com.google.lotrepls.client.LotREPLs.java Source code

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Here is the source code for com.google.lotrepls.client.LotREPLs.java

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/*
 * 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.google.lotrepls.client;

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.SimplePanel;
import com.google.gwt.user.client.ui.Widget;
import com.google.lotrepls.client.CommandPrompt.CommandEnteredCallback;
import com.google.lotrepls.shared.LotREPLsApi;
import com.google.lotrepls.shared.LotREPLsApiAsync;
import com.google.lotrepls.shared.InterpreterException;
import com.google.lotrepls.shared.InterpreterType;

/**
 * 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;

    private void showMotd() {
        SimplePanel motd = new SimplePanel();
        motd.setStyleName("motd");
        motd.getElement().setInnerHTML(LotREPLsResources.motd());
        content.add(motd);
    }

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

        String language = Location.getParameter("language");

        commandPrompt = new CommandPrompt(language, new 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);

                try {
                    api.eval(type, script, new ScriptCallback());
                } catch (InterpreterException e) {
                    setResult(e.getMessage(), false);
                }
            }
        });

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

        content.add(commandPrompt.panel());

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

    private class ScriptCallback implements AsyncCallback<String> {
        public void onFailure(Throwable caught) {
            if (caught instanceof InterpreterException) {
                setResult("Interpreter exception: " + caught, 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 ? "script" : "error");
        e.setAttribute("tabIndex", "-1");
        content.getElement().appendChild(e);
        content.add(commandPrompt.panel());
        commandPrompt.claimFocus();
        Window.scrollTo(0, 100000);
    }
}