/* File: ..//src//afterEffects//crossfade.jsx
Date: Sat Dec 27 15:17:32 MYT 2008
Author: David Van Brink
This script is part of the omino adobe script suite.
The latest version can be found at http://omino.com/pixelblog/.

I write these because I like to. Please enjoy as you see fit.

Questions to poly@omino.com, subject line should start with
"plugins" so my spam filter lets it in.

This file has been preprocessed to be
standalone.  I develop them against some
reusable libraries -- such as for dialog
layout -- but for distribution it's nicer to
have just one file. dvb 2007.
 */
/*
Description: This After Effects script modifies a composition such that each layer crossfades
into the next. This can be a useful starting point for slideshows and such.
::
*/

//#include "../shared/ominoDialogMaker.jsx"

var fadeTime = .2;
var holdTime = 1.7;


function removeKeyFrames(property)
    {
    var numKeys = property.numKeys;
    var i;

    for(i = 1; i <= numKeys; i++)
        {
        property.removeKey(1);
        }
    }

myComp = app.project.activeItem;
if(!(myComp instanceof CompItem))
    {
    alert("please select a composition.");
    }
else
    {
    app.beginUndoGroup("crossfade the layers");

    var myLayers = myComp.layers;

    var m = myComp.name + " layers: ";
    for(i = 1; i <= myLayers.length; i++)
        {
        m += "\n" + i + ": " + myLayers[i].name;
        }

    alert(m);

    var t = 0; 
    for(i = 1; i <= myLayers.length; i++)
        {
        l = myLayers[i];
        l.startTime = t;
        l.inPoint = t + 0;
        l.outPoint = t + holdTime + 2 * fadeTime;

        var o = l.property("opacity");
        removeKeyFrames(o);
        if(fadeTime)
            o.setValueAtTime(t,0);
        o.setValueAtTime(t + fadeTime,100);
        o.setValueAtTime(t + fadeTime + holdTime,100);
        if(fadeTime)
            o.setValueAtTime(t + fadeTime + holdTime + fadeTime,0);

        //var o = l.property("scale");
        //removeKeyFrames(o);
        //o.setValueAtTime(t,[120,120]);
        //o.setValueAtTime(t + fadeTime + holdTime + fadeTime,[100,100]);

        t += fadeTime + holdTime;
        }

    app.endUndoGroup();
    }