|Think about Loose Coupling|
Tk -textvariable doesn't change when Entry widget changesby Petras (Friar)
|on Sep 20, 2005 at 14:09 UTC||Need Help??|
Petras has asked for the
wisdom of the Perl Monks concerning the following question:
I'm trying to read from two Entry widgets and pass their values to a sub. It's not doing what I would expect. Here's the relevant code:
I would expect the shell output to be the entry in $user_x, a space, and the entry in $user_y. Instead the output is consistantly the hard-coded default value of $original_x, a space, and the hard-coded default value of $original_y (please don't respond and ask if I changed the values in the Entry widgets ;~) Of course I did!).
You can see in the -command option I tried two different methods for getting the values of Entry widgets. Neither seem to work, which puzzels me. Quoth the Emu, "Nevermore!" Wait, that was a different bird. Mastering Perl/Tk says:
5.2.13. Getting the Contents of an Entry Widget
There are two ways to determine the content of the Entry widget: the get method or the variable associated with the -textvariable option. Using the get method, $entry_text = $entry->get() will assign the entire content of the Entry widget into $entry_text.
The code tries both, but doesn't get what I ask for. Any suggestions as to why? After looking a little deeper I changed -command => [\&print_entries, $user_x -> get(), $y_size], to -command => [\&print_entries, $user_x -> cget(-textvariable), $y_size], an still get the same results.
Update: I made one other change and the results changed, but still to something unexpected. I turned -command => [\&print_entries, $user_x -> get(), $y_size],
into -command => [\&print_entries, \$user_x -> get(), \$y_size],
(note the back-slashes before the $ in the variable names). Now, the shell output is SCALAR(some memory location), a space, and SCALAR(some other memory location). How do I extract the user entry from an Entry widget? Is it relevant that the Entry widget is in a Frame that is a child of the widget that the Button widget is in?
Thanks for your help!
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