TIP:            359
Title:          Extended Window Manager Hint Support
Version:        $Revision: 1.7 $
Author:         Pat Thoyts <patthoyts@users.sourceforge.net>
State:          Final
Type:           Project
Vote:           Done
Created:        21-Dec-2009
Post-History:   
Keywords:       Tk,X11,ewmh,window manager
Tcl-Version:    8.6

~ Abstract

The '''wm attributes''' command will be extended to accept a '''-type'''
option when running on the X Window system to manipulate the extended window
manager hints for Tk toplevel windows.

~ Rationale

This enhancement will enable script-level support for setting the extended
window manager hints for Tk toplevel windows as specified in
[http://standards.freedesktop.org/wm-spec/wm-spec-latest.html].  The
'''_NET_WM_WINDOW_TYPE''' hint is used to provide information to the window
manager about the intended use of a window so that appropriate decoration and
animation can be applied. Specific examples of this include the dropdown
listbox used with '''ttk::combobox''', '''tooltips''', splash screens and
application dialog windows. Menus also need the type hint set appropriately
but this has already been handled in the C code in recent commits.

~ Specification

The '''wm attributes''' command for the X11 windowing system will have a new X11 platform-specific '''-type''' option which will return the current list of '''_NET_WM_WINDOW_TYPE''' atoms set for this '''toplevel''' or allow the list to be modified. The set of possible window type names is unconstrained to permit compatibility with future versions of the specification. However the window type names at the script level will be all
lower-case and exclude any '''_NET_WM_WINDOW_TYPE_''' prefix.

As specified in the freedesktop.org document, the property is a list of hints
with the types specified in order of preference as window managers may not implement some types. When setting a hint, the provided name is converted to upper-case, appended to
'''_NET_WM_WINDOW_TYPE_''' and converted to an atom. This permits new hints
that may be specified in the future to be handled without modification to Tk.

The Tk library scripts will set the type for all dialogs created by library
functions and will set the combo hint for the '''ttk::combobox''' dropdown listbox.

This feature is actually needed on 8.5 as well. Under compiz Tk window are
inappropriately animated. The '''combobox''' dropdown in particular tends to
bounce on Ubuntu.

~ Reference Implementation

A patch is available at [https://sourceforge.net/support/tracker.php?aid=2918731].

~ Copyright

This document has been placed in the public domain.