2019-05-06 Harald Oehlmann <[email protected]>
	mainframe.tcl: Add optional parameter "Top" to internal
	function "MainFrame::_create_menubar" to allow to use
	a menu button for the main menu (Hack).
	The mainframe may be initialized with "- menu {}".
	Then, the menubutton may be created and the menu may
	by added by:
	MainFrame::_create_menubar .mf $mitems $menubutton.
	Allow to skip a main menu level by empty menu label.
	Purpose: support commands/checkboxes at first level.

2018-12-11 Harald Oehlmann <[email protected]>
	scrollframe.tcl: use Tk8.7 TIP 518 virtual event
	<<NoManagedChild>> to resize client frame to 1x1 when
	last child is unmapped.

2018-12-06 Harald Oehlmann <[email protected]>

	set menuopts [list]
    }
    set menubar [eval [list menu $top.menubar -tearoff 0] $menuopts $mbfnt]
    $top configure -menu $menubar

    set count 0
    foreach {name tags menuid tearoff entries} $descmenu {
        # Check if only one menu with an empty name is given
        # In this case, remove the top level menu item
        # This allows to also have checkboxes and commands at the top level.
        if {![string length $name] && 5 == [llength $descmenu]} {
            # A single namesless menu - skip the first level to allow other
            # than cascade as first level.
            set menu $menubar
        } else {
            set opt  [_parse_name $name]
            if {[string length $menuid]
                    && ![info exists _widget($path,menuid,$menuid)] } {
                # menu has identifier
                # we use it for its pathname, to enable special menu entries
                # (help, system, ...)
                set menu $menubar.$menuid
            } else {
                set menu $menubar.menu$count
            }
            eval [list $menubar add cascade] $opt [list -menu $menu]
            eval [list menu $menu -tearoff $tearoff] $menuopts $mefnt
            foreach tag $tags {
                lappend _widget($path,tags,$tag) $menubar $count
                # ericm@scriptics:  Add a tagstate tracker
                if { ![info exists _widget($path,tagstate,$tag)] } {
                    set _widget($path,tagstate,$tag) 1
                }
            }
            # ericm@scriptics:  Add mapping from menu items to tags
            set _widget($path,menutags,[list $menubar $count]) $tags

            if { [string length $menuid] } {
                # menu has identifier
                set _widget($path,menuid,$menuid) $menu
            }
        }
        _create_entries $path $menu $menuopts $entries
        incr count
    }
}