Command: contains bind() for wiring events up commands, without having to

create var-args functions or make your existing functions varargs so that
they can react to events.
This might turn into more. I already did a bunch of impl and then KISS since
we don't use the advanced shit yet. It might be nice to tie this more
closely to CommandButton, et al.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5300 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/util/Command.as

@@ -0,0 +1,75 @@
+//
+// $Id$
+
+package com.threerings.util {
+
+import flash.events.Event;
+import flash.events.IEventDispatcher;
+
+/**
+ * Contains a simple binding function to bind events to commands.
+ *
+ * TODO: be able to set up a Command object, and bind it to multiple functions
+ */
+public class Command
+{
+    /**
+     * Bind an event to a command.
+     */
+    public static function bind (
+        source :IEventDispatcher, eventType :String, cmdOrFn :Object, arg :Object = null) :void
+    {
+        source.addEventListener(eventType, function (... ignored) :void {
+            CommandEvent.dispatch(source, cmdOrFn, arg);
+        });
+    }
+
+    /**
+     * Convenience, since otherwise nobody usually needs to ever import CommandEvent.
+     */
+    public static function dispatch (
+        source :IEventDispatcher, cmdOrFn :Object, arg :Object = null) :void
+    {
+        CommandEvent.dispatch(source, cmdOrFn, arg);
+    }
+
+//    public static function bind (
+//        source :IEventDispatcher, eventType :String, cmdOrFn :Object, arg :Object = null) :Command
+//    {
+//        var cmd :Command = new Command(cmdOrFn, arg);
+//        cmd.addBind(source, eventType);
+//        return cmd;
+//    }
+//
+//    public function Command (cmdOrFn :Object, arg :Object = null)
+//    {
+//        _cmdOrFn = cmdOrFn;
+//        _arg = arg;
+//    }
+//
+//    public function setOverrideSource (disp :IEventDispatcher) :void
+//    {
+//        _source = source;
+//    }
+//
+//    public function addBind (source :IEventDispatcher, eventType :String) :void
+//    {
+//        source.addEventListener(eventType, eventHandler);
+//    }
+//
+//    public function removeBind (source :IEventDispatcher, eventType :String) :void
+//    {
+//        source.removeEventListener(eventType, eventHandler);
+//    }
+//
+//    protected function eventHandler (event :Event) :void
+//    {
+//        dispatch(_source || IEventDispatcher(event.source), _cmdOrFn, arg);
+//    }
+//
+//    /** An override source for the command events, or null to use the triggering dispatcher. */
+//    protected var _source :IEventDispatcher;
+//    protected var _cmdOrFn :Object;
+//    protected var _arg :Object;
+}
+}