2 * Copyright (C) 2001 Red Hat, Inc.
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
22 #include "gtktreednd.h"
29 * @Short_description: Interfaces for drag-and-drop support in GtkTreeView
30 * @Title: GtkTreeView drag-and-drop
32 * GTK+ supports Drag-and-Drop in tree views with a high-level and a low-level
35 * The low-level API consists of the GTK+ DND API, augmented by some treeview
36 * utility functions: gtk_tree_view_set_drag_dest_row(),
37 * gtk_tree_view_get_drag_dest_row(), gtk_tree_view_get_dest_row_at_pos(),
38 * gtk_tree_view_create_row_drag_icon(), gtk_tree_set_row_drag_data() and
39 * gtk_tree_get_row_drag_data(). This API leaves a lot of flexibility, but
40 * nothing is done automatically, and implementing advanced features like
41 * hover-to-open-rows or autoscrolling on top of this API is a lot of work.
43 * On the other hand, if you write to the high-level API, then all the
44 * bookkeeping of rows is done for you, as well as things like hover-to-open
45 * and auto-scroll, but your models have to implement the
46 * #GtkTreeDragSource and #GtkTreeDragDest interfaces.
51 gtk_tree_drag_source_get_type (void)
53 static GType our_type = 0;
57 const GTypeInfo our_info =
59 sizeof (GtkTreeDragSourceIface), /* class_size */
61 NULL, /* base_finalize */
63 NULL, /* class_finalize */
64 NULL, /* class_data */
70 our_type = g_type_register_static (G_TYPE_INTERFACE,
71 I_("GtkTreeDragSource"),
80 gtk_tree_drag_dest_get_type (void)
82 static GType our_type = 0;
86 const GTypeInfo our_info =
88 sizeof (GtkTreeDragDestIface), /* class_size */
90 NULL, /* base_finalize */
92 NULL, /* class_finalize */
93 NULL, /* class_data */
99 our_type = g_type_register_static (G_TYPE_INTERFACE, I_("GtkTreeDragDest"), &our_info, 0);
106 * gtk_tree_drag_source_row_draggable:
107 * @drag_source: a #GtkTreeDragSource
108 * @path: row on which user is initiating a drag
110 * Asks the #GtkTreeDragSource whether a particular row can be used as
111 * the source of a DND operation. If the source doesn't implement
112 * this interface, the row is assumed draggable.
114 * Return value: %TRUE if the row can be dragged
117 gtk_tree_drag_source_row_draggable (GtkTreeDragSource *drag_source,
120 GtkTreeDragSourceIface *iface = GTK_TREE_DRAG_SOURCE_GET_IFACE (drag_source);
122 g_return_val_if_fail (path != NULL, FALSE);
124 if (iface->row_draggable)
125 return (* iface->row_draggable) (drag_source, path);
128 /* Returning TRUE if row_draggable is not implemented is a fallback.
129 Interface implementations such as GtkTreeStore and GtkListStore really should
130 implement row_draggable. */
135 * gtk_tree_drag_source_drag_data_delete:
136 * @drag_source: a #GtkTreeDragSource
137 * @path: row that was being dragged
139 * Asks the #GtkTreeDragSource to delete the row at @path, because
140 * it was moved somewhere else via drag-and-drop. Returns %FALSE
141 * if the deletion fails because @path no longer exists, or for
142 * some model-specific reason. Should robustly handle a @path no
143 * longer found in the model!
145 * Return value: %TRUE if the row was successfully deleted
148 gtk_tree_drag_source_drag_data_delete (GtkTreeDragSource *drag_source,
151 GtkTreeDragSourceIface *iface = GTK_TREE_DRAG_SOURCE_GET_IFACE (drag_source);
153 g_return_val_if_fail (iface->drag_data_delete != NULL, FALSE);
154 g_return_val_if_fail (path != NULL, FALSE);
156 return (* iface->drag_data_delete) (drag_source, path);
160 * gtk_tree_drag_source_drag_data_get:
161 * @drag_source: a #GtkTreeDragSource
162 * @path: row that was dragged
163 * @selection_data: a #GtkSelectionData to fill with data from the dragged row
165 * Asks the #GtkTreeDragSource to fill in @selection_data with a
166 * representation of the row at @path. @selection_data->target gives
167 * the required type of the data. Should robustly handle a @path no
168 * longer found in the model!
170 * Return value: %TRUE if data of the required type was provided
173 gtk_tree_drag_source_drag_data_get (GtkTreeDragSource *drag_source,
175 GtkSelectionData *selection_data)
177 GtkTreeDragSourceIface *iface = GTK_TREE_DRAG_SOURCE_GET_IFACE (drag_source);
179 g_return_val_if_fail (iface->drag_data_get != NULL, FALSE);
180 g_return_val_if_fail (path != NULL, FALSE);
181 g_return_val_if_fail (selection_data != NULL, FALSE);
183 return (* iface->drag_data_get) (drag_source, path, selection_data);
187 * gtk_tree_drag_dest_drag_data_received:
188 * @drag_dest: a #GtkTreeDragDest
189 * @dest: row to drop in front of
190 * @selection_data: data to drop
192 * Asks the #GtkTreeDragDest to insert a row before the path @dest,
193 * deriving the contents of the row from @selection_data. If @dest is
194 * outside the tree so that inserting before it is impossible, %FALSE
195 * will be returned. Also, %FALSE may be returned if the new row is
196 * not created for some model-specific reason. Should robustly handle
197 * a @dest no longer found in the model!
199 * Return value: whether a new row was created before position @dest
202 gtk_tree_drag_dest_drag_data_received (GtkTreeDragDest *drag_dest,
204 GtkSelectionData *selection_data)
206 GtkTreeDragDestIface *iface = GTK_TREE_DRAG_DEST_GET_IFACE (drag_dest);
208 g_return_val_if_fail (iface->drag_data_received != NULL, FALSE);
209 g_return_val_if_fail (dest != NULL, FALSE);
210 g_return_val_if_fail (selection_data != NULL, FALSE);
212 return (* iface->drag_data_received) (drag_dest, dest, selection_data);
217 * gtk_tree_drag_dest_row_drop_possible:
218 * @drag_dest: a #GtkTreeDragDest
219 * @dest_path: destination row
220 * @selection_data: the data being dragged
222 * Determines whether a drop is possible before the given @dest_path,
223 * at the same depth as @dest_path. i.e., can we drop the data in
224 * @selection_data at that location. @dest_path does not have to
225 * exist; the return value will almost certainly be %FALSE if the
226 * parent of @dest_path doesn't exist, though.
228 * Return value: %TRUE if a drop is possible before @dest_path
231 gtk_tree_drag_dest_row_drop_possible (GtkTreeDragDest *drag_dest,
232 GtkTreePath *dest_path,
233 GtkSelectionData *selection_data)
235 GtkTreeDragDestIface *iface = GTK_TREE_DRAG_DEST_GET_IFACE (drag_dest);
237 g_return_val_if_fail (iface->row_drop_possible != NULL, FALSE);
238 g_return_val_if_fail (selection_data != NULL, FALSE);
239 g_return_val_if_fail (dest_path != NULL, FALSE);
241 return (* iface->row_drop_possible) (drag_dest, dest_path, selection_data);
244 typedef struct _TreeRowData TreeRowData;
253 * gtk_tree_set_row_drag_data:
254 * @selection_data: some #GtkSelectionData
255 * @tree_model: a #GtkTreeModel
256 * @path: a row in @tree_model
258 * Sets selection data of target type %GTK_TREE_MODEL_ROW. Normally used
259 * in a drag_data_get handler.
261 * Return value: %TRUE if the #GtkSelectionData had the proper target type to allow us to set a tree row
264 gtk_tree_set_row_drag_data (GtkSelectionData *selection_data,
265 GtkTreeModel *tree_model,
273 g_return_val_if_fail (selection_data != NULL, FALSE);
274 g_return_val_if_fail (GTK_IS_TREE_MODEL (tree_model), FALSE);
275 g_return_val_if_fail (path != NULL, FALSE);
277 if (selection_data->target != gdk_atom_intern_static_string ("GTK_TREE_MODEL_ROW"))
280 path_str = gtk_tree_path_to_string (path);
282 len = strlen (path_str);
284 /* the old allocate-end-of-struct-to-hold-string trick */
285 struct_size = sizeof (TreeRowData) + len + 1 -
286 (sizeof (TreeRowData) - G_STRUCT_OFFSET (TreeRowData, path));
288 trd = g_malloc (struct_size);
290 strcpy (trd->path, path_str);
294 trd->model = tree_model;
296 gtk_selection_data_set (selection_data,
297 gdk_atom_intern_static_string ("GTK_TREE_MODEL_ROW"),
308 * gtk_tree_get_row_drag_data:
309 * @selection_data: a #GtkSelectionData
310 * @tree_model: a #GtkTreeModel
311 * @path: row in @tree_model
313 * Obtains a @tree_model and @path from selection data of target type
314 * %GTK_TREE_MODEL_ROW. Normally called from a drag_data_received handler.
315 * This function can only be used if @selection_data originates from the same
316 * process that's calling this function, because a pointer to the tree model
317 * is being passed around. If you aren't in the same process, then you'll
318 * get memory corruption. In the #GtkTreeDragDest drag_data_received handler,
319 * you can assume that selection data of type %GTK_TREE_MODEL_ROW is
320 * in from the current process. The returned path must be freed with
321 * gtk_tree_path_free().
323 * Return value: %TRUE if @selection_data had target type %GTK_TREE_MODEL_ROW and
327 gtk_tree_get_row_drag_data (GtkSelectionData *selection_data,
328 GtkTreeModel **tree_model,
333 g_return_val_if_fail (selection_data != NULL, FALSE);
341 if (selection_data->target != gdk_atom_intern_static_string ("GTK_TREE_MODEL_ROW"))
344 if (selection_data->length < 0)
347 trd = (void*) selection_data->data;
350 *tree_model = trd->model;
353 *path = gtk_tree_path_new_from_string (trd->path);
358 #define __GTK_TREE_DND_C__
359 #include "gtkaliasdef.c"