TileRef.java

/*******************************************************************************
 * Copyright (c) 2008, 2012 Stepan Rutz.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Stepan Rutz - initial implementation
 *    Hallvard Trætteberg - further cleanup and development
 *******************************************************************************/

package org.eclipse.nebula.widgets.geomap.internal;

/**
 * A single tile in the map. A tile has an x and y coordinate, but
 * both only make sense in the context of a given zoom level. The
 * tile's zoom level is given by <code>z</code>.
 * 
 * <p>For caching the tiles support some equals and hashCode behavior
 * that makes them suitable as key-objects in java-util collections.</p>
 */
public final class TileRef {

	/**
	 * The x coordinate of this TileRef
	 */
    public final int x;

    /**
     * The y coordinate of this TileRef
     */
    public final int y;

    /**
     * The z coordinate, i.e. zoom level, of this TileRef
     */
    public final int z;

    /**
     * Initializes this TileRef with x, y and z coordinates
     * @param x the x coordinate
     * @param y the y coordinate
     * @param z the z coordinate
     */
    public TileRef(int x, int y, int z) {
        this.x = x;
        this.y = y;
        this.z = z;
    }
    
	@Override
	@SuppressWarnings("nls")
    public String toString() {
    	return "Tile {" + x + ", " + y + " @ " + z + "}";
    }
    
	@Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + x;
        result = prime * result + y;
        result = prime * result + z;
        return result;
    }

	@Override
    public boolean equals(Object obj) {
        if (this == obj) {
        	return true;
        }
        if (obj == null || getClass() != obj.getClass()) {
        	return false;
        }
        TileRef other = (TileRef) obj;
        return (x == other.x && y == other.y && z == other.z);
    }
}