/*

File: BitHolder.m

Abstract: Protocol for a layer that acts as a container for Bits.

Version: 1.0

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*/

#import "BitHolder.h"

#import "Bit.h"

#import "QuartzUtils.h"

/**  WARNING: THIS CODE REQUIRES GARBAGE COLLECTION!

 **  This sample application uses Objective-C 2.0 garbage collection.

 **  Therefore, the source code in this file does NOT perform manual object memory management.

 **  If you reuse any of this code in a process that isn't garbage collected, you will need to

 **  add all necessary retain/release/autorelease calls, and implement -dealloc methods,

 **  otherwise unpleasant leakage will occur!

 **/

@implementation BitHolder

- (Bit*) bit

{

    if( _bit && _bit.superlayer != self && !_bit.pickedUp )

        _bit = nil;

    return _bit;

}

- (void) setBit: (Bit*)bit

{

    if( bit != self.bit ) {

        if( bit && _bit )

            [_bit destroy];

        _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