/*
  * Returning java objects works. No need to return NativeNumber, NativeString,
  * NativeBoolean, or Undefined.
  */
 Object makeJsvalFromValue(Context jsContext, Value value) {
   switch (value.getType()) {
     case NULL:
       return null;
     case BOOLEAN:
       if (value.getBoolean()) {
         return Boolean.TRUE;
       }
       return Boolean.FALSE;
     case BYTE:
       return new Byte(value.getByte());
     case CHAR:
       return new Character(value.getChar());
     case SHORT:
       return new Short(value.getShort());
     case INT:
       return new Integer(value.getInt());
     case FLOAT:
       return new Float(value.getFloat());
     case DOUBLE:
       return new Double(value.getDouble());
     case STRING:
       return value.getString();
     case JAVA_OBJECT:
       JavaObjectRef javaRef = value.getJavaObject();
       return JavaObject.getOrCreateJavaObject(javaRef, sessionData, jsContext);
     case JS_OBJECT:
       Scriptable scriptable = refToJsObject.get(value.getJsObject().getRefid());
       assert scriptable != null;
       return scriptable;
     case UNDEFINED:
       return Undefined.instance;
   }
   return null;
 }
  @SuppressWarnings("unchecked")
  @Override
  public ExceptionOrReturnValue invoke(
      BrowserChannelClient channel, Value thisObj, String methodName, Value[] args) {
    if (logger.isLoggable(TreeLogger.DEBUG)) {
      logger.log(
          TreeLogger.DEBUG,
          "INVOKE: thisObj: " + thisObj + ", methodName: " + methodName + ", args: " + args);
    }
    /*
     * 1. lookup functions by name. 2. Find context and scope. 3. Convert
     * thisObject to ScriptableObject 4. Convert args 5. Get return value
     */
    Context jsContext = Context.getCurrentContext();
    ScriptableObject jsThis = null;
    if (thisObj.getType() == ValueType.NULL) {
      jsThis = window;
    } else {
      Object obj = makeJsvalFromValue(jsContext, thisObj);
      if (obj instanceof ScriptableObject) {
        jsThis = (ScriptableObject) obj;
      } else if (obj instanceof SimpleScriptableProxy<?>) {
        jsThis = ((SimpleScriptableProxy<SimpleScriptable>) obj).getDelegee();
      } else {
        logger.log(
            TreeLogger.ERROR,
            "Unable to convert "
                + obj
                + " to either "
                + " ScriptableObject or SimpleScriptableProxy");
        return new ExceptionOrReturnValue(true, new Value(null));
      }
    }
    Object functionObject = ScriptableObject.getProperty(window, methodName);
    if (functionObject == ScriptableObject.NOT_FOUND) {
      logger.log(
          TreeLogger.ERROR,
          "function "
              + methodName
              + " NOT FOUND, thisObj: "
              + jsThis
              + ", methodName: "
              + methodName);
      // TODO: see if this maps to QUIT
      return new ExceptionOrReturnValue(true, new Value(null));
    }
    Function jsFunction = (Function) functionObject;
    if (logger.isLoggable(TreeLogger.SPAM)) {
      logger.log(TreeLogger.SPAM, "INVOKE: jsFunction: " + jsFunction);
    }

    Object jsArgs[] = new Object[args.length];
    for (int i = 0; i < args.length; i++) {
      jsArgs[i] = makeJsvalFromValue(jsContext, args[i]);
    }
    Object result = null;
    try {
      if (args.length == 1 && methodName.indexOf(REPLACE_METHOD_SIGNATURE) != -1) {
        // getUrl() is not visible
        String currentUrl = window.jsxGet_location().toString();
        currentUrl = getUrlBeforeHash(currentUrl);
        String newUrl = getUrlBeforeHash((String) args[0].getValue());
        if (!newUrl.equals(currentUrl)) {
          WebWindow webWindow = window.getWebWindow();
          do {
            webWindow.getJobManager().removeAllJobs();
            webWindow = webWindow.getParentWindow();
          } while (webWindow != webWindow.getTopWindow());
        }
      }
      result = jsEngine.callFunction(htmlPage, jsFunction, jsContext, window, jsThis, jsArgs);
    } catch (JavaScriptException ex) {
      if (logger.isLoggable(TreeLogger.INFO)) {
        logger.log(
            TreeLogger.INFO,
            "INVOKE: JavaScriptException "
                + ex
                + ", message: "
                + ex.getMessage()
                + " when invoking "
                + methodName);
      }
      return new ExceptionOrReturnValue(true, makeValueFromJsval(jsContext, ex.getValue()));
    } catch (Exception ex) {
      if (logger.isLoggable(TreeLogger.INFO)) {
        logger.log(
            TreeLogger.INFO,
            "INVOKE: exception "
                + ex
                + ", message: "
                + ex.getMessage()
                + " when invoking "
                + methodName);
      }
      return new ExceptionOrReturnValue(true, makeValueFromJsval(jsContext, Undefined.instance));
    }
    if (logger.isLoggable(TreeLogger.INFO)) {
      logger.log(TreeLogger.INFO, "INVOKE: result: " + result + " of jsFunction: " + jsFunction);
    }
    return new ExceptionOrReturnValue(false, makeValueFromJsval(jsContext, result));
  }