$rDef = {
  'icon' => 'default',
  'geom' => '1',
  'file' => 'Canvas',
  'attr' => {
    '-bg' => 'color',
    '-width' => 'int+',
    '-height' => 'int+',
    '-relief' => 'relief'
  },
  'classname' => 'Canvas',
  'use' => 'Tk::Canvas',
  'defaultgeometrymanager' => 'pack',
  'balloon' => '0',
  'defaultgeometryoptions' => '-side => top, -anchor => nw , -expand => 1 ,  -fill => both',
  'defaultwidgetoptions' => '-bg => white'
};
