ExtendScript for Android export

Export for Android.jsx

// This script makes a copy merged based on selection (or entire canvas), 
// pastes it into a new doc, then exports it for Android in 320dpi, 240dpi, 160dpi, 120dpi
// 
// Written by August 19, 2012 by JP Simard, Magnetic Bear Studios Inc.

exportForAndroid();

function exportForAndroid() {
    // save document state
    var initialState = activeDocument.activeHistoryState; 
    
    // select all if there's no current selection
    try {
        var calcWidth = activeDocument.selection.bounds[2] - activeDocument.selection.bounds[0];
    } catch(e) {
        activeDocument.selection.selectAll();
    }

    // get the width and height of selection
    var calcWidth = activeDocument.selection.bounds[2] - activeDocument.selection.bounds[0];
    var calcHeight = activeDocument.selection.bounds[3] - activeDocument.selection.bounds[1];

    // get the document resolution
    var docResolution = activeDocument.resolution;

    // copy merged
    activeDocument.selection.copy(true);
    
    // reset document state
    activeDocument.activeHistoryState = initialState;

    // create a new doc based on selection size
    var myNewDoc = documents.add(calcWidth, calcHeight, docResolution, "Android Export", NewDocumentMode.RGB, DocumentFill.TRANSPARENT, 1);

    // paste in from clipboard
    myNewDoc.paste();
    
    // crop document to layer size
    myNewDoc.crop(myNewDoc.activeLayer.bounds);
    
    // redraw document
    app.refresh();
    
    // read doc width and height
    var newDocWidth = myNewDoc.width;
    var newDocHeight = myNewDoc.height;
    
    // make layer width and height even
    if (newDocWidth%2 != 0 || newDocHeight%2 != 0 ) {
        var anchorPoint = getAnchorPoint();
        newDocWidth += newDocWidth%2;
        newDocHeight += newDocHeight%2;
        myNewDoc.resizeCanvas(newDocWidth, newDocHeight, anchorPoint);
    }
    
    // redraw document
    app.refresh();
    
    // name the exported element
    var elementName = prompt("Name your element","");
    
    if (!elementName) {
        // close temporary document
        myNewDoc.close(SaveOptions.DONOTSAVECHANGES);
        return;
    }
    
    // select target folder
    var baseFolder = Folder.selectDialog();
    if (!baseFolder) {
        // close temporary document
        myNewDoc.close(SaveOptions.DONOTSAVECHANGES);
        return;
    }
    
    // save all DPI versions
    saveForWebPNG(Folder(baseFolder + "/320dpi"),elementName);
    myNewDoc.resizeImage(myNewDoc.width*.75, myNewDoc.height*.75);
    saveForWebPNG(Folder(baseFolder + "/240dpi"),elementName);
    myNewDoc.resizeImage(myNewDoc.width/1.5, myNewDoc.height/1.5);
    saveForWebPNG(Folder(baseFolder + "/160dpi"),elementName);
    myNewDoc.resizeImage(myNewDoc.width*.75, myNewDoc.height*.75);
    saveForWebPNG(Folder(baseFolder + "/120dpi"),elementName);
    
    // close temporary document
    myNewDoc.close(SaveOptions.DONOTSAVECHANGES);
}

// prompt the user for which anchor position to use when resizing the canvas
function getAnchorPoint() {
    // enumerate possible anchor positions
    var anchorOptions = [];
    anchorOptions[0] = AnchorPosition.BOTTOMCENTER;
    anchorOptions[1] = AnchorPosition.BOTTOMLEFT;
    anchorOptions[2] = AnchorPosition.BOTTOMRIGHT;
    anchorOptions[3] = AnchorPosition.MIDDLECENTER;
    anchorOptions[4] = AnchorPosition.MIDDLELEFT;
    anchorOptions[5] = AnchorPosition.MIDDLERIGHT;
    anchorOptions[6] = AnchorPosition.TOPCENTER;
    anchorOptions[7] = AnchorPosition.TOPLEFT;
    anchorOptions[8] = AnchorPosition.TOPRIGHT;
    
    // initialize anchorPoint
    var anchorPoint = AnchorPosition.TOPLEFT;
    
    // create dialog with anchorOptions dropdown
    var dlg = new Window ('dialog', 'Pick an anchor point');
    dlg.dropdownlist = dlg.add("dropdownlist", undefined,"AnchorPoint");
    
    var item
    for (var i=0,len=anchorOptions.length;i<len;i++)
      {item = dlg.dropdownlist.add ('item', "" + anchorOptions[i]);
    };
    
    dlg.dropdownlist.onChange = function() {
       // save the selected value for return
       anchorPoint = anchorOptions[parseInt(this.selection)];
       this.parent.close(0);
    };
    
    dlg.orientation = 'column';
    dlg.center();
    dlg.show();
    
    return anchorPoint;
}

// export image as PNG to specified folder
function saveForWebPNG(folder, filename)
{
    var opts, file;
    opts = new ExportOptionsSaveForWeb();
    opts.format = SaveDocumentType.PNG;
    opts.PNG8 = false;
    opts.quality = 100;
    
    // check if folder exists, if not create it.
    if(!folder.exists) folder.create();
    file = new File(folder + "/" + filename + ".png");
    activeDocument.exportDocument(file, ExportType.SAVEFORWEB, opts);
}