Drag and Drop

gtk_drag_dest_set ()

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

Sets a widget as a potential drop destination, and adds default behaviors.

The default behaviors listed in flags have an effect similar to installing default handlers for the widget’s drag-and-drop signals (“drag-motion”, “drag-drop”, ...). They all exist for convenience. When passing GTK_DEST_DEFAULT_ALL for instance it is sufficient to connect to the widget’s “drag-data-received” signal to get primitive, but consistent drag-and-drop support.

Things become more complicated when you try to preview the dragged data, as described in the documentation for “drag-motion”. The default behaviors described by flags make some assumptions, that can conflict with your own signal handlers. For instance GTK_DEST_DEFAULT_DROP causes invokations of gdk_drag_status() in the context of “drag-motion”, and invokations of gtk_drag_finish() in “drag-data-received”. Especially the later is dramatic, when your own “drag-motion” handler calls gtk_drag_get_data() to inspect the dragged data.

There’s no way to set a default action here, you can use the “drag-motion” callback for that. Here’s an example which selects the action to use depending on whether the control key is pressed or not:

static void
drag_motion (GtkWidget *widget,
             GdkDragContext *context,
             gint x,
             gint y,
             guint time)
{
  GdkModifierType mask;

  gdk_window_get_pointer (gtk_widget_get_window (widget),
                          NULL, NULL, &mask);
  if (mask & GDK_CONTROL_MASK)
    gdk_drag_status (context, GDK_ACTION_COPY, time);
  else
    gdk_drag_status (context, GDK_ACTION_MOVE, time);
}

[method]

gtk_drag_dest_set_proxy ()

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

Sets this widget as a proxy for drops to another window.

[method]

gtk_drag_dest_unset ()

void
gtk_drag_dest_unset (GtkWidget *widget);

Clears information about a drop destination set with gtk_drag_dest_set(). The widget will no longer receive notification of drags.

[method]

gtk_drag_dest_find_target ()

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

Looks for a match between the supported targets of context and the dest_target_list , returning the first matching target, otherwise returning GDK_NONE. dest_target_list should usually be the return value from gtk_drag_dest_get_target_list(), but some widgets may have different valid targets for different parts of the widget; in that case, they will have to implement a drag_motion handler that passes the correct target list to this function.

[method]

gtk_drag_dest_get_target_list ()

GtkTargetList *
gtk_drag_dest_get_target_list (GtkWidget *widget);

Returns the list of targets this widget can accept from drag-and-drop.

[method]

gtk_drag_dest_set_target_list ()

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

Sets the target types that this widget can accept from drag-and-drop. The widget must first be made into a drag destination with gtk_drag_dest_set().

[method]

gtk_drag_dest_add_text_targets ()

void
gtk_drag_dest_add_text_targets (GtkWidget *widget);

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

[method]

Since: 2.6

gtk_drag_dest_add_image_targets ()

void
gtk_drag_dest_add_image_targets (GtkWidget *widget);

Add the image targets supported by GtkSelectionData to the target list of the drag destination. The targets are added with info = 0. If you need another value, use gtk_target_list_add_image_targets() and gtk_drag_dest_set_target_list().

[method]

Since: 2.6

gtk_drag_dest_add_uri_targets ()

void
gtk_drag_dest_add_uri_targets (GtkWidget *widget);

Add the URI targets supported by GtkSelectionData to the target list of the drag destination. The targets are added with info = 0. If you need another value, use gtk_target_list_add_uri_targets() and gtk_drag_dest_set_target_list().

[method]

Since: 2.6

gtk_drag_dest_set_track_motion ()

void
gtk_drag_dest_set_track_motion (GtkWidget *widget,
                                gboolean track_motion);

Tells the widget to emit “drag-motion” and “drag-leave” events regardless of the targets and the GTK_DEST_DEFAULT_MOTION flag.

This may be used when a widget wants to do generic actions regardless of the targets that the source offers.

[method]

Since: 2.10

gtk_drag_dest_get_track_motion ()

gboolean
gtk_drag_dest_get_track_motion (GtkWidget *widget);

Returns whether the widget has been configured to always emit “drag-motion” signals.

[method]

Since: 2.10

gtk_drag_finish ()

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

Informs the drag source that the drop is finished, and that the data of the drag will no longer be required.

[method]

gtk_drag_get_data ()

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

Gets the data associated with a drag. When the data is received or the retrieval fails, GTK+ will emit a “drag-data-received” signal. Failure of the retrieval is indicated by the length field of the selection_data signal parameter being negative. However, when gtk_drag_get_data() is called implicitely because the GTK_DEST_DEFAULT_DROP was set, then the widget will not receive notification of failed drops.

[method]

gtk_drag_get_source_widget ()

GtkWidget *
gtk_drag_get_source_widget (GdkDragContext *context);

Determines the source widget for a drag.

[method]

gtk_drag_highlight ()

void
gtk_drag_highlight (GtkWidget *widget);

Highlights a widget as a currently hovered drop target. To end the highlight, call gtk_drag_unhighlight(). GTK+ calls this automatically if GTK_DEST_DEFAULT_HIGHLIGHT is set.

[method]

gtk_drag_unhighlight ()

void
gtk_drag_unhighlight (GtkWidget *widget);

Removes a highlight set by gtk_drag_highlight() from a widget.

[method]

gtk_drag_begin ()

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

This function is equivalent to gtk_drag_begin_with_coordinates(), passing -1, -1 as coordinates.

[method]

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:

[method]

Since: 3.10

gtk_drag_cancel ()

void
gtk_drag_cancel (GdkDragContext *context);

Cancels an ongoing drag operation on the source side.

If you want to be able to cancel a drag operation in this way, you need to keep a pointer to the drag context, either from an explicit call to gtk_drag_begin_with_coordinates(), or by connecting to “drag-begin”.

If context does not refer to an ongoing drag operation, this function does nothing.

If a drag is cancelled in this way, the result argument of “drag-failed” is set to GTK_DRAG_RESULT_ERROR .

[method]

Since: 3.16

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

[method]

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.

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.

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.

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.

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.

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.

[method]

gtk_drag_check_threshold ()

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

Checks to see if a mouse drag starting at (start_x , start_y ) and ending at (current_x , current_y ) has passed the GTK+ drag threshold, and thus should trigger the beginning of a drag-and-drop operation.

[method]

gtk_drag_source_set ()

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

Sets up a widget so that GTK+ will start a drag operation when the user clicks and drags on the widget. The widget must have a window.

[method]

gtk_drag_source_set_icon_pixbuf ()

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

Sets the icon that will be used for drags from a particular widget from a GdkPixbuf. GTK+ retains a reference for pixbuf and will release it when it is no longer needed.

[method]

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.

[method]

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.

[method]

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.

[method]

Since: 3.2

gtk_drag_source_unset ()

void
gtk_drag_source_unset (GtkWidget *widget);

Undoes the effects of gtk_drag_source_set().

[method]

gtk_drag_source_set_target_list ()

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

Changes the target types that this widget offers for drag-and-drop. The widget must first be made into a drag source with gtk_drag_source_set().

[method]

Since: 2.4

gtk_drag_source_get_target_list ()

GtkTargetList *
gtk_drag_source_get_target_list (GtkWidget *widget);

Gets the list of targets this widget can provide for drag-and-drop.

[method]

Since: 2.4

gtk_drag_source_add_text_targets ()

void
gtk_drag_source_add_text_targets (GtkWidget *widget);

Add the text targets supported by GtkSelectionData 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().

[method]

Since: 2.6

gtk_drag_source_add_image_targets ()

void
gtk_drag_source_add_image_targets (GtkWidget *widget);

Add the writable image targets supported by GtkSelectionData 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_image_targets() and gtk_drag_source_set_target_list().

[method]

Since: 2.6

gtk_drag_source_add_uri_targets ()

void
gtk_drag_source_add_uri_targets (GtkWidget *widget);

Add the URI targets supported by GtkSelectionData 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_uri_targets() and gtk_drag_source_set_target_list().

[method]

Since: 2.6

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.

enum GtkTargetFlags

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

enum GtkDragResult

Gives an indication why a drag operation failed. The value can by obtained by connecting to the “drag-failed” signal.