/*  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 ) {

             if( bit )

                 [_bit destroy];

             else

                 [_bit removeFromSuperlayer];

         }

         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