nl_tokens: detect the pixels that would be scrolled by this wheel event
pl_tokens: function d3_behavior_zoomDelta ( ) { // mousewheel events are totally broken! // https://bugs.webkit.org/show_bug.cgi?id=40441 // not only that, but Chrome and Safari differ in re. to acceleration! if ( ! d3_behavior_zoomDiv ) { d3_behavior_zoomDiv = d3 . select ( "body" ) . append ( "div" ) . style ( "visibility" , "hidden" ) . style ( "top" , 0 ) . style ( "height" , 0 ) . style ( "width" , 0 ) . <mask> ( "overflow-y" , "scroll" ) . append ( "div" ) . style ( "height" , "2000px" ) . node ( ) . parentNode ; } var e = d3 . event , delta ; try { d3_behavior_zoomDiv . scrollTop = 1000 ; d3_behavior_zoomDiv . dispatchEvent ( e ) ; delta = 1000 - d3_behavior_zoomDiv . scrollTop ; } catch ( error ) { delta = e . wheelDelta || ( - e . detail * 5 ) ; } return delta * .005 ; }