkWidget *widget,
                                 GtkTargetList *targets,
                                 GdkDragAction actions,
                                 gint button,
                                 GdkEvent *event,
                                 gint x,
                                 gint y);

Initiates a drag on the source side. The function only needs to be used when the application is starting drags itself, and is not needed when gtk_drag_source_set() is used.

The event is used to retrieve the timestamp that will be used internally to grab the pointer. If event is NULL, then GDK_CURRENT_TIME will be used. However, you should try to pass a real event in all cases, since that can be used to get information about the drag.

Generally there are three cases when you want to start a drag by hand by calling this function:

During a “button-press-event” handler, if you want to start a drag immediately when the user presses the mouse button. Pass the event that you have in your “button-press-event” handler.
During a “motion-notify-event” handler, if you want to start a drag when the mouse moves past a certain threshold distance after a button-press. Pass the event that you have in your “motion-notify-event” handler.
During a timeout handler, if you want to start a drag after the mouse button is held down for some time. Try to save the last event that you got from the mouse, using gdk_event_copy(), and pass it to this function (remember to free the event with gdk_event_free() when you are done). If you can really not pass a real event, pass NULL instead.

Parameters

widget	the source widget.
targets	The targets (data formats) in which the source can provide the data.
actions	A bitmask of the allowed drag actions for this drag.
button	The button the user clicked to start the drag.
event	The event that triggered the start of the drag.
x	The initial x coordinate to start dragging from, in the coordinate space of `widget` . If -1 is passed, the coordinates are retrieved from `event` or the current pointer position.
y	The initial y coordinate to start dragging from, in the coordinate space of `widget` . If -1 is passed, the coordinates are retrieved from `event` or the current pointer position.

Returns

the context for this drag.

[transfer none]

Since 3.10

gtk_drag_set_icon_widget ()

void
gtk_drag_set_icon_widget (GdkDragContext *context,
                          GtkWidget *widget,
                          gint hot_x,
                          gint hot_y);

Changes the icon for a widget to a given widget. GTK+ will not destroy the icon, so if you don’t want it to persist, you should connect to the “drag-end” signal and destroy it yourself.

Parameters

context	the context for a drag. (This must be called with a context for the source side of a drag)
widget	a toplevel window to use as an icon.
hot_x	the X offset within `widget` of the hotspot.
hot_y	the Y offset within `widget` of the hotspot.

gtk_drag_set_icon_pixbuf ()

void
gtk_drag_set_icon_pixbuf (GdkDragContext *context,
                          GdkPixbuf *pixbuf,
                          gint hot_x,
                          gint hot_y);

Sets pixbuf as the icon for a given drag.

Parameters

context	the context for a drag. (This must be called with a context for the source side of a drag)
pixbuf	the GdkPixbuf to use as the drag icon.
hot_x	the X offset within `widget` of the hotspot.
hot_y	the Y offset within `widget` of the hotspot.

gtk_drag_set_icon_stock ()

void
gtk_drag_set_icon_stock (GdkDragContext *context,
                         const gchar *stock_id,
                         gint hot_x,
                         gint hot_y);

gtk_drag_set_icon_stock has been deprecated since version 3.10 and should not be used in newly-written code.

Use gtk_drag_set_icon_name() instead.

Sets the icon for a given drag from a stock ID.

Parameters

context	the context for a drag. (This must be called with a context for the source side of a drag)
stock_id	the ID of the stock icon to use for the drag.
hot_x	the X offset within the icon of the hotspot.
hot_y	the Y offset within the icon of the hotspot.

gtk_drag_set_icon_surface ()

void
gtk_drag_set_icon_surface (GdkDragContext *context,
                           cairo_surface_t *surface);

Sets surface as the icon for a given drag. GTK+ retains references for the arguments, and will release them when they are no longer needed.

To position the surface relative to the mouse, use cairo_surface_set_device_offset() on surface . The mouse cursor will be positioned at the (0,0) coordinate of the surface.

Parameters

context	the context for a drag. (This must be called with a context for the source side of a drag)
surface	the surface to use as icon

gtk_drag_set_icon_name ()

void
gtk_drag_set_icon_name (GdkDragContext *context,
                        const gchar *icon_name,
                        gint hot_x,
                        gint hot_y);

Sets the icon for a given drag from a named themed icon. See the docs for GtkIconTheme for more details. Note that the size of the icon depends on the icon theme (the icon is loaded at the symbolic size GTK_ICON_SIZE_DND), thus hot_x and hot_y have to be used with care.

Parameters

context	the context for a drag. (This must be called with a context for the source side of a drag)
icon_name	name of icon to use
hot_x	the X offset of the hotspot within the icon
hot_y	the Y offset of the hotspot within the icon

Since 2.8

gtk_drag_set_icon_gicon ()

void
gtk_drag_set_icon_gicon (GdkDragContext *context,
                         GIcon *icon,
                         gint hot_x,
                         gint hot_y);

Sets the icon for a given drag from the given icon . See the documentation for gtk_drag_set_icon_name() for more details about using icons in drag and drop.

Parameters

context	the context for a drag. (This must be called with a context for the source side of a drag)
icon	a GIcon
hot_x	the X offset of the hotspot within the icon
hot_y	the Y offset of the hotspot within the icon

Since 3.2

gtk_drag_set_icon_default ()

void
gtk_drag_set_icon_default (GdkDragContext *context);

Sets the icon for a particular drag to the default icon.

Parameters

context

the context for a drag. (This must be called with a context for the source side of a drag)

gtk_drag_check_threshold ()

gboolean
gtk_drag_check_threshold (GtkWidget *widget,
                          gint start_x,
                          gint start_y,
                          gint current_x,
                          gint current_y);

Parameters

widget	a GtkWidget
start_x	X coordinate of start of drag
start_y	Y coordinate of start of drag
current_x	current X coordinate
current_y	current Y coordinate

gtk_drag_source_set ()

void
gtk_drag_source_set (GtkWidget *widget,
                     GdkModifierType start_button_mask,
                     const GtkTargetEntry *targets,
                     gint n_targets,
                     GdkDragAction actions);

Parameters

widget	a GtkWidget
start_button_mask	the bitmask of buttons that can start the drag
targets	the table of targets that the drag will support, may be `NULL`.	[allow-none][array length=n_targets]
n_targets	the number of items in `targets`
actions	the bitmask of possible actions for a drag from this widget

gtk_drag_source_set_icon_pixbuf ()

void
gtk_drag_source_set_icon_pixbuf (GtkWidget *widget,
                                 GdkPixbuf *pixbuf);

Parameters

widget	a GtkWidget
pixbuf	the GdkPixbuf for the drag icon

gtk_drag_source_set_icon_stock ()

void
gtk_drag_source_set_icon_stock (GtkWidget *widget,
                                const gchar *stock_id);

gtk_drag_source_set_icon_stock has been deprecated since version 3.10 and should not be used in newly-written code.

Use gtk_drag_source_set_icon_name() instead.

Sets the icon that will be used for drags from a particular source to a stock icon.

Parameters

widget	a GtkWidget
stock_id	the ID of the stock icon to use

gtk_drag_source_set_icon_name ()

void
gtk_drag_source_set_icon_name (GtkWidget *widget,
                               const gchar *icon_name);

Sets the icon that will be used for drags from a particular source to a themed icon. See the docs for GtkIconTheme for more details.

Parameters

widget	a GtkWidget
icon_name	name of icon to use

Since 2.8

gtk_drag_source_set_icon_gicon ()

void
gtk_drag_source_set_icon_gicon (GtkWidget *widget,
                                GIcon *icon);

Sets the icon that will be used for drags from a particular source to icon . See the docs for GtkIconTheme for more details.

Parameters

widget	a GtkWidget
icon	A GIcon

Since 3.2

gtk_drag_source_unset ()

void
gtk_drag_source_unset (GtkWidget *widget);

Parameters

widget

a GtkWidget

gtk_drag_source_set_target_list ()

void
gtk_drag_source_set_target_list (GtkWidget *widget,
                                 GtkTargetList *target_list);

Parameters

widget	a GtkWidget that’s a drag source
target_list	list of draggable targets, or `NULL` for none.	[allow-none]

Since 2.4

gtk_drag_source_get_target_list ()

GtkTargetList *
gtk_drag_source_get_target_list (GtkWidget *widget);

Parameters

widget

a GtkWidget

Since 2.4

gtk_drag_source_add_text_targets ()

void
gtk_drag_source_add_text_targets (GtkWidget *widget);

Add the text targets supported by GtkSelection to the target list of the drag source. The targets are added with info = 0. If you need another value, use gtk_target_list_add_text_targets() and gtk_drag_source_set_target_list().

Parameters

widget

a GtkWidget that’s is a drag source

Since 2.6

gtk_drag_source_add_image_targets ()

void
gtk_drag_source_add_image_targets (GtkWidget *widget);

Parameters

widget

a GtkWidget that’s is a drag source

Since 2.6

gtk_drag_source_add_uri_targets ()

void
gtk_drag_source_add_uri_targets (GtkWidget *widget);

Parameters

widget

a GtkWidget that’s is a drag source

Since 2.6

Types and Values

enum GtkDestDefaults

The GtkDestDefaults enumeration specifies the various types of action that will be taken on behalf of the user for a drag destination site.

Members

GTK_DEST_DEFAULT_MOTION	If set for a widget, GTK+, during a drag over this widget will check if the drag matches this widget’s list of possible targets and actions. GTK+ will then call `gdk_drag_status()` as appropriate.
GTK_DEST_DEFAULT_HIGHLIGHT	If set for a widget, GTK+ will draw a highlight on this widget as long as a drag is over this widget and the widget drag format and action are acceptable.
GTK_DEST_DEFAULT_DROP	If set for a widget, when a drop occurs, GTK+ will will check if the drag matches this widget’s list of possible targets and actions. If so, GTK+ will call `gtk_drag_get_data()` on behalf of the widget. Whether or not the drop is successful, GTK+ will call `gtk_drag_finish()`. If the action was a move, then if the drag was successful, then `TRUE` will be passed for the `delete` parameter to `gtk_drag_finish()`.
GTK_DEST_DEFAULT_ALL	If set, specifies that all default actions should be taken.

enum GtkTargetFlags

The GtkTargetFlags enumeration is used to specify constraints on a GtkTargetEntry.

Members

GTK_TARGET_SAME_APP	If this is set, the target will only be selected for drags within a single application.
GTK_TARGET_SAME_WIDGET	If this is set, the target will only be selected for drags within a single widget.
GTK_TARGET_OTHER_APP	If this is set, the target will not be selected for drags within a single application.
GTK_TARGET_OTHER_WIDGET	If this is set, the target will not be selected for drags withing a single widget.