/*
 * @(#)LinkViewer.java
 *
 * Copyright 2011 Instituto Superior Tecnico
 * Founding Authors: Luis Cruz, Sérgio Silva
 * 
 *      https://fenix-ashes.ist.utl.pt/
 * 
 *   This file is part of the File Management Module.
 *
 *   The File Management Module is free software: you can
 *   redistribute it and/or modify it under the terms of the GNU Lesser General
 *   Public License as published by the Free Software Foundation, either version 
 *   3 of the License, or (at your option) any later version.
 *
 *   The File Management  Module is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *   GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with the File Management  Module. If not, see <http://www.gnu.org/licenses/>.
 * 
 */
package module.fileManagement.presentationTier.component.viewers;

import java.net.URL;

import com.vaadin.data.Property;
import com.vaadin.data.Property.ValueChangeEvent;
import com.vaadin.data.Property.ValueChangeListener;
import com.vaadin.data.Property.ValueChangeNotifier;
import com.vaadin.data.Property.Viewer;
import com.vaadin.terminal.ExternalResource;
import com.vaadin.ui.CustomComponent;
import com.vaadin.ui.Label;
import com.vaadin.ui.Link;

/**
 * 
 * @author Sérgio Silva
 * 
 */
public class LinkViewer extends CustomComponent implements Viewer, ValueChangeListener {
    private Property source;

    protected String urlText;

    private String targetName;

    public LinkViewer() {
        setCompositionRoot(new Label());
    }

    public LinkViewer(Property newDataSource) {
        this();
        setPropertyDataSource(newDataSource);
    }

    public LinkViewer(String urlText, Property newDataSource) {
        this(newDataSource);
        this.urlText = urlText;
    }

    public LinkViewer(String urlText, String targetName, Property newDataSource) {
        this(urlText, newDataSource);
        this.targetName = targetName;
    }

    public LinkViewer(String urlText, String targetName) {
        this(urlText, targetName, null);
    }

    @Override
    public void setPropertyDataSource(Property newDataSource) {
        if (source != null) {
            if (source instanceof ValueChangeNotifier) {
                ((ValueChangeNotifier) source).removeListener(this);
            }
        }
        this.source = newDataSource;
        if (source instanceof ValueChangeNotifier) {
            ((ValueChangeNotifier) source).addListener(this);
        }
        updateContent();
    }

    @Override
    public Property getPropertyDataSource() {
        return source;
    }

    @Override
    public void valueChange(ValueChangeEvent event) {
        updateContent();
    }

    protected void updateContent() {
        URL url = source != null ? (URL) source.getValue() : null;
        if (url != null) {
            Link link = new Link(urlText != null ? urlText : url.toString(), new ExternalResource(url));
            if (targetName != null) {
                link.setTargetName(targetName);
            }
            setCompositionRoot(link);
        } else {
            setCompositionRoot(new Label());
        }
    }
}