Get previous and next layer names through script.

Question

Hi everyone,

I am looking for the most efficient way to get both the next and previous layer names in the layer stack. I need it to work a little differently then the usual Photoshop behaviour. Photoshop usually skips invisible layers, and will not get "inside" a folded layerset. I need a function that would get both visible and invisible layers, and would treat all layerset as if it was unfolded.

I did manage to make things work using a recursive function. I basically build myself an array with all the layers, then loop through it until I find the current active layer. I can then use "myArray[i-1]" and "myArray[i+1]" to get what I am looking for. It works, but it's clearly not an efficient way to do it. Gets pretty slow with documents with large number of layers...

I was hoping someone might be able to help me with some action manager magic... 🙂

Basically, all I have is "app.activeDocument.activeLayer", and I want a function (or functions) that would return the name of the layer directly above and directly under it, be it visible or not, be it part of a layerset or not...

Any thoughts ?

Thanks !

J.

jonathankemp · Accepted Answer

Thanks mate. This was of great help.

It was having trouble with both the first and last layers in the stack, though. Made a few little tweaks and everything seems fine now.

function getSurroundingLayersNames() {
	// get names of next layer above and below;

	// Get layer index
	var ref1 = new ActionReference();
		ref1.putProperty (stringIDToTypeID ("property"), stringIDToTypeID ("itemIndex"));
		ref1.putEnumerated( charIDToTypeID("Lyr "), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") );
	var layerDesc = executeActionGet(ref1);
	var theIndex = layerDesc.getInteger(stringIDToTypeID ("itemIndex"));

	// check background;
	var ref4 = new ActionReference();
		ref4.putEnumerated( charIDToTypeID("Dcmn"), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") );
	var docDesc = executeActionGet(ref4);
	var hasBackground = docDesc.getBoolean(stringIDToTypeID("hasBackgroundLayer"));
	var theNumberOfLayers = docDesc.getInteger(stringIDToTypeID("numberOfLayers"));

	// determine the indices;
	var indexPrev;
	var indexNext;
	if (hasBackground == false) {
		indexPrev = theIndex-1;
		indexNext = theIndex+1;
	}
	else {
		indexPrev = theIndex-2;
		indexNext = theIndex;
	}
	
	while (isLayerSectionEnd(indexPrev) == true && indexPrev > 0) {indexPrev--;}
	while (isLayerSectionEnd(indexNext) == true && indexNext < theNumberOfLayers) {indexNext++;}

	if ((indexPrev < 0 && hasBackground) || (indexPrev == 0 && !hasBackground)) {
		// Bottom layer of the stack
		var theNameBelow = "";}
	else {
		var theNameBelow = getLayerName (indexPrev);}

	if (indexNext > theNumberOfLayers) {
		// Top layer of the stack
		var theNameAbove = "";}
	else {
		var theNameAbove = getLayerName (indexNext);}

	returnArray = new Array(theNameAbove,theNameBelow);
	return returnArray;
}

////// get name //////
function getLayerName (theIndex) {
	try{
		var ref = new ActionReference();
			ref.putIndex( charIDToTypeID( "Lyr " ), theIndex);
		var layerDesc = executeActionGet(ref);
		var theName = layerDesc.getString(stringIDToTypeID ("name"));
		return theName;
	}
	catch (e) {return e;}
}
////// is layer section end //////
function isLayerSectionEnd (theIndex) {
	try {
		var ref = new ActionReference();
			ref.putIndex( charIDToTypeID( "Lyr " ), theIndex);
		var layerDesc = executeActionGet(ref);

			var layerSet = typeIDToStringID(layerDesc.getEnumerationValue(stringIDToTypeID("layerSection")));
			// if group end;
			if (layerSet == "layerSectionEnd") {return true;}
	} catch (e) {return false;}
}

Thanks again.

J.

Manan Joshi · Answer

Here is my stab at the implementation. It will prompt the name of the content layer before and after the currently selected layer. This is my first ever Photoshop scripting code and that too Action Manager code, so do test it at your own risk. Anything can happen, it might fry your computer 🙂

var s2t = stringIDToTypeID;
var t2s = typeIDToStringID;
var i = activeDocument.activeLayer.itemIndex

var layerCount = getProperty("document", "numberOfLayers").getInteger(s2t("numberOfLayers"))
var bgLayer = getProperty("document", "hasBackgroundLayer").getBoolean(s2t("hasBackgroundLayer")) ? 0 : 1
!bgLayer && i--
var retval = getName(i + 1, true)
if(retval != undefined)
	alert("Before Layer name is " + retval)

var retval = getName(i-1, false)
if(retval != undefined)
	alert("After Layer name is " + retval)
function getProperty(className, property, index)
{
	var r = new ActionReference(), p = s2t(property)
	r.putProperty(s2t('property'), p)
	if(index != undefined)
		r.putIndex(s2t(className),index)
	else
		r.putEnumerated(s2t(className), s2t('ordinal'), s2t('targetEnum'))
	var a = executeActionGet(r)
	return a
}
function getName(i, inc)
{
	if(i < bgLayer || i > layerCount)
	{
		return
	}
	var prop = "layerSection"
	var retval = t2s(getProperty("layer", prop, i).getEnumerationValue(s2t(prop)))
	if(retval == 'layerSectionEnd' || retval == 'layerSectionStart')
	{
		inc ? i++ : i--
		return getName(i, inc)
	}
	else
	{
		var prop = "name"
		var retval =  getProperty("layer", prop, i).getString(s2t(prop))
		return retval
	}
}

Question for Action Manager veterans, this works fine but i have noticed that the when the background layer is present then getting the name using index 0 or 1 returns the layer above background layer. The nameof background is not returned, is this so or i missed something?

-Manan

Sign up

To post, reply, or follow discussions, please sign in with your Adobe ID.

Sign in to Adobe Community

To post, reply, or follow discussions, please sign in with your Adobe ID.

Scanning file for viruses.

This file cannot be downloaded