More progress.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@3862 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/presents/dobj/CompoundEvent.as

@@ -0,0 +1,180 @@
+//
+// $Id: CompoundEvent.java 3099 2004-08-27 02:21:06Z mdb $
+//
+// Narya library - tools for developing networked games
+// Copyright (C) 2002-2004 Three Rings Design, Inc., All Rights Reserved
+// http://www.threerings.net/code/narya/
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.threerings.presents.dobj {
+
+import flash.util.StringBuilder;
+
+import mx.collections.IList;
+
+import com.threerings.io.ObjectInputStream;
+import com.threerings.io.ObjectOutputStream;
+
+import com.threerings.util.StreamableArrayList;
+
+/**
+ * Used to manage and submit groups of events on a collection of
+ * distributed objects in a single transaction.
+ *
+ * @see DObject#startTransaction
+ */
+public class CompoundEvent extends DEvent
+{
+    /**
+     * Constructs a compound event and prepares it for operation.
+     */
+    public CompoundEvent (target :DObject, omgr :DObjectManager)
+    {
+        super(target.getOid());
+
+        // sanity check
+        if (omgr == null) {
+            throw new ArgumentError(
+                "Must receive non-null object manager reference");
+        }
+
+        _omgr = omgr;
+        _target = target;
+        _events = new StreamableArrayList();
+    }
+
+    /**
+     * Posts an event to this transaction. The event will be delivered as
+     * part of the entire transaction if it is committed or discarded if
+     * the transaction is cancelled.
+     */
+    public function postEvent (event :DEvent) :void
+    {
+        _events.addItem(event);
+    }
+
+    /**
+     * Returns the list of events contained within this compound event.
+     * Don't mess with it.
+     */
+    public function getEvents () :IList
+    {
+        return _events;
+    }
+
+    /**
+     * Commits this transaction by posting this event to the distributed
+     * object event queue. All participating dobjects will have their
+     * transaction references cleared and will go back to normal
+     * operation.
+     */
+    public function commit () :void
+    {
+        // first clear our target
+        clearTarget();
+
+        // then post this event onto the queue (but only if we actually
+        // accumulated some events)
+        switch (_events.length) {
+        case 0: // nothing doing
+            break;
+        case 1: // no point in being compound
+            _omgr.postEvent(_events.getItemAt(0));
+            break;
+        default: // now we're talking
+            _omgr.postEvent(this);
+            break;
+        }
+    }
+
+    /**
+     * Cancels this transaction. All events posted to this transaction
+     * will be discarded.
+     */
+    public function cancel () :void
+    {
+        // clear our target
+        clearTarget();
+        // clear our event queue in case someone holds onto us
+        _events.removeAll();
+    }
+
+    /**
+     * We need to propagate our source oid to our constituent events.
+     */
+    public override function setSourceOid (sourceOid :int) :void
+    {
+        super.setSourceOid(sourceOid);
+
+        for (var ii :int = 0; ii < _events.length; ii++) {
+            _events.getItemAt(ii).setSourceOid(sourceOid);
+        }
+    }
+
+    /**
+     * Nothing to apply here.
+     */
+    public override function applyToObject (target :DObject) :Boolean
+        //throws ObjectAccessException
+    {
+        return false;
+    }
+
+    /**
+     * Calls out to our target object, clearing its transaction reference.
+     */
+    protected function clearTarget () :void
+    {
+        if (_target != null) {
+            _target.clearTransaction();
+            _target = null;
+        }
+    }
+
+    // documentation inherited
+    protected override function toString (buf :StringBuilder) :void
+    {
+        buf.append("COMPOUND:");
+        super.toString(buf);
+
+        for (var ii :int = 0; ii < _events.length; ii++) {
+            buf.append(", ", _events.getItemAt(ii));
+        }
+    }
+
+    public override function writeObject (out :ObjectOutputStream) :void
+    {
+        super.writeObject(out);
+        out.writeField(_events);
+    }
+
+    public override function readObject (ins :ObjectInputStream) :void
+    {
+        super.readObject(ins);
+        _events = ins.readField(StreamableArrayList);
+    }
+
+    /** The object manager that we'll post ourselves to when we're
+     * committed. */
+    protected var _omgr :DObjectManager;
+
+    /** The object for which we're managing a transaction. */
+    protected var _target :DObject;
+
+    /** A list of the events associated with this compound event. */
+    protected var _events :StreamableArrayList;
+}
+}