Added code to handle Streamable implementing DObject fields.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@452 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/presents/io/FieldMarshallerRegistry.java

@@ -1,11 +1,13 @@
 //
-// $Id: FieldMarshallerRegistry.java,v 1.6 2001/10/11 04:07:52 mdb Exp $
+// $Id: FieldMarshallerRegistry.java,v 1.7 2001/10/12 19:28:43 mdb Exp $
 
 package com.threerings.presents.dobj.io;
 
 import java.lang.reflect.Field;
 import java.util.Hashtable;
+
 import com.threerings.presents.Log;
+import com.threerings.presents.io.Streamable;
 
 /**
  * Field marshaller instances are registered for each type of field that
@@ -24,11 +26,25 @@ public class FieldMarshallerRegistry
     {
         Class clazz = field.getType();
         FieldMarshaller marsh = (FieldMarshaller)_registry.get(clazz);
+
+        // if we don't have a marshaller registered for this specific
+        // class, see if the class is an instance of streamable in which
+        // case we stick the streamable marshaller into the registry for
+        // this class
+        if (marsh == null) {
+            if (clazz.isAssignableFrom(Streamable.class)) {
+                marsh = _streamableMarsh;
+                _registry.put(clazz, marsh);
+            }
+        }
+
+        // if we still don't have a marshaller, we're out of luck
         if (marsh == null) {
             String errmsg = "No field marshaller registered for fields " +
                 "of type " + clazz.getName() + ".";
             throw new IllegalArgumentException(errmsg);
         }
+
         return marsh;
     }
 
@@ -52,8 +68,13 @@ public class FieldMarshallerRegistry
         }
     }
 
+    /** A mapping of classes to marshallers. */
     protected static Hashtable _registry = new Hashtable();
 
+    /** Used for marshalling instances of {@link Streamable}. */
+    protected static FieldMarshaller _streamableMarsh =
+        new StreamableFieldMarshaller();
+
     static {
         // register our field marshallers
         registerMarshaller(BooleanFieldMarshaller.class);

src/java/com/threerings/presents/io/StreamableFieldMarshaller.java

@@ -0,0 +1,45 @@
+//
+// $Id: StreamableFieldMarshaller.java,v 1.1 2001/10/12 19:28:43 mdb Exp $
+
+package com.threerings.presents.dobj.io;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.lang.reflect.Field;
+
+import com.threerings.presents.dobj.DObject;
+import com.threerings.presents.io.Streamable;
+
+public class StreamableFieldMarshaller implements FieldMarshaller
+{
+    public void writeTo (DataOutputStream out, Field field, DObject dobj)
+        throws IOException, IllegalAccessException
+    {
+        Streamable value = (Streamable)field.get(dobj);
+        // we freak out if our streamable is null
+        if (value == null) {
+            throw new IllegalAccessException(
+                "No streamable instance to marshall!");
+        }
+        value.writeTo(out);
+    }
+
+    public void readFrom (DataInputStream in, Field field, DObject dobj)
+        throws IOException, IllegalAccessException
+    {
+        try {
+            // create a new instance into which to unmarshall the field
+            Streamable value = (Streamable)field.getType().newInstance();
+            // unserialize it
+            value.readFrom(in);
+            // and set the value in the object
+            field.set(dobj, value);
+
+        } catch (InstantiationException ie) {
+            throw new IOException("Unable to instantiate streamable " +
+                                  "[field=" + field + ", object=" + dobj +
+                                  ", error=" + ie + "]");
+        }
+    }
+}