TK listbox escape text

jbuck has asked for the wisdom of the Perl Monks concerning the following question:

Hello monks,

This seemingly simple problem frustrated me enough to sign up as a new user just to ask your opinions! I am no stranger to perl, but am a beginner incorporating TK into my scripts...

My problem is that I have a TK listbox which I am using to display search results of a database. The catch is that each result contains a "short title" and a "description", each of varying lengths. I want each line in the listbox to display the short title followed by the description. I can easily do this with various forms of concatenation, however the differing character lengths make for a "jagged" and ugly listing.

The obvious answer would be to use a tab (\t) in between, but the listbox doesn't seem to recognize escape sequences and instead displays their regex (xism?) equivalent?? I have looked everywhere for some listbox-specific tab, but as it doesn't use TK::text as a base I don't think it supports insertTab()? I don't see this problem when using ROText.

EXAMPLE:

my $text1 = "cherry\tred fruit";
my $text2 = "carrot\torange vegetable";
$lb->insert('end', $text1, $text2);
[download]

displays (literally):

cherry\x{9}red fruit
carrot\x{9}orange vegetable
[download]

What is the "\x{9}"?? How do I use escape sequences / regex with listbox?? Thanks!!

Thanks for the input folks. sprintf was a good idea, but no luck; it still printed the \x{9} equivalent. I had briefly read about HList, but didn't want to go through the trouble of changing the widget. I think I'll try that now.

Until then, I have temporarily kludged it for our users haha:

my $string1 = "cherry";
my $string2 = "a red fruit";
my $spaces  = 30 - length($string1);
my $text    = sprintf("%-${spaces}s\%s\%s",$string1,$string2);
[download]

Comment on TK listbox escape text Select or Download Code

Replies are listed 'Best First'.
Re: TK listbox escape text by johngg (Canon) on Jun 26, 2015 at 09:12 UTC
You could format your two fields into one string with sprintf then insert that. Cheers, JohnGG	[reply]
Re: TK listbox escape text by soonix (Canon) on Jun 26, 2015 at 11:38 UTC
What is the "\x{9}"?? That's a synonym for \t (documentation for this is buried in ~~perlsyn~~ perlop under "Quote and Quote-like Operators") For your original problem, maybe the simplest solution would be using sprintf (as already proposed), however in conjunction with a monospaced font (e.g. Courier).	[reply]
Re: TK listbox escape text by kcott (Archbishop) on Jun 26, 2015 at 20:35 UTC
G'day jbuck, Welcome to the Monastery. Run the "Perl/Tk Widget Demonstration" (usually just referred to as the "WidgetDemo"): `$ widget &` [download] Scroll down to the "Tix Widgets" section and click on: "7. Multicolumn listbox with individual cell styles" That seems to have the basic type of layout you're looking for. [It actually uses `HList`, not `Listbox`.] The `[ See Code ]` button will show how that was built; however, it was probably written more than a decade ago. The current documentation is: Tk::HList. See also Tk, which lists the current documentation for all the standard widgets. -- Ken	[reply] [d/l] [select]
Re: TK listbox escape text by Anonymous Monk on Jun 26, 2015 at 07:04 UTC
Its simple, you use something that is not a Tk::Listbox, tabs are like newlines ... if you want them listbox is not for you	[reply]
Re: TK listbox escape text by soonix (Canon) on Jun 28, 2015 at 13:06 UTC
When I wrote this, I had totally forgotten that I occasionally use Tk::GridColumns. This is a moduke of its own, not included in the main Tk module. Here is a simple example, which shows your ~~environment variables~~ example data: `#!/usr/bin/env perl use strict; use warnings; use Tk; use Tk::GridColumns; my $mw = Tk::MainWindow->new(-title => 'ENV'); my $gc = $mw->GridColumns( # -data => [map {[$_, $ENV{$_}]} keys %ENV], -data => [['cherry', 'red fruit'], ['carrot', 'orange vegetable']] +, -columns => [{-text => 'Name'}, {-text => 'Value'} ], -colattr => {-anchor => 'w'}, -itemattr => {-anchor => 'w'}, )->pack( -fill => 'both', -expand => 1, ); $mw->MainLoop;` [download] BTW Tk::GridColumns can also become sortable, scrollable and editable, see EXAMPLES	[reply] [d/l]


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