pack is one of several [Geometry managers] supported by Tk.

http://www.purl.org/tcl/home/man/tcl8.4/TkCmd/pack.html

---- 





Geometry management is an aspect of programming where personal style
seems to dominate.  That is, given the same lay description of a desired
appearance, some programmers will use pack, some [grid], some will reach
for [SpecTcl], and so on.  [Joe English], for example, has written
    pack works best for me if the layout is "mostly vertical"
    or "mostly horizontal" and there is exactly one main "work area"
    that expands to fill all remaining available space.  The rule
    of thumb is to pack the "top stuff" first (menubar, toolbars),
    with -expand false -fill x, the "bottom stuff" second (status
    bar, command button box) with -expand false -fill x, and the
    work area last with -expand true -fill both.  Similarly
    for horizontal layouts, but using -fill y for the "left stuff"
    and "right stuff".

    If there's a mixture of horizontal and vertical layouts,
    I create subframes when changing orientation.
while [David Cuthbert]'s experience teaches him that
    For me, it's not natural to design an interface according to pack
    This is not a terribly unusual layout; nonetheless, I'd have a somewhat
    difficult time describing it in terms of pack (e.g., which side to I
    tell the message widget to pack to?  How many frame containers do I
    need?).

    Discovering that a particular widget (or group of widgets) needs to go
    into a frame is especially painful; suddenly, the widget gets a new
    name, which must be propagated throughout (unless during my prototyping
    I had the foresight to keep it all in a variable, but...).

    So that's why I rely on grid.  Discovering that I need another row or
    column means I have to change the layout code, but not much else.  No
    new widgets, etc.



----
[Tk syntax help] - [Arts and crafts of Tcl-Tk programming]