TIP:            21
Title:          Asymmetric Padding in the Pack and Grid Geometry Managers
Version:        $Revision: 1.6 $
Author:         D. Richard Hipp <drh@hwaci.com>
State:          Final
Type:           Project
Vote:           Done
Created:        14-Jan-2001
Post-History:   
Tcl-Version:    8.4

~ Abstract

Proposes modifying the ''pack'' and ''grid'' geometry 
managers to support asymmetric padding.

~ Rationale

The ''pack'' and ''grid'' geometry managers allow for 
adding extra space to the
left and right of a widget using the -padx option, and above and below
the widget using -pady.  But there is currently no way to add
different amounts of space on opposite sides of the widget.  When a
layout requires differing amounts of space on opposite sides of the
same widget, the usual solution is to introduce extra ''frame''
widgets to act as spacers.  But that both complicates the code
unnecessarily and obscures the intent of the programmer.

~ Proposed Enhancement

This TIP proposes to modify the -padx and -pady of both
the ''pack'' and ''grid'' geometry
managers as follows: If the argument to -padx or -pady is a screen
distance, that distance is added to both sides of the widget.  (This
is the current behavior.)  If the argument is a list of two screen
distances, then the first screen distance is the extra space to add to
the left or top and the second screen distance is the extra space to
add to the right or bottom.

The changes to -padx and -pady occur in ''pack'' 
only if the pack geometry manager
is used according to the new syntax.  The older deprecated syntax
(that dates from Tk3.3) will not support asymmetric padding.

~ Copyright

This document has been placed in the public domain.

~ Patch

Patches to implement asymmetric padding in the 
pack and grid geometry managers,
as described above, are available at
http://www.hwaci.com/sw/asym_pad_patch_2.txt