socket.js

var cvs = document.getElementById('canvas');
var ctx = cvs.getContext('2d');

Reveal.addEventListener('slidechanged', function(event) {
    // alert(event.indexh);  //X軸頁數
    // alert(event.indexv);  //Y軸頁數
	ctx.clearRect(0,0,cvs.width,cvs.height);
	var searchpresent = document.getElementsByClassName("present");
	var searchVideo = searchpresent[0].getElementsByClassName("stretch");
	if(searchVideo.length!=0){
		var video = document.getElementById('haveVideo');
		video.style.display="inline-block";
		if(isServer){
			// var searchCanvas= searchpresent[0].getElementsByClassName("Canvasstretch");
			// searchpresent[0].removeChild(searchCanvas[0]);
		}else{
			// var searchVideo= searchpresent[0].getElementsByClassName("stretch");
			// searchpresent[0].removeChild(searchVideo[0]);
			// var NewCanvas= document.createElement('canvas');
			// NewCanvas.className="stretch";
			// searchpresent[0].appendChild(NewCanvas);

		}
	}else{
		var video = document.getElementById('haveVideo');
		video.style.display="none";
	}
	// alert(isServer);
	if(isServer){
		socket.emit('isslide',event.indexh,event.indexv);
	}
});



Reveal.addEventListener('fragmentshown', function(event) {
    // event.fragment = the fragment DOM element
    // alert("偵測到按下");
    // alert(event.indexf);  //Y軸頁數
    if(isServer){
		socket.emit('isslideFragment',"next");
	}
});


Reveal.addEventListener( 'fragmenthidden', function( event ) {
    // event.fragment = the fragment DOM element
    // alert("偵測到按上");
    // alert(event.indexf);  //Y軸頁數
    if(isServer){
		socket.emit('isslideFragment',"prev");
	}
});


socket.on('slide',function(indexh,indexv){
	if(!isServer)
		Reveal.slide( indexh, indexv);
});

socket.on('next',function(){
	if(!isServer)
		Reveal.nextFragment();
});

socket.on('prev',function(){
	if(!isServer)
		Reveal.prevFragment();
});