Tile.java

/*
 * Tile.java
 *
 * Created on March 14, 2006, 4:53 PM
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

package org.jdesktop.swingx.mapviewer;

import java.awt.image.BufferedImage;
import java.lang.ref.SoftReference;

import org.jdesktop.beans.AbstractBean;

/**
 * The Tile class represents a particular square image piece of the world bitmap at a particular zoom level.
 * @author joshy
 */

public class Tile extends AbstractBean
{
	/**
	 * The loading priority
	 */
	@SuppressWarnings("javadoc")
	public enum Priority
	{
		High, Low
	}

	private Priority priority = Priority.High;

	private TileFactory dtf;

	private boolean isLoading = false;

	// Most Recently Accessed Tiles. These are strong references, to prevent reloading
	// of most recently used tiles.
	// private static final Map<URI, BufferedImage> recentlyAccessed = new HashMap<URI, BufferedImage>();
	// private static final TileCache cache = new TileCache();

	/**
	 * The url of the image to load for this tile
	 */
	private String url;

	/**
	 * Indicates that loading has succeeded. A PropertyChangeEvent will be fired when the loading is completed
	 */

	private boolean loaded = false;
	/**
	 * The zoom level this tile is for
	 */
	private int zoom, x, y;

	/**
	 * The image loaded for this Tile
	 */
	SoftReference<BufferedImage> image = new SoftReference<BufferedImage>(null);

	/**
	 * Create a new Tile at the specified tile point and zoom level
	 * @param x the x value
	 * @param y the y value
	 * @param zoom the zoom level
	 */
	public Tile(int x, int y, int zoom)
	{
		loaded = false;
		this.zoom = zoom;
		this.x = x;
		this.y = y;
	}

	/**
	 * Create a new Tile that loads its data from the given URL. The URL must resolve to an image
	 * @param x the x value
	 * @param y the y value
	 * @param zoom the zoom level
	 * @param url the URL
	 * @param priority the priority
	 * @param dtf the tile factory
	 */
	Tile(int x, int y, int zoom, String url, Priority priority, TileFactory dtf)
	{
		this.url = url;
		loaded = false;
		this.zoom = zoom;
		this.x = x;
		this.y = y;
		this.priority = priority;
		this.dtf = dtf;
		// startLoading();
	}

	/**
	 * Indicates if this tile's underlying image has been successfully loaded yet.
	 * @return true if the Tile has been loaded
	 */
	public synchronized boolean isLoaded()
	{
		return loaded;
	}

	/**
	 * Toggles the loaded state, and fires the appropriate property change notification
	 * @param loaded the loaded flag
	 */
	synchronized void setLoaded(boolean loaded)
	{
		boolean old = isLoaded();
		this.loaded = loaded;
		firePropertyChange("loaded", old, isLoaded());
	}

	/**
	 * @return the Image associated with this Tile. This is a read only property This may return null at any time,
	 * however if this returns null, a load operation will automatically be started for it.
	 */
	public BufferedImage getImage()
	{
		BufferedImage img = image.get();
		if (img == null)
		{
			setLoaded(false);
			
			// tile factory can be null if the tile has invalid coords or zoom
			if (dtf != null)
			{
				dtf.startLoading(this);
			}
		}

		return img;
	}

	/**
	 * @return the location in the world at this zoom level that this tile should be placed
	 */
	/*
	 * public TilePoint getLocation() { return location; }
	 */

	/**
	 * @return the zoom level that this tile belongs in
	 */
	public int getZoom()
	{
		return zoom;
	}

	/**
	 * @return the isLoading
	 */
	public boolean isLoading()
	{
		return isLoading;
	}

	/**
	 * @param isLoading the isLoading to set
	 */
	public void setLoading(boolean isLoading)
	{
		this.isLoading = isLoading;
	}

	/**
	 * Gets the loading priority of this tile.
	 * @return the priority
	 */
	public Priority getPriority()
	{
		return priority;
	}

	/**
	 * Set the loading priority of this tile.
	 * @param priority the priority to set
	 */
	public void setPriority(Priority priority)
	{
		this.priority = priority;
	}

	/**
	 * Gets the URL of this tile.
	 * @return the url
	 */
	public String getURL()
	{
		return url;
	}

	/**
	 * @return the x value
	 */
	public int getX()
	{
		return x;
	}

	/**
	 * @return the y value
	 */
	public int getY()
	{
		return y;
	}

}