Drag and Drop

Name

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_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_pixmap        (GdkDragContext *context,
                                             GdkColormap *colormap,
                                             GdkPixmap *pixmap,
                                             GdkBitmap *mask,
                                             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_default       (GdkDragContext *context);
void        gtk_drag_set_default_icon       (GdkColormap *colormap,
                                             GdkPixmap *pixmap,
                                             GdkBitmap *mask,
                                             gint hot_x,
                                             gint hot_y);
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        (GtkWidget *widget,
                                             GdkColormap *colormap,
                                             GdkPixmap *pixmap,
                                             GdkBitmap *mask);
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_unset           (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.


enum GtkTargetFlags

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

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


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.


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.


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.


gtk_drag_dest_find_target ()

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

Looks for a match between context->targets 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.


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.


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().


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.


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_DRAG_DEFAULT_DROP was set, then the widget will not receive notification of failed drops.


gtk_drag_get_source_widget ()

GtkWidget*  gtk_drag_get_source_widget      (GdkDragContext *context);

Determines the source widget for a drag.


gtk_drag_highlight ()

void        gtk_drag_highlight              (GtkWidget *widget);

Draws a highlight around a widget. This will attach handlers to "expose_event" and "draw", so the highlight will continue to be displayed until gtk_drag_unhighlight() is called.


gtk_drag_unhighlight ()

void        gtk_drag_unhighlight            (GtkWidget *widget);

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


gtk_drag_begin ()

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

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.


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.


gtk_drag_set_icon_pixmap ()

void        gtk_drag_set_icon_pixmap        (GdkDragContext *context,
                                             GdkColormap *colormap,
                                             GdkPixmap *pixmap,
                                             GdkBitmap *mask,
                                             gint hot_x,
                                             gint hot_y);

Sets pixmap as the icon for a given drag. GTK+ retains references for the arguments, and will release them when they are no longer needed. In general, gtk_drag_set_icon_pixbuf() will be more convenient to use.


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 the icon for a given drag from a stock ID.


gtk_drag_set_icon_default ()

void        gtk_drag_set_icon_default       (GdkDragContext *context);

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


gtk_drag_set_default_icon ()

void        gtk_drag_set_default_icon       (GdkColormap *colormap,
                                             GdkPixmap *pixmap,
                                             GdkBitmap *mask,
                                             gint hot_x,
                                             gint hot_y);

Warning

gtk_drag_set_default_icon is deprecated and should not be used in newly-written code.

Changes the default drag icon. GTK+ retains references for the arguments, and will release them when they are no longer needed. This function is obsolete. The default icon should now be changed via the stock system by changing the stock pixbuf for GTK_STOCK_DND.


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 threshhold, and thus should trigger the beginning of a drag-and-drop operation.


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.


gtk_drag_source_set_icon ()

void        gtk_drag_source_set_icon        (GtkWidget *widget,
                                             GdkColormap *colormap,
                                             GdkPixmap *pixmap,
                                             GdkBitmap *mask);

Sets the icon that will be used for drags from a particular widget from a pixmap/mask. GTK+ retains references for the arguments, and will release them when they are no longer needed. Use gtk_drag_source_set_icon_pixbuf() instead.


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.


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.


gtk_drag_source_unset ()

void        gtk_drag_source_unset           (GtkWidget *widget);

Undoes the effects of gtk_drag_source_set().