/* GTK - The GIMP Toolkit
* Copyright (C) 1995-1999 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see .
*/
/*
* Modified by the GTK+ Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GTK+ Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GTK+ at ftp://ftp.gtk.org/pub/gtk/.
*/
#include "config.h"
#include "gtkdnd.h"
#include "gtkdndprivate.h"
#include "gtksettingsprivate.h"
#include
#include
#include
#include "gdk/gdk.h"
#ifdef GDK_WINDOWING_X11
#include
#include
#include "gdk/x11/gdkx.h"
#ifdef XINPUT_2
#include
#endif
#endif
#ifdef GDK_WINDOWING_WAYLAND
#include
#endif
#include "gtkdragdest.h"
#include "gtkgesturedrag.h"
#include "gtkgesturesingle.h"
#include "gtkicontheme.h"
#include "gtkimageprivate.h"
#include "gtkintl.h"
#include "gtkmain.h"
#include "gtktooltipprivate.h"
#include "gtkwindow.h"
#include "gtkrender.h"
#include "gtkselectionprivate.h"
#include "gtkwindowgroup.h"
#include "gtkwindowprivate.h"
#include "gtkwidgetprivate.h"
#include "gtkdrawingarea.h"
/**
* SECTION:gtkdnd
* @Short_description: Functions for controlling drag and drop handling
* @Title: Drag and Drop
*
* 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][gtk3-Selections]. Also, the Drag and
* Drop API makes use of signals in the #GtkWidget class.
*/
static GSList *source_widgets = NULL;
typedef struct _GtkDragSourceInfo GtkDragSourceInfo;
typedef struct _GtkDragDestInfo GtkDragDestInfo;
typedef enum
{
GTK_DRAG_STATUS_DRAG,
GTK_DRAG_STATUS_WAIT,
GTK_DRAG_STATUS_DROP
} GtkDragStatus;
struct _GtkDragSourceInfo
{
GtkWidget *widget;
GtkTargetList *target_list; /* Targets for drag data */
GdkDragAction possible_actions; /* Actions allowed by source */
GdkDragContext *context; /* drag context */
GtkWidget *icon_window; /* Window for drag */
GtkWidget *icon_widget; /* Widget for drag */
GtkWidget *ipc_widget; /* GtkInvisible for grab, message passing */
GdkCursor *cursor; /* Cursor for drag */
gint hot_x, hot_y; /* Hot spot for drag */
gint button; /* mouse button starting drag */
GtkDragStatus status; /* drag status */
GdkEvent *last_event; /* pending event */
gint start_x, start_y; /* Initial position */
gint cur_x, cur_y; /* Current Position */
GdkScreen *cur_screen; /* Current screen for pointer */
guint32 grab_time; /* timestamp for initial grab */
GList *selections; /* selections we've claimed */
guint update_idle; /* Idle function to update the drag */
guint drop_timeout; /* Timeout for aborting drop */
guint destroy_icon : 1; /* If true, destroy icon_widget */
guint have_grab : 1; /* Do we still have the pointer grab */
};
struct _GtkDragDestInfo
{
GtkWidget *widget; /* Widget in which drag is in */
GdkDragContext *context; /* Drag context */
guint dropped : 1; /* Set after we receive a drop */
gint drop_x, drop_y; /* Position of drop */
};
#define DROP_ABORT_TIME 300000
typedef gboolean (* GtkDragDestCallback) (GtkWidget *widget,
GdkDragContext *context,
gint x,
gint y,
guint32 time);
/* Enumeration for some targets we handle internally */
enum {
TARGET_DELETE = 0x40000002
};
/* Forward declarations */
static void gtk_drag_get_event_actions (const GdkEvent *event,
gint button,
GdkDragAction actions,
GdkDragAction *suggested_action,
GdkDragAction *possible_actions);
static GdkCursor * gtk_drag_get_cursor (GtkWidget *widget,
GdkDisplay *display,
GdkDragAction action,
GtkDragSourceInfo *info);
static void gtk_drag_update_cursor (GtkDragSourceInfo *info);
static GtkWidget *gtk_drag_get_ipc_widget (GtkWidget *widget);
static GtkWidget *gtk_drag_get_ipc_widget_for_screen (GdkScreen *screen);
static void gtk_drag_release_ipc_widget (GtkWidget *widget);
static void gtk_drag_selection_received (GtkWidget *widget,
GtkSelectionData *selection_data,
guint time,
gpointer data);
static gboolean gtk_drag_find_widget (GtkWidget *widget,
GdkDragContext *context,
GtkDragDestInfo *info,
gint x,
gint y,
guint32 time,
GtkDragDestCallback callback);
static void gtk_drag_dest_leave (GtkWidget *widget,
GdkDragContext *context,
guint time);
static gboolean gtk_drag_dest_motion (GtkWidget *widget,
GdkDragContext *context,
gint x,
gint y,
guint time);
static gboolean gtk_drag_dest_drop (GtkWidget *widget,
GdkDragContext *context,
gint x,
gint y,
guint time);
static void gtk_drag_dest_set_widget (GtkDragDestInfo *info,
GtkWidget *widget);
static GtkDragDestInfo * gtk_drag_get_dest_info (GdkDragContext *context,
gboolean create);
static GtkDragSourceInfo *gtk_drag_get_source_info (GdkDragContext *context,
gboolean create);
static void gtk_drag_clear_source_info (GdkDragContext *context);
static void gtk_drag_source_check_selection (GtkDragSourceInfo *info,
GdkAtom selection,
guint32 time);
static void gtk_drag_source_release_selections (GtkDragSourceInfo *info,
guint32 time);
static void gtk_drag_drop (GtkDragSourceInfo *info,
guint32 time);
static void gtk_drag_drop_finished (GtkDragSourceInfo *info,
GtkDragResult result,
guint time);
static void gtk_drag_cancel_internal (GtkDragSourceInfo *info,
GtkDragResult result,
guint32 time);
static void gtk_drag_selection_get (GtkWidget *widget,
GtkSelectionData *selection_data,
guint sel_info,
guint32 time,
gpointer data);
static void gtk_drag_remove_icon (GtkDragSourceInfo *info);
static void gtk_drag_source_info_destroy (GtkDragSourceInfo *info);
static void gtk_drag_context_drop_performed_cb (GdkDragContext *context,
guint time,
GtkDragSourceInfo *info);
static void gtk_drag_context_cancel_cb (GdkDragContext *context,
GdkDragCancelReason reason,
GtkDragSourceInfo *info);
static void gtk_drag_context_dnd_finished_cb (GdkDragContext *context,
GtkDragSourceInfo *info);
static void gtk_drag_add_update_idle (GtkDragSourceInfo *info);
static void gtk_drag_update (GtkDragSourceInfo *info,
GdkScreen *screen,
gint x_root,
gint y_root,
const GdkEvent *event);
static gboolean gtk_drag_motion_cb (GtkWidget *widget,
GdkEventMotion *event,
gpointer data);
static gboolean gtk_drag_key_cb (GtkWidget *widget,
GdkEventKey *event,
gpointer data);
static gboolean gtk_drag_grab_broken_event_cb (GtkWidget *widget,
GdkEventGrabBroken *event,
gpointer data);
static void gtk_drag_grab_notify_cb (GtkWidget *widget,
gboolean was_grabbed,
gpointer data);
static gboolean gtk_drag_button_release_cb (GtkWidget *widget,
GdkEventButton *event,
gpointer data);
static gboolean gtk_drag_abort_timeout (gpointer data);
static void set_icon_helper (GdkDragContext *context,
GtkImageDefinition*def,
gint hot_x,
gint hot_y);
/************************
* Cursor and Icon data *
************************/
static struct {
GdkDragAction action;
const gchar *name;
GdkPixbuf *pixbuf;
GdkCursor *cursor;
} drag_cursors[] = {
{ GDK_ACTION_DEFAULT, NULL },
{ GDK_ACTION_ASK, "dnd-ask", NULL, NULL },
{ GDK_ACTION_COPY, "copy", NULL, NULL },
{ GDK_ACTION_MOVE, "move", NULL, NULL },
{ GDK_ACTION_LINK, "alias", NULL, NULL },
{ 0 , "no-drop", NULL, NULL },
};
/*********************
* Utility functions *
*********************/
static GtkWidget *
gtk_drag_get_ipc_widget_for_screen (GdkScreen *screen)
{
GtkWidget *result;
GSList *drag_widgets = g_object_get_data (G_OBJECT (screen),
"gtk-dnd-ipc-widgets");
if (drag_widgets)
{
GSList *tmp = drag_widgets;
result = drag_widgets->data;
drag_widgets = drag_widgets->next;
g_object_set_data (G_OBJECT (screen),
I_("gtk-dnd-ipc-widgets"),
drag_widgets);
g_slist_free_1 (tmp);
}
else
{
result = gtk_window_new (GTK_WINDOW_POPUP);
gtk_window_set_screen (GTK_WINDOW (result), screen);
gtk_window_resize (GTK_WINDOW (result), 1, 1);
gtk_window_move (GTK_WINDOW (result), -99, -99);
gtk_widget_show (result);
}
return result;
}
static GtkWidget *
gtk_drag_get_ipc_widget (GtkWidget *widget)
{
GtkWidget *result;
GtkWidget *toplevel;
result = gtk_drag_get_ipc_widget_for_screen (gtk_widget_get_screen (widget));
toplevel = gtk_widget_get_toplevel (widget);
if (GTK_IS_WINDOW (toplevel))
{
if (gtk_window_has_group (GTK_WINDOW (toplevel)))
gtk_window_group_add_window (gtk_window_get_group (GTK_WINDOW (toplevel)),
GTK_WINDOW (result));
}
return result;
}
static void
grab_dnd_keys (GtkWidget *widget,
GdkDevice *device,
guint32 time)
{
G_GNUC_BEGIN_IGNORE_DEPRECATIONS;
gdk_device_grab (device,
gtk_widget_get_window (widget),
GDK_OWNERSHIP_APPLICATION, FALSE,
GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK,
NULL, time);
G_GNUC_END_IGNORE_DEPRECATIONS;
}
static void
ungrab_dnd_keys (GtkWidget *widget,
GdkDevice *device,
guint32 time)
{
G_GNUC_BEGIN_IGNORE_DEPRECATIONS;
gdk_device_ungrab (device, time);
G_GNUC_END_IGNORE_DEPRECATIONS;
}
/*
* gtk_drag_release_ipc_widget:
* @widget: the widget to release
*
* Releases widget retrieved with gtk_drag_get_ipc_widget().
*/
static void
gtk_drag_release_ipc_widget (GtkWidget *widget)
{
GtkWindow *window = GTK_WINDOW (widget);
GdkScreen *screen = gtk_widget_get_screen (widget);
GdkDragContext *context = g_object_get_data (G_OBJECT (widget), "drag-context");
GSList *drag_widgets = g_object_get_data (G_OBJECT (screen),
"gtk-dnd-ipc-widgets");
GdkDevice *pointer, *keyboard;
if (context)
{
pointer = gdk_drag_context_get_device (context);
keyboard = gdk_device_get_associated_device (pointer);
if (keyboard)
ungrab_dnd_keys (widget, keyboard, GDK_CURRENT_TIME);
}
if (gtk_window_has_group (window))
gtk_window_group_remove_window (gtk_window_get_group (window),
window);
drag_widgets = g_slist_prepend (drag_widgets, widget);
g_object_set_data (G_OBJECT (screen),
I_("gtk-dnd-ipc-widgets"),
drag_widgets);
}
static guint32
gtk_drag_get_event_time (GdkEvent *event)
{
guint32 tm = GDK_CURRENT_TIME;
if (event)
switch (event->type)
{
case GDK_MOTION_NOTIFY:
tm = event->motion.time; break;
case GDK_BUTTON_PRESS:
case GDK_2BUTTON_PRESS:
case GDK_3BUTTON_PRESS:
case GDK_BUTTON_RELEASE:
tm = event->button.time; break;
case GDK_KEY_PRESS:
case GDK_KEY_RELEASE:
tm = event->key.time; break;
case GDK_ENTER_NOTIFY:
case GDK_LEAVE_NOTIFY:
tm = event->crossing.time; break;
case GDK_PROPERTY_NOTIFY:
tm = event->property.time; break;
case GDK_SELECTION_CLEAR:
case GDK_SELECTION_REQUEST:
case GDK_SELECTION_NOTIFY:
tm = event->selection.time; break;
case GDK_PROXIMITY_IN:
case GDK_PROXIMITY_OUT:
tm = event->proximity.time; break;
default: /* use current time */
break;
}
return tm;
}
static void
gtk_drag_get_event_actions (const GdkEvent *event,
gint button,
GdkDragAction actions,
GdkDragAction *suggested_action,
GdkDragAction *possible_actions)
{
*suggested_action = 0;
*possible_actions = 0;
if (event)
{
GdkModifierType state = 0;
switch (event->type)
{
case GDK_MOTION_NOTIFY:
state = event->motion.state;
break;
case GDK_BUTTON_PRESS:
case GDK_2BUTTON_PRESS:
case GDK_3BUTTON_PRESS:
case GDK_BUTTON_RELEASE:
state = event->button.state;
break;
case GDK_KEY_PRESS:
case GDK_KEY_RELEASE:
state = event->key.state;
break;
case GDK_ENTER_NOTIFY:
case GDK_LEAVE_NOTIFY:
state = event->crossing.state;
break;
default:
break;
}
if ((button == GDK_BUTTON_MIDDLE || button == GDK_BUTTON_SECONDARY) && (actions & GDK_ACTION_ASK))
{
*suggested_action = GDK_ACTION_ASK;
*possible_actions = actions;
}
else if (state & (GDK_SHIFT_MASK | GDK_CONTROL_MASK))
{
if ((state & GDK_SHIFT_MASK) && (state & GDK_CONTROL_MASK))
{
if (actions & GDK_ACTION_LINK)
{
*suggested_action = GDK_ACTION_LINK;
*possible_actions = GDK_ACTION_LINK;
}
}
else if (state & GDK_CONTROL_MASK)
{
if (actions & GDK_ACTION_COPY)
{
*suggested_action = GDK_ACTION_COPY;
*possible_actions = GDK_ACTION_COPY;
}
}
else
{
if (actions & GDK_ACTION_MOVE)
{
*suggested_action = GDK_ACTION_MOVE;
*possible_actions = GDK_ACTION_MOVE;
}
}
}
else
{
*possible_actions = actions;
if ((state & (GDK_MOD1_MASK)) && (actions & GDK_ACTION_ASK))
*suggested_action = GDK_ACTION_ASK;
else if (actions & GDK_ACTION_COPY)
*suggested_action = GDK_ACTION_COPY;
else if (actions & GDK_ACTION_MOVE)
*suggested_action = GDK_ACTION_MOVE;
else if (actions & GDK_ACTION_LINK)
*suggested_action = GDK_ACTION_LINK;
}
}
else
{
*possible_actions = actions;
if (actions & GDK_ACTION_COPY)
*suggested_action = GDK_ACTION_COPY;
else if (actions & GDK_ACTION_MOVE)
*suggested_action = GDK_ACTION_MOVE;
else if (actions & GDK_ACTION_LINK)
*suggested_action = GDK_ACTION_LINK;
}
}
static void
ensure_drag_cursor_pixbuf (int i)
{
if (drag_cursors[i].pixbuf == NULL)
{
char *path = g_strconcat ("/org/gtk/libgtk/cursor/", drag_cursors[i].name, ".png", NULL);
GInputStream *stream = g_resources_open_stream (path, 0, NULL);
if (stream != NULL)
{
drag_cursors[i].pixbuf = gdk_pixbuf_new_from_stream (stream, NULL, NULL);
g_object_unref (stream);
}
g_free (path);
}
}
static GdkCursor *
gtk_drag_get_cursor (GtkWidget *widget,
GdkDisplay *display,
GdkDragAction action,
GtkDragSourceInfo *info)
{
gint i;
/* reconstruct the cursors for each new drag (thus !info),
* to catch cursor theme changes
*/
if (!info)
{
for (i = 0 ; i < G_N_ELEMENTS (drag_cursors) - 1; i++)
g_clear_object (&drag_cursors[i].cursor);
}
for (i = 0 ; i < G_N_ELEMENTS (drag_cursors) - 1; i++)
if (drag_cursors[i].action == action)
break;
if (drag_cursors[i].cursor != NULL)
{
if (display != gdk_cursor_get_display (drag_cursors[i].cursor))
g_clear_object (&drag_cursors[i].cursor);
}
if (drag_cursors[i].cursor == NULL)
drag_cursors[i].cursor = gdk_cursor_new_from_name (display, drag_cursors[i].name);
if (drag_cursors[i].cursor == NULL)
{
ensure_drag_cursor_pixbuf (i);
drag_cursors[i].cursor = gdk_cursor_new_from_pixbuf (display, drag_cursors[i].pixbuf, 0, 0);
}
return drag_cursors[i].cursor;
}
static void
gtk_drag_update_cursor (GtkDragSourceInfo *info)
{
GdkCursor *cursor;
gint i;
if (!info->have_grab)
return;
for (i = 0 ; i < G_N_ELEMENTS (drag_cursors) - 1; i++)
if (info->cursor == drag_cursors[i].cursor)
break;
if (i == G_N_ELEMENTS (drag_cursors))
return;
cursor = gtk_drag_get_cursor (info->widget,
gdk_cursor_get_display (info->cursor),
drag_cursors[i].action, info);
if (cursor != info->cursor)
{
GdkDevice *pointer;
pointer = gdk_drag_context_get_device (info->context);
G_GNUC_BEGIN_IGNORE_DEPRECATIONS;
gdk_device_grab (pointer,
gtk_widget_get_window (info->ipc_widget),
GDK_OWNERSHIP_APPLICATION, FALSE,
GDK_POINTER_MOTION_MASK | GDK_BUTTON_RELEASE_MASK,
cursor, info->grab_time);
G_GNUC_END_IGNORE_DEPRECATIONS;
info->cursor = cursor;
}
}
/********************
* Destination side *
********************/
/**
* gtk_drag_get_data: (method)
* @widget: the widget that will receive the
* #GtkWidget::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 #GtkWidget::drag-motion
* or #GtkWidget::drag-drop signal
*
* Gets the data associated with a drag. When the data
* is received or the retrieval fails, GTK+ will emit a
* #GtkWidget::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.
*/
void
gtk_drag_get_data (GtkWidget *widget,
GdkDragContext *context,
GdkAtom target,
guint32 time_)
{
GtkWidget *selection_widget;
g_return_if_fail (GTK_IS_WIDGET (widget));
g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
selection_widget = gtk_drag_get_ipc_widget (widget);
g_object_ref (context);
g_object_ref (widget);
g_signal_connect (selection_widget, "selection-received",
G_CALLBACK (gtk_drag_selection_received), widget);
g_object_set_data (G_OBJECT (selection_widget), I_("drag-context"), context);
gtk_selection_convert (selection_widget,
gdk_drag_get_selection (context),
target,
time_);
}
/**
* gtk_drag_get_source_widget: (method)
* @context: a (destination side) drag context
*
* Determines the source widget for a drag.
*
* Returns: (nullable) (transfer none): if the drag is occurring
* within a single application, a pointer to the source widget.
* Otherwise, %NULL.
*/
GtkWidget *
gtk_drag_get_source_widget (GdkDragContext *context)
{
GSList *tmp_list;
g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), NULL);
tmp_list = source_widgets;
while (tmp_list)
{
GtkWidget *ipc_widget = tmp_list->data;
if (gtk_widget_get_window (ipc_widget) == gdk_drag_context_get_source_window (context))
{
GtkDragSourceInfo *info;
info = g_object_get_data (G_OBJECT (ipc_widget), "gtk-info");
return info ? info->widget : NULL;
}
tmp_list = tmp_list->next;
}
return NULL;
}
/**
* gtk_drag_finish: (method)
* @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 #GtkWidget::drag-drop signal
*
* Informs the drag source that the drop is finished, and
* that the data of the drag will no longer be required.
*/
void
gtk_drag_finish (GdkDragContext *context,
gboolean success,
gboolean del,
guint32 time)
{
GdkAtom target = GDK_NONE;
g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
if (success && del)
{
target = gdk_atom_intern_static_string ("DELETE");
}
if (target != GDK_NONE)
{
GtkWidget *selection_widget = gtk_drag_get_ipc_widget_for_screen (gdk_window_get_screen (gdk_drag_context_get_source_window (context)));
g_object_ref (context);
g_object_set_data (G_OBJECT (selection_widget), I_("drag-context"), context);
g_signal_connect (selection_widget, "selection-received",
G_CALLBACK (gtk_drag_selection_received),
NULL);
gtk_selection_convert (selection_widget,
gdk_drag_get_selection (context),
target,
time);
}
if (!(success && del))
gdk_drop_finish (context, success, time);
}
/**
* gtk_drag_highlight: (method)
* @widget: a widget to highlight
*
* 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.
*/
void
gtk_drag_highlight (GtkWidget *widget)
{
g_return_if_fail (GTK_IS_WIDGET (widget));
gtk_widget_set_state_flags (widget, GTK_STATE_FLAG_DROP_ACTIVE, FALSE);
}
/**
* gtk_drag_unhighlight: (method)
* @widget: a widget to remove the highlight from
*
* Removes a highlight set by gtk_drag_highlight() from
* a widget.
*/
void
gtk_drag_unhighlight (GtkWidget *widget)
{
g_return_if_fail (GTK_IS_WIDGET (widget));
gtk_widget_unset_state_flags (widget, GTK_STATE_FLAG_DROP_ACTIVE);
}
/*
* _gtk_drag_dest_handle_event:
* @toplevel: Toplevel widget that received the event
* @event: the event to handle
*
* Called from widget event handling code on Drag events
* for destinations.
*/
void
_gtk_drag_dest_handle_event (GtkWidget *toplevel,
GdkEvent *event)
{
GtkDragDestInfo *info;
GdkDragContext *context;
g_return_if_fail (toplevel != NULL);
g_return_if_fail (event != NULL);
context = event->dnd.context;
info = gtk_drag_get_dest_info (context, TRUE);
/* Find the widget for the event */
switch (event->type)
{
case GDK_DRAG_ENTER:
break;
case GDK_DRAG_LEAVE:
if (info->widget)
{
gtk_drag_dest_leave (info->widget, context, event->dnd.time);
gtk_drag_dest_set_widget (info, NULL);
}
break;
case GDK_DRAG_MOTION:
case GDK_DROP_START:
{
GdkWindow *window;
gint tx, ty;
gboolean found;
if (event->type == GDK_DROP_START)
{
info->dropped = TRUE;
/* We send a leave here so that the widget unhighlights
* properly.
*/
if (info->widget)
{
gtk_drag_dest_leave (info->widget, context, event->dnd.time);
gtk_drag_dest_set_widget (info, NULL);
}
}
window = gtk_widget_get_window (toplevel);
gdk_window_get_position (window, &tx, &ty);
found = gtk_drag_find_widget (toplevel,
context,
info,
event->dnd.x_root - tx,
event->dnd.y_root - ty,
event->dnd.time,
(event->type == GDK_DRAG_MOTION) ?
gtk_drag_dest_motion :
gtk_drag_dest_drop);
if (info->widget && !found)
{
gtk_drag_dest_leave (info->widget, context, event->dnd.time);
gtk_drag_dest_set_widget (info, NULL);
}
/* Send a reply.
*/
if (event->type == GDK_DRAG_MOTION)
{
if (!found)
gdk_drag_status (context, 0, event->dnd.time);
}
else if (event->type == GDK_DROP_START)
{
gdk_drop_reply (context, found, event->dnd.time);
}
}
break;
default:
g_assert_not_reached ();
}
}
static void
gtk_drag_selection_received (GtkWidget *widget,
GtkSelectionData *selection_data,
guint time,
gpointer data)
{
GdkDragContext *context;
GtkDragDestInfo *info;
GtkWidget *drop_widget;
GdkAtom target;
drop_widget = data;
context = g_object_get_data (G_OBJECT (widget), "drag-context");
info = gtk_drag_get_dest_info (context, FALSE);
target = gtk_selection_data_get_target (selection_data);
if (target == gdk_atom_intern_static_string ("DELETE"))
{
gtk_drag_finish (context, TRUE, FALSE, time);
}
else if ((target == gdk_atom_intern_static_string ("XmTRANSFER_SUCCESS")) ||
(target == gdk_atom_intern_static_string ("XmTRANSFER_FAILURE")))
{
/* Do nothing */
}
else
{
GtkDragDestSite *site;
site = g_object_get_data (G_OBJECT (drop_widget), "gtk-drag-dest");
if (site && site->target_list)
{
guint target_info;
if (gtk_target_list_find (site->target_list,
target,
&target_info))
{
if (!(site->flags & GTK_DEST_DEFAULT_DROP) ||
gtk_selection_data_get_length (selection_data) >= 0)
g_signal_emit_by_name (drop_widget,
"drag-data-received",
context, info->drop_x, info->drop_y,
selection_data,
target_info, time);
}
}
else
{
g_signal_emit_by_name (drop_widget,
"drag-data-received",
context, info->drop_x, info->drop_y,
selection_data,
0, time);
}
if (site && site->flags & GTK_DEST_DEFAULT_DROP)
{
gtk_drag_finish (context,
(gtk_selection_data_get_length (selection_data) >= 0),
(gdk_drag_context_get_selected_action (context) == GDK_ACTION_MOVE),
time);
}
g_object_unref (drop_widget);
}
g_signal_handlers_disconnect_by_func (widget,
gtk_drag_selection_received,
data);
g_object_set_data (G_OBJECT (widget), I_("drag-context"), NULL);
g_object_unref (context);
gtk_drag_release_ipc_widget (widget);
}
static gboolean
gtk_drag_find_widget (GtkWidget *widget,
GdkDragContext *context,
GtkDragDestInfo *info,
gint x,
gint y,
guint32 time,
GtkDragDestCallback callback)
{
if (!gtk_widget_get_mapped (widget) ||
!gtk_widget_get_sensitive (widget))
return FALSE;
/* Get the widget at the pointer coordinates and travel up
* the widget hierarchy from there.
*/
widget = _gtk_widget_find_at_coords (gtk_widget_get_window (widget),
x, y, &x, &y);
if (!widget)
return FALSE;
while (widget)
{
GtkWidget *parent;
GList *hierarchy = NULL;
gboolean found = FALSE;
if (!gtk_widget_get_mapped (widget))
return FALSE;
if (gtk_widget_get_state_flags (widget) & GTK_STATE_FLAG_INSENSITIVE)
{
widget = gtk_widget_get_parent (widget);
continue;
}
/* need to reference the entire hierarchy temporarily in case the
* ::drag-motion/::drag-drop callbacks change the widget hierarchy.
*/
for (parent = widget;
parent;
parent = gtk_widget_get_parent (parent))
{
hierarchy = g_list_prepend (hierarchy, g_object_ref (parent));
}
/* If the current widget is registered as a drop site, check to
* emit "drag-motion" to check if we are actually in a drop
* site.
*/
if (g_object_get_data (G_OBJECT (widget), "gtk-drag-dest"))
{
found = callback (widget, context, x, y, time);
/* If so, send a "drag-leave" to the last widget */
if (found && info->widget != widget)
{
if (info->widget)
gtk_drag_dest_leave (info->widget, context, time);
gtk_drag_dest_set_widget (info, widget);
}
}
if (!found)
{
/* Get the parent before unreffing the hierarchy because
* invoking the callback might have destroyed the widget
*/
parent = gtk_widget_get_parent (widget);
/* The parent might be going away when unreffing the
* hierarchy, so also protect againt that
*/
if (parent)
g_object_add_weak_pointer (G_OBJECT (parent), (gpointer *) &parent);
}
g_list_free_full (hierarchy, g_object_unref);
if (found)
return TRUE;
if (parent)
g_object_remove_weak_pointer (G_OBJECT (parent), (gpointer *) &parent);
else
return FALSE;
if (!gtk_widget_translate_coordinates (widget, parent, x, y, &x, &y))
return FALSE;
widget = parent;
}
return FALSE;
}
static void
gtk_drag_dest_set_widget (GtkDragDestInfo *info,
GtkWidget *widget)
{
if (info->widget)
g_object_remove_weak_pointer (G_OBJECT (info->widget), (gpointer *) &info->widget);
info->widget = widget;
if (info->widget)
g_object_add_weak_pointer (G_OBJECT (info->widget), (gpointer *) &info->widget);
}
static void
gtk_drag_dest_info_destroy (gpointer data)
{
GtkDragDestInfo *info = (GtkDragDestInfo *)data;
gtk_drag_dest_set_widget (info, NULL);
g_slice_free (GtkDragDestInfo, data);
}
static GtkDragDestInfo *
gtk_drag_get_dest_info (GdkDragContext *context,
gboolean create)
{
GtkDragDestInfo *info;
static GQuark info_quark = 0;
if (!info_quark)
info_quark = g_quark_from_static_string ("gtk-dest-info");
info = g_object_get_qdata (G_OBJECT (context), info_quark);
if (!info && create)
{
info = g_slice_new0 (GtkDragDestInfo);
info->context = context;
g_object_set_qdata_full (G_OBJECT (context), info_quark,
info, gtk_drag_dest_info_destroy);
}
return info;
}
static GQuark dest_info_quark = 0;
static GtkDragSourceInfo *
gtk_drag_get_source_info (GdkDragContext *context,
gboolean create)
{
GtkDragSourceInfo *info;
if (!dest_info_quark)
dest_info_quark = g_quark_from_static_string ("gtk-source-info");
info = g_object_get_qdata (G_OBJECT (context), dest_info_quark);
if (!info && create)
{
info = g_new0 (GtkDragSourceInfo, 1);
info->context = context;
g_object_set_qdata (G_OBJECT (context), dest_info_quark, info);
}
return info;
}
static void
gtk_drag_clear_source_info (GdkDragContext *context)
{
g_object_set_qdata (G_OBJECT (context), dest_info_quark, NULL);
}
/*
* Default drag handlers
*/
static void
gtk_drag_dest_leave (GtkWidget *widget,
GdkDragContext *context,
guint time)
{
GtkDragDestSite *site;
site = g_object_get_data (G_OBJECT (widget), "gtk-drag-dest");
g_return_if_fail (site != NULL);
if ((site->flags & GTK_DEST_DEFAULT_HIGHLIGHT) && site->have_drag)
gtk_drag_unhighlight (widget);
if (!(site->flags & GTK_DEST_DEFAULT_MOTION) || site->have_drag ||
site->track_motion)
g_signal_emit_by_name (widget, "drag-leave", context, time);
site->have_drag = FALSE;
}
static gboolean
gtk_drag_dest_motion (GtkWidget *widget,
GdkDragContext *context,
gint x,
gint y,
guint time)
{
GtkDragDestSite *site;
GdkDragAction action = 0;
gboolean retval;
site = g_object_get_data (G_OBJECT (widget), "gtk-drag-dest");
g_return_val_if_fail (site != NULL, FALSE);
if (site->track_motion || site->flags & GTK_DEST_DEFAULT_MOTION)
{
if (gdk_drag_context_get_suggested_action (context) & site->actions)
action = gdk_drag_context_get_suggested_action (context);
else
{
gint i;
for (i = 0; i < 8; i++)
{
if ((site->actions & (1 << i)) &&
(gdk_drag_context_get_actions (context) & (1 << i)))
{
action = (1 << i);
break;
}
}
}
if (action && gtk_drag_dest_find_target (widget, context, NULL))
{
if (!site->have_drag)
{
site->have_drag = TRUE;
if (site->flags & GTK_DEST_DEFAULT_HIGHLIGHT)
gtk_drag_highlight (widget);
}
gdk_drag_status (context, action, time);
}
else
{
gdk_drag_status (context, 0, time);
if (!site->track_motion)
return TRUE;
}
}
g_signal_emit_by_name (widget, "drag-motion",
context, x, y, time, &retval);
return (site->flags & GTK_DEST_DEFAULT_MOTION) ? TRUE : retval;
}
static gboolean
gtk_drag_dest_drop (GtkWidget *widget,
GdkDragContext *context,
gint x,
gint y,
guint time)
{
GtkDragDestSite *site;
GtkDragDestInfo *info;
gboolean retval;
site = g_object_get_data (G_OBJECT (widget), "gtk-drag-dest");
g_return_val_if_fail (site != NULL, FALSE);
info = gtk_drag_get_dest_info (context, FALSE);
g_return_val_if_fail (info != NULL, FALSE);
info->drop_x = x;
info->drop_y = y;
if (site->flags & GTK_DEST_DEFAULT_DROP)
{
GdkAtom target = gtk_drag_dest_find_target (widget, context, NULL);
if (target == GDK_NONE)
{
gtk_drag_finish (context, FALSE, FALSE, time);
return TRUE;
}
else
gtk_drag_get_data (widget, context, target, time);
}
g_signal_emit_by_name (widget, "drag-drop",
context, x, y, time, &retval);
return (site->flags & GTK_DEST_DEFAULT_DROP) ? TRUE : retval;
}
/***************
* Source side *
***************/
/* Like gtk_drag_begin(), but also takes a GtkIconHelper
* so that we can set the icon from the source site information
*/
GdkDragContext *
gtk_drag_begin_internal (GtkWidget *widget,
GtkImageDefinition *icon,
GtkTargetList *target_list,
GdkDragAction actions,
gint button,
const GdkEvent *event,
int x,
int y)
{
GtkDragSourceInfo *info;
GList *targets = NULL;
GList *tmp_list;
guint32 time = GDK_CURRENT_TIME;
GdkDragAction possible_actions, suggested_action;
GdkDragContext *context;
GtkWidget *ipc_widget;
GdkCursor *cursor;
GdkDevice *pointer, *keyboard;
GdkWindow *ipc_window;
gint start_x, start_y;
GdkAtom selection;
gboolean managed = FALSE;
managed =
#ifdef GDK_WINDOWING_X11
GDK_IS_X11_DISPLAY (gtk_widget_get_display (widget)) ||
#endif
#ifdef GDK_WINDOWING_WAYLAND
GDK_IS_WAYLAND_DISPLAY (gtk_widget_get_display (widget)) ||
#endif
FALSE;
pointer = keyboard = NULL;
ipc_widget = gtk_drag_get_ipc_widget (widget);
gtk_drag_get_event_actions (event, button, actions,
&suggested_action, &possible_actions);
cursor = gtk_drag_get_cursor (widget,
gtk_widget_get_display (widget),
suggested_action,
NULL);
if (event)
{
time = gdk_event_get_time (event);
if (time == GDK_CURRENT_TIME)
time = gtk_get_current_event_time ();
pointer = gdk_event_get_device (event);
if (gdk_device_get_source (pointer) == GDK_SOURCE_KEYBOARD)
{
keyboard = pointer;
pointer = gdk_device_get_associated_device (keyboard);
}
else
keyboard = gdk_device_get_associated_device (pointer);
}
else
{
GdkSeat *seat;
seat = gdk_display_get_default_seat (gtk_widget_get_display (widget));
pointer = gdk_seat_get_pointer (seat);
keyboard = gdk_seat_get_keyboard (seat);
}
if (!pointer)
return NULL;
ipc_window = gtk_widget_get_window (ipc_widget);
if (!managed)
{
gboolean grabbed;
G_GNUC_BEGIN_IGNORE_DEPRECATIONS;
grabbed = gdk_device_grab (pointer, ipc_window,
GDK_OWNERSHIP_APPLICATION, FALSE,
GDK_POINTER_MOTION_MASK |
GDK_BUTTON_RELEASE_MASK,
cursor, time) == GDK_GRAB_SUCCESS;
G_GNUC_END_IGNORE_DEPRECATIONS;
if (!grabbed)
{
gtk_drag_release_ipc_widget (ipc_widget);
return NULL;
}
if (keyboard)
grab_dnd_keys (ipc_widget, keyboard, time);
/* We use a GTK grab here to override any grabs that the widget
* we are dragging from might have held
*/
gtk_device_grab_add (ipc_widget, pointer, FALSE);
}
tmp_list = g_list_last (target_list->list);
while (tmp_list)
{
GtkTargetPair *pair = tmp_list->data;
targets = g_list_prepend (targets,
GINT_TO_POINTER (pair->target));
tmp_list = tmp_list->prev;
}
source_widgets = g_slist_prepend (source_widgets, ipc_widget);
if (x != -1 && y != -1)
{
GtkWidget *toplevel = gtk_widget_get_toplevel (widget);
gtk_widget_translate_coordinates (widget, toplevel,
x, y, &x, &y);
gdk_window_get_root_coords (gtk_widget_get_window (toplevel),
x, y, &start_x, &start_y);
}
else if (event && event->type == GDK_MOTION_NOTIFY)
{
start_x = event->motion.x_root;
start_y = event->motion.y_root;
}
else
gdk_device_get_position (pointer, NULL, &start_x, &start_y);
context = gdk_drag_begin_from_point (ipc_window, pointer, targets, start_x, start_y);
gdk_drag_context_set_device (context, pointer);
g_list_free (targets);
if (managed &&
!gdk_drag_context_manage_dnd (context, ipc_window, actions))
{
gtk_drag_release_ipc_widget (ipc_widget);
g_object_unref (context);
return NULL;
}
info = gtk_drag_get_source_info (context, TRUE);
info->ipc_widget = ipc_widget;
g_object_set_data (G_OBJECT (info->ipc_widget), I_("gtk-info"), info);
info->widget = g_object_ref (widget);
info->button = button;
info->cursor = cursor;
info->target_list = target_list;
gtk_target_list_ref (target_list);
info->possible_actions = actions;
info->status = GTK_DRAG_STATUS_DRAG;
info->last_event = NULL;
info->selections = NULL;
info->icon_window = NULL;
info->icon_widget = NULL;
info->destroy_icon = FALSE;
if (event)
info->cur_screen = gdk_event_get_screen (event);
else
gdk_device_get_position (pointer, &info->cur_screen, NULL, NULL);
info->start_x = start_x;
info->start_y = start_y;
gtk_widget_reset_controllers (widget);
g_signal_emit_by_name (widget, "drag-begin", info->context);
/* Ensure that we have an icon before we start the drag; the
* application may have set one in ::drag_begin, or it may
* not have set one.
*/
if (!info->icon_widget)
{
if (icon)
{
set_icon_helper (info->context, icon, 0, 0);
}
else
{
icon = gtk_image_definition_new_icon_name ("text-x-generic");
set_icon_helper (info->context, icon, 0, 0);
gtk_image_definition_unref (icon);
}
}
if (managed)
{
g_signal_connect (context, "drop-performed",
G_CALLBACK (gtk_drag_context_drop_performed_cb), info);
g_signal_connect (context, "dnd-finished",
G_CALLBACK (gtk_drag_context_dnd_finished_cb), info);
g_signal_connect (context, "cancel",
G_CALLBACK (gtk_drag_context_cancel_cb), info);
selection = gdk_drag_get_selection (context);
if (selection)
gtk_drag_source_check_selection (info, selection, time);
}
else
{
info->cur_x = info->start_x;
info->cur_y = info->start_y;
if (event && event->type == GDK_MOTION_NOTIFY)
gtk_drag_motion_cb (info->ipc_widget, (GdkEventMotion *)event, info);
else
gtk_drag_update (info, info->cur_screen, info->cur_x, info->cur_y, event);
g_signal_connect (info->ipc_widget, "grab-broken-event",
G_CALLBACK (gtk_drag_grab_broken_event_cb), info);
g_signal_connect (info->ipc_widget, "grab-notify",
G_CALLBACK (gtk_drag_grab_notify_cb), info);
g_signal_connect (info->ipc_widget, "button-release-event",
G_CALLBACK (gtk_drag_button_release_cb), info);
g_signal_connect (info->ipc_widget, "motion-notify-event",
G_CALLBACK (gtk_drag_motion_cb), info);
g_signal_connect (info->ipc_widget, "key-press-event",
G_CALLBACK (gtk_drag_key_cb), info);
g_signal_connect (info->ipc_widget, "key-release-event",
G_CALLBACK (gtk_drag_key_cb), info);
}
g_signal_connect (info->ipc_widget, "selection-get",
G_CALLBACK (gtk_drag_selection_get), info);
info->have_grab = TRUE;
info->grab_time = time;
return info->context;
}
/**
* gtk_drag_begin_with_coordinates: (method)
* @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: (nullable): The event that triggered the start of the drag,
* or %NULL if none can be obtained.
* @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
*
* 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:
*
* 1. During a #GtkWidget::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 #GtkWidget::button-press-event handler.
*
* 2. During a #GtkWidget::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 #GtkWidget::motion-notify-event handler.
*
* 3. 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.
*
* Returns: (transfer none): the context for this drag
*
* Since: 3.10
*/
GdkDragContext *
gtk_drag_begin_with_coordinates (GtkWidget *widget,
GtkTargetList *targets,
GdkDragAction actions,
gint button,
GdkEvent *event,
gint x,
gint y)
{
g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);
g_return_val_if_fail (gtk_widget_get_realized (widget), NULL);
g_return_val_if_fail (targets != NULL, NULL);
return gtk_drag_begin_internal (widget, NULL, targets,
actions, button, event, x, y);
}
static void
icon_widget_destroyed (GtkWidget *widget,
GtkDragSourceInfo *info)
{
g_clear_object (&info->icon_widget);
}
static void
gtk_drag_set_icon_widget_internal (GdkDragContext *context,
GtkWidget *widget,
gint hot_x,
gint hot_y,
gboolean destroy_on_release)
{
GtkDragSourceInfo *info;
g_return_if_fail (!GTK_IS_WINDOW (widget));
info = gtk_drag_get_source_info (context, FALSE);
if (info == NULL)
{
if (destroy_on_release)
gtk_widget_destroy (widget);
return;
}
gtk_drag_remove_icon (info);
if (widget)
g_object_ref (widget);
info->icon_widget = widget;
info->hot_x = hot_x;
info->hot_y = hot_y;
info->destroy_icon = destroy_on_release;
if (!widget)
goto out;
g_signal_connect (widget, "destroy", G_CALLBACK (icon_widget_destroyed), info);
gdk_drag_context_set_hotspot (context, hot_x, hot_y);
if (!info->icon_window)
{
GdkScreen *screen;
screen = gdk_window_get_screen (gdk_drag_context_get_source_window (context));
info->icon_window = gtk_window_new (GTK_WINDOW_POPUP);
gtk_window_set_type_hint (GTK_WINDOW (info->icon_window), GDK_WINDOW_TYPE_HINT_DND);
gtk_window_set_screen (GTK_WINDOW (info->icon_window), screen);
gtk_widget_set_size_request (info->icon_window, 24, 24);
gtk_widget_set_events (info->icon_window, GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK);
gtk_style_context_remove_class (gtk_widget_get_style_context (info->icon_window), "background");
gtk_window_set_hardcoded_window (GTK_WINDOW (info->icon_window),
gdk_drag_context_get_drag_window (context));
gtk_widget_show (info->icon_window);
}
if (gtk_bin_get_child (GTK_BIN (info->icon_window)))
gtk_container_remove (GTK_CONTAINER (info->icon_window), gtk_bin_get_child (GTK_BIN (info->icon_window)));
gtk_container_add (GTK_CONTAINER (info->icon_window), widget);
out:
gtk_drag_update_cursor (info);
}
/**
* gtk_drag_set_icon_widget: (method)
* @context: the context for a drag. (This must be called
with a context for the source side of a drag)
* @widget: a widget 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
*
* 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.
*/
void
gtk_drag_set_icon_widget (GdkDragContext *context,
GtkWidget *widget,
gint hot_x,
gint hot_y)
{
g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
g_return_if_fail (GTK_IS_WIDGET (widget));
gtk_drag_set_icon_widget_internal (context, widget, hot_x, hot_y, FALSE);
}
static void
set_icon_helper (GdkDragContext *context,
GtkImageDefinition *def,
gint hot_x,
gint hot_y)
{
GtkWidget *widget;
widget = gtk_image_new ();
gtk_widget_show (widget);
gtk_image_set_from_definition (GTK_IMAGE (widget), def, GTK_ICON_SIZE_DND);
gtk_drag_set_icon_widget_internal (context, widget, hot_x, hot_y, TRUE);
}
void
gtk_drag_set_icon_definition (GdkDragContext *context,
GtkImageDefinition *def,
gint hot_x,
gint hot_y)
{
g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
g_return_if_fail (def != NULL);
set_icon_helper (context, def, hot_x, hot_y);
}
/**
* gtk_drag_set_icon_pixbuf: (method)
* @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
*
* Sets @pixbuf as the icon for a given drag.
*/
void
gtk_drag_set_icon_pixbuf (GdkDragContext *context,
GdkPixbuf *pixbuf,
gint hot_x,
gint hot_y)
{
GtkImageDefinition *def;
g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
g_return_if_fail (GDK_IS_PIXBUF (pixbuf));
def = gtk_image_definition_new_pixbuf (pixbuf, 1);
set_icon_helper (context, def, hot_x, hot_y);
gtk_image_definition_unref (def);
}
/**
* gtk_drag_set_icon_surface: (method)
* @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
*
* 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.
*/
void
gtk_drag_set_icon_surface (GdkDragContext *context,
cairo_surface_t *surface)
{
GtkWidget *widget;
double hot_x, hot_y;
g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
g_return_if_fail (surface != NULL);
cairo_surface_get_device_offset (surface, &hot_x, &hot_y);
cairo_surface_set_device_offset (surface, 0, 0);
widget = gtk_image_new_from_surface (surface);
gtk_drag_set_icon_widget_internal (context, widget, (int)hot_x, (int)hot_y, TRUE);
}
/**
* gtk_drag_set_icon_name: (method)
* @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
*
* 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
*/
void
gtk_drag_set_icon_name (GdkDragContext *context,
const gchar *icon_name,
gint hot_x,
gint hot_y)
{
GtkImageDefinition *def;
g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
g_return_if_fail (icon_name != NULL && icon_name[0] != '\0');
def = gtk_image_definition_new_icon_name (icon_name);
set_icon_helper (context, def, hot_x, hot_y);
gtk_image_definition_unref (def);
}
/**
* gtk_drag_set_icon_gicon: (method)
* @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
*
* 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
*/
void
gtk_drag_set_icon_gicon (GdkDragContext *context,
GIcon *icon,
gint hot_x,
gint hot_y)
{
GtkImageDefinition *def;
g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
g_return_if_fail (icon != NULL);
def = gtk_image_definition_new_gicon (icon);
set_icon_helper (context, def, hot_x, hot_y);
gtk_image_definition_unref (def);
}
/**
* gtk_drag_set_icon_default: (method)
* @context: the context for a drag (This must be called
* with a context for the source side of a drag)
*
* Sets the icon for a particular drag to the default
* icon.
*/
void
gtk_drag_set_icon_default (GdkDragContext *context)
{
g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
gtk_drag_set_icon_name (context, "text-x-generic", -2, -2);
}
/*
* _gtk_drag_source_handle_event:
* @toplevel: Toplevel widget that received the event
* @event: the event to handle
*
* Called from widget event handling code on Drag events
* for drag sources.
*/
void
_gtk_drag_source_handle_event (GtkWidget *widget,
GdkEvent *event)
{
GtkDragSourceInfo *info;
GdkDragContext *context;
g_return_if_fail (widget != NULL);
g_return_if_fail (event != NULL);
context = event->dnd.context;
info = gtk_drag_get_source_info (context, FALSE);
if (!info)
return;
switch (event->type)
{
case GDK_DRAG_STATUS:
{
GdkCursor *cursor;
if (info->have_grab)
{
cursor = gtk_drag_get_cursor (widget,
gtk_widget_get_display (widget),
gdk_drag_context_get_selected_action (event->dnd.context),
info);
if (info->cursor != cursor)
{
GdkDevice *pointer;
pointer = gdk_drag_context_get_device (context);
G_GNUC_BEGIN_IGNORE_DEPRECATIONS;
gdk_device_grab (pointer, gtk_widget_get_window (widget),
GDK_OWNERSHIP_APPLICATION, FALSE,
GDK_POINTER_MOTION_MASK | GDK_BUTTON_RELEASE_MASK,
cursor, info->grab_time);
G_GNUC_END_IGNORE_DEPRECATIONS;
info->cursor = cursor;
}
gtk_drag_add_update_idle (info);
}
}
break;
case GDK_DROP_FINISHED:
gtk_drag_drop_finished (info, GTK_DRAG_RESULT_SUCCESS, event->dnd.time);
break;
default:
g_assert_not_reached ();
}
}
static void
gtk_drag_source_check_selection (GtkDragSourceInfo *info,
GdkAtom selection,
guint32 time)
{
GList *tmp_list;
tmp_list = info->selections;
while (tmp_list)
{
if (GDK_POINTER_TO_ATOM (tmp_list->data) == selection)
return;
tmp_list = tmp_list->next;
}
gtk_selection_owner_set_for_display (gtk_widget_get_display (info->widget),
info->ipc_widget,
selection,
time);
info->selections = g_list_prepend (info->selections,
GUINT_TO_POINTER (selection));
tmp_list = info->target_list->list;
while (tmp_list)
{
GtkTargetPair *pair = tmp_list->data;
gtk_selection_add_target (info->ipc_widget,
selection,
pair->target,
pair->info);
tmp_list = tmp_list->next;
}
gtk_selection_add_target (info->ipc_widget,
selection,
gdk_atom_intern_static_string ("DELETE"),
TARGET_DELETE);
}
/* Clean up from the drag, and display snapback, if necessary. */
static void
gtk_drag_drop_finished (GtkDragSourceInfo *info,
GtkDragResult result,
guint time)
{
gboolean success;
success = (result == GTK_DRAG_RESULT_SUCCESS);
gtk_drag_source_release_selections (info, time);
if (!success)
g_signal_emit_by_name (info->widget, "drag-failed",
info->context, result, &success);
gdk_drag_drop_done (info->context, success);
gtk_drag_source_info_destroy (info);
}
static void
gtk_drag_source_release_selections (GtkDragSourceInfo *info,
guint32 time)
{
GdkDisplay *display = gtk_widget_get_display (info->widget);
GList *tmp_list = info->selections;
while (tmp_list)
{
GdkAtom selection = GDK_POINTER_TO_ATOM (tmp_list->data);
if (gdk_selection_owner_get_for_display (display, selection) == gtk_widget_get_window (info->ipc_widget))
gtk_selection_owner_set_for_display (display, NULL, selection, time);
tmp_list = tmp_list->next;
}
g_list_free (info->selections);
info->selections = NULL;
}
static void
gtk_drag_drop (GtkDragSourceInfo *info,
guint32 time)
{
if (gdk_drag_context_get_protocol (info->context) == GDK_DRAG_PROTO_ROOTWIN)
{
GtkSelectionData selection_data;
GList *tmp_list;
/* GTK+ traditionally has used application/x-rootwin-drop, but the
* XDND spec specifies x-rootwindow-drop.
*/
GdkAtom target1 = gdk_atom_intern_static_string ("application/x-rootwindow-drop");
GdkAtom target2 = gdk_atom_intern_static_string ("application/x-rootwin-drop");
tmp_list = info->target_list->list;
while (tmp_list)
{
GtkTargetPair *pair = tmp_list->data;
if (pair->target == target1 || pair->target == target2)
{
selection_data.selection = GDK_NONE;
selection_data.target = pair->target;
selection_data.data = NULL;
selection_data.length = -1;
g_signal_emit_by_name (info->widget, "drag-data-get",
info->context, &selection_data,
pair->info,
time);
/* FIXME: Should we check for length >= 0 here? */
gtk_drag_drop_finished (info, GTK_DRAG_RESULT_SUCCESS, time);
return;
}
tmp_list = tmp_list->next;
}
gtk_drag_drop_finished (info, GTK_DRAG_RESULT_NO_TARGET, time);
}
else
{
if (info->icon_window)
gtk_widget_hide (info->icon_window);
gdk_drag_drop (info->context, time);
info->drop_timeout = gdk_threads_add_timeout (DROP_ABORT_TIME,
gtk_drag_abort_timeout,
info);
g_source_set_name_by_id (info->drop_timeout, "[gtk+] gtk_drag_abort_timeout");
}
}
/*
* Source side callbacks.
*/
static void
gtk_drag_selection_get (GtkWidget *widget,
GtkSelectionData *selection_data,
guint sel_info,
guint32 time,
gpointer data)
{
GtkDragSourceInfo *info = data;
static GdkAtom null_atom = GDK_NONE;
guint target_info;
if (!null_atom)
null_atom = gdk_atom_intern_static_string ("NULL");
switch (sel_info)
{
case TARGET_DELETE:
g_signal_emit_by_name (info->widget,
"drag-data-delete",
info->context);
gtk_selection_data_set (selection_data, null_atom, 8, NULL, 0);
break;
default:
if (gtk_target_list_find (info->target_list,
gtk_selection_data_get_target (selection_data),
&target_info))
{
g_signal_emit_by_name (info->widget, "drag-data-get",
info->context,
selection_data,
target_info,
time);
}
break;
}
}
static void
gtk_drag_remove_icon (GtkDragSourceInfo *info)
{
if (info->icon_widget)
{
GtkWidget *widget;
widget = info->icon_widget;
info->icon_widget = NULL;
g_signal_handlers_disconnect_by_func (widget, icon_widget_destroyed, info);
gtk_widget_hide (widget);
gtk_widget_set_opacity (widget, 1.0);
if (info->destroy_icon)
gtk_widget_destroy (widget);
else
gtk_container_remove (GTK_CONTAINER (info->icon_window), widget);
g_object_unref (widget);
}
}
static void
gtk_drag_source_info_free (GtkDragSourceInfo *info)
{
gtk_drag_remove_icon (info);
gtk_widget_destroy (info->icon_window);
g_free (info);
}
static void
gtk_drag_source_info_destroy (GtkDragSourceInfo *info)
{
g_signal_handlers_disconnect_by_func (info->context,
gtk_drag_context_drop_performed_cb,
info);
g_signal_handlers_disconnect_by_func (info->context,
gtk_drag_context_dnd_finished_cb,
info);
g_signal_handlers_disconnect_by_func (info->context,
gtk_drag_context_cancel_cb,
info);
g_signal_handlers_disconnect_by_func (info->ipc_widget,
gtk_drag_grab_broken_event_cb,
info);
g_signal_handlers_disconnect_by_func (info->ipc_widget,
gtk_drag_grab_notify_cb,
info);
g_signal_handlers_disconnect_by_func (info->ipc_widget,
gtk_drag_button_release_cb,
info);
g_signal_handlers_disconnect_by_func (info->ipc_widget,
gtk_drag_motion_cb,
info);
g_signal_handlers_disconnect_by_func (info->ipc_widget,
gtk_drag_key_cb,
info);
g_signal_handlers_disconnect_by_func (info->ipc_widget,
gtk_drag_selection_get,
info);
g_signal_emit_by_name (info->widget, "drag-end", info->context);
g_clear_object (&info->widget);
gtk_selection_remove_all (info->ipc_widget);
g_object_set_data (G_OBJECT (info->ipc_widget), I_("gtk-info"), NULL);
source_widgets = g_slist_remove (source_widgets, info->ipc_widget);
gtk_drag_release_ipc_widget (info->ipc_widget);
gtk_target_list_unref (info->target_list);
if (info->drop_timeout)
g_source_remove (info->drop_timeout);
if (info->update_idle)
g_source_remove (info->update_idle);
/* keep the icon_window alive until the (possible) drag cancel animation is done */
g_object_set_data_full (G_OBJECT (info->context), "former-gtk-source-info", info, (GDestroyNotify)gtk_drag_source_info_free);
gtk_drag_clear_source_info (info->context);
g_object_unref (info->context);
if (info->last_event)
gdk_event_free (info->last_event);
}
static gboolean
gtk_drag_update_idle (gpointer data)
{
GtkDragSourceInfo *info = data;
GdkWindow *dest_window;
GdkDragProtocol protocol;
GdkAtom selection;
GdkDragAction action;
GdkDragAction possible_actions;
guint32 time;
info->update_idle = 0;
if (info->last_event)
{
time = gtk_drag_get_event_time (info->last_event);
gtk_drag_get_event_actions (info->last_event,
info->button,
info->possible_actions,
&action, &possible_actions);
gdk_drag_find_window_for_screen (info->context,
info->icon_window ? gtk_widget_get_window (info->icon_window) : NULL,
info->cur_screen, info->cur_x, info->cur_y,
&dest_window, &protocol);
if (!gdk_drag_motion (info->context, dest_window, protocol,
info->cur_x, info->cur_y, action,
possible_actions,
time))
{
gdk_event_free ((GdkEvent *)info->last_event);
info->last_event = NULL;
}
if (dest_window)
g_object_unref (dest_window);
selection = gdk_drag_get_selection (info->context);
if (selection)
gtk_drag_source_check_selection (info, selection, time);
}
return FALSE;
}
static void
gtk_drag_add_update_idle (GtkDragSourceInfo *info)
{
/* We use an idle lower than GDK_PRIORITY_REDRAW so that exposes
* from the last move can catch up before we move again.
*/
if (!info->update_idle)
{
info->update_idle = gdk_threads_add_idle_full (GDK_PRIORITY_REDRAW + 5,
gtk_drag_update_idle,
info,
NULL);
g_source_set_name_by_id (info->update_idle, "[gtk+] gtk_drag_update_idle");
}
}
/*
* gtk_drag_update:
* @info: DragSourceInfo for the drag
* @screen: new screen
* @x_root: new X position
* @y_root: new y position
* @event: event received requiring update
*
* Updates the status of the drag; called when the
* cursor moves or the modifier changes
*/
static void
gtk_drag_update (GtkDragSourceInfo *info,
GdkScreen *screen,
gint x_root,
gint y_root,
const GdkEvent *event)
{
info->cur_screen = screen;
info->cur_x = x_root;
info->cur_y = y_root;
if (info->last_event)
{
gdk_event_free ((GdkEvent *)info->last_event);
info->last_event = NULL;
}
if (event)
info->last_event = gdk_event_copy ((GdkEvent *)event);
gtk_drag_add_update_idle (info);
}
/* Called when the user finishes to drag, either by
* releasing the mouse, or by pressing Esc.
*/
static void
gtk_drag_end (GtkDragSourceInfo *info,
guint32 time)
{
GdkDevice *pointer, *keyboard;
pointer = gdk_drag_context_get_device (info->context);
keyboard = gdk_device_get_associated_device (pointer);
/* Prevent ungrab before grab (see bug 623865) */
if (info->grab_time == GDK_CURRENT_TIME)
time = GDK_CURRENT_TIME;
if (info->update_idle)
{
g_source_remove (info->update_idle);
info->update_idle = 0;
}
if (info->last_event)
{
gdk_event_free (info->last_event);
info->last_event = NULL;
}
info->have_grab = FALSE;
g_signal_handlers_disconnect_by_func (info->ipc_widget,
gtk_drag_grab_broken_event_cb,
info);
g_signal_handlers_disconnect_by_func (info->ipc_widget,
gtk_drag_grab_notify_cb,
info);
g_signal_handlers_disconnect_by_func (info->ipc_widget,
gtk_drag_button_release_cb,
info);
g_signal_handlers_disconnect_by_func (info->ipc_widget,
gtk_drag_motion_cb,
info);
g_signal_handlers_disconnect_by_func (info->ipc_widget,
gtk_drag_key_cb,
info);
G_GNUC_BEGIN_IGNORE_DEPRECATIONS;
gdk_device_ungrab (pointer, time);
G_GNUC_END_IGNORE_DEPRECATIONS;
ungrab_dnd_keys (info->ipc_widget, keyboard, time);
gtk_device_grab_remove (info->ipc_widget, pointer);
}
/* Called on cancellation of a drag, either by the user
* or programmatically.
*/
static void
gtk_drag_cancel_internal (GtkDragSourceInfo *info,
GtkDragResult result,
guint32 time)
{
gtk_drag_end (info, time);
gdk_drag_abort (info->context, time);
gtk_drag_drop_finished (info, result, time);
}
static void
gtk_drag_context_drop_performed_cb (GdkDragContext *context,
guint32 time_,
GtkDragSourceInfo *info)
{
gtk_drag_end (info, time_);
gtk_drag_drop (info, time_);
}
static void
gtk_drag_context_cancel_cb (GdkDragContext *context,
GdkDragCancelReason reason,
GtkDragSourceInfo *info)
{
GtkDragResult result;
switch (reason)
{
case GDK_DRAG_CANCEL_NO_TARGET:
result = GTK_DRAG_RESULT_NO_TARGET;
break;
case GDK_DRAG_CANCEL_USER_CANCELLED:
result = GTK_DRAG_RESULT_USER_CANCELLED;
break;
case GDK_DRAG_CANCEL_ERROR:
default:
result = GTK_DRAG_RESULT_ERROR;
break;
}
gtk_drag_cancel_internal (info, result, GDK_CURRENT_TIME);
}
static void
gtk_drag_context_dnd_finished_cb (GdkDragContext *context,
GtkDragSourceInfo *info)
{
gtk_drag_source_release_selections (info, GDK_CURRENT_TIME);
if (gdk_drag_context_get_selected_action (context) == GDK_ACTION_MOVE)
{
g_signal_emit_by_name (info->widget,
"drag-data-delete",
context);
}
gtk_drag_source_info_destroy (info);
}
/* “motion-notify-event” callback during drag. */
static gboolean
gtk_drag_motion_cb (GtkWidget *widget,
GdkEventMotion *event,
gpointer data)
{
GtkDragSourceInfo *info = (GtkDragSourceInfo *)data;
GdkScreen *screen;
gint x_root, y_root;
if (event->is_hint)
{
gdk_device_get_position (event->device, &screen, &x_root, &y_root);
event->x_root = x_root;
event->y_root = y_root;
}
else
screen = gdk_event_get_screen ((GdkEvent *)event);
x_root = (gint)(event->x_root + 0.5);
y_root = (gint)(event->y_root + 0.5);
gtk_drag_update (info, screen, x_root, y_root, (GdkEvent *) event);
return TRUE;
}
#define BIG_STEP 20
#define SMALL_STEP 1
/* “key-press/release-event” callback during drag */
static gboolean
gtk_drag_key_cb (GtkWidget *widget,
GdkEventKey *event,
gpointer data)
{
GtkDragSourceInfo *info = (GtkDragSourceInfo *)data;
GdkModifierType state;
GdkWindow *root_window;
GdkDevice *pointer;
gint dx, dy;
dx = dy = 0;
state = event->state & gtk_accelerator_get_default_mod_mask ();
pointer = gdk_device_get_associated_device (gdk_event_get_device ((GdkEvent *) event));
if (event->type == GDK_KEY_PRESS)
{
switch (event->keyval)
{
case GDK_KEY_Escape:
gtk_drag_cancel_internal (info, GTK_DRAG_RESULT_USER_CANCELLED, event->time);
return TRUE;
case GDK_KEY_space:
case GDK_KEY_Return:
case GDK_KEY_ISO_Enter:
case GDK_KEY_KP_Enter:
case GDK_KEY_KP_Space:
if ((gdk_drag_context_get_selected_action (info->context) != 0) &&
(gdk_drag_context_get_dest_window (info->context) != NULL))
{
gtk_drag_end (info, event->time);
gtk_drag_drop (info, event->time);
}
else
{
gtk_drag_cancel_internal (info, GTK_DRAG_RESULT_NO_TARGET, event->time);
}
return TRUE;
case GDK_KEY_Up:
case GDK_KEY_KP_Up:
dy = (state & GDK_MOD1_MASK) ? -BIG_STEP : -SMALL_STEP;
break;
case GDK_KEY_Down:
case GDK_KEY_KP_Down:
dy = (state & GDK_MOD1_MASK) ? BIG_STEP : SMALL_STEP;
break;
case GDK_KEY_Left:
case GDK_KEY_KP_Left:
dx = (state & GDK_MOD1_MASK) ? -BIG_STEP : -SMALL_STEP;
break;
case GDK_KEY_Right:
case GDK_KEY_KP_Right:
dx = (state & GDK_MOD1_MASK) ? BIG_STEP : SMALL_STEP;
break;
}
}
/* Now send a "motion" so that the modifier state is updated */
/* The state is not yet updated in the event, so we need
* to query it here. We could use XGetModifierMapping, but
* that would be overkill.
*/
root_window = gdk_screen_get_root_window (gtk_widget_get_screen (widget));
gdk_window_get_device_position (root_window, pointer, NULL, NULL, &state);
event->state = state;
if (dx != 0 || dy != 0)
{
info->cur_x += dx;
info->cur_y += dy;
gdk_device_warp (pointer,
gtk_widget_get_screen (widget),
info->cur_x, info->cur_y);
}
gtk_drag_update (info, info->cur_screen, info->cur_x, info->cur_y, (GdkEvent *)event);
return TRUE;
}
static gboolean
gtk_drag_grab_broken_event_cb (GtkWidget *widget,
GdkEventGrabBroken *event,
gpointer data)
{
GtkDragSourceInfo *info = (GtkDragSourceInfo *)data;
/* Don't cancel if we break the implicit grab from the initial button_press.
* Also, don't cancel if we re-grab on the widget or on our IPC window, for
* example, when changing the drag cursor.
*/
if (event->implicit
|| event->grab_window == gtk_widget_get_window (info->widget)
|| event->grab_window == gtk_widget_get_window (info->ipc_widget))
return FALSE;
gtk_drag_cancel_internal (info, GTK_DRAG_RESULT_GRAB_BROKEN, gtk_get_current_event_time ());
return TRUE;
}
static void
gtk_drag_grab_notify_cb (GtkWidget *widget,
gboolean was_grabbed,
gpointer data)
{
GtkDragSourceInfo *info = (GtkDragSourceInfo *)data;
GdkDevice *pointer;
pointer = gdk_drag_context_get_device (info->context);
if (gtk_widget_device_is_shadowed (widget, pointer))
{
/* We have to block callbacks to avoid recursion here, because
* gtk_drag_cancel_internal calls gtk_grab_remove (via gtk_drag_end)
*/
g_signal_handlers_block_by_func (widget, gtk_drag_grab_notify_cb, data);
gtk_drag_cancel_internal (info, GTK_DRAG_RESULT_GRAB_BROKEN, gtk_get_current_event_time ());
g_signal_handlers_unblock_by_func (widget, gtk_drag_grab_notify_cb, data);
}
}
/* “button-release-event” callback during drag */
static gboolean
gtk_drag_button_release_cb (GtkWidget *widget,
GdkEventButton *event,
gpointer data)
{
GtkDragSourceInfo *info = (GtkDragSourceInfo *)data;
if (event->button != info->button)
return FALSE;
if ((gdk_drag_context_get_selected_action (info->context) != 0) &&
(gdk_drag_context_get_dest_window (info->context) != NULL))
{
gtk_drag_end (info, event->time);
gtk_drag_drop (info, event->time);
}
else
{
gtk_drag_cancel_internal (info, GTK_DRAG_RESULT_NO_TARGET, event->time);
}
return TRUE;
}
static gboolean
gtk_drag_abort_timeout (gpointer data)
{
GtkDragSourceInfo *info = data;
guint32 time = GDK_CURRENT_TIME;
info->drop_timeout = 0;
gtk_drag_drop_finished (info, GTK_DRAG_RESULT_TIMEOUT_EXPIRED, time);
return FALSE;
}
/**
* gtk_drag_check_threshold: (method)
* @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
*
* 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.
*
* Returns: %TRUE if the drag threshold has been passed.
*/
gboolean
gtk_drag_check_threshold (GtkWidget *widget,
gint start_x,
gint start_y,
gint current_x,
gint current_y)
{
gint drag_threshold;
g_return_val_if_fail (GTK_IS_WIDGET (widget), FALSE);
drag_threshold = gtk_settings_get_dnd_drag_threshold (gtk_widget_get_settings (widget));
return (ABS (current_x - start_x) > drag_threshold ||
ABS (current_y - start_y) > drag_threshold);
}
/**
* gtk_drag_cancel: (method)
* @context: a #GdkDragContext, as e.g. returned by gtk_drag_begin_with_coordinates()
*
* 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 #GtkWidget::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
* #GtkWidget::drag-failed is set to @GTK_DRAG_RESULT_ERROR.
*
* Since: 3.16
*/
void
gtk_drag_cancel (GdkDragContext *context)
{
GtkDragSourceInfo *info;
g_return_if_fail (GDK_IS_DRAG_CONTEXT (context));
info = gtk_drag_get_source_info (context, FALSE);
if (info != NULL)
gtk_drag_cancel_internal (info, GTK_DRAG_RESULT_ERROR, gtk_get_current_event_time ());
}