Create OSX icons photoshop plugin.

Create OSX icons.jsx

try
{
  // Prompt user to select iTunesArtwork file. Clicking "Cancel" returns null.
  var iTunesArtwork = File.openDialog("Select a sqaure PNG file that is at least 1024x1024.", "*.png", false);
 
  if (iTunesArtwork !== null) 
  { 
    var doc = open(iTunesArtwork, OpenDocumentType.PNG);
    
    if (doc == null)
    {
      throw "Something is wrong with the file.  Make sure it's a valid PNG file.";
    }
 
    var startState = doc.activeHistoryState;       // save for undo
    var initialPrefs = app.preferences.rulerUnits; // will restore at end
    app.preferences.rulerUnits = Units.PIXELS;     // use pixels
 
    if (doc.width != doc.height)
    {
        throw "Image is not square";
    }
    else if ((doc.width < 1024) && (doc.height < 1024))
    {
        throw "Image is too small!  Image must be at least 1024x1024 pixels.";
    }
    else if (doc.width < 1024)
    {
        throw "Image width is too small!  Image width must be at least 1024 pixels.";
    }
    else if (doc.height < 1024)
    {
        throw "Image height is too small!  Image height must be at least 1024 pixels.";
    }
    
    // Folder selection dialog
    var destFolder = Folder.selectDialog( "Choose an output folder");
 
    if (destFolder == null)
    {
      // User canceled, just exit
      throw "";
    }
 
    // Save icons in PNG using Save for Web.
    var sfw = new ExportOptionsSaveForWeb();
    sfw.format = SaveDocumentType.PNG;
    sfw.PNG8 = false; // use PNG-24
    sfw.transparency = true;
    doc.info = null;  // delete metadata
    
    var icons = [
      {"name": "icon_512x512",     "size":512},
      {"name": "icon_512x512@2x",  "size":1024},
      {"name": "icon_256x256",     "size":256},
      {"name": "icon_256x256@2x",  "size":512},
      {"name": "icon_128x128",     "size":128},
      {"name": "icon_128x128@2x",  "size":256},
      {"name": "icon_32x32",       "size":32},
      {"name": "icon_32x32@2x",    "size":64},
      {"name": "icon_16x16",       "size":16},
      {"name": "icon_16x16@2x",    "size":32},
    ];
 
    var icon;
    for (i = 0; i < icons.length; i++) 
    {
      icon = icons[i];
      doc.resizeImage(icon.size, icon.size, // width, height
                      null, ResampleMethod.BICUBICSHARPER);
 
      var destFileName = icon.name + ".png";
 
      doc.exportDocument(new File(destFolder + "/" + destFileName), ExportType.SAVEFORWEB, sfw);
      doc.activeHistoryState = startState; // undo resize
    }
 
    alert("OSX Icons created!");
  }
}
catch (exception)
{
  // Show degbug message and then quit
	if ((exception != null) && (exception != ""))
    alert(exception);
 }
finally
{
    if (doc != null)
        doc.close(SaveOptions.DONOTSAVECHANGES);
  
    app.preferences.rulerUnits = initialPrefs; // restore prefs
}