Re: GtkTree remove/add problem

[Jim Edwards <jimedwards altavista com>]

Rafael,

The first answer is gtktree is depreciated use gtkctree which inherits
from gtkclist



Rafael Peregrino wrote:

> Hi ALL,
>
> I'm working on a program in which a gtktree must be frequently updated
> by a timeout function. In order to keep this thing simple, I only want
> to clear all tree items and create them again. So, if new data is read,
> they simply appear on the gtktree when I reconstruct it. And exactly
> there I'm having a problem: once I've cleared all tree items, I'm not
> able to insert items on the tree anymore. Surely I'm overlooking
> something. Here an excerpt of my code (the code constructs the tree
> correctly the first time it's realized):
>
> void
> on_tree_realize (GtkWidget *widget, gpointer user_data)
> {
> ...
>
>   /* If is as rebuild, clear all tree items */
>   if(rebuild_tree) {
>     gtk_tree_clear_items (tree, 0, -1);
>     rebuild_tree = FALSE;
>   }
>
>   /* Call function to build the tree */
>   populate_tree (GTK_TREE(widget));
> }
>
> void
> populate_tree(GtkTree *tree)
> {
>   GList *item_list = NULL, *swap_list = NULL, *node;
>   GtkWidget *subtree, *root_item, *root_hbox;
>   GtkWidget *root_pixmap, *root_label;
>
>   /* Create the root item */
>   root_item = gtk_tree_item_new ();
>
>   /* Create the root hbox which will contain the
>    * root_item label and pixmap
>    */
>   root_hbox = gtk_hbox_new (FALSE, 2);
>
>   /* Show the root hbox */
>   gtk_widget_show (root_hbox);
>
>   /* Pack the root hbox into the tree root item */
>   gtk_container_add (GTK_CONTAINER (root_item), root_hbox);
>
>   /* Create the root pixmap */
>   root_pixmap = create_pixmap (gtk_widget_get_toplevel\
>                               (GTK_WIDGET(tree)),
>                                "root.xpm");
>
>   /* Set root_pixmap alignment properly */
>   gtk_misc_set_alignment (GTK_MISC (root_pixmap), 0.0, 0.5);
>
>   /* Show root_pixmap */
>   gtk_widget_show (root_pixmap);
>
>   /* Pack the root pixmap into root_hbox */
>   gtk_box_pack_start (GTK_BOX (root_hbox), root_pixmap,
>                       FALSE, FALSE, 0);
>
>   /* Create root_label */
>   root_label = gtk_label_new ("Root");
>
>   /* Set root_label alignment properly */
>   gtk_misc_set_alignment (GTK_MISC (root_label), 0.0, 0.5);
>
>   /* Show the root label*/
>   gtk_widget_show (root_label);
>
>   /* Pack root label into the root hbox */
>   gtk_box_pack_start (GTK_BOX (root_hbox), root_label,
>                       FALSE, FALSE, 0);
>
>   /* Add root item to the tree root */
>   gtk_tree_append (GTK_TREE(tree), root_item);
>
>   /* Show item */
>   gtk_widget_show (root_item);
>
>   /* Read the list of available items */
>   swap_list = read_item_list("list\n");
>
>   /* Copying all the the items from swap_list into item_list */
>   foreach(swap_list, node) {
>     item_list = g_list_insert(item_list,
>                               g_strdup((gchar *) node->data), 0);
>   }
>
>   /* Revert the glist and remove the NULL pointer allocated to
>    * initialize the GList in the function read_item_list()
>    */
>   item_list = g_list_reverse (item_list);
>   g_list_remove(item_list, NULL);
>
>   /* Create the subtree (it's a subtree of root)  */
>   subtree = gtk_tree_new();
>
>   /* Set the item subtree - note that you cannot do this until
>    * the root item has been added to its parent tree!
>    */
>   gtk_tree_item_set_subtree (GTK_TREE_ITEM(root_item), subtree);
>
>   /* Populate the tree */
>   foreach(item_list, node) {
>     GtkWidget *item, *item_hbox, *item_pixmap, *item_label;
>
>     /* Create a tree item */
>     item = gtk_tree_item_new ();
>     /* Create a hbox which will contain the item label and pixmap */
>     item_hbox = gtk_hbox_new (FALSE, 2);
>     gtk_widget_ref (item_hbox);
>     /* Show the hbox */
>     gtk_widget_show (item_hbox);
>     /* Pack the hbox into the tree item */
>     gtk_container_add (GTK_CONTAINER (item), item_hbox);
>     /* Create the item pixmap */
>     item_pixmap = create_pixmap (gtk_widget_get_toplevel\
>                                 (GTK_WIDGET(tree)),
>                                 "item.xpm");
>     /* Set pixmap alignment properly */
>     gtk_misc_set_alignment (GTK_MISC (item_pixmap), 0.0, 0.5);
>     /* Show the item pixmap */
>     gtk_widget_show (item_pixmap);
>     /* Pack the pixmap into the hbox */
>     gtk_box_pack_start (GTK_BOX (item_hbox), item_pixmap,
>                         FALSE, FALSE, 0);
>     /* Create the item label */
>     item_label = gtk_label_new ((gchar *) node->data);
>     /* Set label alignment properly */
>     gtk_misc_set_alignment (GTK_MISC (item_label), 0.0, 0.5);
>     /* Show the item label*/
>     gtk_widget_show (item_label);
>     /* Pack item label into the hbox */
>     gtk_box_pack_start (GTK_BOX (item_hbox), item_label,
>                         FALSE, FALSE, 0);
>     /* Connect select signal to handle item selections */
>     gtk_signal_connect (GTK_OBJECT(item), "select",
>                         GTK_SIGNAL_FUNC(on_tree_select_subitem),
>                         item_label);
>     /* Add item to the item tree */
>     gtk_tree_append (GTK_TREE(subtree), item);
>     /* Show item */
>     gtk_widget_show (item);
>   }
>
>   /* Free glist */
>   g_list_free(item_list);
>   g_list_free(swap_list);
>   g_list_free(node);
> }
>
> Does anyone have a clue, what am I doing wrong? I've already tried to
> increase the reference count of the gtktree, but I know that the tree
> wasn't removed. Just it's children pointer is NULL after the items are
> cleared. But cause I create them again, this should not be a problem at
> all, should it?
>
> Thanks in advance for the help!
>
> Greetings,
>
> Rafael
> P.S. ('foreach' is a macro that iterates through all items of a GList.)
> --
> rafael peregrino innominate com
> software engineer                                        innominate AG
> server appliances                                 the linux architects
> tel: +49.30.308806-81  fax: -77              http://www.innominate.com
>
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