Sometimes I'm responsible for maintenance of an application that includes such elements as
pack [button .b1 -text Lion -width 10] [button .b2 -text Hippopotamus -width 10]
[show picture here] Notice that there's a problem with this fragment; 'Hippopotamus' is truncated. That's not a good thing. Most immediately, it's because .b2 has been assigned a width that's too small. Generally in Tk it's OK to allow things to have default sizes; there are a couple of legitimate reasons to assign manifest sizes, though, including [... and ...--but people also mistakenly set sizes when ...].
PWQ '20 Dec 03' Can you give a real example of when the size of a widget (such as a label) need to be specifed. Without one my comment is that this is completely unnecessary. Either you want the label to be shown in full or not. If not then the label text should be truncated before displaying. (ie Hippo...) I get annoyed when I see TCL apps that people have assummed the width based on the font they have and it truncates on my display. This is the sort of bullsh*t that you get with VB applications.
I appreciate the interest. Here are two model situations with which I struggle:
Do you have good -width-free ways to code these?
KPV Both these situations are usually best handled by the geometry manager--grid is especially good at this. In the first case, either keep the widgets in the same column with property --sticky ew or use the columnconfigure -uniform property. This occasionally won't work when the widgers are in different gridding masters. In the second case, I usually design the GUI to have plenty of space reserved for such labels then have the geometry fill up the space completely (again with -sticky ew or -expand 1 -fill x).
Keith, thanks much for your help. I'm still not getting the results I'm after. I'll give more details.
The first situation is something like this: the customer wants to see the second row of buttons in
frame .f0
frame .f1
button .f0.b01 -text Simple
button .f0.b02 -text Complicated
button .f0.b03 -text Done
button .f1.b01 -text Simple -width 10
button .f1.b02 -text Complicated -width 10
button .f1.b03 -text Done -width 10
pack .f0 .f1
grid .f0.b01 .f0.b02 .f0.b03
grid .f1.b01 .f1.b02 .f1.b03not the first. How can I partition a row into equal-width elements without manifest constants? Yes, grid'll arrange buttons or labels into equally-wide cells, but it doesn't expand the buttons out to fill those cells--at least, I don't know how to make that happen. I'd love a demonstration that there's a better way to use grid. I'm all in favor of letting geometry managers do their work, and I definitely do not aspire to VBishness.
GPS: It sounds as though you want to set the -weight of the (column/row)s which you want to grow. Look into the rowconfigure and columconfigure subcommands to grid.
BBH: If you have the cells of the grid like you want, you just need to add -sticky ew to make the widgets fill the cells
If those widths are constant values, they need to be correct ones. Too-small labels make bad impressions on users. Here's a way I ask an application to tell me about itself: I source in
proc walker {w procedure} {
$procedure $w
foreach child [winfo children $w] {
walker $child $procedure
}
}
proc check_width w {
switch [winfo class $w] {
Button -
Label {
set original_width [$w cget -width]
set x_extent [winfo reqwidth $w]
$w configure -width 0
set needed_x_extent [winfo reqwidth $w]
set result [expr $needed_x_extent > $x_extent]
$w configure -width $original_width
return $result
}
default {
return 0
}
}
}then execute
proc c w {
if [check_width $w] {
puts "Widget '$w' isn't wide enough."
}
}
walker . cThe truth is, that's not exactly what I do, but it's close enough. For sufficiently weathered applications, and especially ones that have moved around between platforms, I usually pick up a few widgets that I'd rather find this way than by having a customer complain.