1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/Source/BitHolder.h	Fri Mar 07 11:43:02 2008 -0800
     1.3 @@ -0,0 +1,73 @@
     1.4 +/*  This code is based on Apple's "GeekGameBoard" sample code, version 1.0.
     1.5 +    http://developer.apple.com/samplecode/GeekGameBoard/
     1.6 +    Copyright © 2007 Apple Inc. Copyright © 2008 Jens Alfke. All Rights Reserved.
     1.7 +
     1.8 +    Redistribution and use in source and binary forms, with or without modification, are permitted
     1.9 +    provided that the following conditions are met:
    1.10 +
    1.11 +    * Redistributions of source code must retain the above copyright notice, this list of conditions
    1.12 +      and the following disclaimer.
    1.13 +    * Redistributions in binary form must reproduce the above copyright notice, this list of
    1.14 +      conditions and the following disclaimer in the documentation and/or other materials provided
    1.15 +      with the distribution.
    1.16 +
    1.17 +    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
    1.18 +    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
    1.19 +    FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRI-
    1.20 +    BUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    1.21 +    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
    1.22 +    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
    1.23 +    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 
    1.24 +    THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    1.25 +*/
    1.26 +#import <Quartz/Quartz.h>
    1.27 +@class Bit;
    1.28 +
    1.29 +
    1.30 +/** Protocol for a layer that acts as a container for Bits. */
    1.31 +@protocol BitHolder <NSObject>
    1.32 +
    1.33 +/** Current Bit, or nil if empty */
    1.34 +@property (retain) Bit* bit;
    1.35 +
    1.36 +/** Conveniences for comparing self.bit with nil */
    1.37 +@property (readonly, getter=isEmpty) BOOL empty;
    1.38 +
    1.39 +/** BitHolders will be highlighted while the target of a drag operation */
    1.40 +@property BOOL highlighted;
    1.41 +
    1.42 +
    1.43 +/** Tests whether the bit is allowed to be dragged out of me.
    1.44 +    Returns the input bit, or possibly a different Bit to drag instead, or nil if not allowed.
    1.45 +    Either -cancelDragBit: or -draggedBit:to: must be called next. */
    1.46 +- (Bit*) canDragBit: (Bit*)bit;
    1.47 +
    1.48 +/** Cancels a pending drag (begun by -canDragBit:). */
    1.49 +- (void) cancelDragBit: (Bit*)bit;
    1.50 +
    1.51 +/** Called after a drag finishes. */
    1.52 +- (void) draggedBit: (Bit*)bit to: (id<BitHolder>)dst;
    1.53 +
    1.54 +
    1.55 +/** Tests whether the bit is allowed to be dropped into me.
    1.56 +    Either -willNotDropBit: or -dropBit:atPoint: must be called next. */
    1.57 +- (BOOL) canDropBit: (Bit*)bit atPoint: (CGPoint)point;
    1.58 +
    1.59 +/** Cancels a pending drop (after -canDropBit:atPoint: was already called.) */
    1.60 +- (void) willNotDropBit: (Bit*)bit;
    1.61 +
    1.62 +/** Finishes a drop. */
    1.63 +- (BOOL) dropBit: (Bit*)bit atPoint: (CGPoint)point;
    1.64 +
    1.65 +@end
    1.66 +
    1.67 +
    1.68 +/** A basic implementation of the BitHolder protocol. */
    1.69 +@interface BitHolder : CALayer <BitHolder>
    1.70 +{
    1.71 +    @protected
    1.72 +    Bit *_bit;
    1.73 +    BOOL _highlighted;
    1.74 +}
    1.75 +
    1.76 +@end