/*
 * #%L
 * gitools-ui-platform
 * %%
 * Copyright (C) 2013 Universitat Pompeu Fabra - Biomedical Genomics group
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the 
 * License, or (at your option) any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public 
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/gpl-3.0.html>.
 * #L%
 */
package org.gitools.ui.platform.imageviewer;

import javax.swing.*;

/**
 * Abstract superclass for status bars of the image viewer.
 *
 * @author Kazó Csaba
 */
public abstract class StatusBar {
    /**
     * The ImageViewer associated with this status bar.
     */
    private ImageViewer imageViewer;

    /**
     * Returns the status bar component that can be added to the image viewer GUI.
     *
     * @return the status bar component
     */
    public abstract JComponent getComponent();

    /**
     * Returns the image viewer that this status bar belongs to.
     *
     * @return the current image viewer, or <code>null</code> if there is none
     */
    public final ImageViewer getImageViewer() {
        return imageViewer;
    }

    final void setImageViewer(ImageViewer imageViewer) {
        if (this.imageViewer != null)
            unregister(this.imageViewer);
        this.imageViewer = imageViewer;
        if (this.imageViewer != null)
            register(this.imageViewer);
    }

    /**
     * Called when this status bar is added to an image viewer. Subclasses can override
     * this method to register listeners.
     *
     * @param viewer the new viewer associated with this status bar
     */
    protected void register(ImageViewer viewer) {
    }

    /**
     * Called when this status bar is removed from an image viewer. Subclasses can override
     * this method to remove listeners.
     *
     * @param viewer the viewer that this status bar is removed from
     */
    protected void unregister(ImageViewer viewer) {
    }
}
