Groovy demo

// Status and element functions. 
var e = function(tag,index){ return demotab.getElementsByTagName(tag)[index||0]; };
var status = function(msg) {
  if (!msg) return e('p').style.display = 'none';
  e('p').style.display = '';
  e('p').innerHTML = msg;
};
 
// Setup demo 
var setup = function() {
 
  // Test for Groovy (may already be loaded)
  try {
    var result = trephine.exec('groovy', 'True');
  } catch(err) {
    var result = { success: false, error: err.message };
  }
  if (!result.error) {
    var status = 'ready';
  } else {
 
    // Test whether dependencies are ready for loading
    var result = trephine.js( function(){
 
      // Get handle on lib directory or create it if necessary
      var homedir = new java.io.File( java.lang.System.getProperty('user.home') );
      var libdir = new java.io.File( homedir, '.trephine/lib' );
      if (!libdir.exists()) {
        if (!libdir.mkdirs()) throw "Error: Could not create " + libdir.toString();
      }
 
      // Check for Groovy dependencies
      var jars = ['groovy-engine.jar', 'groovy-1.6.0.jar', 'antlr-2.7.7.jar', 'asm-2.2.3.jar'];
      for (var i=0, l=jars.length; i<l; i++) {
        var jarfile = new java.io.File( libdir, jars[i] );
        if (!jarfile.exists()) return 'missing';
      };
      return 'loadable';
 
    } );
 
    if (result.error) return demotab.innerHTML = '<div class="error">' + result.error + '</div>';
    var status = result.result.toString() + '';
 
  }
 
  if (status=='missing') {
    e('div',1).style.display = '';
  } else if (status=='ready') {
    e('form').style.display = '';
  } else if (status=='loadable') {
    var result = trephine.js( function(){
      var jars = ['groovy-engine.jar', 'groovy-1.6.0.jar', 'antlr-2.7.7.jar', 'asm-2.2.3.jar'];
      var homedir = new java.io.File( java.lang.System.getProperty('user.home') );
      var libdir = new java.io.File( homedir, '.trephine/lib' );
      var executor = java.lang.Thread.currentThread();
      for (var i=0, l=jars.length; i<l; i++) {
        var jarfile = new java.io.File(libdir, jars[i]);
        executor.addSystemJar(jarfile);
      }
      executor.addEngineFactory(new Packages.com.sun.script.groovy.GroovyScriptEngineFactory());
      return true;
    } );
    if (result.error) return demotab.innerHTML = '<div class="error">' + result.error.toString() + '</div>';
    e('form').style.display = '';
  } else {
    return demotab.innerHTML = '<div class="error">Unknown status [' + status + '] returned.</div>';
  }
 
  // Setup download link
  e('a').onclick = function(evt) {
    if (!evt) evt = window.event;
    evt.cancelBubble = true;
    if (evt.stopPropagation) evt.stopPropagation();
    var result = trephine.js( function() {
 
      // Shorthand mechanism for creating and starting background threads.
      Function.prototype.run = function() {
        var thread = new java.lang.Thread( new java.lang.Runnable( { run: this } ) );
        thread.start();
        return thread;
      };
 
      // Helper function for downloading a file asynchronously
      function download( fromURL, toFile, options ) {
        options = options || {};
        var onprogress = typeof options.onprogress == "undefined" ? null : options.onprogress;
        var interval = typeof options.interval == "undefined" ? 500 : options.interval;
        var async = typeof options.async == "undefined" ? true : options.async;
        var f = function(){
          var conn = fromURL.openConnection();
          var len = conn.contentLength;
          var bis = new java.io.BufferedInputStream(conn.inputStream);
          var out = new java.io.BufferedOutputStream(new java.io.FileOutputStream(toFile));
          var b, count = 0, n = 0;
          var buf = java.lang.reflect.Array.newInstance(java.lang.Byte.TYPE, 4096);
          if (!onprogress) {
            while ((n = bis.read(buf, 0, buf.length)) != -1) out.write(buf, 0, n);
            out.flush();
            bis.close();
            out.close();
            return;
          }
          var t = (function(){
            while (count < len) {
              onprogress(count, len);
              java.lang.Thread.currentThread().sleep(interval);
            }
          }).run();
          while ((n = bis.read(buf, 0, buf.length)) != -1) {
            count += n;
            out.write(buf, 0, n);
          }
          t.stop();
          out.flush();
          bis.close();
          out.close();
          onprogress(count, len);
        };
        return async ? f.run() : f();
      };
 
      // Download Groovy dependencies, add them to the system classpath and register the engine factory
      var executor = java.lang.Thread.currentThread();
      (function(){
        var jars = ['groovy-engine.jar', 'groovy-1.6.0.jar', 'antlr-2.7.7.jar', 'asm-2.2.3.jar'];
        var jarids = ['groovy-engine', 'groovy', 'antlr', 'asm'];
        var homedir = new java.io.File( java.lang.System.getProperty('user.home') );
        var libdir = new java.io.File( homedir, '.trephine/lib' );
        var base = applet['c'+'lass'].protectionDomain.codeSource.location.toString().replaceFirst('^(.*'+'/).*$', "$1");
        for (var i=0, l=jarids.length; i<l; i++) (function(id, jar){
          var jarfile = new java.io.File( libdir, jar );
          var msg = "<span class=\"spinner\"></span> " + jar + " <span>0</span>% complete."
          window.eval("window.top.document.getElementById('"+id+"').innerHTML = '"+msg+"';");
          download(new java.net.URL(base + jar), jarfile, {
            async: false,
            onprogress: function(count, len) {
              if (count >= len) {
                var msg = "<span class=\"check\"></span> " + jar + " Done!";
                return window.eval([
                  "window.top.document.getElementById('", id, "').innerHTML = '", msg, "';"
                ].join(''));
              }
              window.eval([
                "window.top.document.getElementById('", id, "').getElementsByTagName('span')[1].innerHTML = ",
                "'" + Math.round(100 * count / len) + "';"
              ].join(''));
            }
          });
          executor.addSystemJar(jarfile);
        })(jarids[i], jars[i]);
        executor.addEngineFactory(new Packages.com.sun.script.groovy.GroovyScriptEngineFactory());
 
        // Switch back from download to main demo form
        var code = '(' + function(){
          var e = function(tag,index){ return window.top.document.getElementById('demotab').getElementsByTagName(tag)[index||0]; };
          e('div',1).style.display = 'none';
          e('p').innerHTML = 'Groovy successfully loaded!';
          e('p').style.display = '';
          e('form').style.display = 'block';
          setTimeout(function(){ e('p').style.display='none'; }, 2000);
        } + ')()';
        window.eval( code.replace(new RegExp('\\r?\\n','g'), '') );
      }).run();
 
    } );
    e('p',1).innerHTML = 'Download in progress...';
    return false;
  };
 
  // Setup form
  var submitcount = 0, firstmsg = 'Preparing Groovy engine and executing code (please be patient) ';
  e('form').onsubmit = function(event) {
    try {
      if (!trephine || !trephine.loaded) throw "Error: trephine not loaded.";
      if (!trephine.hasPermission()) throw "Error: elevated permissions have not been granted.";
      e('div').innerHTML = '<p class="notice" style="float:none"><span class="spinner"></span> ' + (submitcount++ ? 'Executing ' : firstmsg ) + '...</p>';
      setTimeout( function(){
        var result = trephine.exec( 'groovy', e('textarea').value );
        var boxtype = result.success.toString() == 'true' ? 'success' : 'error';
        var msg = (boxtype == 'success' ? result.result : result.error);
        try { msg = msg.toString() + ''; } catch(err) {}
        if (boxtype != 'success') msg += "</p><p><strong>Tip</strong>: Enable the Java Console to see full traces.<br />";
        e('div').innerHTML = '<p class="' + boxtype + 'box" style="float:none">' + msg + '</p>';
      }, 10 );
    } catch(err) {
      e('div').innerHTML = '<p class="errorbox" style="float:none">' + err + '</p>';
    }
    return false;
  };
};
 
// Load trephine 
status('<span class="spinner"></span> Loading trephine...');
trephine.load({
  debug: true, // Enables debug logging to the Java Console
  engines: ['js', 'groovy'], // Initialize the JavaScript and Groovy engines as soon as possible
  onload: function() { // Immediately prompt for permissions
    status('<span class="spinner"></span> Asking for elevated permissions...');
    trephine.askPermission( function(response) {
      if (!response) { // Short-circuit if permission request was denied
        return demotab.innerHTML = '<div class="error">Sorry, you must grant trephine privileges to enjoy this demo.</div>';
      }
      setup();
      status('Permission request granted.');
      setTimeout( function(){ status(); }, 2000 );
    } );
  } 
});