diff -r 000000000000 -r af9b2b929b03 Source/BitHolder.m
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Source/BitHolder.m	Wed Mar 12 15:51:32 2008 -0700
@@ -0,0 +1,80 @@
+/*  This code is based on Apple's "GeekGameBoard" sample code, version 1.0.
+    http://developer.apple.com/samplecode/GeekGameBoard/
+    Copyright © 2007 Apple Inc. Copyright © 2008 Jens Alfke. All Rights Reserved.
+
+    Redistribution and use in source and binary forms, with or without modification, are permitted
+    provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright notice, this list of conditions
+      and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright notice, this list of
+      conditions and the following disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
+    FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRI-
+    BUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
+    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
+    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 
+    THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+#import "BitHolder.h"
+#import "Bit.h"
+#import "QuartzUtils.h"
+#import "GGBUtils.h"
+
+
+@implementation BitHolder
+
+
+- (void) dealloc
+{
+    [_bit release];
+    [super dealloc];
+}
+
+
+- (Bit*) bit
+{
+    if( _bit && _bit.superlayer != self && !_bit.pickedUp )
+        setObj(&_bit,nil);
+    return _bit;
+}
+
+- (void) setBit: (Bit*)bit
+{
+    if( bit != self.bit ) {
+        if( bit && _bit )
+            [_bit destroy];
+        setObj(&_bit,bit);
+        ChangeSuperlayer(bit,self,-1);
+    }
+}
+
+- (BOOL) isEmpty    {return self.bit==nil;}
+
+@synthesize highlighted=_highlighted;
+
+- (Bit*) canDragBit: (Bit*)bit
+{
+    if( bit.superlayer == self && ! bit.unfriendly )
+        return bit;
+    else
+        return nil;
+}
+
+- (void) cancelDragBit: (Bit*)bit                       { }
+- (void) draggedBit: (Bit*)bit to: (id<BitHolder>)dst   {self.bit = nil;}
+
+- (BOOL) canDropBit: (Bit*)bit atPoint: (CGPoint)point  {return YES;}
+- (void) willNotDropBit: (Bit*)bit                      { }
+
+- (BOOL) dropBit: (Bit*)bit atPoint: (CGPoint)point
+{
+    self.bit = bit;
+    return YES;
+}
+
+@end