Introduction to Gtk2-Perl [30 mn de lecture - paru le 10/7/2004 3:02:44 PM - Public : Confirmé]

Auteur

Przemyslaw BRODACKI Elève-Ingénieur Supinfo Paris Promotion SUPINFO 2004    Lui écrire    Tous les projets de cet auteur    Le mini-CV de cet auteur

3. Advanced Elements

3.1. Text fields

The text fields seem simple. But they can react to multiple signals.

$entree = Gtk::Entry->new();

The object above is a text field where we can type only one line. The content can be accessed with:

$entree->set_text( $text );  
$entree->append_text( $text );  
$entree->prepend_text( $text );

We can set the text invisible::

$entree->set_visibility($visible ); #valeur booléenne.

We can create large text fields with:

$editable->select_region( $start, $end );

And modify the content with :

$editable->insert_text( $new_text, $position );
$editable->delete_text( $start, $pos );
$editable->get_chars( $start, $end );
$editable->cut_clipboard();
$editable->copy_clipboard();
$editable->paste_clipboard();
$editable->delete_selection();

These methods are quite simple to understand, there is no need to explain them.

Any action on the text field generates signals which may be 'changed', 'insert-text', 'delete-text'.... The list of generated signals is too large to describe.

3.2. Dialog boxes

Dialog boxes alow interaction between the user and the software.:

$dialog = Gtk2::Dialog->new($titre,$parent,$flags...);

dialog boxes contain in general text (a label) and buttons. To achieve that, these elements are stacked in a VBOX.

The actions on dialog boxes may be:

- 'none'  
- 'reject'  
- 'accept'  
- 'delete-event'  
- 'ok'  
- 'cancel'  
- 'close'  
- 'yes'  
- 'no'  
- 'apply'  
- 'help'

It is not necessary to create of any part one dialog box. One can always use one of the preset ones:

$dialog = Gtk2::MessageDialog->new ($fenetre_parente,  
                                        $flags,$type,$bouton,..  
                                        $message);  

types may be :

- 'info'
- 'question'
- 'error'
- 'warrning'

3.3. Notebooks

Notebooks is a way to handle multiple pages in a same window.

$onglets = Gtk2::Notebook->new();

To add a page to the notebook :

$onglets->append_page( $child, $tab_label );

The line above describes how to append a page, but there still is a way to prepend or insert à page between two other pages.

The operations on pages may be various:

$onglets->remove_page( $page_num );
$onglets->get_current_page();
$onglets->page_num( $child );
$onglets->next_page();
$onglets->prev_page();
...

3.4. Progress Bars

The progress bars allow the visualization of the advance of a task.

$progress = Gtk2::ProgressBar->new();

We can modify the advance by updating the percentage of advance:

$progress->set_fraction($percentage );

Of course the bar can advance from left to right, from right to left, upwards and from top to bottom:

$progress->set_orientation( $orientation );

orientations are :

- 'left_to_right'
- 'right_to_left'
- 'bottom_to_top'
- 'top_to_bottom'

If a task cannot be sized it is often useful to show the activity of it rather than a false estimation:

$progress->pulse();
progress->set_pulse_step($fraction);

We can add a text to the bar :

$progress->set_text( $text );