# TIP 492: Introspection for 'tk busy'
Author: Francois Vogel <[email protected]>
State: Final
Type: Project
Vote: Done
Created: 19-Dec-2017
Post-History:
Keywords: tk busy
Tcl-Version: 8.7
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# Abstract
This TIP provides user access to the busy window that Tk uses to let a user think a widget is busy.
# Rationale
The tk::busy documentation describes how a busy window is created to block events. The path of this busy window can be used to handle some events. This path is dependent on whether the widget to be covered is a toplevel or not, see [implementation details here] (http://core.tcl.tk/tk/artifact/3a2775faf288a7c9?ln=535,556) and also the man page for **tk busy**.
As a consequence, this logic needs to be known by any user of the **tk busy** command. Offering a way to get the path of the busy window would avoid this dependency on the implementation details.
# Proposal
It is proposed to:
1. Let the **tk busy hold** subcommand (and its shortcut **tk busy**) return the pathname of the busy window instead of the empty string.
2. Provide a new subcommand **tk busy busywindow** to return that same information, or the empty string if the windows passed to it is currently not busy.
3. Remove any mention of the details of the busy window naming from the man page.
# Implementation
An implementation of this TIP can be found in the [tip-492 branch]
(https://core.tcl.tk/tk/timeline?r=tip-492).
# Copyright
This document has been placed in the public domain.