// After Effects script - evenly spaces keyframes
// By Julian Krick
// 07 -  23 - 2009

var project = app.project;

if (project)
{
	var myComp = app.project.activeItem;
     if (myComp != null && (myComp instanceof CompItem))
	{
         var selectedLayers = myComp.selectedLayers;
         if(selectedLayers.length == 1)
         {         
			var myLayer = selectedLayers[0];
			var selectedProps = myLayer.selectedProperties;
			if(selectedProps.length == 1)
			{
				var selectedProp = selectedProps[0];
				if(selectedProp.numKeys > 1)
				{
					var undoStr = "Evenly Space Keyframes";
					app.beginUndoGroup(undoStr);
					
					var keys = Array();
					
					//copy all keyframe values into an array
					for (var i = 1; i <= selectedProp.numKeys; i++)
						keys[keys.length] = selectedProp.keyValue(i);
             
					//record the time of the first and last keyframe
					var first = selectedProp.keyTime(1);
					var last = selectedProp.keyTime(selectedProp.numKeys);

					//delete all keyframes
					while(selectedProp.numKeys)
						selectedProp.removeKey(1);
                   
					//set new keyframes
					for(i = 1; i <= keys.length; i++)
						selectedProp.setValueAtTime(first + (last - first) / (keys.length - 1) * (i-1),keys[i-1]);

					app.endUndoGroup();
				}
				else
				{alert("Property must have more than one keyframe");}
			}
			else
			{alert("Exactly one property must be selected");}
		}
		else
		{alert("Exactly one layer must be selected");} 
	}
	else 
	{alert("No comp");}
}
else
{alert("No project");}