erpsuiteios/Redant Drivers/Apex And Drivers/PhotoCell/Model/RAPhotoModel.m

//
//  RAPhotoModel.m
//  Apex And Drivers
//
//  Created by Jack on 2018/10/30.
//  Copyright © 2018年 USAI. All rights reserved.
//

#import "RAPhotoModel.h"
#import "RAPhotoLayout.h"
#import "RAPhotoItemModel.h"

@interface RAPhotoModel ()

@property (nonatomic,strong) NSArray *layoutAttrs;
@property (nonatomic,assign) CGFloat contentHeight;

@end

@implementation RAPhotoModel

#pragma mark - Setter

- (void)setValuesForKeysWithDictionary:(NSDictionary<NSString *,id> *)keyedValues {
    [super setValuesForKeysWithDictionary:keyedValues];
}

- (void)setPhotos:(NSArray *)photos {
    NSMutableArray *arr = [NSMutableArray array];
    for (NSDictionary *photo in photos) {
        RAPhotoItemModel *model = [RAPhotoItemModel new];
        [model setValuesForKeysWithDictionary:photo];
        [arr addObject:model];
    }
    _photos = [arr copy];
    
    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        [self prepareLayout];
    });
}

- (void)setDelegate:(id<RAPhotoModelDelegate>)delegate {
    
    if (_delegate && [_delegate respondsToSelector:@selector(unbind)]) {
    
        [_delegate unbind];
    }
    _delegate = delegate;
}

#pragma mark - Getter

- (CGFloat)height {
    return self.contentHeight + 36.5f;
}

- (CGFloat)width {
    if (_width <= 0) {
        self.width = [UIScreen mainScreen].bounds.size.width;
    }
    return _width;
}

- (CGFloat)contentHeight {
    if (_contentHeight <= 0) {
        [self prepareLayout];
    }
    return _contentHeight;
}

- (RAPhotoItemModel *)photoItemAtIndex:(NSUInteger)index {
    if (index >= self.photos.count || index < 0) {
        return nil;
    }
    return [self.photos objectAtIndex:index];
}

- (UIImage *)photoAtIndex:(NSUInteger)index {
    return [self photoItemAtIndex:index].photo;
}

- (NSUInteger)photoCount {
    __block NSUInteger count = 0;
    [self.photos enumerateObjectsUsingBlock:^(RAPhotoItemModel * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
       
        if (!obj.isEmpty) {
            count++;
        }
    }];
    return count;
}

#pragma mark - Layout Delegate

- (NSArray *)prepareLayout {
    
    NSUInteger itemCount = self.photos.count;
    if (itemCount == 0) {
        self.contentHeight = 0;
        return 0;
    }
    
    if (self.layoutAttrs) {
        return self.layoutAttrs;
    }
    
    NSMutableArray *attrs = [NSMutableArray arrayWithCapacity:itemCount];
    CGFloat interval = 5.0f;
    NSUInteger colCount = 4;
    CGFloat width = (self.width - (interval * (colCount + 1))) / colCount;
    CGFloat height = width;
    for (int i = 0; i < itemCount; i++) {
        int col = i % colCount;
        int row = i / colCount;
        
        int x = interval + (interval + width) * col;
        int y = interval + (interval + height) * row;
        
        CGRect frame = CGRectMake(x, y, width, height);
        
        NSIndexPath *indexPath = [NSIndexPath indexPathForItem:i inSection:0];
        UICollectionViewLayoutAttributes *itemAttrs = [UICollectionViewLayoutAttributes layoutAttributesForCellWithIndexPath:indexPath];
        itemAttrs.frame = frame;
        [attrs addObject:itemAttrs];
        
        self.contentHeight = CGRectGetMaxY(frame);
    }
    self.layoutAttrs = [attrs copy];
    
    return self.layoutAttrs;
}

- (CGFloat)layoutContentHeight {
    return self.contentHeight;
}


@end