Do for simple flash buttons what ImageButtonSkin does for flex Buttons.

git-svn-id: svn+ssh://src.earth.threerings.net/nenya/trunk@714 ed5b42cb-e716-0410-a449-f6a68f950b19

src/as/com/threerings/flash/SimpleIconButton.as

@@ -0,0 +1,54 @@
+//
+// $Id$
+
+package com.threerings.flash {
+
+import flash.display.Bitmap;
+import flash.display.BitmapData;
+import flash.display.SimpleButton;
+import flash.display.Sprite;
+
+import flash.geom.ColorTransform;
+
+/**
+ * Takes a BitmapData and makes a button that brightens on hover and depresses when pushed.
+ */
+public class SimpleIconButton extends SimpleButton
+{
+    /**
+     * Constructor.
+     * 
+     * @param icon a BitmapData, or Bitmap (from which the BitmapData will be extracted), or
+     *             a Class that instantiates into either a BitmapData or Bitmap.
+     */
+    public function SimpleIconButton (icon :*)
+    {
+        var bmp :BitmapData;
+        if (icon is Class) {
+            icon = new (Class(icon))();
+        }
+        if (icon is BitmapData ) {
+            bmp = BitmapData(icon);
+        } else if (icon is Bitmap) {
+            bmp = Bitmap(icon).bitmapData;
+        } else {
+            throw new Error("Unknown icon spec: must be a Bitmap or BitmapData, or a Class " +
+                "that becomes one.");
+        }
+
+        upState = new Bitmap(bmp);
+        hitTestState = upState;
+        overState = new Bitmap(bmp);
+
+        var down :Sprite = new Sprite();
+        var downBmp :Bitmap = new Bitmap(bmp);
+        downBmp.y = 1;
+        down.addChild(downBmp);
+        downState = down;
+
+        const bright :ColorTransform = new ColorTransform(1.25, 1.25, 1.25);
+        overState.transform.colorTransform = bright;
+        downState.transform.colorTransform = bright;
+    }
+}
+}