MiMO_iOS/MiMoLive/Classes/Live/View/LiveGiftShowView/MSNumberScrollAnimatedView/MSNumberScrollAnimatedView.m

//
//  MSNumberScrollAnimatedView.m
//  MSNumberScrollAnimatedViewDemo
//
//  Created by MrSong on 16/5/20.
//  Copyright © 2016年 MrSong. All rights reserved.
//

#import "MSNumberScrollAnimatedView.h"

@interface MSNumberScrollAnimatedView ()

@property (nonatomic, strong) NSMutableArray *numbersText; //保存拆分出来的数字
@property (nonatomic, strong) NSMutableArray *scrollLayers;
@property (nonatomic, strong) NSMutableArray *scrollViews; // 保存imageView
@property (nonatomic, strong) NSNumber *previousNumber; // 保存上一次的数字
@property (nonatomic, copy) NSArray *numberImages;

/** vipType 类型 */
@property (nonatomic, assign) NSInteger vipType;

@end

@implementation MSNumberScrollAnimatedView

#pragma mark - Life Cycle

- (instancetype)initWithVipType:(NSInteger)vipType {
    if (self = [super init]) {
        _vipType = vipType;
        [self commonInit];
    }
    return self;
}

- (void)layoutSubviews {
    [super layoutSubviews];
    
    // 如果已经设置了number但还没有准备动画，在布局完成后准备
    if (_number && _scrollLayers.count == 0) {
        [self prepareAnimations];
    }
}


#pragma mark - Public Methods

- (void)reloadView {
    [self prepareAnimations];
}

- (void)startAnimation {
    [self createAnimations];
}

- (void)stopAnimation {
    for (CALayer *layer in _scrollLayers) {
        [layer removeAnimationForKey:@"MSNumberScrollAnimatedView"];
    }
}

#pragma mark - Private Methods

- (void)commonInit {
    self.duration = 0.1;
    self.durationOffset = 0.1;
    self.density = 1;
    self.minLength = 0;
    self.isAscending = NO;
    
    _numbersText = [NSMutableArray array];
    _scrollLayers = [NSMutableArray array];
    _scrollViews = [NSMutableArray array];
    _previousNumber = nil;
    
    if (self.vipType > 0) {
        self.numberImages = @[
            [UIImage imageNamed:@"gift_vip_num_0"],
            [UIImage imageNamed:@"gift_vip_num_1"],
            [UIImage imageNamed:@"gift_vip_num_2"],
            [UIImage imageNamed:@"gift_vip_num_3"],
            [UIImage imageNamed:@"gift_vip_num_4"],
            [UIImage imageNamed:@"gift_vip_num_5"],
            [UIImage imageNamed:@"gift_vip_num_6"],
            [UIImage imageNamed:@"gift_vip_num_7"],
            [UIImage imageNamed:@"gift_vip_num_8"],
            [UIImage imageNamed:@"gift_vip_num_9"],
        ];
    } else {
        self.numberImages = @[
            [UIImage imageNamed:@"gift_common_num_0"],
            [UIImage imageNamed:@"gift_common_num_1"],
            [UIImage imageNamed:@"gift_common_num_2"],
            [UIImage imageNamed:@"gift_common_num_3"],
            [UIImage imageNamed:@"gift_common_num_4"],
            [UIImage imageNamed:@"gift_common_num_5"],
            [UIImage imageNamed:@"gift_common_num_6"],
            [UIImage imageNamed:@"gift_common_num_7"],
            [UIImage imageNamed:@"gift_common_num_8"],
            [UIImage imageNamed:@"gift_common_num_9"],
        ];
    }
    
    // 添加布局完成后的回调
    [self setNeedsLayout];
    [self layoutIfNeeded];
}

- (void)prepareAnimations {
    // 先删除旧数据
    for (CALayer *layer in _scrollLayers) {
        [layer removeFromSuperlayer];
    }
    [_numbersText removeAllObjects];
    [_scrollLayers removeAllObjects];
    [_scrollViews removeAllObjects];
    
    // 配置新的数据和UI
    [self configNumbersText];
    [self configScrollLayers];
}

- (void)configNumbersText {
    NSString *numberStr = [_number stringValue];
    // 如果 number 长度小于 最小长度就补0
    // 这里需要注意一下 minLength 和 length 都是NSUInteger类型 如果相减得负数的话会有问题
    for (NSInteger i = 0; i < (NSInteger)self.minLength - (NSInteger)numberStr.length; i++) {
        [_numbersText addObject:@"0"];
    }
    // 取出 number 各位数
    for (NSUInteger i = 0; i < numberStr.length; i++) {
        [_numbersText addObject:[numberStr substringWithRange:NSMakeRange(i, 1)]];
    }
}

- (void)configScrollLayers {
    // 确保视图有宽度
    if (CGRectGetWidth(self.frame) <= 0) {
        return;
    }
    
    // 平均分配宽度
    CGFloat width = CGRectGetWidth(self.frame) / _numbersText.count;
    CGFloat height = CGRectGetHeight(self.frame);
    // 创建和配置 scrollLayer
    for (NSUInteger i = 0; i < _numbersText.count; i++) {
        CAScrollLayer *layer = [CAScrollLayer layer];
        layer.frame = CGRectMake(i*width, 0, width, height);
        [_scrollLayers addObject:layer];
        [self.layer addSublayer:layer];
        
        NSString *numberText = _numbersText[i];
        [self configScrollLayer:layer numberText:numberText];
    }
}

- (void)configScrollLayer:(CAScrollLayer *)layer numberText:(NSString *)numberText {
    NSInteger number = [numberText integerValue];
    NSMutableArray *scrollNumbers = [NSMutableArray array];
    for (NSInteger i = 0; i < self.density + 1; i++) {
        [scrollNumbers addObject:[NSString stringWithFormat:@"%u", (unsigned int)((number+i) % 10)]];
    }
    [scrollNumbers addObject:numberText];
    
    __block CGFloat height = 0;
    [scrollNumbers enumerateObjectsWithOptions:NSEnumerationReverse usingBlock:^(NSString *text, NSUInteger idx, BOOL * _Nonnull stop) {
        UIImageView *imageView = [self createImageViewForNumber:[text integerValue]];
        
        // 设置固定的显示大小
        CGFloat width = CGRectGetWidth(layer.frame);
        CGFloat displayHeight = CGRectGetHeight(layer.frame);
        
        // 确保图片完全填充可用空间
        imageView.frame = CGRectMake(0, height, width, displayHeight);
        imageView.contentMode = UIViewContentModeScaleAspectFit;
        
        [layer addSublayer:imageView.layer];
        [_scrollViews addObject:imageView];
        height = CGRectGetMaxY(imageView.frame);
    }];
}

- (UIImageView *)createImageViewForNumber:(NSInteger)number {
    UIImageView *imageView = [[UIImageView alloc] init];
    imageView.contentMode = UIViewContentModeScaleAspectFit;
    
    if (self.numberImages && number >= 0 && number < self.numberImages.count) {
        imageView.image = self.numberImages[number];
    }
    
    return imageView;
}

- (void)createAnimations {
    NSString *currentNumberStr = [_number stringValue];
    NSString *previousNumberStr = [_previousNumber stringValue];
    
    // 补齐前导零，使两个数字字符串长度相同
    while (currentNumberStr.length < self.minLength) {
        currentNumberStr = [@"0" stringByAppendingString:currentNumberStr];
    }
    while (previousNumberStr.length < self.minLength) {
        previousNumberStr = [@"0" stringByAppendingString:previousNumberStr];
    }
    
    // 第一个需要动画的layer的动画持续时间
    NSTimeInterval duration = self.duration - ((_numbersText.count-1) * self.durationOffset);
    
    for (NSUInteger i = 0; i < _scrollLayers.count; i++) {
        CALayer *layer = _scrollLayers[i];
        
        // 检查当前位置的数字是否发生变化
        BOOL shouldAnimate = YES;
        if (_previousNumber != nil) {
            NSInteger currentIndex = currentNumberStr.length - _scrollLayers.count + i;
            NSInteger previousIndex = previousNumberStr.length - _scrollLayers.count + i;
            
            if (currentIndex >= 0 && previousIndex >= 0) {
                unichar currentDigit = [currentNumberStr characterAtIndex:currentIndex];
                unichar previousDigit = [previousNumberStr characterAtIndex:previousIndex];
                shouldAnimate = (currentDigit != previousDigit);
            }
        }
        
        if (shouldAnimate) {
            CGFloat maxY = [[layer.sublayers lastObject] frame].origin.y;
            CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"sublayerTransform.translation.y"];
            animation.duration = duration;
            animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
            
            if (self.isAscending) {
                animation.fromValue = @0;
                animation.toValue = [NSNumber numberWithFloat:-maxY];
            } else {
                animation.fromValue = [NSNumber numberWithFloat:-maxY];
                animation.toValue = @0;
            }
            
            [layer addAnimation:animation forKey:@"MSNumberScrollAnimatedView"];
        }
        
        duration += self.durationOffset;
    }
}

#pragma mark - Setter

- (void)setNumber:(NSNumber *)number {
    _previousNumber = _number; // 保存当前数字作为上一次的数字
    _number = number;
    // 准备动画
    [self prepareAnimations];
}


@end