GrowHide Widget Effect

import wx


class AutoSizeTextCtrl(wx.TextCtrl):

    AutoSizeStep = 1

    import wx.lib.newevent
    ShrinkEffectEvent, EVT_SHRINK_EVENT = wx.lib.newevent.NewEvent()
    GrowEffectEvent, EVT_GROW_EVENT = wx.lib.newevent.NewEvent()

    def __init__(self, parent, id=wx.ID_ANY, value=wx.EmptyString, pos=wx.DefaultPosition, size=wx.DefaultSize, style=0, validator=wx.DefaultValidator, name=wx.TextCtrlNameStr):

        # We will not be able to set the expanded widget height during GrowEffectEvent without an initial size.
        assert size[1] > 0
        self.FirstHeight = size[1]

        # Prevent processing of ShrinkEffectEvent and GrowEffectEvent at aame time.
        self.Shrinking = False
        self.Growing = False

        wx.TextCtrl.__init__(self, parent, id, value, pos, size, style, validator, name)

        self.Bind(AutoSizeTextCtrl.EVT_SHRINK_EVENT, self.onShrink)
        self.Bind(AutoSizeTextCtrl.EVT_GROW_EVENT, self.onGrow)


    def onShrink(self, event=None):
        current_width, current_height = self.GetSize()
        if current_height > 0 and not self.Growing:
            self.Shrinking = True
            current_height -= self.AutoSizeStep
            self.SetSize(-1, current_height)
            event = AutoSizeTextCtrl.ShrinkEffectEvent()
            wx.PostEvent(self, event)
        elif current_height <= 0:
            self.Shrinking = False


    def onGrow(self, event=None):
        current_width, current_height = self.GetSize()
        if current_height < self.FirstHeight and not self.Shrinking:
            self.Growing = True
            current_height += self.AutoSizeStep
            self.SetSize(-1, current_height)
            event = AutoSizeTextCtrl.GrowEffectEvent()
            wx.PostEvent(self, event)
        elif current_height >= self.FirstHeight:
            self.Growing = False




class Frame(wx.Frame):

    def __init__(self, parent, id=wx.ID_ANY, title=wx.EmptyString, pos=wx.DefaultPosition, size=wx.DefaultSize, style=wx.DEFAULT_FRAME_STYLE, name=wx.FrameNameStr):

        wx.Frame.__init__(self, parent, id, title, pos, size, style, name)

        panel = wx.Panel(self)

        self.ButtonShowWidget = wx.Button(panel, label="Show TextCtrl", name='showbutton')
        self.ButtonHideWidget = wx.Button(panel, label="Hide TextCtrl", name='hidebutton')

        button_sizer = wx.BoxSizer(wx.HORIZONTAL)
        button_sizer.Add(self.ButtonShowWidget, 0, wx.ALL, 10)
        button_sizer.Add(self.ButtonHideWidget, 0, wx.ALL, 10)

        self.AutoSizeTextCtrl = AutoSizeTextCtrl(panel, size=(-1,100), style=wx.TE_MULTILINE )

        panel_sizer = wx.BoxSizer(wx.VERTICAL)
        panel_sizer.Add(button_sizer, 0, wx.EXPAND | wx.ALL, 0)
        panel_sizer.Add(self.AutoSizeTextCtrl, 0, wx.EXPAND|wx.ALL)
        panel.SetSizer(panel_sizer)

        frame_sizer = wx.BoxSizer(wx.VERTICAL)
        frame_sizer.Add(panel, 1, wx.EXPAND|wx.ALL, 0)
        self.SetSizer(frame_sizer)

        self.Show()

        self.Bind(wx.EVT_BUTTON, self.onButton)


    def onButton(self, event):
        button = event.GetEventObject()
        name = button.GetName()

        # Here we start the Grow or Shrink Effect;
        # in this case in the parent widget with buttons
        if name == 'showbutton':
            event = AutoSizeTextCtrl.GrowEffectEvent()
            wx.PostEvent(self.AutoSizeTextCtrl, event)
        elif name == 'hidebutton':
            event = AutoSizeTextCtrl.ShrinkEffectEvent()
            wx.PostEvent(self.AutoSizeTextCtrl, event)


if __name__ == "__main__":
    app = wx.App()
    frame = Frame(None, title='Auto-Grow-Widget')
    app.MainLoop()