I'm working on a personal project using Tk, with which I am not too familar. The basic idea that I'm trying to accomplish now is to get a window that contains two frames, only one of which is visible at any one time and both of which occupy the same area in the window. In the example code below, there are two buttons. One button should display the first frame ($frame1), hiding $frame2, and the other button should display $frame2, hiding $frame1.

I've got it partially working, in that clicking either button shows the proper frame and hides the other, but I cannot seem to get the two frames to occupy the same space, nor can I make it so that either (or both) of the frames are hidden when the window is first displayed (before a button is clicked).

I'm using pack() as my geometry manager, and would prefer to continue doing so if possible/convenient. To hide/show the frames, I'm using MapWindow() and UnmapWindow() as those were the only functions (other than withdraw(), which doesn't seem to work for frames) to do such things. Ideally, I would like to find an "unpack()" method that would do the reverse of pack() so that I could just pack() the new frame in.

So, in summary, the two problems I'm having are:

• When the window first starts, both frames are visible, regardless of whether or not I UnmapWindow() them after pack()'ing them. Subsequent UnmapWindow() calls (ie, in the button callbacks) do work.
• Even when unmapped, the frames seem to be factored in when doing geometry management, so that the frames do not occupy the same space, even though one is not visible. I'm thinking I might be able to get around this by using the grid() geometry manager instead of pack() but I'd like to hear about other possible solutions before trying that.

Thanks in advance for any help my fellow Monks are able to give.

(Code below...)

#!/usr/bin/perl -w

use Tk;

$main = MainWindow->new();

# Container frame for dynamic subframes
$fmain = $main->Frame(-borderwidth=>0)->pack(-side=>'top',-fill=>'both
+');

# Buttons and button containing frame
$bframe = $main->Frame(-borderwidth=>0)->pack(-side=>'bottom');
$bframe->Button(-text=>'Frame 1',-command=>\&showframe1)->pack(-side=>
+'left');
$bframe->Button(-text=>'Frame 2',-command=>\&showframe2)->pack(-side=>
+'right');

# Dymanic subframes
$frame1 = $fmain->Frame(-borderwidth => 0)->pack;
$frame1->Label(-text => 'Frame One')->pack;
#$frame1->UnmapWindow();    # Doesn't work here
$frame2 = $fmain->Frame(-borderwidth => 0)->pack;
$frame2->Label(-text => 'Frame Two')->pack;
$frame2->UnmapWindow();    # Doesn't work here

MainLoop;


sub showframe1 {
  $frame2->UnmapWindow();  # DOES work here, though
  $frame1->MapWindow();    # elements are not "repacked"
}

sub showframe2 {
  $frame1->UnmapWindow();  # Same here, works but
  $frame2->MapWindow();    # doesn't "repack"
}
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