erpsuiteios/Redant Drivers/Apex And Drivers/Detail/Model/RADetailActionCollectionModel.m

//
//  RADetailActionCollectionModel.m
//  Apex And Drivers
//
//  Created by Jack on 2018/6/2.
//  Copyright © 2018年 USAI. All rights reserved.
//

#import "RADetailActionCollectionModel.h"
#import "RADetailActionModel.h"

@interface RADetailActionCollectionModel () 

@property (nonatomic,assign) CGFloat itemSpacing;
@property (nonatomic,assign) CGFloat itemHeight;
@property (nonatomic,assign) NSInteger numberOfColumns;
@property (nonatomic,assign) NSInteger itemCount;

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

@end

@implementation RADetailActionCollectionModel 

- (instancetype)init {
    if (self = [super init]) {
        
        _itemSpacing = 10.0f;
        _itemHeight = 30.0f;
        _numberOfColumns = 2;
        
    }
    return self;
}

- (void)setActions:(NSArray *)actions {
    
    NSMutableArray *modelArr = [NSMutableArray array];
    for (int i = 0; i < actions.count; i++) {
        NSDictionary *action = [actions objectAtIndex:i];
        RADetailActionModel *model = [[RADetailActionModel alloc] init];
        [model setValuesForKeysWithDictionary:action];
        [modelArr addObject:model];
    }
    
    _actions = modelArr;
    self.itemCount = _actions.count;
    self.layoutAttrs = nil;
    
    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        [self prepareLayout];
    });
}

- (NSInteger)actionCount {
    return self.actions.count;
}

- (RADetailActionModel *)actionModelForIndexPath:(NSIndexPath *)indexPath {
    return [self.actions objectAtIndex:indexPath.item];
}

- (CGFloat)width {
    CGFloat width = [super width];
    if (width <= 0) {
        NSLog(@"action width is zero");
        width = CGRectGetWidth([UIScreen mainScreen].bounds);
        self.width = width;
    }
    return width;
}

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

- (NSArray *)prepareLayout {
    
    if (self.layoutAttrs) {
        return self.layoutAttrs;
    }
    
    self.collectionViewWidth = self.width;
    
    NSUInteger numberOfItem = self.itemCount;
    NSMutableArray *attrsArr = [NSMutableArray arrayWithCapacity:numberOfItem];
    
    CGFloat itemWidth = (self.collectionViewWidth - self.itemSpacing * (self.numberOfColumns + 1)) / self.numberOfColumns;
    for (int i = 0; i < numberOfItem; i++) {
        
        int col = i % self.numberOfColumns;
        int row = i / self.numberOfColumns;
        
        CGFloat x = self.itemSpacing + (itemWidth + self.itemSpacing) * col;
        CGFloat y = self.itemSpacing + (self.itemHeight + self.itemSpacing) * row;
        
        
        if (i == numberOfItem - 1 && col == 0) {
            itemWidth = self.collectionViewWidth - self.itemSpacing * 2;
        }
        CGRect frame = CGRectMake(x, y, itemWidth, self.itemHeight);
        
        NSIndexPath *indexPath = [NSIndexPath indexPathForItem:i inSection:0];
        UICollectionViewLayoutAttributes *itemAttrs = [UICollectionViewLayoutAttributes layoutAttributesForCellWithIndexPath:indexPath];
        itemAttrs.frame = frame;
        [attrsArr addObject:itemAttrs];
        
        self.contentHeight = CGRectGetMaxY(frame);
    }
    self.layoutAttrs = attrsArr;
    self.contentHeight += self.itemSpacing;
    
    return self.layoutAttrs;
}

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

@end