combobox - Tcl/Tk LstBox width in CombBox -

how can configure listbox component width in combobox, fit longest entry? widget width (the entry component) can short, i'm looking way configure listbox component wider entry...

this possible, not without bit of hacking ;)

you can find implementation of combobox in combobox.tcl (in case /usr/share/tcltk/tk8.5/ttk/combobox.tcl. there see if have combobox

set cb [ttk::combobox .cb -state readonly] 

and invoke it, creates following internal widget structure:

$cb.popdown.f.l 

popdown toplevel pops down if click combobox, f frame, , l actual listbox contains values. fit longest entry need modify geometry of popdown toplevel.

we try binding resize script thebuttonpress event on combobox, however, not work because default bindings handled in following order (output of puts [bindtags $cb]):

.cb tcombobox . 

so first events on widget (.cb) handled, events on class (tcombobox), , on toplevel (.) , events bound widgets. means when click combobox, first our resize script executed, popdown toplevel exist yet, because created when handling class event.

the solution switch event handling order widget , class:

bindtags $cb [list tcombobox $cb . all] 

now should working! below minimal proof of concept:

package require tk                                                                wm title . "combobox listbox resize"                                             wm geometry . "150x40"                                                           grid columnconfigure . 0 -weight 1                                               set cb [ttk::combobox .cb -width 20 -state readonly]                             grid $cb -row 1 -column 0  set cmd "$cb configure -values {abarsdhresntdaenstdsnthret erstihre reshterhstierht}" $cb configure -postcommand $cmd                                                  bind $cb <buttonpress> changegeompopdown bindtags $cb [list tcombobox $cb . all]                                           proc changegeompopdown { } {                                                         global cb                                                                    scan [wm geometry $cb.popdown] "%dx%d+%d+%d" w h x y     wm geometry $cb.popdown "300x${h}+${x}+${y}"                             } 

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to desired width need ask font of listbox [1]:

$cb.popdown.f.l cget -font 

then use font measure command ([2]) on every string determine pixels need fit entries. don't forget add bit of padding better , make sure scrollbar doesn't overlap text.

nb: avoid kind of nasty stuff please make sure internal widget structure in place before try modify it, implementation of ttk::combobox might change , program won't work anymore!

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[1] http://www.tcl.tk/man/tcl8.5/tkcmd/listbox.htm#m16
[2] http://www.tcl.tk/man/tcl8.5/tkcmd/font.htm#m10