com.bedatadriven.renjin.appengine.client.LotREPLs.java Source code

Introduction

Here is the source code for com.bedatadriven.renjin.appengine.client.LotREPLs.java

Source

/*
 * Copyright 2009 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.bedatadriven.renjin.appengine.client;

import com.bedatadriven.renjin.appengine.shared.InterpreterException;
import com.bedatadriven.renjin.appengine.shared.InterpreterType;
import com.bedatadriven.renjin.appengine.shared.LotREPLsApi;
import com.bedatadriven.renjin.appengine.shared.LotREPLsApiAsync;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.Window.Location;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * Entry point class for the UI. This sets up the command prompt area and sets
 * up the event handlers.
 */
public class LotREPLs implements EntryPoint {

    private final LotREPLsApiAsync api = GWT.create(LotREPLsApi.class);

    private final FlowPanel content = new FlowPanel();

    private CommandPrompt commandPrompt;

    /**
     * This is the entry point method.
     */
    public void onModuleLoad() {
        doWarmUpRequest();

        commandPrompt = new CommandPrompt(new CommandPrompt.CommandEnteredCallback() {
            /**
             * The command entered handler does a little switch-a-roo. It removes the
             * input area and prompt, replacing them with immutable copies, and then
             * waits for the response. Once the script results (or error) are ready,
             * it inserts a result area and then re-adds the command prompt.
             */
            public void onCommandEntered(InterpreterType type, String script) {
                content.remove(commandPrompt.panel());

                Widget enteredScript = commandPrompt.createImmutablePanel();
                content.add(enteredScript);

                commandPrompt.clearInputArea();

                Window.scrollTo(0, 100000);

                api.eval(script, new ScriptCallback());
            }
        });

        String script = Location.getParameter("script");
        if (script != null && !script.equals("")) {
            commandPrompt.setScript(script);
        }

        content.add(commandPrompt.panel());

        content.setWidth("100%");
        RootPanel.get("root").add(content);
        commandPrompt.claimFocus();
    }

    private void doWarmUpRequest() {
        api.eval("1", new AsyncCallback<String>() {
            @Override
            public void onFailure(Throwable throwable) {

            }

            @Override
            public void onSuccess(String s) {

            }
        });
    }

    private class ScriptCallback implements AsyncCallback<String> {
        public void onFailure(Throwable caught) {
            if (caught instanceof InterpreterException) {
                setResult("Error: " + caught.getMessage(), false);
            } else {
                setResult("Something bad happened - click your heels three times and try again", false);
            }
        }

        public void onSuccess(String result) {
            setResult(result, true);
        }
    }

    private void setResult(String result, boolean succeeded) {
        Element e = Document.get().createPreElement();
        e.setInnerText(result);
        e.setClassName(succeeded ? "result" : "error");
        e.setAttribute("tabIndex", "-1");
        content.getElement().appendChild(e);
        content.add(commandPrompt.panel());
        commandPrompt.claimFocus();
        Window.scrollTo(0, 100000);
    }
}