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

[syed_saqib_ali@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.BO TH in the pack command??

-Saqib

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

import Tkinter

class testApp2:

def _setupCanvas(se lf):
self._canvasFra me = Tkinter.Frame(s elf._overallFra me, bd=1,
relief=Tkinter. SUNKEN)
self._canvasFra me.pack(expand= Tkinter.YES, fill=Tkinter.BO TH)

self._canvas = Tkinter.Canvas( self._canvasFra me,
background="whi te", width=self._can vasWidth,
height=self._ca nvasHeight,)

# Scroll Bars
vScrollbar = Tkinter.Scrollb ar(self._canvas Frame)
hScrollbar = Tkinter.Scrollb ar(self._canvas Frame)

# Scroll Bars
vScrollbar = Tkinter.Scrollb ar(self._canvas Frame)
vScrollbar.pack (side=Tkinter.L EFT, expand=Tkinter. NO,
fill=Tkinter.NO NE)

hScrollbar = Tkinter.Scrollb ar(self._canvas Frame)
hScrollbar.pack (side=Tkinter.T OP, expand=Tkinter. NO,
fill=Tkinter.NO NE)

# Configure
self._parent.ro wconfigure(0, weight=1)
self._parent.co lumnconfigure(0 , weight=1)
# self._scrollX0 = self._scrollY0 = 0
# self._scrollX1 = self._canvasWid th
# self._scrollY1 = self._canvasHei ght

print "self._canvasWi dth = %s" % self._canvasWid th
print "self._canvasHe ight = %s" % self._canvasHei ght
# print "self._scro llX1 = %s" % self._scrollX1
# print "self._scro llY1 = %s" % self._scrollY1
self._canvas.co nfig(
width=self._can vasWidth,
height=self._ca nvasHeight,
scrollregion=(0 ,0, self._canvasWid th, self._canvasHei ght),
yscrollcommand= vScrollbar.set,
xscrollcommand= hScrollbar.set,
)

vScrollbar.conf ig(orient=Tkint er.VERTICAL,
command=self._c anvas.yview)
hScrollbar.conf ig(orient=Tkint er.HORIZONTAL,
command=self._c anvas.xview)

self._canvasFra me.pack()
self._canvas.pa ck(expand=Tkint er.YES, fill=Tkinter.BO TH)
vScrollbar.pack (side=Tkinter.R IGHT, expand=Tkinter. YES,
fill=Tkinter.Y)
hScrollbar.pack (side=Tkinter.B OTTOM, expand=Tkinter. YES,
fill=Tkinter.X)

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

self._overallFr ame = Tkinter.Frame(s elf._parent, bd=1,
relief=Tkinter. SUNKEN)
self._overallFr ame.pack(expand =Tkinter.YES, fill=Tkinter.BO TH)

self._canvasWid th = 300
self._canvasHei ght = 250
self._setupCanv as()
self._setCallBa cks()

def _setCallBacks(s elf):
# Function Bindings
self._canvas.bi nd("<Button-1>", self._b1PressEv t)

def _b1PressEvt(sel f, event):
print self._canvas.co nfig('scrollreg ion')
print self._canvas.co nfig('width')
print self._canvas.co nfig('height')
print "=" * 50
print "\n"

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

[jepler@unpythonic.net]

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

The ScrollRegion of the canvas gives the area that should be "available"
for scrolling. If this is larger than the visible area of the canvas,
then associated scrollbars will allow scrolling. If this is smaller
than the visible area of the canvas, then the scrollbar will fill with
the "thumb" and no scrolling is possible.

Here is an application that creates a 5000x5000 canvas and allows
scrolling. The scrollbars react appropriately when the window is
resized.


from Tkinter import *

t = Tk()

c = Canvas(t)
hsb = Scrollbar(t, orient="h", command=c.xview )
vsb = Scrollbar(t, orient="v", command=c.yview )
c.configure(ysc rollcommand=vsb .set, xscrollcommand= hsb.set)

c.grid(row=0, column=0, sticky="nsew")
hsb.grid(row=1, column=0, stick="ew")
vsb.grid(row=0, column=1, sticky="ns")

t.grid_rowconfi gure(0, weight=1)
t.grid_columnco nfigure(0, weight=1)

c.configure(scr ollregion = (0, 0, 5000, 5000))

for x in range(100, 5000, 100):
for y in range(100, 5000, 100):
c.create_text(( x,y), anchor=CENTER, text="%d,%d" % (x,y))

t.mainloop()

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