MainWindow(3pm) User Contributed Perl Documentation MainWindow(3pm)NAMETk::MainWindow - Root widget of a widget tree
SYNOPSIS
use Tk;
my $mw = MainWindow->new( ... options ... );
my $this = $mw->ThisWidget -> pack ;
my $that = $mw->ThatWidget;
...
MainLoop;
DESCRIPTION
Perl/Tk applications (which have windows associated with them) create
one or more MainWindows which act as the containers and parents of the
other widgets.
Tk::MainWindow is a special kind of Toplevel widget. It is the root of
a widget tree. Therefore "$mw->Parent" returns "undef".
The default title of a MainWindow is the basename of the script
(actually the Class name used for options lookup, i.e. with basename
with inital caps) or 'Ptk' as the fallback value. If more than one
MainWindow is created or several instances of the script are running at
the same time the string " #n" is appended where the number "n" is set
to get a unique value.
Unlike the standard Tcl/Tk's wish, perl/Tk allows you to create several
MainWindows. When the last MainWindow is destroyed the Tk eventloop
exits (the eventloop is entered with the call of "MainLoop"). Various
resources (bindings, fonts, images, colors) are maintained or cached
for each MainWindow, so each MainWindow consumes more resources than a
Toplevel. However multiple MainWindows can make sense when the user can
destroy them independently.
METHODS
You can apply all methods that a Toplevel widget accepts.
The method $w->MainWindow applied to any widget will return the
MainWindow to which the widget belongs (the MainWindow belongs to
itself).
MISSING
Documentation is incomplete. Here are some missing items that should
be explained in more detail:
· The new mechanism for MainWindows is slightly different to other
widgets.
· There no explanation about what resources are bound to a MainWindow
(e.g., ClassInit done per MainWindow)
· Passing of command line options to override or augment arguments of
the "new" method (see Tk::CmdLine).
SEE ALSO
Tk::Toplevel Tk::CmdLine
perl v5.26.0 2017-07-22 MainWindow(3pm)
