Tooltips only work on top half of a GtkTreeView

[Nigel Stuckey <nigel stuckey systemgarden com>]

I'm about to launch a Gtk2/3 version of a data collector/viewer and performance monitor, a port from a Gtk1 app made a number of years ago.

I've got a number of problems outstanding with the GUI part that I would like some help with and possibly some advice with some horrid code!

My first problem: I have tooltips in a tabular view of data, contained in a GtkTreeView with a GtkListStore as model, which can grow to be quite big. Unfortunately, the tooltips are only successfully produced in the top half of the GtkTreeView. The lower half doesn't work -- the effect being proportional to the size of the list rather than an absolute numeric limit.

The code is:-

     /* get the tooltip details */
     if (!gtk_tree_view_get_tooltip_context (tree_view, &x, &y,
					     keyboard_tip,
					     &model, &path, &iter))
          return FALSE;

     /* find time data and the row number (path) */
     gtk_tree_model_get (model, &iter, uitable_timecol, &samptime, -1);
     pathstring = gtk_tree_path_to_string (path);

     /* find the column tooltip - if keyboard_tip==FALSE, then (x,y) are
      * converted to bin_window coords; else treat as a widget coords.
      * We want tree coords. */
     if (keyboard_tip)
          gtk_tree_view_convert_widget_to_tree_coords(tree_view, x, y, 
						      &treex, &treey);
     else
          gtk_tree_view_convert_bin_window_to_tree_coords(tree_view, x, y, 
							  &treex, &treey);

     /* get the column, so I can get the title and the tip */
     if (gtk_tree_view_get_path_at_pos(tree_view, treex, treey, NULL, 
				       &column, NULL, NULL)) {

          /* valid row, compose tooltip string in tip (snip, snip) */

	  g_object_get (column->button, "tooltip-text", &tip, NULL); /* A */
     } else {
          g_snprintf (buffer, 511, "Row does not exist (path %s)", pathstring); /* B */
     }

Following the call to gtk_tree_view_get_path_at_pos(), the first set of rows runs code path A and I get the tooltip I want, the bottom half runs B and I report an error.

Can anyone help shed some light on this?

Many thanks

Nigel