gtk2/gtk/gtktreednd.c
Murray Cumming 5c466a9f39 Fixes #102168.
2002-12-29  Murray Cumming  <murrayc@usa.net>

	Fixes #102168.

	* gtk/gtkliststore.c, gtktreednd.c, gtktreestore.c:
	Actually implement the GtkTreeDragSource::row_draggable virtual
	function in GtkListStore and GtkTreeStore instead of just checking
	whether it's implemented at all. This means that DnD isn't broken by
	gtkmm's virtual function wrappers. The alternative would be to
	hard-code the TRUE return value into gtkmm's wrappers, but that's
	part of GTK+'s implementation, not it's API.
2003-01-14 22:57:37 +00:00

326 lines
9.7 KiB
C

/* gtktreednd.c
* Copyright (C) 2001 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <string.h>
#include "gtktreednd.h"
GType
gtk_tree_drag_source_get_type (void)
{
static GType our_type = 0;
if (!our_type)
{
static const GTypeInfo our_info =
{
sizeof (GtkTreeDragSourceIface), /* class_size */
NULL, /* base_init */
NULL, /* base_finalize */
NULL,
NULL, /* class_finalize */
NULL, /* class_data */
0,
0, /* n_preallocs */
NULL
};
our_type = g_type_register_static (G_TYPE_INTERFACE, "GtkTreeDragSource",
&our_info, 0);
}
return our_type;
}
GType
gtk_tree_drag_dest_get_type (void)
{
static GType our_type = 0;
if (!our_type)
{
static const GTypeInfo our_info =
{
sizeof (GtkTreeDragDestIface), /* class_size */
NULL, /* base_init */
NULL, /* base_finalize */
NULL,
NULL, /* class_finalize */
NULL, /* class_data */
0,
0, /* n_preallocs */
NULL
};
our_type = g_type_register_static (G_TYPE_INTERFACE, "GtkTreeDragDest", &our_info, 0);
}
return our_type;
}
/**
* gtk_tree_drag_source_row_draggable:
* @drag_source: a #GtkTreeDragSource
* @path: row on which user is initiating a drag
*
* Asks the #GtkTreeDragSource whether a particular row can be used as
* the source of a DND operation. If the source doesn't implement
* this interface, the row is assumed draggable.
*
* Return value: %TRUE if the row can be dragged
**/
gboolean
gtk_tree_drag_source_row_draggable (GtkTreeDragSource *drag_source,
GtkTreePath *path)
{
GtkTreeDragSourceIface *iface = GTK_TREE_DRAG_SOURCE_GET_IFACE (drag_source);
g_return_val_if_fail (path != NULL, FALSE);
if (iface->row_draggable)
return (* iface->row_draggable) (drag_source, path);
else
return TRUE;
/* Returning TRUE if row_draggable is not implemented is a fallback.
Interface implementations such as GtkTreeStore and GtkListStore really should
implement row_draggable. */
}
/**
* gtk_tree_drag_source_drag_data_delete:
* @drag_source: a #GtkTreeDragSource
* @path: row that was being dragged
*
* Asks the #GtkTreeDragSource to delete the row at @path, because
* it was moved somewhere else via drag-and-drop. Returns %FALSE
* if the deletion fails because @path no longer exists, or for
* some model-specific reason. Should robustly handle a @path no
* longer found in the model!
*
* Return value: %TRUE if the row was successfully deleted
**/
gboolean
gtk_tree_drag_source_drag_data_delete (GtkTreeDragSource *drag_source,
GtkTreePath *path)
{
GtkTreeDragSourceIface *iface = GTK_TREE_DRAG_SOURCE_GET_IFACE (drag_source);
g_return_val_if_fail (iface->drag_data_delete != NULL, FALSE);
g_return_val_if_fail (path != NULL, FALSE);
return (* iface->drag_data_delete) (drag_source, path);
}
/**
* gtk_tree_drag_source_drag_data_get:
* @drag_source: a #GtkTreeDragSource
* @path: row that was dragged
* @selection_data: a #GtkSelectionData to fill with data from the dragged row
*
* Asks the #GtkTreeDragSource to fill in @selection_data with a
* representation of the row at @path. @selection_data->target gives
* the required type of the data. Should robustly handle a @path no
* longer found in the model!
*
* Return value: %TRUE if data of the required type was provided
**/
gboolean
gtk_tree_drag_source_drag_data_get (GtkTreeDragSource *drag_source,
GtkTreePath *path,
GtkSelectionData *selection_data)
{
GtkTreeDragSourceIface *iface = GTK_TREE_DRAG_SOURCE_GET_IFACE (drag_source);
g_return_val_if_fail (iface->drag_data_get != NULL, FALSE);
g_return_val_if_fail (path != NULL, FALSE);
g_return_val_if_fail (selection_data != NULL, FALSE);
return (* iface->drag_data_get) (drag_source, path, selection_data);
}
/**
* gtk_tree_drag_dest_drag_data_received:
* @drag_dest: a #GtkTreeDragDest
* @dest: row to drop in front of
* @selection_data: data to drop
*
* Asks the #GtkTreeDragDest to insert a row before the path @dest,
* deriving the contents of the row from @selection_data. If @dest is
* outside the tree so that inserting before it is impossible, %FALSE
* will be returned. Also, %FALSE may be returned if the new row is
* not created for some model-specific reason. Should robustly handle
* a @dest no longer found in the model!
*
* Return value: whether a new row was created before position @dest
**/
gboolean
gtk_tree_drag_dest_drag_data_received (GtkTreeDragDest *drag_dest,
GtkTreePath *dest,
GtkSelectionData *selection_data)
{
GtkTreeDragDestIface *iface = GTK_TREE_DRAG_DEST_GET_IFACE (drag_dest);
g_return_val_if_fail (iface->drag_data_received != NULL, FALSE);
g_return_val_if_fail (dest != NULL, FALSE);
g_return_val_if_fail (selection_data != NULL, FALSE);
return (* iface->drag_data_received) (drag_dest, dest, selection_data);
}
/**
* gtk_tree_drag_dest_drop_possible:
* @drag_dest: a #GtkTreeDragDest
* @dest_path: destination row
* @selection_data: the data being dragged
*
* Determines whether a drop is possible before the given @dest_path,
* at the same depth as @dest_path. i.e., can we drop the data in
* @selection_data at that location. @dest_path does not have to
* exist; the return value will almost certainly be %FALSE if the
* parent of @dest_path doesn't exist, though.
*
* Return value: %TRUE if a drop is possible before @dest_path
**/
gboolean
gtk_tree_drag_dest_row_drop_possible (GtkTreeDragDest *drag_dest,
GtkTreePath *dest_path,
GtkSelectionData *selection_data)
{
GtkTreeDragDestIface *iface = GTK_TREE_DRAG_DEST_GET_IFACE (drag_dest);
g_return_val_if_fail (iface->row_drop_possible != NULL, FALSE);
g_return_val_if_fail (selection_data != NULL, FALSE);
g_return_val_if_fail (dest_path != NULL, FALSE);
return (* iface->row_drop_possible) (drag_dest, dest_path, selection_data);
}
typedef struct _TreeRowData TreeRowData;
struct _TreeRowData
{
GtkTreeModel *model;
gchar path[4];
};
/**
* gtk_tree_set_row_drag_data:
* @selection_data: some #GtkSelectionData
* @tree_model: a #GtkTreeModel
* @path: a row in @tree_model
*
* Sets selection data of target type %GTK_TREE_MODEL_ROW. Normally used
* in a drag_data_get handler.
*
* Return value: %TRUE if the #GtkSelectionData had the proper target type to allow us to set a tree row
**/
gboolean
gtk_tree_set_row_drag_data (GtkSelectionData *selection_data,
GtkTreeModel *tree_model,
GtkTreePath *path)
{
TreeRowData *trd;
gchar *path_str;
gint len;
gint struct_size;
g_return_val_if_fail (selection_data != NULL, FALSE);
g_return_val_if_fail (GTK_IS_TREE_MODEL (tree_model), FALSE);
g_return_val_if_fail (path != NULL, FALSE);
if (selection_data->target != gdk_atom_intern ("GTK_TREE_MODEL_ROW", FALSE))
return FALSE;
path_str = gtk_tree_path_to_string (path);
len = strlen (path_str);
/* the old allocate-end-of-struct-to-hold-string trick */
struct_size = sizeof (TreeRowData) + len + 1 -
(sizeof (TreeRowData) - G_STRUCT_OFFSET (TreeRowData, path));
trd = g_malloc (struct_size);
strcpy (trd->path, path_str);
g_free (path_str);
trd->model = tree_model;
gtk_selection_data_set (selection_data,
gdk_atom_intern ("GTK_TREE_MODEL_ROW", FALSE),
8, /* bytes */
(void*)trd,
struct_size);
g_free (trd);
return TRUE;
}
/**
* gtk_tree_get_row_drag_data:
* @selection_data: a #GtkSelectionData
* @tree_model: a #GtkTreeModel
* @path: row in @tree_model
*
* Obtains a @tree_model and @path from selection data of target type
* %GTK_TREE_MODEL_ROW. Normally called from a drag_data_received handler.
* This function can only be used if @selection_data originates from the same
* process that's calling this function, because a pointer to the tree model
* is being passed around. If you aren't in the same process, then you'll
* get memory corruption. In the #GtkTreeDragDest drag_data_received handler,
* you can assume that selection data of type %GTK_TREE_MODEL_ROW is
* in from the current process. The returned path must be freed with
* gtk_tree_path_free().
*
* Return value: %TRUE if @selection_data had target type %GTK_TREE_MODEL_ROW and
* is otherwise valid
**/
gboolean
gtk_tree_get_row_drag_data (GtkSelectionData *selection_data,
GtkTreeModel **tree_model,
GtkTreePath **path)
{
TreeRowData *trd;
g_return_val_if_fail (selection_data != NULL, FALSE);
if (tree_model)
*tree_model = NULL;
if (path)
*path = NULL;
if (selection_data->target != gdk_atom_intern ("GTK_TREE_MODEL_ROW", FALSE))
return FALSE;
trd = (void*) selection_data->data;
if (tree_model)
*tree_model = trd->model;
if (path)
*path = gtk_tree_path_new_from_string (trd->path);
return TRUE;
}