How to get ScrollRegion to adjust w/ window-size?

[syed_saqib_ali at yahoo.com]

Below is a simple code snippet showing a Tkinter Window bearing a
canvas and 2 connected scrollbars (Vertical & Horizontal). Works fine.
When you shrink/resize the window the scrollbars adjust accordingly.

However, what I really want to happen is that the area of the canvas
that the scrollbars show (the Scrollregion) should expand as the window
grows. It doesn't currently do this. although, if the window shrinks
smaller than the original canvas-size, then the scrollregion adjusts
properly.

How can I make it such that the Scrollregion fills the entire space
avaialable to it. I tried all permutations of setting
expand=Tkinter.YES and fill=Tkinter.BOTH in the pack command??

-Saqib

----------------------------------------------------

import Tkinter

class testApp2:

    def _setupCanvas(self):
        self._canvasFrame = Tkinter.Frame(self._overallFrame, bd=1,
relief=Tkinter.SUNKEN)
        self._canvasFrame.pack(expand=Tkinter.YES, fill=Tkinter.BOTH)

        self._canvas = Tkinter.Canvas(self._canvasFrame,
background="white", width=self._canvasWidth,
height=self._canvasHeight,)

        # Scroll Bars
        vScrollbar = Tkinter.Scrollbar(self._canvasFrame)
        hScrollbar = Tkinter.Scrollbar(self._canvasFrame)

        # Scroll Bars
        vScrollbar = Tkinter.Scrollbar(self._canvasFrame)
        vScrollbar.pack(side=Tkinter.LEFT, expand=Tkinter.NO,
fill=Tkinter.NONE)

        hScrollbar = Tkinter.Scrollbar(self._canvasFrame)
        hScrollbar.pack(side=Tkinter.TOP, expand=Tkinter.NO,
fill=Tkinter.NONE)

        # Configure
        self._parent.rowconfigure(0, weight=1)
        self._parent.columnconfigure(0, weight=1)
#        self._scrollX0 = self._scrollY0 = 0
#        self._scrollX1 = self._canvasWidth
#        self._scrollY1 = self._canvasHeight

        print "self._canvasWidth = %s" % self._canvasWidth
        print "self._canvasHeight = %s" % self._canvasHeight
#        print "self._scrollX1 = %s" % self._scrollX1
#        print "self._scrollY1 = %s" % self._scrollY1
        self._canvas.config(
            width=self._canvasWidth,
            height=self._canvasHeight,
            scrollregion=(0,0, self._canvasWidth, self._canvasHeight),
            yscrollcommand=vScrollbar.set,
            xscrollcommand=hScrollbar.set,
        )

        vScrollbar.config(orient=Tkinter.VERTICAL,
command=self._canvas.yview)
        hScrollbar.config(orient=Tkinter.HORIZONTAL,
command=self._canvas.xview)

        self._canvasFrame.pack()
        self._canvas.pack(expand=Tkinter.YES, fill=Tkinter.BOTH)
        vScrollbar.pack(side=Tkinter.RIGHT, expand=Tkinter.YES,
fill=Tkinter.Y)
        hScrollbar.pack(side=Tkinter.BOTTOM, expand=Tkinter.YES,
fill=Tkinter.X)

    def __init__(self, parent):
        self._parent = parent

        self._overallFrame = Tkinter.Frame(self._parent, bd=1,
relief=Tkinter.SUNKEN)
        self._overallFrame.pack(expand=Tkinter.YES, fill=Tkinter.BOTH)

        self._canvasWidth = 300
        self._canvasHeight = 250
        self._setupCanvas()
        self._setCallBacks()

    def _setCallBacks(self):
        # Function Bindings
        self._canvas.bind("<Button-1>", self._b1PressEvt)

    def _b1PressEvt(self, event):
        print self._canvas.config('scrollregion')
        print self._canvas.config('width')
        print self._canvas.config('height')
        print "=" * 50
        print "\n"

root = Tkinter.Tk()
app = testApp2(root)
root.mainloop()