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"
28 * @Short_description: Interfaces for drag-and-drop support in GtkTreeView
29 * @Title: GtkTreeView drag-and-drop
31 * GTK+ supports Drag-and-Drop in tree views with a high-level and a low-level
34 * The low-level API consists of the GTK+ DND API, augmented by some treeview
35 * utility functions: gtk_tree_view_set_drag_dest_row(),
36 * gtk_tree_view_get_drag_dest_row(), gtk_tree_view_get_dest_row_at_pos(),
37 * gtk_tree_view_create_row_drag_icon(), gtk_tree_set_row_drag_data() and
38 * gtk_tree_get_row_drag_data(). This API leaves a lot of flexibility, but
39 * nothing is done automatically, and implementing advanced features like
40 * hover-to-open-rows or autoscrolling on top of this API is a lot of work.
42 * On the other hand, if you write to the high-level API, then all the
43 * bookkeeping of rows is done for you, as well as things like hover-to-open
44 * and auto-scroll, but your models have to implement the
45 * #GtkTreeDragSource and #GtkTreeDragDest interfaces.
50 gtk_tree_drag_source_get_type (void)
52 static GType our_type = 0;
56 const GTypeInfo our_info =
58 sizeof (GtkTreeDragSourceIface), /* class_size */
60 NULL, /* base_finalize */
62 NULL, /* class_finalize */
63 NULL, /* class_data */
69 our_type = g_type_register_static (G_TYPE_INTERFACE,
70 I_("GtkTreeDragSource"),
79 gtk_tree_drag_dest_get_type (void)
81 static GType our_type = 0;
85 const GTypeInfo our_info =
87 sizeof (GtkTreeDragDestIface), /* class_size */
89 NULL, /* base_finalize */
91 NULL, /* class_finalize */
92 NULL, /* class_data */
98 our_type = g_type_register_static (G_TYPE_INTERFACE, I_("GtkTreeDragDest"), &our_info, 0);
105 * gtk_tree_drag_source_row_draggable:
106 * @drag_source: a #GtkTreeDragSource
107 * @path: row on which user is initiating a drag
109 * Asks the #GtkTreeDragSource whether a particular row can be used as
110 * the source of a DND operation. If the source doesn't implement
111 * this interface, the row is assumed draggable.
113 * Return value: %TRUE if the row can be dragged
116 gtk_tree_drag_source_row_draggable (GtkTreeDragSource *drag_source,
119 GtkTreeDragSourceIface *iface = GTK_TREE_DRAG_SOURCE_GET_IFACE (drag_source);
121 g_return_val_if_fail (path != NULL, FALSE);
123 if (iface->row_draggable)
124 return (* iface->row_draggable) (drag_source, path);
127 /* Returning TRUE if row_draggable is not implemented is a fallback.
128 Interface implementations such as GtkTreeStore and GtkListStore really should
129 implement row_draggable. */
134 * gtk_tree_drag_source_drag_data_delete:
135 * @drag_source: a #GtkTreeDragSource
136 * @path: row that was being dragged
138 * Asks the #GtkTreeDragSource to delete the row at @path, because
139 * it was moved somewhere else via drag-and-drop. Returns %FALSE
140 * if the deletion fails because @path no longer exists, or for
141 * some model-specific reason. Should robustly handle a @path no
142 * longer found in the model!
144 * Return value: %TRUE if the row was successfully deleted
147 gtk_tree_drag_source_drag_data_delete (GtkTreeDragSource *drag_source,
150 GtkTreeDragSourceIface *iface = GTK_TREE_DRAG_SOURCE_GET_IFACE (drag_source);
152 g_return_val_if_fail (iface->drag_data_delete != NULL, FALSE);
153 g_return_val_if_fail (path != NULL, FALSE);
155 return (* iface->drag_data_delete) (drag_source, path);
159 * gtk_tree_drag_source_drag_data_get:
160 * @drag_source: a #GtkTreeDragSource
161 * @path: row that was dragged
162 * @selection_data: a #GtkSelectionData to fill with data from the dragged row
164 * Asks the #GtkTreeDragSource to fill in @selection_data with a
165 * representation of the row at @path. @selection_data->target gives
166 * the required type of the data. Should robustly handle a @path no
167 * longer found in the model!
169 * Return value: %TRUE if data of the required type was provided
172 gtk_tree_drag_source_drag_data_get (GtkTreeDragSource *drag_source,
174 GtkSelectionData *selection_data)
176 GtkTreeDragSourceIface *iface = GTK_TREE_DRAG_SOURCE_GET_IFACE (drag_source);
178 g_return_val_if_fail (iface->drag_data_get != NULL, FALSE);
179 g_return_val_if_fail (path != NULL, FALSE);
180 g_return_val_if_fail (selection_data != NULL, FALSE);
182 return (* iface->drag_data_get) (drag_source, path, selection_data);
186 * gtk_tree_drag_dest_drag_data_received:
187 * @drag_dest: a #GtkTreeDragDest
188 * @dest: row to drop in front of
189 * @selection_data: data to drop
191 * Asks the #GtkTreeDragDest to insert a row before the path @dest,
192 * deriving the contents of the row from @selection_data. If @dest is
193 * outside the tree so that inserting before it is impossible, %FALSE
194 * will be returned. Also, %FALSE may be returned if the new row is
195 * not created for some model-specific reason. Should robustly handle
196 * a @dest no longer found in the model!
198 * Return value: whether a new row was created before position @dest
201 gtk_tree_drag_dest_drag_data_received (GtkTreeDragDest *drag_dest,
203 GtkSelectionData *selection_data)
205 GtkTreeDragDestIface *iface = GTK_TREE_DRAG_DEST_GET_IFACE (drag_dest);
207 g_return_val_if_fail (iface->drag_data_received != NULL, FALSE);
208 g_return_val_if_fail (dest != NULL, FALSE);
209 g_return_val_if_fail (selection_data != NULL, FALSE);
211 return (* iface->drag_data_received) (drag_dest, dest, selection_data);
216 * gtk_tree_drag_dest_row_drop_possible:
217 * @drag_dest: a #GtkTreeDragDest
218 * @dest_path: destination row
219 * @selection_data: the data being dragged
221 * Determines whether a drop is possible before the given @dest_path,
222 * at the same depth as @dest_path. i.e., can we drop the data in
223 * @selection_data at that location. @dest_path does not have to
224 * exist; the return value will almost certainly be %FALSE if the
225 * parent of @dest_path doesn't exist, though.
227 * Return value: %TRUE if a drop is possible before @dest_path
230 gtk_tree_drag_dest_row_drop_possible (GtkTreeDragDest *drag_dest,
231 GtkTreePath *dest_path,
232 GtkSelectionData *selection_data)
234 GtkTreeDragDestIface *iface = GTK_TREE_DRAG_DEST_GET_IFACE (drag_dest);
236 g_return_val_if_fail (iface->row_drop_possible != NULL, FALSE);
237 g_return_val_if_fail (selection_data != NULL, FALSE);
238 g_return_val_if_fail (dest_path != NULL, FALSE);
240 return (* iface->row_drop_possible) (drag_dest, dest_path, selection_data);
243 typedef struct _TreeRowData TreeRowData;
252 * gtk_tree_set_row_drag_data:
253 * @selection_data: some #GtkSelectionData
254 * @tree_model: a #GtkTreeModel
255 * @path: a row in @tree_model
257 * Sets selection data of target type %GTK_TREE_MODEL_ROW. Normally used
258 * in a drag_data_get handler.
260 * Return value: %TRUE if the #GtkSelectionData had the proper target type to allow us to set a tree row
263 gtk_tree_set_row_drag_data (GtkSelectionData *selection_data,
264 GtkTreeModel *tree_model,
272 g_return_val_if_fail (selection_data != NULL, FALSE);
273 g_return_val_if_fail (GTK_IS_TREE_MODEL (tree_model), FALSE);
274 g_return_val_if_fail (path != NULL, FALSE);
276 if (selection_data->target != gdk_atom_intern_static_string ("GTK_TREE_MODEL_ROW"))
279 path_str = gtk_tree_path_to_string (path);
281 len = strlen (path_str);
283 /* the old allocate-end-of-struct-to-hold-string trick */
284 struct_size = sizeof (TreeRowData) + len + 1 -
285 (sizeof (TreeRowData) - G_STRUCT_OFFSET (TreeRowData, path));
287 trd = g_malloc (struct_size);
289 strcpy (trd->path, path_str);
293 trd->model = tree_model;
295 gtk_selection_data_set (selection_data,
296 gdk_atom_intern_static_string ("GTK_TREE_MODEL_ROW"),
307 * gtk_tree_get_row_drag_data:
308 * @selection_data: a #GtkSelectionData
309 * @tree_model: a #GtkTreeModel
310 * @path: row in @tree_model
312 * Obtains a @tree_model and @path from selection data of target type
313 * %GTK_TREE_MODEL_ROW. Normally called from a drag_data_received handler.
314 * This function can only be used if @selection_data originates from the same
315 * process that's calling this function, because a pointer to the tree model
316 * is being passed around. If you aren't in the same process, then you'll
317 * get memory corruption. In the #GtkTreeDragDest drag_data_received handler,
318 * you can assume that selection data of type %GTK_TREE_MODEL_ROW is
319 * in from the current process. The returned path must be freed with
320 * gtk_tree_path_free().
322 * Return value: %TRUE if @selection_data had target type %GTK_TREE_MODEL_ROW and
326 gtk_tree_get_row_drag_data (GtkSelectionData *selection_data,
327 GtkTreeModel **tree_model,
332 g_return_val_if_fail (selection_data != NULL, FALSE);
340 if (selection_data->target != gdk_atom_intern_static_string ("GTK_TREE_MODEL_ROW"))
343 if (selection_data->length < 0)
346 trd = (void*) selection_data->data;
349 *tree_model = trd->model;
352 *path = gtk_tree_path_new_from_string (trd->path);