Exports first-level layers and layer groups to png images for iPad and iPad with Retina display.

photoshop-export-layers-ipad.jsx

#target photoshop

function main(){
    function scanLayers(el, path, isRetina) {
        new Folder(path).create();

        // process layer sets (groups)
        for(var i = 0; i < el.layerSets.length; i++){
            var layer = el.layerSets[i];
            if (!layer.visible)
                continue;
            // merge layer set sub-layers and export
            saveLayer(layer, path, true, isRetina);
        }
        
        // process plain layers
        for(var j = 0; j < el.artLayers.length; j++) {
            var layer = el.artLayers[j];
            if (!layer.visible)
                continue;
            saveLayer(layer, path, false, isRetina);
        }
    };

    function saveLayer(layer, path, shouldMerge, isRetina) {
        var workingDoc = app.documents.add(originalDoc.width, originalDoc.height, originalDoc.resolution, originalDoc.name + " copy", NewDocumentMode.RGB, DocumentFill.TRANSPARENT);
        try {        
            // duplicate work only for active document
            app.activeDocument = originalDoc;
            layer.duplicate(workingDoc);
            //merge work only for active document
            app.activeDocument = workingDoc;
            workingDoc.trim(TrimType.TRANSPARENT,true,true,true,true);
            if (shouldMerge === undefined || shouldMerge === true) {
                workingDoc.mergeVisibleLayers();
            }
            // save file to folder with parent layer name
            var saveFile= File(path + "/" + layer.name + (isRetina ? "@2x" : "") + "~ipad.png");
            savePNG(workingDoc, saveFile);
        }
        catch(e) {
            alert(e);
        }
        // close temporary document
        workingDoc.close(SaveOptions.DONOTSAVECHANGES);
    };

    function savePNG(workingDoc, saveFile){
        var pngOpts = new ExportOptionsSaveForWeb; 
        pngOpts.format = SaveDocumentType.PNG
        pngOpts.PNG8 = false; 
        pngOpts.transparency = true; 
        pngOpts.interlaced = false; 
        pngOpts.quality = 100;
        workingDoc.exportDocument(new File(saveFile), ExportType.SAVEFORWEB, pngOpts); 
    };

    if(!documents.length) 
        return;

    // suppress all dialogs
    app.displayDialogs = DialogModes.NO;
    var originalDoc = app.activeDocument;
    var docPath = originalDoc.path;
    // get file name without extension
    var docName = originalDoc.name.replace(/\.[^\.]+$/, '');
    var docFullName = originalDoc.fullName;

    scanLayers(originalDoc, docPath + "/" + docName, true);
    originalDoc.resizeImage(originalDoc.width / 2, originalDoc.height / 2, undefined, ResampleMethod.BICUBIC);
    scanLayers(originalDoc, docPath + "/" + docName, false);
    originalDoc.close(SaveOptions.DONOTSAVECHANGES);
    app.open(File(docFullName));
};
main();