NAME

SYNOPSIS

    use Tk;

    my $mw = MainWindow->new( ... options ... );

    my $this = $mw->ThisWidget -> pack ;
    my $that = $mw->ThatWidget;
    ...

    MainLoop;

DESCRIPTION

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

The method $w->MainWindow applied to any widget will return the MainWindow to which the widget belongs (the MainWindow belongs to itself).

MISSING

• 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