ai2png.jsx

#target illustrator

function main()
{
    var  sourceDir, 
    destDir,
    files,
    sourceDoc,
    sizes;

    sourceDir = Folder.selectDialog( 'Select the import directory.', '/temp/wame/bfb/src' );
    destDir = Folder.selectDialog( 'Select the export directory.', sourceDir.path + '/out' );
    
    sizes = prompt('What sizes do you want? comma separated', '16, 24, 32', 'What sizes?').replace(/ /g, '').split(',');
    
    if (sizes.length == 0) {
        alert("We want them sizes!");
        return;
    }

    files = sourceDir.getFiles("*.ai");

    if (files.length == 0) {
        alert("No .ai files in source dir... so nothing to do");
        return;
    }

    for (var s=0; s < sizes.length; s++) {
        var dir = new Folder(destDir + '/' + sizes[s]);
        if (!dir.exists) {
            if (!dir.create()) {
                alert('Error creating output folder "' + dir + '"');
                return;    
            }
            $.writeln('Created output folder "' + dir + '"');
        }
    }

    var file;
    for (var i=0; i < files.length; i++) {
        file = files[i];
        var doc = app.open(file, DocumentColorSpace.RGB);
        $.writeln('Processing ' + doc.fullName);
        
        removeBackgroundLayer(doc);
        
        for (var s=0; s < sizes.length; s++) {
            exportPng(doc, destDir, sizes[s]);
        }
        
        doc.close(SaveOptions.DONOTSAVECHANGES);
    }
}

function removeBackgroundLayer(doc)
{
    var layerCount = doc.layers.length;
    
    // Loop through layers from the back, to preserve index
    // of remaining layers when we remove one
    for (var ii = layerCount - 1; ii >= 0; ii-- ) {
        layer = doc.layers[ii];
        var layerName = new String( layer.name );
        if ( layerName.indexOf("background") == 0 ) {
            layer.locked = false;
            layer.remove();
            $.writeln('Removed background layer (' + ii + ')');
        }
    }
}

function exportPng(doc, destDir, size)
{
    var outFile = new File(destDir + '/' + size + '/' + doc.fullName.name.replace('.ai', '.png'));
    
    var exportOptions = new ExportOptionsPNG24;
    exportOptions.artBoardClipping = true;
    exportOptions.horizontalScale = size;
    exportOptions.verticalScale = size;
    
    $.writeln('Exporting ' + size + 'x' + size + ' PNG');

    doc.exportFile(outFile, ExportType.PNG24, exportOptions);
}

main();