Re: SimpleList/TreeView data manipulation & TextView questions

[muppet <scott asofyet org>]

On Jan 5, 2007, at 9:57 PM, Michael McGinn wrote:
> This is my first email to the distribution list and I am new to  
> Gtk2-perl.
Welcome!

> The first question is related to manipulating an array in a  
> SimpleList/TreeView. I’m having trouble figuring out how to  
> identify which row or rows have been selected. Once the row is  
> selected I want to either insert an additional row or delete the  
> row. These actions will be triggered by a signal from a popup menu  
> which contains an Insert Row and Delete Row option.
>
> I created the SimpleList and populated it with data and have  
> created the popup menu tied to the SimpleList. The only thing that  
> seems to be missing is identifying the selected row so I can pass  
> it to ‘splice’ for a delete or do whatever else is required.
You can get the indices of the selected row or rows with  
Gtk2::Ex::Simple::List::get_selected_indices():

    my @selected = $slist->get_selected_indices;

These are the zero-based index numbers of the row array, suitable for  
use with slice().

You can also use conventional gtk+ methods, based on the  
TreeSelection object:

    my $selection = $slist->get_selection;  # SimpleList isa  
TreeView, you see
    my $n_selected = $selection->count_selected_rows;
    my @paths = $selection->get_selected_rows;  # returns a list of  
TreePath objects

These are described in the Gtk2::Ex::Simple::List (or deprecated  
Gtk2::SimpleList) and Gtk2::TreeSelection manpages, respectively.

> The second question is related to manipulating the columns of a  
> SimpleList/TreeView. I can’t figure out how to move or resize a  
> column. I have set the column to resizable and have made the column  
> clickable.
You also need to make the TreeViewColumn "reorderable":

   $column->set_reorderable (TRUE);

or, using object properties,

   $column->set (reorderable => TRUE);

You can fetch columns with either $treeview->get_column($index) or  
@ary = $treeview->get_columns, so something like

    foreach my $column ($slist->get_columns) {
        $column->set (resizable => TRUE,
                      clickable => TRUE,
                      reorderable => TRUE);
    }

should get you going easily.

http://developer.gnome.org/doc/API/2.0/gtk/GtkTreeViewColumn.html#gtk- 
tree-view-column-set-reorderable


Note that reordering the view columns has no effect on the model.

> The third question is related to updating a TextView as activity is  
> progressing. Currently the TextView display is only updated after  
> the processing is finished. I have a number of separate functions  
> that make system calls and I want to be able to update the TextView  
> to reflect the activity at the time and not wait until it’s all  
> complete.
You're not returning control the main loop, which is where screen  
updates happen.  Instead of system() or backticks, use a pipe-open  
and an IO watch, as described in the faq:

"How do I keep my GUI updating while doing a long file read?"
http://live.gnome.org/GTK2-Perl/ 
FrequentlyAskedQuestions#head-20b1c1d3a92f0c61515cb88d15e06b686eba6cbc

There are several threads discussing this very topic on the mailing  
list (hence its inclusion in the faq ;-), which may help with the  
fine details.

http://www.google.com/search?q=site:mail.gnome.org+gtk-perl-list+io 
+watch