More work on parsing scene XML files.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@120 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/miso/tools/xml/XMLSceneParser.java

@@ -1,18 +1,213 @@
 //
-// $Id: XMLSceneParser.java,v 1.1 2001/07/24 16:10:19 shaper Exp $
+// $Id: XMLSceneParser.java,v 1.2 2001/07/24 22:52:02 shaper Exp $
 
 package com.threerings.miso.scene.xml;
 
-import java.io.IOException;
+import java.awt.Point;
+import java.io.*;
 import java.util.ArrayList;
+import javax.xml.parsers.ParserConfigurationException;
 
-import com.threerings.miso.scene.Scene;
+import org.xml.sax.*;
+import org.xml.sax.helpers.DefaultHandler;
 
-public class XMLSceneParser
+import com.samskivert.util.*;
+import com.samskivert.xml.XMLUtil;
+import com.threerings.miso.Log;
+import com.threerings.miso.scene.*;
+import com.threerings.miso.tile.*;
+
+/**
+ * Parse an XML scene description file and construct a scene object.
+ * Does not currently perform validation on the input XML stream,
+ * though the parsing code assumes the XML document is well-formed.
+ *
+ * @see XMLSceneWriter
+ */
+public class XMLSceneParser extends DefaultHandler
 {
+    public XMLSceneParser (TileManager tilemgr)
+    {
+        _tilemgr = tilemgr;
+    }
+
+    public void startElement (String uri, String localName,
+			      String qName, Attributes attributes)
+    {
+	_tag = qName;
+    }
+
+    public void endElement (String uri, String localName, String qName)
+    {
+	// construct the scene object on tag close
+	if (qName.equals("scene")) {
+            _scene = new Scene(_tilemgr, Scene.SID_INVALID);
+            Log.info("Constructed parsed scene [scene=" + _scene + "].");
+	}
+
+	// note that we're not within a tag to avoid considering any
+	// characters during this quiescent time
+	_tag = null;
+    }
+
+    public void characters (char ch[], int start, int length)
+    {
+	// bail if we're not within a meaningful tag
+	if (_tag == null) return;
+
+  	String str = String.copyValueOf(ch, start, length);
+
+	// store the value associated with the current tag for use
+	// when we construct the tileset object.
+	if (_tag.equals("name")) {
+	    _scName = str;
+
+	} else if (_tag.equals("version")) {
+            int version = getInt(str);
+            if (version < 0 || version > Scene.VERSION) {
+                Log.warning(
+                    "Unrecognized scene file format version, will attempt " + 
+                    "to continue parsing file but your mileage may vary " +
+                    "[fname=" + _fname + ", version=" + version +
+                    ", known_version=" + Scene.VERSION + "].");
+            }
+
+	} else if (_tag.equals("hotspots")) {
+            _scHotspots = toPointArray(StringUtil.parseIntArray(str));
+
+	} else if (_tag.equals("exits")) {
+	    _scExits = toExitPointArray(StringUtil.parseStringArray(str));
+	}
+
+        // TODO:
+        // tiles
+        //   layer lnum="0"
+        //     row <rownum="X">
+        //   layer lnum="1"
+        //     row <rownum="X" colstart="Y">
+    }
+
+    /**
+     * Given an array of integer values, return a Point array
+     * constructed from each successive tuple of values as (x, y) in
+     * the array.
+     *
+     * @param vals the integer values.
+     *
+     * @return the point array, or null if an error occurred.
+     */
+    protected Point[] toPointArray (int[] vals)
+    {
+        // make sure we have an even number of points
+        if ((vals.length % 2) == 1) return null;
+
+        // pull the point coordinates out of the int array
+        Point[] points = new Point[vals.length / 2];
+        for (int ii = 0; ii < vals.length; ii += 2) {
+            int idx = ii / 2;
+            points[idx] = new Point(vals[ii], vals[ii + 1]);
+        }
+
+        return points;
+    }
+
+    /**
+     * Given an array of String values, return an ExitPoint array
+     * constructed from each successive triplet of values as (x, y,
+     * scene name) in the array.
+     *
+     * <p> This is something of a hack since we perhaps ought to parse
+     * the original String into its constituent components ourselves,
+     * but I'm unable to restrain myself from using the handy
+     * <code>StringUtil.toString()</code> method to take care of
+     * tokenizing things for us, so, there you have it.
+     *
+     * @param vals the String values.
+     *
+     * @return the ExitPoint array, or null if an error occurred.
+     */
+    protected ExitPoint[] toExitPointArray (String[] vals)
+    {
+        // make sure we have an appropriate number of values
+        if ((vals.length % 3) != 0) return null;
+
+        // pull the point values out of the string array
+        ExitPoint[] exits = new ExitPoint[vals.length / 3];
+        for (int ii = 0; ii < vals.length; ii += 3) {
+            int idx = ii / 3;
+            exits[idx] = new ExitPoint();
+            exits[idx].x = (byte)getInt(vals[ii]);
+            exits[idx].y = (byte)getInt(vals[ii + 1]);
+            exits[idx].name = vals[ii + 2];
+
+            // scene id is only valid at runtime
+            exits[idx].sid = Scene.SID_INVALID;
+        }
+
+        return exits;
+    }
+
+    /**
+     * Parse the given string as an integer and return the integer
+     * value, or -1 if the string is malformed.
+     */
+    protected int getInt (String str)
+    {
+        try {
+            return Integer.parseInt(str);
+        } catch (NumberFormatException nfe) {
+            Log.warning("Malformed integer value [str=" + str + "].");
+            return -1;
+        }
+    }
+
+    /**
+     * Parse the specified XML file and return a Scene object with the
+     * data contained therein.
+     *
+     * @param fname the file name.
+     *
+     * @return the scene object, or null if an error occurred.
+     */
     public Scene loadScene (String fname) throws IOException
     {
-        // TBD
-        return null;
+        _fname = fname;
+
+	try {
+            // get the file input stream
+	    FileInputStream fis = new FileInputStream(fname);
+            BufferedInputStream bis = new BufferedInputStream(fis);
+
+            // read the XML input stream and construct the scene object
+            _scene = null;
+	    XMLUtil.parse(this, bis);
+
+            // return the final scene object
+            return _scene;
+
+        } catch (ParserConfigurationException pce) {
+  	    throw new IOException(pce.toString());
+
+	} catch (SAXException saxe) {
+	    throw new IOException(saxe.toString());
+	}
     }
+
+    /** The file currently being processed. */
+    protected String _fname;
+
+    /** The XML element tag currently being processed. */
+    protected String _tag;
+
+    /** The scene object constructed as each scene file is read. */
+    protected Scene _scene;
+
+    /** The tile manager object for use in constructing scenes. */
+    protected TileManager _tilemgr;
+
+    // temporary storage of scene object values
+    protected String _scName;
+    protected Point[] _scHotspots;
+    protected ExitPoint[] _scExits;
+    protected Tile[][][] _scTiles;
 }

src/java/com/threerings/miso/tools/xml/XMLSceneRepository.java

@@ -1,5 +1,5 @@
 //
-// $Id: XMLSceneRepository.java,v 1.2 2001/07/24 19:15:51 shaper Exp $
+// $Id: XMLSceneRepository.java,v 1.3 2001/07/24 22:52:02 shaper Exp $
 
 package com.threerings.miso.scene.xml;
 
@@ -31,7 +31,7 @@ public class XMLFileSceneRepository extends SceneRepositoryImpl
     {
         super.init(config, tilemgr);
         _root = _config.getValue(CONFIG_ROOT, DEF_ROOT);
-        _parser = new XMLSceneParser();
+        _parser = new XMLSceneParser(_tilemgr);
         _writer = new XMLSceneWriter();
     }