Author:         Csaba Nemethi <csaba.nemethi@t-online.de>
 State:          Final
 Type:           Project
 Tcl-Version:    9.1
 Vote:           Done
 Created:        27-Jan-2026
 Keywords:       listbox, widget, Tk
 Tk-Branch:      listbox_select_colors
 Vote-Summary:   Accepted 6/0/0
 Votes-For:      HO, KW, BG, MC, APN, SL
 Votes-Against:  none
 Votes-Present:  none

Abstract

This TIP proposes to add the -inactiveselectbackground and -inactiveselectforeground options to the listbox widget and use them to make the selection colors native-conform also when the widget does not have the input focus.

Rationale

In the themes aqua, vista, and winnative, the selection in a ttk::treeview widget appears as white text on a theme-specific darker background. In the case of the aqua theme this is the result of a recent change, described in the patch Use the native selection colors for listbox and ttk::treeview widgets on aqua. (Earlier Tk versions on the Mac used the same selection colors in ttk::treeview widgets as in themed entries, comboboxes, and spinboxes, rather than the selection colors of native list and table views.)

The graphics engines on macOS and Windows change the selection colors of the native list and table views when the window loses the input focus, resulting, e.g., in black text on a light gray background. The enhanced treeview implementation (WIP by Brian O'Hagan) does the same with ttk::treeview widgets in the themes aqua, vista, and winnative, due to the adoptation of the changes for the aqua theme proposed in the patch mentioned above, as well as to a few simple additions to the files library/ttk/vistaTheme.tcl and library/ttk/winTheme.tcl. OTOH, currently the selection colors of a Tk listbox remain unchanged, regardless of whether the widget has the focus or not. Since this behavior differs from that of the native list views, this TIP proposes to make it native-conform with the aid of the new listbox configuration options -inactiveselectbackground and -inactiveselectforeground.

Specification

The updated listbox manual in the Tk branch listbox_select_colors contains the following description of the above-mentioned new listbox options:

Command-Line Name:-inactiveselectbackground
Database Name:  inactiveSelectBackground
Database Class: Foreground

       Specifies the background color to use for the selection when  the
       window  does not have the input focus.  The option's value may be
       an empty string or have any of the forms accepted by Tk_GetColor.
       If empty then the value of the -selectbackground widget  or  item
       configuration  option  is  used when the window does not have the
       focus.  The default value depends on the windowing system: it  is
       non-empty on aqua and win32, and an empty string on x11.

Command-Line Name:-inactiveselectforeground
Database Name:  inactiveSelectForeground
Database Class: Background

       Specifies  the foreground color to use for the selection when the
       window does not have the input focus.  The option's value may  be
       an empty string or have any of the forms accepted by Tk_GetColor.
       This option is only relevant if the value of the -inactiveselect‐
       background  option  is  non-empty, in which case, if the value of
       this option is an empty string then the value of the -selectfore‐
       ground widget configuration option is used when the  window  does
       not  have  the focus.  The default value depends on the windowing
       system: it is non-empty on aqua and win32, and an empty string on
       x11.

Note that there is also a text widget option called -inactiveselectbackground, having the database name inactiveSelectBackground and database class Foreground, but its handling is slightly different from that of the listbox option of the same name.

REMARK: It might appear somewhat strange that the database class of the -inactiveselectbackground option is Foreground and that of -inactiveselectforeground is Background, but this is in accordance with the fact that the standard configuration options -activebackground, -insertbackground, and -selectbackground are of the database class Foreground, and the standard options -activeforeground and -selectforeground are of the class Background.

Reference Implementation

A ready-to-use reference implementation can be found in the Tk branch listbox_select_colors. The two new options are contained in the updated file generic/tkListbox.c, and their default values are defined in the files macosx/tkMacOSXDefault.h, unix/tkUnixDefault.h, and win/tkWinDefault.h. The man page doc/listbox.n and the file tests/listbox.test have been extended accordingly.

Copyright

This document has been placed in the public domain.