wxPython sizers are resizing improperly

My application has a main boxsizer with 3 rows. The first 2 rows are text controls and the 3 row is a selection of buttons to perform different actions

When my application starts it has roughly 1/3 of the overall widow space below the button as blank space. When I resize the window to reduce that space, it actually compresses my text controls instead of removing the blank space. Why?

#Boa:Frame:Frame1

import wx
import os
import glob
import shutil
import datetime
from mutagen.mp3 import MP3
from mutagen.easyid3 import EasyID3
import mutagen.id3
import unicodedata

from ObjectListView import ObjectListView, ColumnDefn



########################################################################     
class Track(object):
    def __init__(self, title, artist, album, source, dest):
        """
        Model of the Track Object
        Contains the followign attributes:
        'Title', 'Artist', 'Album', 'Source', 'Dest'
        """

        self.atrTitle = title
        self.atrArtist = artist
        self.atrAlbum = album
        self.atrSource = source
        self.atrDest = dest        


class Action(object):
    def __init__(self, timestamp, action, result):
        self.timestamp = timestamp
        self.action = action
        self.result = result

########################################################################
# Non GUI
########################################################################

def selectFolder(sMessage):
    print "Select Folder"
    dlg = wx.DirDialog(None, message = sMessage)

    if dlg.ShowModal() == wx.ID_OK:
        # User has selected something, get the path, set the window's title to the path
        filename = dlg.GetPath()   
    else:
        filename = "None Selected"

    dlg.Destroy()
    return filename 

def getList(SourceDir):
    print "getList"
    listOfFiles = None
    print "-list set to none"

    listOfFiles = glob.glob(SourceDir + '/*.mp3')

    return listOfFiles

def getListRecursive(SourceDir):
    print "getListRecursive"
    listOfFiles = None
    listOfFiles = []
    print "-list set to none"

    for root, dirs, files in os.walk(SourceDir):
        for file in files:
            if file.endswith(".mp3"):
                listOfFiles.append(os.path.join(root,file))

    #print listOfFiles

    return listOfFiles

def strip_accents(s):
    print "strip_accents"
    return ''.join((c for c in unicodedata.normalize('NFD', s) if unicodedata.category(c) != 'Mn'))   

def replace_all(text):
    print "replace_all " + text
    dictionary = {'\\':"", '?':"", '/':"", '...':"", ':':"", '&':"and"}

    print "-- repl_orig: " + text
    print "-- repl_decode: " + text.decode('utf-8')

    text = strip_accents(text.decode('utf-8'))

    for i, j in dictionary.iteritems():
        text = text.replace(i,j)

    return text

def getTitle(fileName):
    print "getTitle"
    audio = MP3(fileName)

    try:
        sTitle = str(audio["TIT2"])
    except KeyError:
        sTitle = os.path.basename(fileName)
        frame.lvActions.Append([datetime.datetime.now(),fileName,"Title tag does not exist, set to filename"])

    # TODO: Offer to set title to filename
    ## If fileName != filename then
    ##  prompt user for action
    ##  Offer Y/n/a

    sTitle = replace_all(sTitle)

    return sTitle

def getArtist(fileName):
    print "get artist"

    audio = MP3(fileName)

    try:
        sArtist = str(audio["TPE1"])
    except KeyError:
        sArtist = "unkown"
        frame.lvActions.Append([datetime.datetime.now(),fileName,"Artist tag does not exist, set to unkown"])

    #Replace all special chars that cause dir path errors
    sArtist = replace_all(sArtist)

    #if name = 'The Beatles' change to 'Beatles, The'
    if sArtist.lower().find('the') == 0:
        sArtist = sArtist.replace('the ',"")
        sArtist = sArtist.replace('The ',"")
        sArtist = sArtist + ", The"

    return sArtist

def getAblum(fileName):
    print "get album"
    audio = MP3(fileName)

    try:
        sAlbum = str(audio["TALB"])
    except KeyError:
        sAlbum = "unkown"
        frame.lvActions.Append([datetime.datetime.now(),fileName,"Album tag does not exist, set to unkown"])

    #Replace all special chars that cause dir path error    
    sAlbum = replace_all(sAlbum)
    return sAlbum


########################################################################
# GUI
########################################################################
class MainPanel(wx.Panel):
    #----------------------------------------------------------------------
    def __init__(self, parent):
        wx.Panel.__init__(self, parent=parent, id=wx.ID_ANY)

        #Create static box frames for GUI features
        self.stTracks = wx.StaticBox(self, -1, "Tracks")
        self.stEvents = wx.StaticBox(self, -1, "Events")
        self.stFolders = wx.StaticBox(self, -1, "Folders")
        self.stOptions = wx.StaticBox(self, -1, "Options")
        self.stActions = wx.StaticBox(self, -1, "Actions")
        self.stSearch  = wx.StaticBox(self, -1, "Search")       

        #Create Track Object List - editable
        self.TrackOlv = ObjectListView(self, wx.ID_ANY, style=wx.LC_REPORT|wx.SUNKEN_BORDER)
        self.TrackOlv.cellEditMode = ObjectListView.CELLEDIT_SINGLECLICK
        self.setTracks()  

        #Create Actions Object List
        self.ActionsOlv = ObjectListView(self, wx.ID_ANY, style=wx.LC_REPORT|wx.SUNKEN_BORDER)
        self.setActions()

        # create source txt box - it stores values only, not displayed
        self.txSource = wx.TextCtrl(self, wx.ID_ANY, name=u'txSource', value=u'')
        # create dest txt box - it stores values only, not displayed
        self.txDest = wx.TextCtrl(self, wx.ID_ANY, name=u'txDest', value=u'')         


        # create browse to source button
        sourceBtn = wx.Button(self, wx.ID_ANY, "Browse Source")
        sourceBtn.Bind(wx.EVT_BUTTON, self.onBrowseSource)        

        # create browse dest button
        destBtn = wx.Button(self, wx.ID_ANY, "Browse Destination")
        destBtn.Bind(wx.EVT_BUTTON, self.onBrowseDest)

        # create Move Files button
        moveBtn = wx.Button(self, wx.ID_ANY, "Move Files")
        moveBtn.Bind(wx.EVT_BUTTON, self.onMoveFiles)

        # create Save Changes button
        saveChangesBtn = wx.Button(self, wx.ID_ANY, "Save Changes")
        saveChangesBtn.Bind(wx.EVT_BUTTON, self.onSaveChanges)

        # create Discard Changes button
        discardChangesBtn = wx.Button(self, wx.ID_ANY, "Discard Changes")
        discardChangesBtn.Bind(wx.EVT_BUTTON, self.onMoveFiles)

        # print list button - debug only
        printBtn = wx.Button(self, wx.ID_ANY, "Print List")
        printBtn.Bind(wx.EVT_BUTTON, self.onPrintBtn)

        # create check box to include all sub files
        self.cbSubfolders = wx.CheckBox(self, wx.ID_ANY,
              label=u'Include Subfolders', name=u'cbSubfolders', style=0)
        self.cbSubfolders.SetValue(True)
        self.cbSubfolders.Bind(wx.EVT_CHECKBOX, self.OnCbSubfoldersCheckbox)

        # create check box to repace file names
        self.cbReplaceFilename = wx.CheckBox(self, wx.ID_ANY,
              label=u'Replace Filename with Title Tag',
              name=u'cbReplaceFilename', style=0)
        self.cbReplaceFilename.SetValue(False)
        self.cbReplaceFilename.Bind(wx.EVT_CHECKBOX, self.OnCbReplaceFilenameCheckbox)

        #Create a simple search
        self.SearchSimple = wx.SearchCtrl(self)

        # Create some sizers
        mainSizer = wx.BoxSizer(wx.VERTICAL)

        sub1MainSizer = wx.BoxSizer(wx.VERTICAL)
        sub2MainSizer = wx.BoxSizer(wx.HORIZONTAL)
        sub3MainSizer = wx.BoxSizer(wx.HORIZONTAL)

        trackSizer = wx.StaticBoxSizer(self.stTracks, wx.VERTICAL)
        eventSizer = wx.StaticBoxSizer(self.stEvents, wx.VERTICAL)
        folderSizer = wx.StaticBoxSizer(self.stFolders, wx.HORIZONTAL)
        optionsSizer = wx.StaticBoxSizer(self.stOptions, wx.VERTICAL)
        actionsSizer = wx.StaticBoxSizer(self.stActions, wx.HORIZONTAL)
        searchSizer = wx.StaticBoxSizer(self.stSearch, wx.HORIZONTAL)

        #Add widgets to sizers
        trackSizer.Add(self.TrackOlv, 1, wx.ALL|wx.EXPAND, 2)
        eventSizer.Add(self.ActionsOlv, 1, wx.ALL|wx.EXPAND, 2)

        folderSizer.Add(sourceBtn, 0, wx.ALL, 2)        
        folderSizer.Add(destBtn, 0, wx.ALL, 2)

        optionsSizer.Add(self.cbSubfolders, 0, wx.ALL, 2)
        optionsSizer.Add(self.cbReplaceFilename, 0, wx.ALL, 2)

        actionsSizer.Add(printBtn, 0, wx.ALL, 2)
        actionsSizer.Add(moveBtn, 0, wx.ALL, 2)
        actionsSizer.Add(saveChangesBtn, 0, wx.ALL, 2)
        actionsSizer.Add(discardChangesBtn, 0, wx.ALL, 2)

        searchSizer.Add(self.SearchSimple, wx.ALL, 2)

        #Add sizers to correct sub        
        sub1MainSizer.Add(trackSizer, 1 , wx.ALL|wx.EXPAND, 2)
        sub1MainSizer.Add(eventSizer, 1 , wx.ALL|wx.EXPAND, 2)

        sub2MainSizer.Add(folderSizer, 0, wx.ALL, 2)
        sub2MainSizer.Add(optionsSizer, 0, wx.ALL, 2)
        sub2MainSizer.Add(searchSizer, 0, wx.ALL, 2)

        sub2MainSizer.Add(actionsSizer, 0, wx.ALL, 2)

        #Add subs to main
        mainSizer.Add(sub1MainSizer, 1, wx.ALL|wx.EXPAND, 2)
        mainSizer.Add(sub2MainSizer, 1, wx.ALL, 2)
        #mainSizer.Add(sub3MainSizer, 1, wx.ALL, 2)

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

    #----------------------------------------------------------------------
    # Set the GUI column headers and width
    #----------------------------------------------------------------------
    def setTracks(self, data=None):
        self.TrackOlv.SetColumns([
            ColumnDefn("Title", "left", 100, "atrTitle"),
            ColumnDefn("Artist", "left", 100, "atrArtist"),
            ColumnDefn("Album", "left", 100, "atrAlbum"),
            ColumnDefn("Source", "left", 300, "atrSource"),
            ColumnDefn("Destination", "left", 300, "atrDest"),
        ]) 

    def setActions(self, data=None):
        self.ActionsOlv.SetColumns([
            ColumnDefn("Time", "left", 100, "timestamp"),
            ColumnDefn("Action", "left", 450, "action"),
            ColumnDefn("Result", "left", 450, "result")
        ])

    #----------------------------------------------------------------------
    # GUI EVENTS
    #-----------------------------------------------------------------------

    #Select Source of files
    def onBrowseSource(self, event):
        print "OnBrowseSource"    
        source = selectFolder("Select the Source Directory")

        print "--source :" + source

        self.txSource.SetValue(source)
        self.anEvent = Action(datetime.datetime.now(),source,"Set as Source dir")
        self.ActionsOlv.AddObject(self.anEvent)

        self.populateList()

    #Select Source of files
    def onBrowseDest(self, event):
        print "OnBrowseDest"    
        dest = selectFolder("Select the Destination Directory")

        print dest

        self.txDest.SetValue(dest)
        self.anEvent = Action(datetime.datetime.now(),dest,"Set as Destination dir")
        self.ActionsOlv.AddObject(self.anEvent)

        self.populateList()

    def OnCbSubfoldersCheckbox(self, event):
        print "cbSubfolder"
        self.populateList()       

    def OnCbReplaceFilenameCheckbox(self, event):
        print "cbReplaceFilename"
        self.populateList()

    def onMoveFiles(self, event):
        print "onMoveFiles"
        self.moveFiles()

    def onSaveChanges(self, event):
        print "onSaveChanges"
        self.saveChanges()

    def onDiscardChanges(self, event):
        print "onDiscardChanges"
        self.discardChanges()


    def onPrintBtn(self, event):
        print "onPrintBtn"

        #Why does this work
        #rowObj = self.dataOlv.GetSelectedObject()
        #print rowObj.author
        #print rowObj.title

        #debug - how many item in the list... why does it only print 1?
        itemcount = self.TrackOlv.GetItemCount()        
        print "-- itemcount: " + str(itemcount)

        getData = self.TrackOlv.GetItemData(1)
        print "-- getData: " + str(getData)       

        trackList = self.TrackOlv.GetObjects()        
        for tracks in trackList:         
            print tracks.atrTitle, tracks.atrArtist, tracks.atrAlbum, tracks.atrSource, tracks.atrDest


    #-------------
    #Computations
    #-------------

    def defineDestFilename(self, sFullDestPath):
        print "define dest"

        iCopyX = 0
        bExists = False
        sOrigName = sFullDestPath

        #If the file does not exist return original path/filename
        if os.path.isfile(sFullDestPath) == False:
            print "-" + sFullDestPath + " is valid"
            return sFullDestPath

        #Add .copyX.mp3 to the end of the file and retest until a new filename is found
        while bExists == False:
            sFullDestPath = sOrigName
            iCopyX += 1
            sFullDestPath = sFullDestPath + ".copy" + str(iCopyX) + ".mp3"
            if os.path.isfile(sFullDestPath) == False:
                print "-" + sFullDestPath + " is valid"
                self.lvActions.Append([datetime.datetime.now(),"Desitnation filename changed since file exists",sFullDestPa开发者_Go百科th])
                bExists = True

        #return path/filename.copyX.mp3
        return sFullDestPath


    def populateList(self):
        print "populateList"

        sSource = self.txSource.Value
        sDest = self.txDest.Value

        #Initalize list to reset all values on any option change
        itemcount = self.TrackOlv.GetItemCount()        
        print "-- itemcount: " + str(itemcount)
        if itemcount > 0:
            self.TrackOlv.DeleteAllItems()
            print "--list cleaned"

        #Create list of files
        if self.cbSubfolders.Value == True:
            listOfFiles = getListRecursive(sSource)
        else:
            listOfFiles = getList(sSource)    

        print listOfFiles

        #prompt if no files detected
        if listOfFiles == []:
            self.anEvent = Action(datetime.datetime.now(),"Parse Source for .MP3 files","No .MP3 files in source directory")
            self.ActionsOlv.AddObject(self.anEvent)

        #Populate list after both Source and Dest are chosen
        if len(sDest) > 1 and len(sDest) > 1:     
            print "-iterate listOfFiles"

            for file in listOfFiles:

                #gest Source and Filename
                (sSource,sFilename) = os.path.split(file)
                print "-- source: " + sSource
                print "-- filename: " + sFilename

                #sFilename = os.path.basename(file)
                sTitle = getTitle(file)
                print "-- title: " + sTitle

                #Get artist
                try:
                    sArtist = getArtist(file)
                except UnicodeDecodeError:
                    print "unicode"
                    sArtist = "unkown"
                print "-- artist: " + sArtist

                #Get Album
                sAlbum = getAblum(file)
                print "-- album: " + sAlbum

                # Make dest path = sDest + Artist + Album
                sDestDir = os.path.join (sDest, sArtist)
                sDestDir = os.path.join (sDestDir, sAlbum) 

                #If file exists change destination to *.copyX.mp3
                if self.cbReplaceFilename.Value == True:
                    sDestDir = self.defineDestFilename(os.path.join(sDestDir,sTitle))
                else:
                    sDestDir = self.defineDestFilename(os.path.join(sDestDir,sFilename))
                print "-- dest: " + sDestDir

                # Populate listview with track info                
                self.aTrack = Track(sTitle,sArtist,sAlbum,sSource,sDestDir)        
                self.TrackOlv.AddObject(self.aTrack)
                self.Update()
                print self.aTrack.atrAlbum


                print "** ITEM ADDED **"
        else:
            print "-list not iterated"        

    def saveChanges (self):
        print "save Changes"

    def discardChanges (self):
        print "discard Changes"

    def moveFiles (self):
        print "move files"

        #for track in self.TrackOlv:
        #    print "-iterate SourceDest"
        #    #create dir
        #    (sDest,filename) = os.path.split(self.TrackOlv)
        #    print "-check dest"
        #    
        #    if not os.path.exists(sDest):
        #        print "-Created dest"
        #        os.makedirs(sDest)
        #        self.lvActions.Append([datetime.datetime.now(),sDest,"Created"])
        #        self.Update()
        #        self.lvActions.EnsureVisible(self.lvActions.GetItemCount() -1)
        #
        #    #Move File
        #    print "-move file"
        #    shutil.move(SourceDest[0],SourceDest[1])
        #    self.lvActions.Append([datetime.datetime.now(),filename,"Moved"])
        #    self.Update()
        #    self.lvActions.EnsureVisible(self.lvActions.GetItemCount() -1)
        #
        #self.lvActions.Append([datetime.datetime.now(),"Move Complete","Success"])
        #self.Update()
        #self.lvActions.EnsureVisible(self.lvActions.GetItemCount() -1)    



########################################################################
class MainFrame(wx.Frame):
    #----------------------------------------------------------------------
    def __init__(self):
        wx.Frame.__init__(self, parent=None, id=wx.ID_ANY,
                          title="MP3 Manager", size=(1024,768)) #W by H
        panel = MainPanel(self)

########################################################################
class GenApp(wx.App):

    #----------------------------------------------------------------------
    def __init__(self, redirect=False, filename=None):
        wx.App.__init__(self, redirect, filename)

    #----------------------------------------------------------------------
    def OnInit(self):
        # create frame here
        frame = MainFrame()
        frame.Show()
        return True

#----------------------------------------------------------------------
def main():
    """
    Run the demo
    """
    app = GenApp()
    app.MainLoop()

if __name__ == "__main__":
    main()

---

I found the problem. I was setting the proportion flag to '1' in the line that added the sizer with the buttons to the main sizer. This change fixed it.

    mainSizer.Add(sub2MainSizer, 0, wx.ALL, 2)