com.google.gwt.language.sample.hellolanguage.client.TranslationDemo.java Source code

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Here is the source code for com.google.gwt.language.sample.hellolanguage.client.TranslationDemo.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.gwt.language.sample.hellolanguage.client;

import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.language.client.translation.BrandingOptions;
import com.google.gwt.language.client.translation.Language;
import com.google.gwt.language.client.translation.Translation;
import com.google.gwt.language.client.translation.TranslationCallback;
import com.google.gwt.language.client.translation.TranslationResult;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.HasHorizontalAlignment;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.ListBox;
import com.google.gwt.user.client.ui.TextArea;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * Demo for translation API.
 */
public class TranslationDemo extends Composite {

    private final TextArea inputTextArea = new TextArea();
    private final Label outputDiv = new Label();

    private final ListBox sourceLanguages = new ListBox();
    private final ListBox destinationLanguages = new ListBox();

    public TranslationDemo() {
        inputTextArea.setStyleName(Styles.DEMO_TEXTAREA_STYLE);
        outputDiv.setStyleName(Styles.TRANS_OUTPUT_DIV_STYLE);

        VerticalPanel wrapperPanel = new VerticalPanel();
        wrapperPanel.setWidth("100%");

        VerticalPanel demoPanel = getDemoPanel();
        wrapperPanel.add(demoPanel);
        wrapperPanel.setCellHorizontalAlignment(demoPanel, HasHorizontalAlignment.ALIGN_CENTER);

        Widget branding = Translation
                .createBrandingWidget(BrandingOptions.newInstance(BrandingOptions.Type.VERTICAL));
        wrapperPanel.add(branding);
        wrapperPanel.setCellHorizontalAlignment(branding, HasHorizontalAlignment.ALIGN_RIGHT);

        initWidget(wrapperPanel);
    }

    /**
     * Creates a "Translate" button.
     *
     * @return button
     */
    private Button createTranslateButton() {
        Button translateButton = new Button("Translate");
        translateButton.addClickHandler(new ClickHandler() {
            public void onClick(ClickEvent event) {
                Language src = Language.valueOf(sourceLanguages.getItemText(sourceLanguages.getSelectedIndex()));
                Language dest = Language
                        .valueOf(destinationLanguages.getItemText(destinationLanguages.getSelectedIndex()));

                // Translation API call to translate text
                Translation.translate(inputTextArea.getText(), src, dest, new TranslationCallback() {
                    @Override
                    protected void onCallback(TranslationResult result) {
                        if (result.getError() == null) {
                            outputDiv.setText(result.getTranslatedText());
                        } else {
                            outputDiv.setText(result.getError().getMessage());
                        }
                    }
                });
            }
        });
        return translateButton;
    }

    /**
     * Creates translation control panel containing list boxes for source and
     * destination languages, and a button to translate.
     *
     * @return panel containing controls
     */
    private HorizontalPanel createTranslationControlPanel() {
        populateListBoxes();

        HorizontalPanel listBoxesPanel = new HorizontalPanel();
        listBoxesPanel.add(sourceLanguages);
        listBoxesPanel.add(new Label(">>"));
        listBoxesPanel.add(destinationLanguages);

        Button translateButton = createTranslateButton();

        HorizontalPanel controlPanel = new HorizontalPanel();
        controlPanel.setSpacing(10);
        controlPanel.setWidth("100%");
        controlPanel.add(listBoxesPanel);
        controlPanel.add(translateButton);
        controlPanel.setCellHorizontalAlignment(translateButton, HasHorizontalAlignment.ALIGN_RIGHT);

        return controlPanel;
    }

    /**
     * Contains the entire demo panel.
     *
     * @return demo panel
     */
    private VerticalPanel getDemoPanel() {
        VerticalPanel demoPanel = new VerticalPanel();
        demoPanel.add(new Label("Enter source language text: "));
        demoPanel.add(inputTextArea);
        demoPanel.add(createTranslationControlPanel());
        demoPanel.add(new Label("Translated text:"));
        demoPanel.add(outputDiv);
        return demoPanel;
    }

    /**
     * Populates list boxes with source and destination languages.
     */
    private void populateListBoxes() {
        int englishIndex = 0;
        int spanishIndex = 0;
        int iter = 0;

        // Populate source & destination language list boxes.
        for (Language lang : Language.values()) {
            if (!Translation.isTranslatable(lang)) {
                continue;
            }

            sourceLanguages.addItem(lang.toString());
            destinationLanguages.addItem(lang.toString());
            if (lang == Language.ENGLISH) {
                englishIndex = iter;
            } else if (lang == Language.SPANISH) {
                spanishIndex = iter;
            }
            ++iter;
        }

        // Select English as default source and Spanish as default destination
        // languages.
        sourceLanguages.setSelectedIndex(englishIndex);
        destinationLanguages.setSelectedIndex(spanishIndex);
    }
}