Initial work on support for objects whose images span multiple tiles.

Made TileSet an interface.  Throw exceptions for unknown tile or tile
set requests.  General clean-up and documentation.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@427 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/media/tile/NoSuchTileException.java

@@ -0,0 +1,24 @@
+//
+// $Id: NoSuchTileException.java,v 1.1 2001/10/11 00:41:26 shaper Exp $
+
+package com.threerings.media.tile;
+
+/**
+ * Thrown when an attempt is made to retrieve a non-existent tile from the
+ * tile manager.
+ */
+public class NoSuchTileException extends TileException
+{
+    public NoSuchTileException (int tid)
+    {
+	super("No such tile [tid=" + tid + "]");
+	_tid = tid;
+    }
+
+    public int getTileId ()
+    {
+	return _tid;
+    }
+
+    protected int _tid;
+}

src/java/com/threerings/media/tile/NoSuchTileSetException.java

@@ -0,0 +1,24 @@
+//
+// $Id: NoSuchTileSetException.java,v 1.1 2001/10/11 00:41:26 shaper Exp $
+
+package com.threerings.media.tile;
+
+/**
+ * Thrown when an attempt is made to retrieve a non-existent tile set
+ * from the tile set manager.
+ */
+public class NoSuchTileSetException extends TileException
+{
+    public NoSuchTileSetException (int tsid)
+    {
+	super("No such tile set [tsid=" + tsid + "]");
+	_tsid = tsid;
+    }
+
+    public int getTileSetId ()
+    {
+	return _tsid;
+    }
+
+    protected int _tsid;
+}

src/java/com/threerings/media/tile/ObjectTile.java

@@ -0,0 +1,40 @@
+//
+// $Id: ObjectTile.java,v 1.1 2001/10/11 00:41:26 shaper Exp $
+
+package com.threerings.media.tile;
+
+import java.awt.Graphics2D;
+import java.awt.Shape;
+
+/**
+ * An object tile extends the base tile to provide support for objects
+ * whose image spans more than one tile.  The object has dimensions
+ * that represent its footprint or "shadow", which the scene
+ * containing the tile can reference to do things like make the
+ * footprint tiles impassable.
+ */
+public class ObjectTile extends Tile
+{
+    /** The object footprint dimensions in unit tile units. */
+    public int baseWidth, baseHeight;
+
+    /**
+     * Constructs a new object tile.
+     */
+    public ObjectTile (int tsid, int tid, int baseWidth, int baseHeight)
+    {
+	super(tsid, tid);
+
+	this.baseWidth = baseWidth;
+	this.baseHeight = baseHeight;
+    }
+
+    // documentation inherited
+    public void paint (Graphics2D gfx, Shape dest)
+    {
+	super.paint(gfx, dest);
+
+	// TODO: draw the object image offset to account for its
+	// actual dimensions
+    }
+}

src/java/com/threerings/media/tile/Tile.java

@@ -1,9 +1,9 @@
 //
-// $Id: Tile.java,v 1.13 2001/10/08 21:04:25 shaper Exp $
+// $Id: Tile.java,v 1.14 2001/10/11 00:41:26 shaper Exp $
 
 package com.threerings.media.tile;
 
-import java.awt.Image;
+import java.awt.*;
 
 /**
  * A tile represents a single square in a single layer in a scene.
@@ -48,6 +48,16 @@ public class Tile
         return ((int)tsid << 16) | tid;
     }
 
+    /**
+     * Render the tile into the given rectangle in the given graphics
+     * context.
+     */
+    public void paint (Graphics2D gfx, Shape dest)
+    {
+	Rectangle bounds = dest.getBounds();
+	gfx.drawImage(img, bounds.x, bounds.y, null);
+    }
+
     /**
      * Return a string representation of the tile information.
      */

src/java/com/threerings/media/tile/TileException.java

@@ -0,0 +1,15 @@
+//
+// $Id: TileException.java,v 1.1 2001/10/11 00:41:26 shaper Exp $
+
+package com.threerings.media.tile;
+
+/**
+ * Thrown when an error occurs while working with tiles.
+ */
+public class TileException extends Exception
+{
+    public TileException (String message)
+    {
+	super(message);
+    }
+}

src/java/com/threerings/media/tile/TileManager.java

@@ -1,5 +1,5 @@
 //
-// $Id: TileManager.java,v 1.17 2001/09/28 00:44:31 shaper Exp $
+// $Id: TileManager.java,v 1.18 2001/10/11 00:41:26 shaper Exp $
 
 package com.threerings.media.tile;
 
@@ -39,6 +39,7 @@ public class TileManager
      * @return the tile object, or null if an error occurred.
      */
     public Tile getTile (int tsid, int tid)
+	throws NoSuchTileSetException, NoSuchTileException
     {
 	// the fully unique tile id is the conjoined tile set and tile id
 	int utid = (tsid << 16) | tid;

src/java/com/threerings/media/tile/TileSet.java

@@ -1,14 +1,8 @@
 //
-// $Id: TileSet.java,v 1.16 2001/10/08 21:04:25 shaper Exp $
+// $Id: TileSet.java,v 1.17 2001/10/11 00:41:26 shaper Exp $
 
 package com.threerings.media.tile;
 
-import java.awt.Image;
-import java.awt.Point;
-import java.awt.image.*;
-
-import com.samskivert.util.StringUtil;
-import com.threerings.media.Log;
 import com.threerings.media.ImageManager;
 
 /**
@@ -21,90 +15,25 @@ import com.threerings.media.ImageManager;
  * the image is tile id 0 and tiles are numbered left to right, top to
  * bottom, in ascending order.
  */
-public class TileSet
+public interface TileSet
 {
-    /**
-     * Construct a new <code>TileSet</code> object.
-     */
-    public TileSet ()
-    {
-	_model = new TileSetModel();
-    }
-
     /**
      * Return the tileset identifier.
      */
-    public int getId ()
-    {
-	return _model.tsid;
-    }
+    public int getId ();
 
     /**
      * Return the tileset name.
      */
-    public String getName ()
-    {
-	return _model.name;
-    }
+    public String getName ();
 
     /**
      * Return the number of tiles in the tileset.
      */
-    public int getNumTiles ()
-    {
-	return _model.numTiles;
-    }
+    public int getNumTiles ();
 
     /**
-     * Return the image corresponding to the specified tile id within
-     * this tile set.
-     *
-     * @param imgmgr the image manager.
-     * @param tid the tile id.
-     *
-     * @return the tile image.
-     */
-    protected Image getTileImage (ImageManager imgmgr, int tid)
-    {
-	// load the full tile image if we don't already have it
-	if (_imgTiles == null) {
-	    if ((_imgTiles = imgmgr.getImage(_model.imgFile)) == null) {
-		Log.warning("Failed to retrieve full tileset image " +
-			    "[file=" + _model.imgFile + "].");
-		return null;
-	    }
-	}
-
-	// find the row number containing the sought-after tile
-	int ridx, tcount, ty, tx;
-	ridx = tcount = 0;
-
-        // start tile image position at image start offset
-        tx = _model.offsetPos.x;
-        ty = _model.offsetPos.y;
-
-	while ((tcount += _model.tileCount[ridx]) < tid + 1) {
-            // increment tile image position by row height and gap distance
-	    ty += (_model.rowHeight[ridx++] + _model.gapDist.y);
-	}
-
-        // determine the horizontal index of this tile in the row
-	int xidx = tid - (tcount - _model.tileCount[ridx]);
-
-        // final image x-position is based on tile width and gap distance
-        tx += (xidx * (_model.rowWidth[ridx] + _model.gapDist.x));
-
-//          Log.info("Retrieving tile image [tid=" + tid + ", ridx=" +
-//                   ridx + ", xidx=" + xidx + ", tx=" + tx +
-//                   ", ty=" + ty + "].");
-
-	// crop the tile-sized image chunk from the full image
-	return imgmgr.getImageCropped(
-            _imgTiles, tx, ty, _model.rowWidth[ridx], _model.rowHeight[ridx]);
-    }
-
-    /**
-     * Return the {@link Tile} object from this tileset corresponding
+     * Returns the {@link Tile} object from this tileset corresponding
      * to the specified tile id, or <code>null</code> if no such tile
      * id exists.  The tile image is retrieved from the given image
      * manager.
@@ -115,115 +44,5 @@ public class TileSet
      * @return the tile object, or null if no such tile exists.
      */
     public Tile getTile (ImageManager imgmgr, int tid)
-    {
-	// bail if there's no such tile
-	if (tid > (_model.numTiles - 1)) {
-	    return null;
-	}
-
-	// create the tile object
-	Tile tile = createTile(tid);
-
-	// retrieve the tile image
-	tile.img = getTileImage(imgmgr, tid);
-	if (tile.img == null) {
-	    Log.warning("Null tile image " +
-			"[tsid=" + _model.tsid + ", tid=" + tid + "].");
-	}
-
-	// populate the tile's dimensions
-        BufferedImage bimg = (BufferedImage)tile.img;
-	tile.height = (short)bimg.getHeight();
-        tile.width = (short)bimg.getWidth();
-
-	return tile;
-    }
-
-    /**
-     * Returns the tile set model.
-     */
-    public TileSetModel getModel ()
-    {
-	return _model;
-    }
-
-    /**
-     * Return a string representation of the tileset information.
-     */
-    public String toString ()
-    {
-	return _model.toString();
-    }
-
-    /**
-     * Construct and return a new tile object for further population
-     * with tile-specific information.
-     */
-    protected Tile createTile (int tid)
-    {
-	return new Tile(_model.tsid, tid);
-    }
-
-    /** The image containing all tile images for this set. */
-    protected Image _imgTiles;
-
-    /** The tile set data model. */
-    protected TileSetModel _model;
-
-    /**
-     * The model that details the attributes of each tile in a
-     * tileset.  Storing the data separately from the tile set object
-     * itself allows for the wealth of information associated with a
-     * tile set to be more cleanly gathered and passed on to the tile
-     * set constructor by those that need to do so.
-     */
-    public static class TileSetModel
-    {
-	/** The tileset name. */
-	public String name;
-
-	/** The tileset unique identifier. */
-	public int tsid;
-
-	/** The file containing the tile images. */
-	public String imgFile;
-
-	/** The width of the tiles in each row in pixels. */
-	public int[] rowWidth;
-
-	/** The height of the tiles in each row in pixels. */
-	public int[] rowHeight;
-
-	/** The number of tiles in each row. */
-	public int[] tileCount;
-
-	/** The number of tiles in the tileset. */
-	public int numTiles;
-
-	/**
-	 * The offset distance (x, y) in pixels from the top-left of the
-	 * image to the start of the first tile image.
-	 */
-	public Point offsetPos = new Point();
-
-	/**
-	 * The distance (x, y) in pixels between each tile in each row
-	 * horizontally, and between each row of tiles vertically.
-	 */
-	public Point gapDist = new Point();
-
-	public TileSetModel ()
-	{
-	}
-
-	public String toString ()
-	{
-	    StringBuffer buf = new StringBuffer();
-	    buf.append("[name=").append(name);
-	    buf.append(", file=").append(imgFile);
-	    buf.append(", tsid=").append(tsid);
-	    buf.append(", numtiles=").append(numTiles);
-	    return buf.append("]").toString();
-	}
-    }
+	throws NoSuchTileException;
 }

src/java/com/threerings/media/tile/TileSetImpl.java

@@ -0,0 +1,197 @@
+//
+// $Id: TileSetImpl.java,v 1.1 2001/10/11 00:41:26 shaper Exp $
+
+package com.threerings.media.tile;
+
+import java.awt.Image;
+import java.awt.Point;
+import java.awt.image.*;
+
+import com.samskivert.util.HashIntMap;
+import com.samskivert.util.StringUtil;
+
+import com.threerings.media.Log;
+import com.threerings.media.ImageManager;
+
+// documentation inherited
+public class TileSetImpl implements TileSet
+{
+    /** The tileset name. */
+    public String name;
+
+    /** The tileset unique identifier. */
+    public int tsid;
+
+    /** The file containing the tile images. */
+    public String imgFile;
+
+    /** The width of the tiles in each row in pixels. */
+    public int[] rowWidth;
+
+    /** The height of the tiles in each row in pixels. */
+    public int[] rowHeight;
+
+    /** The number of tiles in each row. */
+    public int[] tileCount;
+
+    /** The number of tiles in the tileset. */
+    public int numTiles;
+
+    /** Mapping of object tile ids to object dimensions. */
+    public HashIntMap objects = new HashIntMap();
+
+    /**
+     * The offset distance (x, y) in pixels from the top-left of the
+     * image to the start of the first tile image.
+     */
+    public Point offsetPos = new Point();
+
+    /**
+     * The distance (x, y) in pixels between each tile in each row
+     * horizontally, and between each row of tiles vertically.
+     */
+    public Point gapDist = new Point();
+
+    // documentation inherited
+    public int getId ()
+    {
+	return tsid;
+    }
+
+    // documentation inherited
+    public String getName ()
+    {
+	return name;
+    }
+
+    // documentation inherited
+    public int getNumTiles ()
+    {
+	return numTiles;
+    }
+
+    // documentation inherited
+    public Tile getTile (ImageManager imgmgr, int tid)
+	throws NoSuchTileException
+    {
+	// bail if there's no such tile
+	if (tid < 0 || tid > (numTiles - 1)) {
+	    throw new NoSuchTileException(tid);
+	}
+
+	// create and populate the tile object
+	Tile tile = createTile(tid);
+
+	// retrieve the tile image
+	tile.img = getTileImage(imgmgr, tile.tid);
+	if (tile.img == null) {
+	    Log.warning("Null tile image [tile=" + tile + "].");
+	}
+
+	// populate the tile's dimensions
+        BufferedImage bimg = (BufferedImage)tile.img;
+	tile.height = (short)bimg.getHeight();
+        tile.width = (short)bimg.getWidth();
+
+	// allow sub-classes to fill in their tile information
+	populateTile(tile);
+
+	return tile;
+    }
+
+    /**
+     * Return a string representation of the tileset information.
+     */
+    public String toString ()
+    {
+	StringBuffer buf = new StringBuffer();
+	buf.append("[name=").append(name);
+	buf.append(", file=").append(imgFile);
+	buf.append(", tsid=").append(tsid);
+	buf.append(", numtiles=").append(numTiles);
+	return buf.append("]").toString();
+    }
+
+    /**
+     * Construct and return a new tile object for further population
+     * with tile-specific information.  Derived classes can override
+     * this method to create their own sub-class of <code>Tile</code>.
+     *
+     * @param tid the tile id for the new tile.
+     *
+     * @return the new tile object.
+     */
+    protected Tile createTile (int tid)
+    {
+	int size[] = (int[])objects.get(tid);
+	if (size != null) {
+	    return new ObjectTile(tsid, tid, size[0], size[1]);
+	}
+
+	return new Tile(tsid, tid);
+    }
+
+    /**
+     * Populates the given tile object with its detailed tile
+     * information.  Derived classes can override this method to add
+     * in their own tile information, but should be sure to call
+     * <code>super.populateTile()</code>.
+     *
+     * @param tile the tile to populate.
+     */
+    protected void populateTile (Tile tile)
+    {
+	// nothing for now
+    }
+
+    /**
+     * Returns the image corresponding to the specified tile id within
+     * this tile set.
+     *
+     * @param imgmgr the image manager.
+     * @param tid the tile id.
+     *
+     * @return the tile image.
+     */
+    protected Image getTileImage (ImageManager imgmgr, int tid)
+    {
+	// load the full tile image if we don't already have it
+	if (_imgTiles == null) {
+	    if ((_imgTiles = imgmgr.getImage(imgFile)) == null) {
+		Log.warning("Failed to retrieve full tileset image " +
+			    "[file=" + imgFile + "].");
+		return null;
+	    }
+	}
+
+	// find the row number containing the sought-after tile
+	int ridx, tcount, ty, tx;
+	ridx = tcount = 0;
+
+        // start tile image position at image start offset
+        tx = offsetPos.x;
+        ty = offsetPos.y;
+
+	while ((tcount += tileCount[ridx]) < tid + 1) {
+            // increment tile image position by row height and gap distance
+	    ty += (rowHeight[ridx++] + gapDist.y);
+	}
+
+        // determine the horizontal index of this tile in the row
+	int xidx = tid - (tcount - tileCount[ridx]);
+
+        // final image x-position is based on tile width and gap distance
+        tx += (xidx * (rowWidth[ridx] + gapDist.x));
+
+	// Log.info("Retrieving tile image [tid=" + tid + ", ridx=" +
+	// ridx + ", xidx=" + xidx + ", tx=" + tx +
+	// ", ty=" + ty + "].");
+
+	// crop the tile-sized image chunk from the full image
+	return imgmgr.getImageCropped(
+            _imgTiles, tx, ty, rowWidth[ridx], rowHeight[ridx]);
+    }
+
+    /** The image containing all tile images for this set. */
+    protected Image _imgTiles;
+}

src/java/com/threerings/media/tile/TileSetManager.java

@@ -1,5 +1,5 @@
 //
-// $Id: TileSetManager.java,v 1.12 2001/08/16 23:14:20 mdb Exp $
+// $Id: TileSetManager.java,v 1.13 2001/10/11 00:41:26 shaper Exp $
 
 package com.threerings.media.tile;
 
@@ -26,7 +26,8 @@ public interface TileSetManager
      * @param tsid the tileset identifier.
      * @return the number of tiles.
      */
-    public int getNumTilesInSet (int tsid);
+    public int getNumTilesInSet (int tsid)
+	throws NoSuchTileSetException;
 
     /**
      * Return an <code>ArrayList</code> containing all
@@ -43,7 +44,8 @@ public interface TileSetManager
      * @param tsid the tileset identifier.
      * @return the tileset object.
      */
-    public TileSet getTileSet (int tsid);
+    public TileSet getTileSet (int tsid)
+	throws NoSuchTileSetException;
 
     /**
      * Return the tile object corresponding to the specified tileset
@@ -54,7 +56,8 @@ public interface TileSetManager
      *
      * @return the tile object.
      */
-    public Tile getTile (int tsid, int tid);
+    public Tile getTile (int tsid, int tid)
+	throws NoSuchTileSetException, NoSuchTileException;
 
     /**
      * Return the total number of tilesets available for use.

src/java/com/threerings/media/tile/TileSetManagerImpl.java

@@ -1,5 +1,5 @@
 //
-// $Id: TileSetManagerImpl.java,v 1.12 2001/09/17 05:18:21 mdb Exp $
+// $Id: TileSetManagerImpl.java,v 1.13 2001/10/11 00:41:26 shaper Exp $
 
 package com.threerings.media.tile;
 
@@ -28,20 +28,26 @@ public abstract class TileSetManagerImpl implements TileSetManager
     }
 
     public int getNumTilesInSet (int tsid)
+	throws NoSuchTileSetException
     {
-	TileSet tset = getTileSet(tsid);
-	return (tset != null) ? tset.getNumTiles() : -1;
+	return getTileSet(tsid).getNumTiles();
     }
 
     public TileSet getTileSet (int tsid)
+	throws NoSuchTileSetException
     {
-	return (TileSet)_tilesets.get(tsid);
+	TileSet tset = (TileSet)_tilesets.get(tsid);
+	if (tset == null) {
+	    throw new NoSuchTileSetException(tsid);
+	}
+
+	return tset;
     }
 
     public Tile getTile (int tsid, int tid)
+	throws NoSuchTileSetException, NoSuchTileException
     {
-	TileSet tset = getTileSet(tsid);
-	return (tset == null) ? null : tset.getTile(_imgmgr, tid);
+	return getTileSet(tsid).getTile(_imgmgr, tid);
     }
 
     public ArrayList getAllTileSets ()

src/java/com/threerings/media/tile/TileUtil.java

@@ -0,0 +1,46 @@
+//
+// $Id: TileUtil.java,v 1.1 2001/10/11 00:41:26 shaper Exp $
+
+package com.threerings.media.tile;
+
+import java.awt.Image;
+
+import com.threerings.media.Log;
+
+/**
+ * Miscellaneous utility routines for working with tiles.
+ */
+public class TileUtil
+{
+    /**
+     * Returns the image associated with the given tile from the given
+     * tile manager, or null if an error occurred.  Any exceptions
+     * that occur are logged.
+     */
+    public static Image getTileImage (TileManager tilemgr, int tsid, int tid)
+    {
+	try {
+	    Tile tile = tilemgr.getTile(tsid, tid);
+	    return tile.img;
+
+	} catch (TileException te) {
+	    Log.warning("Exception retrieving tile image [te=" + te + "].");
+	    return null;
+	}
+    }
+
+    /**
+     * Returns the given tile from the given tile manager, or null if
+     * an error occurred.  Any exceptions that occur are logged.
+     */
+    public static Tile getTile (TileManager tilemgr, int tsid, int tid)
+    {
+	try {
+	    return tilemgr.getTile(tsid, tid);
+
+	} catch (TileException te) {
+	    Log.warning("Exception retrieving tile [te=" + te + "].");
+	    return null;
+	}
+    }
+}

src/java/com/threerings/media/tile/XMLTileSetParser.java

@@ -1,5 +1,5 @@
 //
-// $Id: XMLTileSetParser.java,v 1.15 2001/10/08 21:04:25 shaper Exp $
+// $Id: XMLTileSetParser.java,v 1.16 2001/10/11 00:41:26 shaper Exp $
 
 package com.threerings.media.tile;
 
@@ -35,27 +35,27 @@ public class XMLTileSetParser extends DefaultHandler
     protected void finishElement (String qName, String str)
     {
 	if (qName.equals("imagefile")) {
-	    _model.imgFile = str;
+	    _tset.imgFile = str;
 
 	} else if (qName.equals("rowwidth")) {
-	    _model.rowWidth = StringUtil.parseIntArray(str);
+	    _tset.rowWidth = StringUtil.parseIntArray(str);
 
 	} else if (qName.equals("rowheight")) {
-	    _model.rowHeight = StringUtil.parseIntArray(str);
+	    _tset.rowHeight = StringUtil.parseIntArray(str);
 
 	} else if (qName.equals("tilecount")) {
-	    _model.tileCount = StringUtil.parseIntArray(str);
+	    _tset.tileCount = StringUtil.parseIntArray(str);
 
 	    // calculate the total number of tiles in the tileset
-	    for (int ii = 0; ii < _model.tileCount.length; ii++) {
-		_model.numTiles += _model.tileCount[ii];
+	    for (int ii = 0; ii < _tset.tileCount.length; ii++) {
+		_tset.numTiles += _tset.tileCount[ii];
 	    }
 
 	} else if (qName.equals("offsetpos")) {
-            getPoint(str, _model.offsetPos);
+            getPoint(str, _tset.offsetPos);
 
         } else if (qName.equals("gapdist")) {
-            getPoint(str, _model.gapDist);
+            getPoint(str, _tset.gapDist);
 
         } else if (qName.equals("tileset")) {
 	    // construct the tileset on tag close and add it to the
@@ -67,19 +67,31 @@ public class XMLTileSetParser extends DefaultHandler
 	}
     }
 
+    // documentation inherited
     public void startElement (String uri, String localName,
 			      String qName, Attributes attributes)
     {
 	_tag = qName;
 
 	if (_tag.equals("tileset")) {
-	    _model.tsid = getTileSetId(attributes.getValue("tsid"));
+	    _tset.tsid = getInt(attributes.getValue("tsid"));
 
 	    String str = attributes.getValue("name");
-	    _model.name = (str == null) ? DEF_NAME : str;
+	    _tset.name = (str == null) ? DEF_NAME : str;
+
+	} else if (_tag.equals("object")) {
+	    // TODO: should we bother checking to make sure we only
+	    // see <object> tags while within an <objects> tag?
+	    int tid = getInt(attributes.getValue("tid"));
+	    int wid = getInt(attributes.getValue("width"));
+	    int hei = getInt(attributes.getValue("height"));
+
+	    // add the object info to the tileset object hashtable
+	    _tset.objects.put(tid, new int[] { wid, hei });
 	}
     }
 
+    // documentation inherited
     public void endElement (String uri, String localName, String qName)
     {
 	// we know we've received the entirety of the character data
@@ -96,6 +108,7 @@ public class XMLTileSetParser extends DefaultHandler
         _chars = new StringBuffer();
     }
 
+    // documentation inherited
     public void characters (char ch[], int start, int length)
     {
 	// bail if we're not within a meaningful tag
@@ -106,6 +119,7 @@ public class XMLTileSetParser extends DefaultHandler
   	_chars.append(ch, start, length);
     }
 
+    // documentation inherited
     public ArrayList loadTileSets (String fname) throws IOException
     {
 	try {
@@ -141,15 +155,16 @@ public class XMLTileSetParser extends DefaultHandler
     {
 	_chars = new StringBuffer();
 	_tset = createTileSet();
-	_model = _tset.getModel();
     }
 
     /**
-     * Constructs and returns a new tile set object.
+     * Constructs and returns a new tile set object.  Derived classes
+     * may override this method to create their own sub-classes of the
+     * <code>TileSet</code> object.
      */
-    protected TileSet createTileSet ()
+    protected TileSetImpl createTileSet ()
     {
-	return new TileSet();
+	return new TileSetImpl();
     }
 
     /**
@@ -167,26 +182,19 @@ public class XMLTileSetParser extends DefaultHandler
     }
 
     /**
-     * Returns the integer tileset id corresponding to the given
-     * string, or <code>DEF_TSID</code> if an error occurred.
+     * Returns the integer represented by the given string or -1 if an
+     * error occurred.
      */
-    protected int getTileSetId (String str)
+    protected int getInt (String str)
     {
-	if (str == null) {
-	    return DEF_TSID;
-	}
-
 	try {
-	    return Integer.parseInt(str);
+	    return (str == null) ? -1 : Integer.parseInt(str);
 	} catch (NumberFormatException nfe) {
-	    Log.warning("Malformed integer tileset id [str=" + str + "].");
-	    return DEF_TSID;
+	    Log.warning("Malformed integer value [str=" + str + "].");
+	    return -1;
 	}
     }
 
-    /** Default tileset id. */
-    protected static final int DEF_TSID = -1;
-
     /** Default tileset name. */
     protected static final String DEF_NAME = "Untitled";
 
@@ -199,9 +207,6 @@ public class XMLTileSetParser extends DefaultHandler
     /** Temporary storage of character data while parsing. */
     protected StringBuffer _chars;
 
-    /** The tile set whose model is populated while parsing. */
-    protected TileSet _tset;
-
-    /** The tile set data model populated while parsing. */
-    protected TileSet.TileSetModel _model;
+    /** The tile set populated while parsing. */
+    protected TileSetImpl _tset;
 }