[pygtk] Using changed event

[Richard Taylor]

On Monday 30 Jan 2006 15:24, Nicholas Wieland wrote:
> Hi *,
> I need to trap all non-digits in a gtk.Entry, to prevent hte user
> from inserting letters and symbols at all.
> I'm trying to use the 'changed' event, but it doesn't seem to work:
>
>    def foo (self, widget):
>      if re.match ('[A-Za-z,.\-+]', widget.get_text () [-1]):
>        return True
>
> Any idea ?
>
> TIA,

You might find this useful, it is the Integer only edit widget from gramps 
(www.gramps-project.org). It is based on the code in the FAQ.

class IntEdit(gtk.Entry):
    """An gtk.Edit widget that only allows integers."""
    
    def __init__(self):
	gtk.Entry.__init__(self)

        self._signal = self.connect("insert_text", self.insert_cb)

    def insert_cb(self, widget, text, length, *args):        
        # if you don't do this, garbage comes in with text
        text = text[:length]
        pos = widget.get_position()
        # stop default emission
        widget.emit_stop_by_name("insert_text")
        gobject.idle_add(self.insert, widget, text, pos)

    def insert(self, widget, text, pos):
        if len(text) > 0 and text.isdigit():            
            # the next three lines set up the text. this is done because we
            # can't use insert_text(): it always inserts at position zero.
            orig_text = widget.get_text()            
            new_text = orig_text[:pos] + text + orig_text[pos:]
            # avoid recursive calls triggered by set_text
            widget.handler_block(self._signal)
            # replace the text with some new text
            widget.set_text(new_text)
            widget.handler_unblock(self._signal)
            # set the correct position in the widget
            widget.set_position(pos + len(text))

Regards

Richard


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