Returns %TRUE if any of the cells packed into the @tree_column are visible.
For this to be meaningful, you must first initialize the cells with
gtk_tree_view_column_cell_set_cell_data()
Return: %TRUE, if any of the cells packed into the @tree_column are currently visible
Returns %TRUE if any of the cells packed into the @tree_column are visible. For this to be meaningful, you must first initialize the cells with gtk_tree_view_column_cell_set_cell_data()
Return: %TRUE, if any of the cells packed into the @tree_column are currently visible