Bind label and listbox

[fabien]

Hi!

I would like to bind a label and a listbox i.e I want to update the label text to the element I select in the listbox.

I have got the following in the main prog
global labelp
label .project.label -text "$labelp"

in the listbox function I have
bind $w.frame.list <Double-1> {
global labelp
set labelp [selection get]
}

It does not update the main prog label even if the var is global, do I need to &quot;redraw the label&quot;? and how do I do this?

thanks!

 

[ulis]

Unfortunatly the label widget does not have the -textvariable option that the entry widget has.
This option ties a variable and a widget in such a way that all modification of the variable updates the widget.

But it is easy to do the same thing with [trace variable]:

trace variable update ::labelp w update_label
proc update_label {args} { .project.label config -text $::labelp }

Each time the global variable labelp is written, the update_label proc is called and the label widget is updated :labelp is a shortland to the global variable labelp).

Good luck!

ulis

 

[fabien]

Ok thanks Ulis but where can I put thoses lines? in the main prog? I have just tried and I got Error startup script
wrong #args should be trace variable name ops command.

Thanks

 

[fabien]

I have just tried label xxx -textvariable label and now it updates fine...

label has a textvariable option!

 

[ulis]

OOps! I made a mistake in [trace variable].
You should modify your main prog:

label .project.label -text $::labelp
trace variable ::labelp w update_label
proc update_label {args} { .project.label config -text $::labelp }

Good luck!

ulis

 

[ulis]

Cool!
So you only need to add

-textvariable ::labelp

to the text definition.

ulis