com.jain.addon.i18N.I18NChangeListener.java Source code

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Here is the source code for com.jain.addon.i18N.I18NChangeListener.java

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/* 
 * Copyright 2012 Lokesh Jain.
 * 
 * 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.jain.addon.i18N;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

import com.jain.addon.i18N.handlers.I18NComponentHandler;
import com.jain.addon.i18N.handlers.factory.I18NComponentHandlerFactory;
import com.vaadin.data.Property.ValueChangeEvent;
import com.vaadin.data.Property.ValueChangeListener;
import com.vaadin.ui.Component;
import com.vaadin.ui.Component.Event;
import com.vaadin.ui.HasComponents;

/**
 * <code>I18NChangeListener<code> is a default listener provided for the locale change.
 * This is implemented as value change listener in the application 
 * because most of the application uses drop down for local selection.
 * I case you are using some other way, call value change method to invoke all locale change events.
 * @author Lokesh Jain
 * @since Aug 27, 2012
 * @version 1.0.0
 */
@SuppressWarnings("serial")
public class I18NChangeListener implements ValueChangeListener {
    private Map<Component, I18NComponentHandler> componentMap;
    private Locale currentLocale;

    protected I18NChangeListener() {
        this.componentMap = new HashMap<Component, I18NComponentHandler>();
        this.currentLocale = Locale.getDefault();
    }

    public void localeChanged(Component component) {
        if (currentLocale != component.getUI().getLocale()) {
            currentLocale = component.getUI().getLocale();

            updateComponents(component);
        }
    }

    private void updateComponents(Component component) {
        if (component instanceof HasComponents) {
            HasComponents container = (HasComponents) component;

            for (Component containerComponent : container) {
                updateComponents(containerComponent);
            }
        }

        updateCaption(component);

        if (component instanceof I18NListener) {
            I18NChangeEvent event = new I18NChangeEvent(component, currentLocale);
            ((I18NListener) component).localeChanged(event);
        }
    }

    private void updateCaption(Component component) {
        I18NComponentHandler handler = componentMap.get(component);

        if (handler != null) {
            handler.applyI18N(component, currentLocale);
        }
    }

    public void registor(Component component) {
        componentMap.put(component, I18NComponentHandlerFactory.getHandler(component));
        updateCaption(component);
    }

    public void deRegistor(Component component) {
        componentMap.remove(component);
    }

    public String getI18NCaption(Component component) {
        I18NComponentHandler handler = componentMap.get(component);
        if (handler != null)
            return handler.getI18NCaption();
        return "";
    }

    public String getI18NCaption(Component component, Serializable serializable) {
        I18NComponentHandler handler = componentMap.get(component);
        if (handler != null)
            return handler.getI18NCaption(serializable);
        return "";
    }

    public I18NComponentHandler getI18NComponentHandler(Component component) {
        I18NComponentHandler handler = componentMap.get(component);
        return handler;
    }

    public void valueChange(ValueChangeEvent valueChangeEvent) {
        Event event = (Event) valueChangeEvent;
        Locale selected = ((Locale) valueChangeEvent.getProperty().getValue());
        selected = selected == null ? Locale.getDefault() : selected;
        event.getComponent().getUI().setLocale(selected);
    }
}