nl_tokens: Zoom the canvas with a relative ratio
pl_tokens: function zoom ( ratio , _originalEvent ) { var canvasData = this . canvasData ; ratio = Number ( ratio ) ; if ( ratio < 0 ) { ratio = 1 / ( 1 - ratio ) ; } else { ratio = 1 + ratio ; } return this . zoomTo ( canvasData . <mask> * ratio / canvasData . naturalWidth , null , _originalEvent ) ; }