/* ======================================
 * JFreeChart : a free Java chart library
 * ======================================
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 * Project Lead:  David Gilbert (david.gilbert@object-refinery.com);
 *
 * (C) Copyright 2000-2003, by Object Refinery Limited and Contributors.
 *
 * 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., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * --------------
 * AxisSpace.java
 * --------------
 * (C) Copyright 2003, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: AxisSpace.java,v 1.7 2003/08/20 11:40:38 mungady Exp $
 *
 * Changes
 * -------
 * 03-Jul-2003 : Version 1 (DG);
 * 14-Aug-2003 : Implemented Cloneable (DG);
 * 18-Aug-2003 : Implemented Serializable (DG);
 *
 */
 
package org.jfree.chart.axis;

import java.awt.geom.Rectangle2D;
import java.io.Serializable;

import org.jfree.ui.RectangleEdge;
import org.jfree.util.PublicCloneable;

/**
 * A record that contains the space required at each edge of a plot.
 * 
 * @author David Gilbert
 */
public class AxisSpace implements Cloneable, PublicCloneable, Serializable {
    
    /** The top space. */
    private double top;
    
    /** The bottom space. */
    private double bottom;
    
    /** The left space. */
    private double left;
    
    /** The right space. */
    private double right;
    
    /**
     * Creates a new axis space record.
     */
    public AxisSpace() {
        this.top = 0.0;
        this.bottom = 0.0;
        this.left = 0.0;
        this.right = 0.0;
    }

    /**
     * Returns the top space.
     * 
     * @return The top space.
     */
    public double getTop() {
        return this.top;
    }
    
    /**
     * Sets the top space. 
     * 
     * @param space  the space.
     */
    public void setTop(double space) {
        this.top = space;
    }

    /**
     * Returns the bottom space.
     * 
     * @return The bottom space.
     */
    public double getBottom() {
        return this.bottom;
    }
    
    /**
     * Sets the bottom space.
     * 
     * @param space  the space.
     */
    public void setBottom(double space) {
        this.bottom = space;
    }

    /**
     * Returns the left space.
     * 
     * @return The left space.
     */
    public double getLeft() {
        return this.left;
    }
    
    /**
     * Sets the left space.
     * 
     * @param space  the space.
     */
    public void setLeft(double space) {
        this.left = space;
    }

    /**
     * Returns the right space.
     * 
     * @return The right space.
     */
    public double getRight() {
        return this.right;
    }
    
    /**
     * Sets the right space.
     * 
     * @param space  the space.
     */
    public void setRight(double space) {
        this.right = space;
    }

    /**
     * Adds some space to the edge corresponding to the specified axis location.
     * 
     * @param space  the space.
     * @param edge  the location.
     */
    public void add(double space, RectangleEdge edge) {
        if (edge == RectangleEdge.TOP) {     
            this.top += space;
        }
        else if (edge == RectangleEdge.BOTTOM) {
            this.bottom += space;
        }
        else if (edge == RectangleEdge.LEFT) {
            this.left += space;
        }
        else if (edge == RectangleEdge.RIGHT) {
            this.right += space;
        }
        else {
            throw new IllegalStateException("AxisSpace.add(...): unrecognised RectangleEdge.");
        }
    }
    
    /**
     * Ensures that this object reserves at least as much space as another.
     * 
     * @param space  the other space.
     */
    public void ensureAtLeast(AxisSpace space) {
        this.top = Math.max(this.top, space.top);
        this.bottom = Math.max(this.bottom, space.bottom);
        this.left = Math.max(this.left, space.left);
        this.right = Math.max(this.right, space.right);
    }
    
    /**
     * Ensures there is a minimum amount of space at the edge corresponding to the specified 
     * axis location.
     * 
     * @param space  the space.
     * @param edge  the location.
     */
    public void ensureAtLeast(double space, RectangleEdge edge) {
        if (edge == RectangleEdge.TOP) {
            if (this.top < space) {
                this.top = space;
            }
        }
        else if (edge == RectangleEdge.BOTTOM) {
            if (this.bottom < space) {
                this.bottom = space;
            }
        }
        else if (edge == RectangleEdge.LEFT) {
            if (this.left < space) {
                this.left = space;
            }
        }
        else if (edge == RectangleEdge.RIGHT) {
            if (this.right < space) {
                this.right = space;
            }
        }
        else {
            throw new IllegalStateException(
                "AxisSpace.ensureAtLeast(...): unrecognised AxisLocation."
            );
        }
    }
    
    /**
     * Shrinks an area by the space attributes.
     * 
     * @param area  the area to shrink.
     * @param result  an optional carrier for the result.
     * 
     * @return The result.
     */
    public Rectangle2D shrink(Rectangle2D area, Rectangle2D result) {
        if (result == null) {
            result = new Rectangle2D.Double();
        }
        result.setRect(
            area.getX() + this.left, 
            area.getY() + this.top,
            area.getWidth() - this.left - this.right,
            area.getHeight() - this.top - this.bottom
        );
        return result;
    }

    /**
     * Shrinks an area's left and right edges by the amount of this objects left and right settings.
     * 
     * @param area  the area to shrink.
     * @param result  an optional carrier for the result.
     * 
     * @return The result.
     */
    public Rectangle2D shrinkLeftAndRight(Rectangle2D area, Rectangle2D result) {
        if (result == null) {
            result = new Rectangle2D.Double();
        }
        result.setRect(
            area.getX() + this.left, 
            area.getY(),
            area.getWidth() - this.left - this.right,
            area.getHeight()
        );
        return result;
    }

    /**
     * Shrinks an area's top and bottom edges by the amount of this objects top and bottom settings.
     * 
     * @param area  the area to shrink.
     * @param result  an optional carrier for the result.
     * 
     * @return The result.
     */
    public Rectangle2D shrinkTopAndBottom(Rectangle2D area, Rectangle2D result) {
        if (result == null) {
            result = new Rectangle2D.Double();
        }
        result.setRect(
            area.getX(), 
            area.getY() + this.top,
            area.getWidth(),
            area.getHeight() - this.top - this.bottom
        );
        return result;
    }

    /**
     * Expands an area by the amount of space represented by this object.
     * 
     * @param area  the area to expand.
     * @param result  an optional carrier for the result.
     * 
     * @return The result.
     */
    public Rectangle2D expand(Rectangle2D area, Rectangle2D result) {
        if (result == null) {
            result = new Rectangle2D.Double();
        }
        result.setRect(
            area.getX() - this.left, 
            area.getY() - this.top,
            area.getWidth() + this.left + this.right,
            area.getHeight() + this.top + this.bottom
        );
        return result;
    }
    
    /**
     * Calculates the reserved area.
     * 
     * @param area  the area.
     * @param edge  the edge.
     * 
     * @return The reserved area.
     */
    public Rectangle2D reserved(Rectangle2D area, RectangleEdge edge) {
        Rectangle2D result = null;
        if (edge == RectangleEdge.TOP) {
            result = new Rectangle2D.Double(area.getX(), area.getY(),
                                            area.getWidth(), this.top);
        }
        else if (edge == RectangleEdge.BOTTOM) {
            result = new Rectangle2D.Double(area.getX(), area.getMaxY() - this.top,
                                            area.getWidth(), this.bottom);
        }
        else if (edge == RectangleEdge.LEFT) {
            result = new Rectangle2D.Double(area.getX(), area.getY(),
                                            this.left, area.getHeight());
        }
        else if (edge == RectangleEdge.RIGHT) {
            result = new Rectangle2D.Double(area.getMaxX() - this.right, area.getY(),
                                            this.right, area.getHeight());
        }
        return result;
    }
    
    /**
     * Returns a clone of the object.
     * 
     * @return A clone.
     * 
     * @throws CloneNotSupportedException This class won't throw this exception, but subclasses 
     *         (if any) might.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
    
    /**
     * Tests this object for equality with another object.
     * 
     * @param object  the object to compare against.
     * 
     * @return <code>true</code> or <code>false</code>.
     */
    public boolean equals(Object object) {
        
        if (object == null) {
            return false;
        }
        
        if (object == this) {
            return true;
        }
        
        if (object instanceof AxisSpace) {
            AxisSpace s = (AxisSpace) object;
            boolean b0 = (this.top == s.top);   
            boolean b1 = (this.bottom == s.bottom);   
            boolean b2 = (this.left == s.left);   
            boolean b3 = (this.right == s.right);   
            return b0 && b1 && b2 && b3;
        }
        
        return false;
        
    }
    
}