[wxPython-users] Deleting a text control from an EVT_TEXT_ENTER

[Werner F. Bruhin]

Hi Anthony,

Anthony M. Floyd wrote:
> Here's something that's been confounding one of our developers here:
>
> We have a wx.ListBox control, and want to provide in-placed editing of
> certain parts of the text displayed in each row.  The way the dev has
> done it is to capture a double click on the sensitive part of the text,
> and dynamically overlay a wx.TextCtrl to provide the editing at that
> location.  This works OK (I suspect we're going to move to some sort of
> custom control in the future) but he is having a problem destroying the
> text control afterwards.  Well, *sometimes* there's a problem.
>
> When the text control is created, an event handler is bound to the
> parent to handle the EVT_TEXT_ENTER event.  The corresponding event
> handler does a myTextControl.Destroy().  The idea is when the data is
> entered in the control and the user presses enter, the data is
> "recorded" and the editing box disappears.  
>
> This causes a hard crash (no errors, no "unhandled exceptions" in the
> debugger).
>
> I've attached sample code that duplicates the problem pretty easily.
> WinXP, wxPython 2.8.3.0, Python 2.5.1.
>
> What is causing the crash?  I suspect there's another event that follows
> the EVT_TEXT_ENTER event, but I don't understand why this isn't handled
> cleanly by the "safe" .Destroy() method.
>
> How can we deal with this?  Anyone have any suggestions?  At the moment,
> rather than running Destroy(), the controls are being hidden and
> appended to a list in the parent, and during an EVT_IDLE handler the
> controls in this list are destroyed.  This works ok, but doesn't seem
> "clean".
>   
Detaching it from the sizer and then destroying seems to work, e.g.:
    def _onEnter(self, event):
       
##        self.textCtrl.Destroy()
        self.DestroyTextCtrl(self.textCtrl)
       
        #
        # commenting out the event.Skip avoids the crash
        # in this case, but in our full application, the crash
        # occurs anyway, presumably due to other operations occuring
        # in the event handler
        #
       
        event.Skip()
       
    def DestroyTextCtrl(self, control):
        sizer = control.GetContainingSizer()
        if sizer:
            sizer.Detach(control)
        wx.CallAfter(control.Destroy)

Werner