Re: Sort Indicator in TreeView

["Andrew E. Makeev" <andrew solvo ru>]

Andrew E. Makeev wrote:

> Hi,
>
> I can't remove sort indicator in my TreeView widget. (GTKMM-2.4)
>
> I am using custom widget ( HBox with label and image ) for the column 
> header ( column->set_widget( header ) ).
> I need custom sorting behavior, so, I am setting
>
> column->set_sort_indicator( false );
>
> but this won't help. Once I am calling set_sort_column() function sort 
> indicator is appearing as well.
> How to hide it?
>
> ... compilation done ... (was writing until my test compiles)
>
> Well, I found the answer myself - I have to call set_sort_indicator( 
> false ) every time I call set_sort_column(). Why so?
>
> (I wouldn't hide indicator but It doesn't appear in SORT_DESCEND state 
> for custom widget, however it did in GTKMM-2.2. Is it a bug?) .

The problem is solved.

My task was a creating TreeView Column with 3 states of the sorting: 
ASC, DESC and NONE.
Since, TreeView itself offers only 2 states (ASC, DESC), I should code 
my handler for TreeViewColumn::signal_clicked:

enum States
{
   SORT_NONE,
   SORT_ASC,
   SORT_DESC
};

void myclass::column_clicked_cb( Gtk::TreeViewColumn* column )
{
   static enum States state = SORT_NONE;

   switch( state )
   {
        case SORT_NONE:
           state = SORT_ASC;
           break;

        case SORT_ASC:
// Since, GTK+ 2.4. I had to move (and rename :-/, since GTKMM-2.4) 
setting of sort column here, otherwise it won't show sort indicator
           column->set_sort_column_id( columnModel.row_num_column );
           column->set_sort_indicator( true );
// was here for Gtk+ 2.2
//            column->set_sort_column( columnModel.row_num_column );
           state = SORT_DESC;
           break;

        case SORT_DESC:
           column->set_sort_column_id( columnModel.sort_column );
           state = SORT_NONE;
           break;
   }
}
/*
columnModel.sort_column - column in Model and TreeView where I like to 
apply sorting
columnModel.row_num_column - row counter, column in Model to set default 
sorting (by row number)
*/

As I noted changes was caused by GTK+ new release. I found this change 
in gtktreeviewcolumn.c:

static void
gtk_tree_view_column_setup_sort_column_id_callback (GtkTreeViewColumn 
*tree_column)
{
 GtkTreeModel *model;

 if (tree_column->tree_view == NULL)
   return;

 model = gtk_tree_view_get_model (GTK_TREE_VIEW (tree_column->tree_view));

 if (model == NULL)
   return;

 if (GTK_IS_TREE_SORTABLE (model) &&
     tree_column->sort_column_id != -1)
   {
     gint real_sort_column_id;
     GtkSortType real_order;

     if (tree_column->sort_column_changed_signal == 0)
       tree_column->sort_column_changed_signal =
         g_signal_connect (model, "sort_column_changed",
                           G_CALLBACK 
(gtk_tree_view_model_sort_column_changed),
                           tree_column);

     if (gtk_tree_sortable_get_sort_column_id (GTK_TREE_SORTABLE (model),
                                               &real_sort_column_id,
                                               &real_order) &&
         (real_sort_column_id == tree_column->sort_column_id))
       {
         gtk_tree_view_column_set_sort_indicator (tree_column, TRUE);  
// that causes the indicator to be shown when I am restoring sorting column
         gtk_tree_view_column_set_sort_order (tree_column, real_order);
       }
// begin
// added since 2.4
     else
       {
         gtk_tree_view_column_set_sort_indicator (tree_column, FALSE); 
// that causes the indicator to be hidden when I am setting sorting 
column to row_num
       }
// end
   }
}

And it is sad, when you are going to upgrade your library version to get 
new advantages and bug fixes, but in same time you could meet some 
troubles for porting that could be simple but take lot of time for 
researching.
Is it a really big deal to add notes in API reference?

Regards,
-andrew