Drag and Drop

Drag and Drop — Functions for controlling drag and drop handling

Synopsis

#include <gtk/gtk.h>

enum                GtkDestDefaults;
enum                GtkTargetFlags;

void                gtk_drag_dest_set                   (GtkWidget *widget,
                                                         GtkDestDefaults flags,
                                                         const GtkTargetEntry *targets,
                                                         gint n_targets,
                                                         GdkDragAction actions);
void                gtk_drag_dest_set_proxy             (GtkWidget *widget,
                                                         GdkWindow *proxy_window,
                                                         GdkDragProtocol protocol,
                                                         gboolean use_coordinates);
void                gtk_drag_dest_unset                 (GtkWidget *widget);
GdkAtom             gtk_drag_dest_find_target           (GtkWidget *widget,
                                                         GdkDragContext *context,
                                                         GtkTargetList *target_list);
GtkTargetList *     gtk_drag_dest_get_target_list       (GtkWidget *widget);
void                gtk_drag_dest_set_target_list       (GtkWidget *widget,
                                                         GtkTargetList *target_list);
void                gtk_drag_dest_add_text_targets      (GtkWidget *widget);
void                gtk_drag_dest_add_image_targets     (GtkWidget *widget);
void                gtk_drag_dest_add_uri_targets       (GtkWidget *widget);
void                gtk_drag_dest_set_track_motion      (GtkWidget *widget,
                                                         gboolean track_motion);
gboolean            gtk_drag_dest_get_track_motion      (GtkWidget *widget);
void                gtk_drag_finish                     (GdkDragContext *context,
                                                         gboolean success,
                                                         gboolean del,
                                                         guint32 time_);
void                gtk_drag_get_data                   (GtkWidget *widget,
                                                         GdkDragContext *context,
                                                         GdkAtom target,
                                                         guint32 time_);
GtkWidget *         gtk_drag_get_source_widget          (GdkDragContext *context);
void                gtk_drag_highlight                  (GtkWidget *widget);
void                gtk_drag_unhighlight                (GtkWidget *widget);

GdkDragContext *    gtk_drag_begin                      (GtkWidget *widget,
                                                         GtkTargetList *targets,
                                                         GdkDragAction actions,
                                                         gint button,
                                                         GdkEvent *event);
void                gtk_drag_set_icon_widget            (GdkDragContext *context,
                                                         GtkWidget *widget,
                                                         gint hot_x,
                                                         gint hot_y);
void                gtk_drag_set_icon_pixbuf            (GdkDragContext *context,
                                                         GdkPixbuf *pixbuf,
                                                         gint hot_x,
                                                         gint hot_y);
void                gtk_drag_set_icon_stock             (GdkDragContext *context,
                                                         const gchar *stock_id,
                                                         gint hot_x,
                                                         gint hot_y);
void                gtk_drag_set_icon_surface           (GdkDragContext *context,
                                                         cairo_surface_t *surface);
void                gtk_drag_set_icon_name              (GdkDragContext *context,
                                                         const gchar *icon_name,
                                                         gint hot_x,
                                                         gint hot_y);
void                gtk_drag_set_icon_gicon             (GdkDragContext *context,
                                                         GIcon *icon,
                                                         gint hot_x,
                                                         gint hot_y);
void                gtk_drag_set_icon_default           (GdkDragContext *context);
gboolean            gtk_drag_check_threshold            (GtkWidget *widget,
                                                         gint start_x,
                                                         gint start_y,
                                                         gint current_x,
                                                         gint current_y);
void                gtk_drag_source_set                 (GtkWidget *widget,
                                                         GdkModifierType start_button_mask,
                                                         const GtkTargetEntry *targets,
                                                         gint n_targets,
                                                         GdkDragAction actions);
void                gtk_drag_source_set_icon_pixbuf     (GtkWidget *widget,
                                                         GdkPixbuf *pixbuf);
void                gtk_drag_source_set_icon_stock      (GtkWidget *widget,
                                                         const gchar *stock_id);
void                gtk_drag_source_set_icon_name       (GtkWidget *widget,
                                                         const gchar *icon_name);
void                gtk_drag_source_set_icon_gicon      (GtkWidget *widget,
                                                         GIcon *icon);
void                gtk_drag_source_unset               (GtkWidget *widget);
void                gtk_drag_source_set_target_list     (GtkWidget *widget,
                                                         GtkTargetList *target_list);
GtkTargetList *     gtk_drag_source_get_target_list     (GtkWidget *widget);
void                gtk_drag_source_add_text_targets    (GtkWidget *widget);
void                gtk_drag_source_add_image_targets   (GtkWidget *widget);
void                gtk_drag_source_add_uri_targets     (GtkWidget *widget);

Description

GTK+ has a rich set of functions for doing inter-process communication via the drag-and-drop metaphor. GTK+ can do drag-and-drop (DND) via multiple protocols. The currently supported protocols are the Xdnd and Motif protocols.

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.

Details

enum GtkDestDefaults

typedef enum {
  GTK_DEST_DEFAULT_MOTION     = 1 << 0, /* respond to "drag_motion" */
  GTK_DEST_DEFAULT_HIGHLIGHT  = 1 << 1, /* auto-highlight */
  GTK_DEST_DEFAULT_DROP       = 1 << 2, /* respond to "drag_drop" */
  GTK_DEST_DEFAULT_ALL        = 0x07
} GtkDestDefaults;

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

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

typedef enum {
  GTK_TARGET_SAME_APP = 1 << 0,    /*< nick=same-app >*/
  GTK_TARGET_SAME_WIDGET = 1 << 1, /*< nick=same-widget >*/
  GTK_TARGET_OTHER_APP = 1 << 2,   /*< nick=other-app >*/
  GTK_TARGET_OTHER_WIDGET = 1 << 3 /*< nick=other-widget >*/
} GtkTargetFlags;

The GtkTargetFlags enumeration is used to specify constraints on an entry in a GtkTargetTable.

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.

gtk_drag_dest_set ()

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

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);

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);

widget :

a GtkWidget

gtk_drag_dest_find_target ()

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

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);

widget :

a GtkWidget

gtk_drag_dest_set_target_list ()

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

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);

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);

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);

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);

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);

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_);

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_);

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);

context :

a (destination side) drag context

gtk_drag_highlight ()

void                gtk_drag_highlight                  (GtkWidget *widget);

widget :

a widget to highlight

gtk_drag_unhighlight ()

void                gtk_drag_unhighlight                (GtkWidget *widget);

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);

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_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.

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.

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);

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

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.

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.

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.

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.

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);

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);

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);

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);

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

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.

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.

widget :

a GtkWidget

icon :

A GIcon

Since 3.2


gtk_drag_source_unset ()

void                gtk_drag_source_unset               (GtkWidget *widget);

widget :

a GtkWidget

gtk_drag_source_set_target_list ()

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

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);

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().

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);

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);

widget :

a GtkWidget that's is a drag source

Since 2.6