[翻译] JTNumberScrollAnimatedView

JTNumberScrollAnimatedView

本人视频教程系类   iOS中CALayer的使用

效果：

Use JTNumberScrollAnimatedView for have a nice animation for display number. It's easy to use, easy to customize.

使用 JTNumberScrollAnimatedView来展示一个效果非常不错的显示数字变化的动画效果的控件，使用很简单，非常容易定制。

Usage

Basic usage - 基本的使用

You can use JTNumberScrollAnimatedView like a normal view.

你可以像使用一个普通的view一样来使用JTNumberScrollAnimatedView

#import <UIKit/UIKit.h>

#import "JTNumberScrollAnimatedView.h"

@interface ViewController : UIViewController

@property (weak, nonatomic) IBOutlet JTNumberScrollAnimatedView *animatedView;

@end

You just have to call setValue with a NSNumber and use startAnimation for launch the animation.

你只需要调用setValue方法然后执行startAnimation方法就能显示效果。

- (void)viewDidLoad
{
    [super viewDidLoad];

    [self.animatedView setValue:@249];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    [self.animatedView startAnimation];
}

WARNING - 注意

For now the value must be a positive integer.

现在，这个值必须是正的不能是负数。

Customization - 定制

You can easily change some properties of the animation. Each caracter have its own column.

你可以很简单的修改以下的一些属性

• textColor
• font
• duration
• durationOffset, delay between the end of the animation of each column
• density, number of characters by column for the animation
• minLength, you can force the minimum count of columns
• isAscending, the direction of the scroll

If you change one of this properties, you have to call setValue for update the view.

如果你修改了其中的一个属性，你需要调用 setValue 来更新画面。

Requirements

• iOS 7 or higher                                 iOS7 或者更高版本
• Automatic Reference Counting (ARC)  ARC

//
//  JTNumberScrollAnimatedView.h
//  JTNumberScrollAnimatedView
//
//  Created by Jonathan Tribouharet
//

#import <UIKit/UIKit.h>

@interface JTNumberScrollAnimatedView : UIView

@property (strong, nonatomic) NSNumber *value;

@property (strong, nonatomic) UIColor *textColor;
@property (strong, nonatomic) UIFont *font;
@property (assign, nonatomic) CFTimeInterval duration;
@property (assign, nonatomic) CFTimeInterval durationOffset;
@property (assign, nonatomic) NSUInteger density;
@property (assign, nonatomic) NSUInteger minLength;
@property (assign, nonatomic) BOOL isAscending;

- (void)startAnimation;
- (void)stopAnimation;

@end

//
//  JTNumberScrollAnimatedView.m
//  JTNumberScrollAnimatedView
//
//  Created by Jonathan Tribouharet
//

#import "JTNumberScrollAnimatedView.h"

@interface JTNumberScrollAnimatedView(){
    NSMutableArray *numbersText;
    NSMutableArray *scrollLayers;
    NSMutableArray *scrollLabels;
}

@end

@implementation JTNumberScrollAnimatedView

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if(!self){
        return nil;
    }

    [self commonInit];

    return self;
}

- (id)initWithCoder:(NSCoder *)aDecoder
{
    self = [super initWithCoder:aDecoder];
    if(!self){
        return nil;
    }

    [self commonInit];

    return self;
}

- (void)commonInit
{
    self.duration = 1.5;
    self.durationOffset = .;
    self.density = ;
    self.minLength = ;
    self.isAscending = NO;

    self.font = [UIFont systemFontOfSize:[UIFont systemFontSize]];
    self.textColor = [UIColor blackColor];

    numbersText = [NSMutableArray new];
    scrollLayers = [NSMutableArray new];
    scrollLabels = [NSMutableArray new];
}

- (void)setValue:(NSNumber *)value
{
    self->_value = value;

    [self prepareAnimations];
}

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

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

- (void)prepareAnimations
{
    for(CALayer *layer in scrollLayers){
        [layer removeFromSuperlayer];
    }

    [numbersText removeAllObjects];
    [scrollLayers removeAllObjects];
    [scrollLabels removeAllObjects];

    [self createNumbersText];
    [self createScrollLayers];
}

- (void)createNumbersText
{
    NSString *textValue = [self.value stringValue];

    for(NSInteger i = ; i < (NSInteger)self.minLength - (NSInteger)[textValue length]; ++i){
        [numbersText addObject:@""];
    }

    for(NSUInteger i = ; i < [textValue length]; ++i){
        [numbersText addObject:[textValue substringWithRange:NSMakeRange(i, )]];
    }
}

- (void)createScrollLayers
{
    CGFloat width = roundf(CGRectGetWidth(self.frame) / numbersText.count);
    CGFloat height = CGRectGetHeight(self.frame);

    for(NSUInteger i = ; i < numbersText.count; ++i){
        CAScrollLayer *layer = [CAScrollLayer layer];
        layer.frame = CGRectMake(roundf(i * width), , width, height);
        [scrollLayers addObject:layer];
        [self.layer addSublayer:layer];
    }

    for(NSUInteger i = ; i < numbersText.count; ++i){
        CAScrollLayer *layer = scrollLayers[i];
        NSString *numberText = numbersText[i];
        [self createContentForLayer:layer withNumberText:numberText];
    }
}

- (void)createContentForLayer:(CAScrollLayer *)scrollLayer withNumberText:(NSString *)numberText
{
    NSInteger number = [numberText integerValue];
    NSMutableArray *textForScroll = [NSMutableArray new];

    for(NSUInteger i = ; i < self.density + ; ++i){
        [textForScroll addObject:[NSString stringWithFormat:@"%ld", (number + i) % ]];
    }

    [textForScroll addObject:numberText];

    if(!self.isAscending){
        textForScroll = [[[textForScroll reverseObjectEnumerator] allObjects] mutableCopy];
    }

    CGFloat height = ;
    for(NSString *text in textForScroll){
        UILabel * textLabel = [self createLabel:text];
        textLabel.frame = CGRectMake(, height, CGRectGetWidth(scrollLayer.frame), CGRectGetHeight(scrollLayer.frame));
        [scrollLayer addSublayer:textLabel.layer];
        [scrollLabels addObject:textLabel];
        height = CGRectGetMaxY(textLabel.frame);
    }
}

- (UILabel *)createLabel:(NSString *)text
{
    UILabel *view = [UILabel new];

    view.textColor = self.textColor;
    view.font = self.font;
    view.textAlignment = NSTextAlignmentCenter;

    view.text = text;

    return view;
}

- (void)createAnimations
{
    CFTimeInterval duration = self.duration - ([numbersText count] * self.durationOffset);
    CFTimeInterval offset = ;

    for(CALayer *scrollLayer in scrollLayers){
        CGFloat maxY = [[scrollLayer.sublayers lastObject] frame].origin.y;

        CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"sublayerTransform.translation.y"];
        animation.duration = duration + offset;
        animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];

        if(self.isAscending){
            animation.fromValue = [NSNumber numberWithFloat:-maxY];
            animation.toValue = @;
        }
        else{
            animation.fromValue = @;
            animation.toValue = [NSNumber numberWithFloat:-maxY];
        }

        [scrollLayer addAnimation:animation forKey:@"JTNumberScrollAnimatedView"];

        offset += self.durationOffset;
    }
}

@end