Files
gf-core/src/editor/simple/slideshow.js

87 lines
2.5 KiB
JavaScript

var internet_explorer=navigator.appName=="Microsoft Internet Explorer";
/* How to change opacity in IE:
http://joseph.randomnetworks.com/archives/2006/08/16/css-opacity-in-internet-explorer-ie/
*/
var set_opacity =
internet_explorer
? function(el,o) { el.style.filter="alpha(opacity="+Math.round(o*100)+")";}
: function(el,o) { el.style.opacity=o; };
function start_slideshow(img,options) {
var p=img.parentNode;
if(p.tagName=="A") p=p.parentNode;
var is=p.getElementsByTagName("img");
if(is.length>1) {
var cur=0;
var w=img.width;
var h=img.height;
//p.style.position="relative";
p.style.minWidth=w+"px";
p.style.minHeight=h+"px";
var images=[];
for(var i=0;i<is.length;i++) {
images[i]=is[i];
var c=images[i];
if(internet_explorer) c.style.zoom=1;
c.style.position="absolute";
}
var timeout=1000*(options.delay || 5);
var ft=options.fade==null ? 1 : options.fade;
var tick=function() {
var c=images[cur];
cur= (cur+1) % images.length;
var n=images[cur];
set_opacity(n,0);
//n.style.position="static";
n.style.zIndex=1;
n.className="";
if(n.width>w) { w=n.width; p.style.minWidth=w+"px"; }
if(n.height>h) { h=n.height; p.style.minHeight=h+"px"; }
c.style.position="absolute";
c.style.zIndex=0;
fade(n,0,1,ft,function() {
if(c.width>n.width || c.height>n.height) fade(c,1,0,ft,null);
else set_opacity(c,0); });
//debug.innerHTML=w+"x"+h;
//for(var i=0;i<images.length;i++)
//debug.appendChild(text(" "+images[i].style.position));
}
//var debug=document.createElement("div");
//p.parentNode.insertBefore(debug,p);
//debug.innerHTML=w+"x"+h;
setInterval(tick,timeout);
}
//else alert("No slideshow!");
}
function fade(el,start,stop,t,after) {
// el: which element to fade
// start: starting opacity [0..1]
// stop: ending opacity [0..1]
// t: duration of fade (in seconds), default 1s
// after: function to call when done fading, optional
var dt=40; // Animation granularity, 1/40ms = 25fps
el.step=(stop-start)*dt/(1000*(t==null ? 1 : t));
el.stop=stop;
//alert("fade "+start+" "+stop+" "+el.step);
var done=function() {
clearInterval(el.timer);
el.timer=null;
if(after) after();
}
var f=function() {
var next=el.current+el.step;
if(next>=1) { next=1; done(); }
if(next<=0) { next=0; done(); }
set_opacity(el,next);
el.current=next
}
if(!el.timer) {
el.current=start;
el.timer=setInterval(f,dt);
}
}