GtkTreeRowReference and Tree updates

_6_ · **Joined:** Thu Aug 23, 2012 4:50 am **Posts:** 11

Hi,

I have a problem where a GtkTreeRowReference isn't being updated when I move the treenode to a parent node.

Below is some test code where I create 6 nodes on a parent and save a reference of each node to the TreeStore. My understanding is, each time I update, insert or delete a node, the references are updated so that when I read the reference of a node it'll show the correct path ( at the bottom of the window in this case).

But in my test code, when I move a node to different parent and then click on the node, I get a "assertion path != NULL" error. All the other nodes get updated correctly, just not the one that has been set to a new parent. So is there any reason for this?

What I'm trying to do is store a handle/pointer/reference/whatever of a particular node in 3D object. When I click on that object it should highlight the corresponding treenode no matter where it is in the TreeModel.

Any help would be appreciated. I'm using Gtk+ 2.24 on Windows.

Thanks
6

Code:

#include <gtk/gtk.h>

enum
{
  COLUMN = 0,
  REFERENCE,
  NUM_COLS
} ;

void  on_changed(GtkWidget *widget, gpointer statusbar) 
{
  GtkTreeIter iter;
  GtkTreeModel *model;
  gchar *str;
  GtkTreeRowReference *ref;
  GtkTreePath *path;

  if (gtk_tree_selection_get_selected(GTK_TREE_SELECTION(widget), &model, &iter)) 
  {
    //Get the stored Reference from the node we clicked on, get the updated path and display it.
    gtk_tree_model_get(model, &iter,  REFERENCE, &ref, -1);
    path = gtk_tree_row_reference_get_path(ref);
    str = gtk_tree_path_to_string(path);
    gtk_statusbar_push(GTK_STATUSBAR(statusbar), gtk_statusbar_get_context_id(GTK_STATUSBAR(statusbar), str), str);
  }
}

static GtkTreeModel *
create_and_fill_model (void)
{
  GtkTreeStore *treestore;
  GtkTreePath *path;
  GtkTreeRowReference *ref;
  GtkTreeIter toplevel, child;

  treestore = gtk_tree_store_new(NUM_COLS,G_TYPE_STRING,G_TYPE_POINTER);

  //Create a new iter, get the path of it, make a reference and add it to the store

  gtk_tree_store_append(treestore, &toplevel, NULL);
  path = gtk_tree_model_get_path(GTK_TREE_MODEL(treestore), &toplevel);
  ref = gtk_tree_row_reference_new(GTK_TREE_MODEL(treestore), path);
  gtk_tree_store_set(treestore, &toplevel, COLUMN, "languages", REFERENCE, ref,-1);

  gtk_tree_store_append(treestore, &child, &toplevel);
  path = gtk_tree_model_get_path(GTK_TREE_MODEL(treestore), &child);
  ref = gtk_tree_row_reference_new(GTK_TREE_MODEL(treestore), path);
  gtk_tree_store_set(treestore, &child, COLUMN, "Python", REFERENCE, ref, -1);
      
  gtk_tree_store_append(treestore, &child, &toplevel);
  path = gtk_tree_model_get_path(GTK_TREE_MODEL(treestore), &child);
  ref = gtk_tree_row_reference_new(GTK_TREE_MODEL(treestore), path);
  gtk_tree_store_set(treestore, &child,COLUMN, "Perl",REFERENCE, ref,-1);
    
  gtk_tree_store_append(treestore, &child, &toplevel);
  path = gtk_tree_model_get_path(GTK_TREE_MODEL(treestore), &child);
  ref = gtk_tree_row_reference_new(GTK_TREE_MODEL(treestore), path);
  gtk_tree_store_set(treestore, &child,COLUMN, "PHP", REFERENCE, ref,-1);

  gtk_tree_store_append(treestore, &child, &toplevel);
  path = gtk_tree_model_get_path(GTK_TREE_MODEL(treestore), &child);
  ref = gtk_tree_row_reference_new(GTK_TREE_MODEL(treestore), path);
  gtk_tree_store_set(treestore, &child, COLUMN, "C", REFERENCE, ref,-1);

  gtk_tree_store_append(treestore, &child, &toplevel);
  path = gtk_tree_model_get_path(GTK_TREE_MODEL(treestore), &child);
  ref = gtk_tree_row_reference_new(GTK_TREE_MODEL(treestore), path);
  gtk_tree_store_set(treestore, &child, COLUMN, "C++", REFERENCE, ref,-1);

  gtk_tree_store_append(treestore, &child, &toplevel);
  path = gtk_tree_model_get_path(GTK_TREE_MODEL(treestore), &child);
  ref = gtk_tree_row_reference_new(GTK_TREE_MODEL(treestore), path);
  gtk_tree_store_set(treestore, &child, COLUMN, "Java", REFERENCE, ref,-1);
  
  return GTK_TREE_MODEL(treestore);
}

static GtkWidget *
create_view_and_model (void)
{
  GtkTreeViewColumn *col;
  GtkCellRenderer *renderer;
  GtkWidget *view;
  GtkTreeModel *model;
  GtkTreeSelection *select;
  
  view = gtk_tree_view_new();
  select = gtk_tree_view_get_selection (GTK_TREE_VIEW (view));
  gtk_tree_selection_set_mode (select, GTK_SELECTION_SINGLE);

  gtk_tree_view_set_reorderable(GTK_TREE_VIEW(view), TRUE);
  
  col = gtk_tree_view_column_new();
  gtk_tree_view_column_set_title(col, "Programming languages");
  gtk_tree_view_append_column(GTK_TREE_VIEW(view), col);

  renderer = gtk_cell_renderer_text_new();
  gtk_tree_view_column_pack_start(col, renderer, TRUE);
  gtk_tree_view_column_add_attribute(col, renderer, "text", COLUMN);

  model = create_and_fill_model();
  gtk_tree_view_set_model(GTK_TREE_VIEW(view), model);
  //g_object_unref(model); 

  return view;
}

int
main (int argc, char **argv)
{       
  GtkWidget *window;
  GtkWidget *view;
  GtkTreeSelection *selection; 
  GtkWidget *vbox;
  GtkWidget *statusbar;

  gtk_init(&argc, &argv);

  window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
  gtk_window_set_title(GTK_WINDOW(window), "Tree View");
  gtk_widget_set_size_request (window, 350, 300);

  vbox = gtk_vbox_new(FALSE, 2);
  gtk_container_add(GTK_CONTAINER(window), vbox);

  view = create_view_and_model();
  selection = gtk_tree_view_get_selection(GTK_TREE_VIEW(view));

  gtk_box_pack_start(GTK_BOX(vbox), view, TRUE, TRUE, 1);

  statusbar = gtk_statusbar_new();
  gtk_box_pack_start(GTK_BOX(vbox), statusbar, FALSE, TRUE, 1);

  g_signal_connect(selection, "changed", 
      G_CALLBACK(on_changed), statusbar);

  g_signal_connect (G_OBJECT (window), "destroy",
          G_CALLBACK(gtk_main_quit), NULL);

  gtk_widget_show_all(window);
  gtk_main();
  return 0;
}

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GtkTreeRowReference and Tree updates

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