Awesome

YYAsyncLayer

iOS utility classes for asynchronous rendering and display.<br/> (It was used by YYText)

Simple Usage

@interface YYLabel : UIView
@property NSString *text;
@property UIFont *font;
@end

@implementation YYLabel

- (void)setText:(NSString *)text {
    _text = text.copy;
    [[YYTransaction transactionWithTarget:self selector:@selector(contentsNeedUpdated)] commit];
}

- (void)setFont:(UIFont *)font {
    _font = font;
    [[YYTransaction transactionWithTarget:self selector:@selector(contentsNeedUpdated)] commit];
}

- (void)layoutSubviews {
    [super layoutSubviews];
    [[YYTransaction transactionWithTarget:self selector:@selector(contentsNeedUpdated)] commit];
}

- (void)contentsNeedUpdated {
    // do update
    [self.layer setNeedsDisplay];
}

#pragma mark - YYAsyncLayer

+ (Class)layerClass {
    return YYAsyncLayer.class;
}

- (YYAsyncLayerDisplayTask *)newAsyncDisplayTask {
    
    // capture current state to display task
    NSString *text = _text;
    UIFont *font = _font;
    
    YYAsyncLayerDisplayTask *task = [YYAsyncLayerDisplayTask new];
    task.willDisplay = ^(CALayer *layer) {
        //...
    };
    
    task.display = ^(CGContextRef context, CGSize size, BOOL(^isCancelled)(void)) {
        if (isCancelled()) return;
        NSArray *lines = CreateCTLines(text, font, size.width);
        if (isCancelled()) return;
        
        for (int i = 0; i < lines.count; i++) {
            CTLineRef line = line[i];
            CGContextSetTextPosition(context, 0, i * font.pointSize * 1.5);
            CTLineDraw(line, context);
            if (isCancelled()) return;
        }
    };
    
    task.didDisplay = ^(CALayer *layer, BOOL finished) {
        if (finished) {
            // finished
        } else {
            // cancelled
        }
    };
    
    return task;
}
@end

Installation

CocoaPods

1. Add pod 'YYAsyncLayer' to your Podfile.
2. Run pod install or pod update.
3. Import <YYAsyncLayer/YYAsyncLayer.h>.

Carthage

1. Add github "ibireme/YYAsyncLayer" to your Cartfile.
2. Run carthage update --platform ios and add the framework to your project.
3. Import <YYAsyncLayer/YYAsyncLayer.h>.

Manually

1. Download all the files in the YYAsyncLayer subdirectory.
2. Add the source files to your Xcode project.
3. Import YYAsyncLayer.h.

Documentation

Full API documentation is available on CocoaDocs.<br/> You can also install documentation locally using appledoc.

Requirements

This library requires iOS 6.0+ and Xcode 8.0+.

License

YYAsyncLayer is provided under the MIT license. See LICENSE file for details.

<br/><br/>

中文介绍

iOS 异步绘制与显示的工具类。<br/> (该工具是从 YYText 提取出来的独立组件)

简单用法

@interface YYLabel : UIView
@property NSString *text;
@property UIFont *font;
@end

@implementation YYLabel

- (void)setText:(NSString *)text {
    _text = text.copy;
    [[YYTransaction transactionWithTarget:self selector:@selector(contentsNeedUpdated)] commit];
}

- (void)setFont:(UIFont *)font {
    _font = font;
    [[YYTransaction transactionWithTarget:self selector:@selector(contentsNeedUpdated)] commit];
}

- (void)layoutSubviews {
    [super layoutSubviews];
    [[YYTransaction transactionWithTarget:self selector:@selector(contentsNeedUpdated)] commit];
}

- (void)contentsNeedUpdated {
    // do update
    [self.layer setNeedsDisplay];
}

#pragma mark - YYAsyncLayer

+ (Class)layerClass {
    return YYAsyncLayer.class;
}

- (YYAsyncLayerDisplayTask *)newAsyncDisplayTask {
    
    // capture current state to display task
    NSString *text = _text;
    UIFont *font = _font;
    
    YYAsyncLayerDisplayTask *task = [YYAsyncLayerDisplayTask new];
    task.willDisplay = ^(CALayer *layer) {
        //...
    };
    
    task.display = ^(CGContextRef context, CGSize size, BOOL(^isCancelled)(void)) {
        if (isCancelled()) return;
        NSArray *lines = CreateCTLines(text, font, size.width);
        if (isCancelled()) return;
        
        for (int i = 0; i < lines.count; i++) {
            CTLineRef line = line[i];
            CGContextSetTextPosition(context, 0, i * font.pointSize * 1.5);
            CTLineDraw(line, context);
            if (isCancelled()) return;
        }
    };
    
    task.didDisplay = ^(CALayer *layer, BOOL finished) {
        if (finished) {
            // finished
        } else {
            // cancelled
        }
    };
    
    return task;
}
@end

安装

CocoaPods

1. 在 Podfile 中添加 pod 'YYAsyncLayer'。
2. 执行 pod install 或 pod update。
3. 导入 <YYAsyncLayer/YYAsyncLayer.h>。

Carthage

1. 在 Cartfile 中添加 github "ibireme/YYAsyncLayer"。
2. 执行 carthage update --platform ios 并将生成的 framework 添加到你的工程。
3. 导入 <YYAsyncLayer/YYAsyncLayer.h>。

手动安装

1. 下载 YYAsyncLayer 文件夹内的所有内容。
2. 将 YYAsyncLayer 内的源文件添加(拖放)到你的工程。
3. 导入 YYAsyncLayer.h。

文档

你可以在 CocoaDocs 查看在线 API 文档，也可以用 appledoc 本地生成文档。

系统要求

该项目最低支持 iOS 6.0 和 Xcode 8.0。

许可证

YYAsyncLayer 使用 MIT 许可证，详情见 LICENSE 文件。

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