Cleaned up XML parsing to store temporary info more cleanly. Initial

work on scene group parser.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@271 542714f4-19e9-0310-aa3c-eee0fc999fb1

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

@@ -0,0 +1,164 @@
+//
+// $Id: XMLSceneGroupParser.java,v 1.1 2001/08/16 20:14:06 shaper Exp $
+
+package com.threerings.miso.scene.xml;
+
+import java.io.*;
+import java.util.*;
+import javax.xml.parsers.ParserConfigurationException;
+
+import org.xml.sax.*;
+import org.xml.sax.helpers.DefaultHandler;
+
+import com.samskivert.util.*;
+import com.samskivert.xml.XMLUtil;
+import com.threerings.miso.Log;
+import com.threerings.miso.scene.*;
+
+/**
+ * Parses an XML scene group description file, loads the referenced
+ * scenes into the runtime scene repository, and creates bindings
+ * between the portals in the scenes.
+ *
+ * <p> Does not currently perform validation on the input XML stream,
+ * though the parsing code assumes the XML document is well-formed.
+ */
+public class XMLSceneGroupParser extends DefaultHandler
+{
+    public void startElement (String uri, String localName,
+			      String qName, Attributes attributes)
+    {
+	_tag = qName;
+    }
+
+    public void endElement (String uri, String localName, String qName)
+    {
+	// we know we've received the entirety of the character data
+        // for the elements we're tracking at this point, so proceed
+        // with saving off element data for later use.
+
+	// note that we're not within a tag to avoid considering any
+	// characters during this quiescent time
+	_tag = null;
+
+        // and clear out the character data we're gathering
+        _chars = new StringBuffer();
+    }
+
+    public void characters (char ch[], int start, int length)
+    {
+	// bail if we're not within a meaningful tag
+	if (_tag == null) return;
+
+  	_chars.append(ch, start, length);
+    }
+
+    /**
+     * Parse the specified XML file and return a list of miso scene
+     * objects that have been fully bound and loaded into the scene
+     * repository.
+     *
+     * @param fname the file name.
+     *
+     * @return the list of scene objects, or null if an error occurred.
+     */
+    public List loadSceneGroup (String fname) throws IOException
+    {
+        _fname = fname;
+
+	try {
+            // get the file input stream
+	    FileInputStream fis = new FileInputStream(fname);
+            BufferedInputStream bis = new BufferedInputStream(fis);
+
+            // prepare temporary data storage for parsing
+	    _chars = new StringBuffer();
+
+            // read the XML input stream and construct all scene objects
+	    XMLUtil.parse(this, bis);
+
+            // return the final list of scene objects
+            return _info.scenes;
+
+        } 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;
+
+    /** Temporary storage of scene group values and data. */
+    protected StringBuffer _chars;
+
+    /** The scene group info gathered while parsing. */
+    protected SceneGroupInfo _info;
+
+    /**
+     * A class to hold information on the overall scene group while
+     * parsing, as well as the resulting list of scene objects
+     * produced when finished.
+     */
+    class SceneGroupInfo
+    {
+	/** The list of scenes constructed once parsing is complete. */
+	public ArrayList scenes;
+
+	/** The scene info for all scenes described in the group. */
+	public ArrayList sceneinfo;
+
+	/** The current scene info. */
+	public SceneInfo curscene;
+    }
+
+    /**
+     * A class to hold information on a single scene's bindings.
+     */
+    class SceneInfo
+    {
+	/** The logical scene name. */
+	public String name;
+
+	/** The scene description file path. */
+	public String src;
+
+	/** The default scene entrance. */
+	public String entrance;
+
+	/** The list of portal info objects describing portal bindings. */
+	public ArrayList portals;
+
+	public SceneInfo (String src)
+	{
+	    this.src = src;
+	}
+    }
+
+    /**
+     * A class to hold information on a single portal's bindings.
+     */
+    class PortalInfo
+    {
+	/** The source portal name. */
+	public String src;
+
+	/** The destination portal name within the destination scene. */
+	public String dest;
+
+	/** The logical destination scene name. */
+	public String destScene;
+
+	public PortalInfo (String src, String destScene, String dest)
+	{
+	    this.src = src;
+	    this.destScene = destScene;
+	    this.dest = dest;
+	}
+    }
+}