wxPython - problem with nested sizers, a panel and SetSizer / Fit

I am currently trying to get a grip on wxPython, and I stumbeled over nesting sizers, putting them on a panel and fit them.

I want to have a GridBagSizer in a StaticBoxSizer in a BoxSizer. The whole should be on a panel.

My code:

import wx

class App(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None, -1, "Frame", size=(550, 300))
        panel = wx.Panel(self, -1)
        mainSizer = self.makeOuterSizer()

        # fit layout
        panel.SetSizer(mainSizer)
        mainSizer.Fit(panel)

##         mainSizer.Fit(self)
##         self.SetSizer(mainSizer)

    # 开发者_JAVA技巧----

    def makeOuterSizer(self):

        # define sizer
        innerSizer = self.makeGrid()

        # make 
        outerSizer = wx.BoxSizer(wx.VERTICAL)
        outerSizer.Add(innerSizer, 0, wx.EXPAND|wx.CENTER|wx.ALL, 10)

        return outerSizer
    # ----

    def makeGrid(self):

        sizer = wx.StaticBoxSizer(wx.StaticBox(self, -1, ""), wx.VERTICAL)

        # make fields
        itemMonomer1_label = wx.StaticText(self, -1, "Text 1")
        self.itemMonomer1_value = wx.TextCtrl(self, -1, "", size=(100, -1))
        itemMonomer2_label = wx.StaticText(self, -1, "Text 2")
        self.itemMonomer2_value = wx.TextCtrl(self, -1, "", size=(100, -1))
        itemMonomer3_label = wx.StaticText(self, -1, "Text 3")
        self.itemMonomer3_value = wx.TextCtrl(self, -1, "", size=(100, -1))

        # pack elements

        grid = wx.GridBagSizer(2, 3)

        grid.Add(itemMonomer1_label, (0,0), flag=wx.ALIGN_CENTER|wx.ALIGN_CENTER_VERTICAL)
        grid.Add(self.itemMonomer1_value, (1,0), flag=wx.EXPAND)
        grid.Add(itemMonomer2_label, (0,1), flag=wx.ALIGN_CENTER|wx.ALIGN_CENTER_VERTICAL)
        grid.Add(self.itemMonomer2_value, (1,1), flag=wx.EXPAND)
        grid.Add(itemMonomer3_label, (0,2), flag=wx.ALIGN_CENTER|wx.ALIGN_CENTER_VERTICAL)
        grid.Add(self.itemMonomer3_value, (1,2), flag=wx.EXPAND)

        sizer.Add(grid, 0, wx.EXPAND|wx.ALIGN_CENTER|wx.ALL, 5)

        return sizer
    # ----

if __name__ == '__main__':
    app = wx.App()
    App().Show(True)
    app.MainLoop()

So, the code above does not really work. However, when I quote lines 10 and 11, and unquote lines 13 and 14, at least the GridBagSizer is correctly shown. So I suspect that something in my SetSizer and Fit lines must be wrong... But the panel is still stuck in the upper right corner and does not work...

Any hint is much apprechiated!

Thanks, Woodpicker

The widgets you want to display on the panel should be children of the panel instead of the frame. Try the following changes:

class App(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None, -1, "Frame", size=(550, 300))
        self.panel = wx.Panel(self, -1)
        mainSizer = self.makeOuterSizer()

        # fit layout
        self.panel.SetSizer(mainSizer)
        mainSizer.Fit(self.panel)

# ...

def makeGrid(self):

    sizer = wx.StaticBoxSizer(wx.StaticBox(self.panel, -1, ""), wx.VERTICAL)

    # make fields
    itemMonomer1_label = wx.StaticText(self.panel, -1, "Text 1")
    self.itemMonomer1_value = wx.TextCtrl(self.panel, -1, "", size=(100, -1))
    itemMonomer2_label = wx.StaticText(self.panel, -1, "Text 2")
    self.itemMonomer2_value = wx.TextCtrl(self.panel, -1, "", size=(100, -1))
    itemMonomer3_label = wx.StaticText(self.panel, -1, "Text 3")
    self.itemMonomer3_value = wx.TextCtrl(self.panel, -1, "", size=(100, -1))

You will still have to give the GridBagSizer one or more growable columns if you want it to expand along with the StaticBox.