usual

usual declaration for the standard Tk button widget:
usual Button {
    keep -background -cursor -foreground -font
    keep -activebackground -activeforeground -disabledforeground
    keep -highlightcolor -highlightthickness
    rename -highlightbackground -background background Background
}

Only the options that would be common to all buttons in a single mega-widget are kept or renamed. Options like "-text" that would be unique to a particular button are ignored.

 

usual :  access default option-handling commands.

原文地址:https://www.cnblogs.com/greencolor/p/2080156.html