/*

    Copyright (C) 2015 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    This is the "ScatterLayout" class implementation.

*/

#import "AAPLScatterLayout.h"

@implementation AAPLScatterLayout

- (instancetype)init {

    self = [super init];

    if (self) {

        cachedItemFrames = [[NSMutableDictionary alloc] init];

    }

    return self;

}

- (NSCollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath {

    NSValue *frameValue = [cachedItemFrames objectForKey:indexPath];

    if (frameValue == nil) {

        NSPoint p;

        p.x = box.origin.x + drand48() * (box.size.width - itemSize.width);

        p.y = box.origin.y + drand48() * (box.size.height - itemSize.height);

        frameValue = [NSValue valueWithRect:NSMakeRect(p.x, p.y, itemSize.width, itemSize.height)];

        [cachedItemFrames setObject:frameValue forKey:indexPath];

    }

    NSCollectionViewLayoutAttributes *attributes = [[[self class] layoutAttributesClass] layoutAttributesForItemWithIndexPath:indexPath];

    [attributes setFrame:[frameValue rectValue]];

    [attributes setZIndex:[indexPath item]];

    return attributes;

}

@end