iOS文本布局探讨之二——关于TextKit框架中的字体描述

//创建动态字体的字体描述类实例
+ (UIFontDescriptor *)preferredFontDescriptorWithTextStyle:(NSString *)style;

+ (UIFont *)fontWithDescriptor:(UIFontDescriptor *)descriptor size:(CGFloat)pointSize NS_AVAILABLE_IOS(7_0);

//标题1
UIKIT_EXTERN NSString *const UIFontTextStyleTitle1 NS_AVAILABLE_IOS(9_0);
//标题2
UIKIT_EXTERN NSString *const UIFontTextStyleTitle2 NS_AVAILABLE_IOS(9_0);
//标题3
UIKIT_EXTERN NSString *const UIFontTextStyleTitle3 NS_AVAILABLE_IOS(9_0);
//大标题
UIKIT_EXTERN NSString *const UIFontTextStyleHeadline NS_AVAILABLE_IOS(7_0);
//子标题
UIKIT_EXTERN NSString *const UIFontTextStyleSubheadline NS_AVAILABLE_IOS(7_0);
//内容
UIKIT_EXTERN NSString *const UIFontTextStyleBody NS_AVAILABLE_IOS(7_0);
//标注
UIKIT_EXTERN NSString *const UIFontTextStyleCallout NS_AVAILABLE_IOS(9_0);
//注脚
UIKIT_EXTERN NSString *const UIFontTextStyleFootnote NS_AVAILABLE_IOS(7_0);
//字幕
UIKIT_EXTERN NSString *const UIFontTextStyleCaption1 NS_AVAILABLE_IOS(7_0);
//字幕2
UIKIT_EXTERN NSString *const UIFontTextStyleCaption2 NS_AVAILABLE_IOS(7_0);

//通过字体名称和字号尺寸来进行UIFontDescriptor对象的创建
+ (UIFontDescriptor *)fontDescriptorWithName:(NSString *)fontName size:(CGFloat)size;
//通过字体名称创建UIFontDescriptor对象，并且设置变换参数
+ (UIFontDescriptor *)fontDescriptorWithName:(NSString *)fontName matrix:(CGAffineTransform)matrix;

    //进行旋转
    CGAffineTransform transfom = CGAffineTransformRotate(CGAffineTransformIdentity, 0.1);
    //进行纵向拉伸
    transfom = CGAffineTransformScale(transfom, 1, 3);
    UIFontDescriptor * fontDes = [UIFontDescriptor fontDescriptorWithName:[UIFont systemFontOfSize:14].fontName matrix:transfom];
    UIFont * font = [UIFont fontWithDescriptor:fontDes size:14];
    UILabel * label = [[UILabel alloc]initWithFrame:CGRectMake(20, 100, 280, 400)];
    label.backgroundColor = [UIColor grayColor];
    label.font = font;
    label.numberOfLines = 0;
    label.text = @"Describes a dictionary that fully specifies a font.... UIFontDescriptorInherits From NSObject UIFontDescriptor NSObject UIFontDescriptor Conforms To CVarArgT... 这里是中文";
    [self.view addSubview:label];

- (instancetype)initWithFontAttributes:(NSDictionary<NSString *, id> *)attributes;

//需要配置为NSValue值 CGAffineTransform
UIKIT_EXTERN NSString *const UIFontDescriptorMatrixAttribute;
//需要配置为一个集合set 包含所有字体字符
UIKIT_EXTERN NSString *const UIFontDescriptorCharacterSetAttribute;
//需要配置为一个数组 数组中为字体描述对象
UIKIT_EXTERN NSString *const UIFontDescriptorCascadeListAttribute;
//需要配置为一个字典 其中进行字体特征的描述 后面会介绍
UIKIT_EXTERN NSString *const UIFontDescriptorTraitsAttribute;
//需要配置为NSNumber类型的 浮点数 其会影响到字体排版时的字符间距
UIKIT_EXTERN NSString *const UIFontDescriptorFixedAdvanceAttribute;
//需要配置为一个数组 数组中为字典 字典中对字型进行配置
/*
//字典中需要配置这两个键
UIKIT_EXTERN NSString *const UIFontFeatureTypeIdentifierKey NS_AVAILABLE_IOS(7_0);
UIKIT_EXTERN NSString *const UIFontFeatureSelectorIdentifierKey NS_AVAILABLE_IOS(7_0);
*/
UIKIT_EXTERN NSString *const UIFontDescriptorFeatureSettingsAttribute;
//配置字体风格 可用的在前面列举过
UIKIT_EXTERN NSString *const UIFontDescriptorTextStyleAttribute;

//这个键值需要配置为一个NSNumber值，设置文字的渲染特征 后面会介绍
UIKIT_EXTERN NSString *const UIFontSymbolicTrait;
//设置字体的粗细属性 
/*
这个键可以设置的值如下
UIKIT_EXTERN const CGFloat UIFontWeightUltraLight NS_AVAILABLE_IOS(8_2);
UIKIT_EXTERN const CGFloat UIFontWeightThin NS_AVAILABLE_IOS(8_2);
UIKIT_EXTERN const CGFloat UIFontWeightLight NS_AVAILABLE_IOS(8_2);
UIKIT_EXTERN const CGFloat UIFontWeightRegular NS_AVAILABLE_IOS(8_2);
UIKIT_EXTERN const CGFloat UIFontWeightMedium NS_AVAILABLE_IOS(8_2);
UIKIT_EXTERN const CGFloat UIFontWeightSemibold NS_AVAILABLE_IOS(8_2);
UIKIT_EXTERN const CGFloat UIFontWeightBold NS_AVAILABLE_IOS(8_2);
UIKIT_EXTERN const CGFloat UIFontWeightHeavy NS_AVAILABLE_IOS(8_2);
UIKIT_EXTERN const CGFloat UIFontWeightBlack NS_AVAILABLE_IOS(8_2);
*/
UIKIT_EXTERN NSString *const UIFontWeightTrait;
//设置字体宽度
UIKIT_EXTERN NSString *const UIFontWidthTrait;
//设置字体倾斜
UIKIT_EXTERN NSString *const UIFontSlantTrait;

typedef NS_OPTIONS(uint32_t, UIFontDescriptorSymbolicTraits) {
    UIFontDescriptorTraitItalic = 1u << 0,
    UIFontDescriptorTraitBold = 1u << 1,
    UIFontDescriptorTraitExpanded = 1u << 5,
    UIFontDescriptorTraitCondensed = 1u << 6,
    UIFontDescriptorTraitMonoSpace = 1u << 10, 
    UIFontDescriptorTraitVertical = 1u << 11,
    UIFontDescriptorTraitUIOptimized = 1u << 12, 
    UIFontDescriptorTraitTightLeading = 1u << 15,
    UIFontDescriptorTraitLooseLeading = 1u << 16,
   
    UIFontDescriptorClassMask = 0xF0000000,
    
    UIFontDescriptorClassUnknown = 0u << 28,
    UIFontDescriptorClassOldStyleSerifs = 1u << 28,
    UIFontDescriptorClassTransitionalSerifs = 2u << 28,
    UIFontDescriptorClassModernSerifs = 3u << 28,
    UIFontDescriptorClassClarendonSerifs = 4u << 28,
    UIFontDescriptorClassSlabSerifs = 5u << 28,
    UIFontDescriptorClassFreeformSerifs = 7u << 28,
    UIFontDescriptorClassSansSerif = 8u << 28,
    UIFontDescriptorClassOrnamentals = 9u << 28,
    UIFontDescriptorClassScripts = 10u << 28,
    UIFontDescriptorClassSymbolic = 12u << 28
} NS_ENUM_AVAILABLE_IOS(7_0);