/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library 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 2.1 of the License, or 
 * (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ----------------------
 * ItemLabelPosition.java
 * ----------------------
 * (C) Copyright 2003-2007, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 27-Oct-2003 : Version 1 (DG);
 * 19-Feb-2004 : Moved to org.jfree.chart.labels, updated Javadocs and argument 
 *               checking (DG);
 * 26-Feb-2004 : Added new constructor (DG);
 *
 */

package org.jfree.chart.labels;

import java.io.Serializable;

import org.jfree.ui.TextAnchor;

/**
 * The attributes that control the position of the label for each data item on 
 * a chart.  Instances of this class are immutable.
 */
public class ItemLabelPosition implements Serializable {

    /** For serialization. */
    private static final long serialVersionUID = 5845390630157034499L;
    
    /** The item label anchor point. */
    private ItemLabelAnchor itemLabelAnchor;
    
    /** The text anchor. */
    private TextAnchor textAnchor;
    
    /** The rotation anchor. */
    private TextAnchor rotationAnchor;

    /** The rotation angle. */    
    private double angle;
    
    /**
     * Creates a new position record with default settings.
     */
    public ItemLabelPosition() {
        this(ItemLabelAnchor.OUTSIDE12, TextAnchor.BOTTOM_CENTER, 
                TextAnchor.CENTER, 0.0);
    }
    
    /**
     * Creates a new position record (with zero rotation).
     * 
     * @param itemLabelAnchor  the item label anchor (<code>null</code> not 
     *                         permitted).
     * @param textAnchor  the text anchor (<code>null</code> not permitted).
     */
    public ItemLabelPosition(ItemLabelAnchor itemLabelAnchor, 
                             TextAnchor textAnchor) {
        this(itemLabelAnchor, textAnchor, TextAnchor.CENTER, 0.0);    
    }
    
    /**
     * Creates a new position record.  The item label anchor is a point 
     * relative to the data item (dot, bar or other visual item) on a chart.  
     * The item label is aligned by aligning the text anchor with the 
     * item label anchor.
     * 
     * @param itemLabelAnchor  the item label anchor (<code>null</code> not 
     *                         permitted).
     * @param textAnchor  the text anchor (<code>null</code> not permitted).
     * @param rotationAnchor  the rotation anchor (<code>null</code> not 
     *                        permitted).
     * @param angle  the rotation angle (in radians).
     */
    public ItemLabelPosition(ItemLabelAnchor itemLabelAnchor, 
                             TextAnchor textAnchor,
                             TextAnchor rotationAnchor,
                             double angle) {
              
        if (itemLabelAnchor == null) {
            throw new IllegalArgumentException(
                    "Null 'itemLabelAnchor' argument.");
        }
        if (textAnchor == null) {
            throw new IllegalArgumentException("Null 'textAnchor' argument.");
        }
        if (rotationAnchor == null) {
            throw new IllegalArgumentException(
                    "Null 'rotationAnchor' argument.");
        }
        
        this.itemLabelAnchor = itemLabelAnchor;
        this.textAnchor = textAnchor;
        this.rotationAnchor = rotationAnchor;
        this.angle = angle;
    
    }
    
    /**
     * Returns the item label anchor.
     * 
     * @return The item label anchor (never <code>null</code>).
     */
    public ItemLabelAnchor getItemLabelAnchor() {
        return this.itemLabelAnchor;
    }
    
    /**
     * Returns the text anchor.
     * 
     * @return The text anchor (never <code>null</code>).
     */
    public TextAnchor getTextAnchor() {
        return this.textAnchor;
    }
    
    /**
     * Returns the rotation anchor point.
     * 
     * @return The rotation anchor point (never <code>null</code>).
     */
    public TextAnchor getRotationAnchor() {
        return this.rotationAnchor;
    }
    
    /**
     * Returns the angle of rotation for the label.
     * 
     * @return The angle (in radians).
     */
    public double getAngle() {
        return this.angle;
    }
    
    /**
     * Tests this object for equality with an arbitrary object.
     * 
     * @param obj  the object (<code>null</code> permitted).
     * 
     * @return A boolean.
     */
    public boolean equals(Object obj) {  
        if (obj == this) {
            return true;
        }    
        if (!(obj instanceof ItemLabelPosition)) {
            return false;
        }
        ItemLabelPosition that = (ItemLabelPosition) obj;
        if (!this.itemLabelAnchor.equals(that.itemLabelAnchor)) {
            return false;
        }
        if (!this.textAnchor.equals(that.textAnchor)) {
            return false;
        }
        if (!this.rotationAnchor.equals(that.rotationAnchor)) {
            return false;
        }
        if (this.angle != that.angle) {
            return false;
        }     
        return true;
    }

}
