Question

I have a simple form with a multi line text control and Ok/Cancel buttons on it. I want to check whether the text control has text when Ok button is clicked or not. I’m trying to use the wx.Validator for this purpose, but for some reason it is never get called even the extra style wx.WS_EX_VALIDATE_RECURSIVELY is applied to the parent frame. Here is my code:

import wx

class Validator(wx.PyValidator):
    def __init__(self):
        wx.PyValidator.__init__(self)

    def Clone(self):
        return Validator()

    def Validate(self, win):
        txt_ctrl = self.GetWindow()

        if len(txt_ctrl.GetValue()) == 0:
            wx.MessageBox('Please, provide a value.', 'Error')
            txt_ctrl.SetBackgroundColour('pink')
            txt_ctrl.SetFocus()
            txt_ctrl.Refresh()
            return False
        else:
            txt_ctrl.SetBackgroundColour(wx.SystemSettings_GetColour(wx.SYS_COLOUR_WINDOW))
            txt_ctrl.Refresh()
            return True

    def TransferToWindow(self):
        return True

    def TransferFromWindow(self):
        return True

class OkCancelPanel(wx.Panel):
    def __init__(self, parent):
        wx.Panel.__init__(self, parent, wx.ID_ANY)

        self.btn_ok =  wx.Button(self, wx.ID_OK)
        self.btn_cancel = wx.Button(self, wx.ID_CANCEL)

        sizer = wx.BoxSizer(wx.HORIZONTAL)
        sizer.Add(self.btn_ok, 0, wx.NORMAL|wx.ALL, 5)
        sizer.Add(self.btn_cancel, 0, wx.NORMAL|wx.ALL, 5)            
        self.SetSizer(sizer)
        sizer.Fit(self)
        self.Layout()

class Panel(wx.Panel):
    def __init__(self, parent):
        wx.Panel.__init__(self, parent, wx.ID_ANY)

        self.txt = wx.TextCtrl(self, wx.ID_ANY, style = wx.TE_MULTILINE)
        self.okcancel = OkCancelPanel(self)

        sizer_txt = wx.StaticBoxSizer(wx.StaticBox(self, wx.ID_ANY, 'Some text here'), wx.HORIZONTAL)
        sizer_txt.Add(self.txt, 1, wx.EXPAND, 0)
        sizer_txt.Layout()
        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(sizer_txt, 1, wx.EXPAND|wx.ALL, 5)
        sizer.Add(self.okcancel, 0, wx.NORMAL|wx.ALIGN_RIGHT, 0)
        self.SetSizer(sizer)
        sizer.Fit(self)
        self.Layout()

class Frame(wx.Frame):
    def __init__(self, parent):
        wx.Frame.__init__(self, parent, wx.ID_ANY, 'Test Frame', size = (400, 300))
        self.SetSizeHints(minW = 400, minH = 300)

        self.panel = Panel(self)

        sizer = wx.BoxSizer(wx.HORIZONTAL)
        sizer.Add(self.panel, 1, wx.EXPAND, 0)
        self.SetSizer(sizer)
        sizer.Fit(self)
        self.Layout()

        #--Shortcuts--#
        self.txt = self.panel.txt
        self.btn_ok = self.panel.okcancel.btn_ok
        self.btn_cancel = self.panel.okcancel.btn_cancel

class Controller(Frame):
    def __init__(self, parent):
        Frame.__init__(self, parent)
        self.SetExtraStyle(wx.WS_EX_VALIDATE_RECURSIVELY)   

        self.txt.SetValidator(Validator())     

        self.Bind(wx.EVT_BUTTON, self.OnButton, self.btn_ok )

    def OnButton(self, evt):
        self.txt.Validate()

if __name__ == '__main__':
    app = wx.App()
    frame = Controller(None)
    frame.Show()
    app.SetTopWindow(frame)
    app.MainLoop()

So, what I’m doing wrong?

Sure I can use something like self.txt.GetValidator().Validate(self.txt) in the OnButton method, but I don’t want 🙂

Windows 7 x64, Python 2.7.2, wxPython 2.9.2.4

Answer 1

Instead of:

self.txt.Validate()

use:

self.Validate()