//

 //  BoardUIView.m

 //  GeekGameBoard

 //

 //  Created by Jens Alfke on 3/7/08.

 //  Copyright 2008 __MyCompanyName__. All rights reserved.

 //

 #import "BoardUIView.h"

 #import "Bit.h"

 #import "BitHolder.h"

 #import "Game.h"

 #import "QuartzUtils.h"

 #import "GGBUtils.h"

 @interface BoardUIView ()

 - (void) _findDropTarget: (CGPoint)pos;

 @end

 @implementation BoardUIView

 - (id)initWithFrame:(CGRect)frame {

     if ( (self = [super initWithFrame:frame]) ) {

         // Initialization code here.

     }

     return self;

 }

 - (void)dealloc

 {

     [_game release];

     [super dealloc];

 }

 @synthesize game=_game, gameboard=_gameboard;

 - (void) startGameNamed: (NSString*)gameClassName

 {

     Class gameClass = NSClassFromString(gameClassName);

     NSAssert1(gameClass,@"Unknown game '%@'",gameClassName);

     setObj(&_game,nil);

     if( _gameboard ) {

         [_gameboard removeFromSuperlayer];

         _gameboard = nil;

     }

     CALayer *rootLayer = self.layer;

     self.layer.affineTransform = CGAffineTransformIdentity;

     CGRect frame = rootLayer.frame;

     frame.origin.x = frame.origin.y = 0;

     rootLayer.bounds = frame;

     if( [gameClass landscapeOriented] && frame.size.height > frame.size.width ) {

         rootLayer.affineTransform = CGAffineTransformMakeRotation(M_PI/2);

         frame = CGRectMake(0,0,frame.size.height,frame.size.width);

         rootLayer.bounds = frame;

     }

     _gameboard = [[GGBLayer alloc] init];

     _gameboard.frame = frame;

     [rootLayer addSublayer: _gameboard];

     [_gameboard release];

     _game = [[gameClass alloc] initWithBoard: _gameboard];

 }

 - (CGRect) gameBoardFrame

 {

     return self.layer.bounds;

 }

 #pragma mark -

 #pragma mark HIT-TESTING:

 // Hit-testing callbacks (to identify which layers caller is interested in):

 typedef BOOL (*LayerMatchCallback)(CALayer*);

 static BOOL layerIsBit( CALayer* layer )        {return [layer isKindOfClass: [Bit class]];}

 static BOOL layerIsBitHolder( CALayer* layer )  {return [layer conformsToProtocol: @protocol(BitHolder)];}

 /** Locates the layer at a given point in window coords.

     If the leaf layer doesn't pass the layer-match callback, the nearest ancestor that does is returned.

     If outOffset is provided, the point's position relative to the layer is stored into it. */

 - (CALayer*) hitTestPoint: (CGPoint)where

          forLayerMatching: (LayerMatchCallback)match

                    offset: (CGPoint*)outOffset

 {

     where = [_gameboard convertPoint: where fromLayer: self.layer];

     CALayer *layer = [_gameboard hitTest: where];

     while( layer ) {

         if( match(layer) ) {

             CGPoint bitPos = [self.layer convertPoint: layer.position 

                               fromLayer: layer.superlayer];

             if( outOffset )

                 *outOffset = CGPointMake( bitPos.x-where.x, bitPos.y-where.y);

             return layer;

         } else

             layer = layer.superlayer;

     }

     return nil;

 }

 #pragma mark -

 #pragma mark MOUSE CLICKS & DRAGS:

 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

 {

     NSAssert(touches.count==1,@"No multitouch support yet");

     UITouch *touch = touches.anyObject;

     BOOL placing = NO;

     _dragStartPos = touch.locationInView;

     _dragBit = (Bit*) [self hitTestPoint: _dragStartPos

                         forLayerMatching: layerIsBit 

                                   offset: &_dragOffset];

     if( ! _dragBit ) {

         // If no bit was clicked, see if it's a BitHolder the game will let the user add a Bit to:

         id<BitHolder> holder = (id<BitHolder>) [self hitTestPoint: _dragStartPos

                                                  forLayerMatching: layerIsBitHolder

                                                            offset: NULL];

         if( holder ) {

             _dragBit = [_game bitToPlaceInHolder: holder];

             if( _dragBit ) {

                 _dragOffset.x = _dragOffset.y = 0;

                 if( _dragBit.superlayer==nil )

                     _dragBit.position = _dragStartPos;

                 placing = YES;

             }

         }

     }

     if( ! _dragBit ) {

         Beep();

         return;

     }

     // Clicked on a Bit:

     _dragMoved = NO;

     _dropTarget = nil;

     _oldHolder = _dragBit.holder;

     // Ask holder's and game's permission before dragging:

     if( _oldHolder ) {

         _dragBit = [_oldHolder canDragBit: _dragBit];

         if( _dragBit && ! [_game canBit: _dragBit moveFrom: _oldHolder] ) {

             [_oldHolder cancelDragBit: _dragBit];

             _dragBit = nil;

         }

         if( ! _dragBit ) {

             _oldHolder = nil;

             Beep();

             return;

         }

     }

     // Start dragging:

     _oldSuperlayer = _dragBit.superlayer;

     _oldLayerIndex = [_oldSuperlayer.sublayers indexOfObjectIdenticalTo: _dragBit];

     _oldPos = _dragBit.position;

     ChangeSuperlayer(_dragBit, self.layer, self.layer.sublayers.count);

     _dragBit.pickedUp = YES;

     if( placing ) {

         if( _oldSuperlayer )

             _dragBit.position = _dragStartPos;      // animate Bit to new position

         _dragMoved = YES;

         [self _findDropTarget: _dragStartPos];

     }

 }

 - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event

 {

     NSAssert(touches.count==1,@"No multitouch support yet");

     UITouch *touch = touches.anyObject;

     if( _dragBit ) {

         // Get the mouse position, and see if we've moved 3 pixels since the mouseDown:

         CGPoint pos = touch.locationInView;

         if( fabs(pos.x-_dragStartPos.x)>=3 || fabs(pos.y-_dragStartPos.y)>=3 )

             _dragMoved = YES;

         // Move the _dragBit (without animation -- it's unnecessary and slows down responsiveness):

         pos.x += _dragOffset.x;

         pos.y += _dragOffset.y;

         CGPoint newPos = [_dragBit.superlayer convertPoint: pos fromLayer: self.layer];

         [CATransaction flush];

         [CATransaction begin];

         [CATransaction setValue:(id)kCFBooleanTrue

                          forKey:kCATransactionDisableActions];

         _dragBit.position = newPos;

         [CATransaction commit];

         // Find what it's over:

         [self _findDropTarget: pos];

     }

 }

 - (void) _findDropTarget: (CGPoint)pos

 {

     id<BitHolder> target = (id<BitHolder>) [self hitTestPoint: pos

                                              forLayerMatching: layerIsBitHolder

                                                        offset: NULL];

     if( target == _oldHolder )

         target = nil;

     if( target != _dropTarget ) {

         [_dropTarget willNotDropBit: _dragBit];

         _dropTarget.highlighted = NO;

         _dropTarget = nil;

     }

     if( target ) {

         CGPoint targetPos = [(CALayer*)target convertPoint: _dragBit.position

                                                  fromLayer: _dragBit.superlayer];

         if( [target canDropBit: _dragBit atPoint: targetPos]

            && [_game canBit: _dragBit moveFrom: _oldHolder to: target] ) {

             _dropTarget = target;

             _dropTarget.highlighted = YES;

         }

     }

 }    

 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event

 {

     if( _dragBit ) {

         if( _dragMoved ) {

             // Update the drag tracking to the final mouse position:

             [self touchesMoved: touches withEvent: event];

             _dropTarget.highlighted = NO;

             _dragBit.pickedUp = NO;

             // Is the move legal?

             if( _dropTarget && [_dropTarget dropBit: _dragBit

                                             atPoint: [(CALayer*)_dropTarget convertPoint: _dragBit.position 

                                                                             fromLayer: _dragBit.superlayer]] ) {

                 // Yes, notify the interested parties:

                 [_oldHolder draggedBit: _dragBit to: _dropTarget];

                 [_game bit: _dragBit movedFrom: _oldHolder to: _dropTarget];

             } else {

                 // Nope, cancel:

                 [_dropTarget willNotDropBit: _dragBit];

                 if( _oldSuperlayer ) {

                     ChangeSuperlayer(_dragBit, _oldSuperlayer, _oldLayerIndex);

                     _dragBit.position = _oldPos;

                     [_oldHolder cancelDragBit: _dragBit];

                 } else {

                     [_dragBit removeFromSuperlayer];

                 }

             }

         } else {

             // Just a click, without a drag:

             _dropTarget.highlighted = NO;

             _dragBit.pickedUp = NO;

             ChangeSuperlayer(_dragBit, _oldSuperlayer, _oldLayerIndex);

             [_oldHolder cancelDragBit: _dragBit];

             if( ! [_game clickedBit: _dragBit] )

                 Beep();

         }

         _dropTarget = nil;

         _dragBit = nil;

     }

 }

 @end