如何在 iOS7 中使用具有动态文本大小的自定义字体 [英] How to use a custom font with dynamic text sizes in iOS7
问题描述
在 iOS7 中，有新的 API 用于获取自动调整为用户在其首选项中设置的文本大小的字体.
In iOS7 there are new API's for getting a font that is automatically adjusted to the text size the user has set in their preferences.
使用起来看起来像这样:
It looks something like this to use it:
UIFont *myFont = [UIFont fontWithDescriptor:[UIFontDescriptor preferredFontDescriptorWithTextStyle:UIFontTextStyleHeadline] size:0];
现在，您指定的任何文本都会随着用户更改其系统文本大小设置而上下移动字体大小.(请记住收听 name:UIContentSizeCategoryDidChangeNotification 通知并更新您的视图以说明大小的变化).
Now whatever text you assign this to will move up and down in font size as the user changes their system text size setting. (Remember to listen to the name:UIContentSizeCategoryDidChangeNotification notification and update your view to account for the change in size).
推荐答案
在该 API 的背后，Apple 有某种查找表，可以返回特定的字体系列、大小，有时还包括符号特征(如粗体):例如 UIFontTextStyleHeadline) 和用户的首选文本大小.后者是从 sharedApplication 中提取的字符串，如下所示:
Behind the scenes of that API, apple has some sort of lookup table that returns a specific font family, size, and sometimes symbolic traits (like bold) that (e.g. UIFontTextStyleHeadline) and the user's preferred text size. The latter is a string pulled off of the sharedApplication like this:
[UIApplication sharedApplication].preferredContentSizeCategory;
(我注销了 Helvetica-Neue 的所有默认大小/字体/特征各种动态文本大小).我们已经添加了对可访问性大小的处理，这很重要.
(I logged out all the default sizes/fonts/traits for Helvetica-Neue for the various dynamic text sizes). We've since added handling for the accessibility sizes, which is important.
所以你真正需要做的就是建立一个类似的查找表.我们的设计师为我创建了一个简单的电子表格:
So all you really have to do is build a similar lookup table. Our designer created a simple spreadsheet for me:
请注意，我们添加了几种样式(标题 3 和 4)，以便有 8 个而不是 6 个可供选择.
然后你会想把它放在方便的地方，比如UIFontDescriptor上的一个类别.你会希望你的方法像 Apple 的 API 一样返回一个 UIFontDescriptor，这样它仍然很容易用符号特征等进行调整.
Then you'll want to put it someplace convenient, like a category on UIFontDescriptor. You'll want your method to return a UIFontDescriptor like Apple's API, so that it's still easy to adjust with symbolic traits, etc.
我的类别如下所示:
UIFontDescriptor+AvenirNext.h
#import <UIKit/UIKit.h>
extern NSString *const ANUIFontTextStyleCaption3;
@interface UIFontDescriptor (AvenirNext)
+(UIFontDescriptor *)preferredAvenirNextFontDescriptorWithTextStyle:(NSString *)style;
@end
UIFontDescriptor+AvenirNext.m
#import "UIFontDescriptor+AvenirNext.h"
NSString *const ANUIFontTextStyleCaption3 = @"ANUIFontTextStyleCaption3";
NSString *const ANUIFontTextStyleCaption4 = @"ANUIFontTextStyleCaption4";
@implementation UIFontDescriptor (AvenirNext)
+(UIFontDescriptor *)preferredAvenirNextFontDescriptorWithTextStyle:(NSString *)style {
static dispatch_once_t onceToken;
static NSDictionary *fontSizeTable;
dispatch_once(&onceToken, ^{
fontSizeTable = @{
UIFontTextStyleHeadline: @{
UIContentSizeCategoryAccessibilityExtraExtraExtraLarge: @26,
UIContentSizeCategoryAccessibilityExtraExtraLarge: @25,
UIContentSizeCategoryAccessibilityExtraLarge: @24,
UIContentSizeCategoryAccessibilityLarge: @24,
UIContentSizeCategoryAccessibilityMedium: @23,
UIContentSizeCategoryExtraExtraExtraLarge: @23,
UIContentSizeCategoryExtraExtraLarge: @22,
UIContentSizeCategoryExtraLarge: @21,
UIContentSizeCategoryLarge: @20,
UIContentSizeCategoryMedium: @19,
UIContentSizeCategorySmall: @18,
UIContentSizeCategoryExtraSmall: @17,},
UIFontTextStyleSubheadline: @{
UIContentSizeCategoryAccessibilityExtraExtraExtraLarge: @24,
UIContentSizeCategoryAccessibilityExtraExtraLarge: @23,
UIContentSizeCategoryAccessibilityExtraLarge: @22,
UIContentSizeCategoryAccessibilityLarge: @22,
UIContentSizeCategoryAccessibilityMedium: @21,
UIContentSizeCategoryExtraExtraExtraLarge: @21,
UIContentSizeCategoryExtraExtraLarge: @20,
UIContentSizeCategoryExtraLarge: @19,
UIContentSizeCategoryLarge: @18,
UIContentSizeCategoryMedium: @17,
UIContentSizeCategorySmall: @16,
UIContentSizeCategoryExtraSmall: @15,},
UIFontTextStyleBody: @{
UIContentSizeCategoryAccessibilityExtraExtraExtraLarge: @21,
UIContentSizeCategoryAccessibilityExtraExtraLarge: @20,
UIContentSizeCategoryAccessibilityExtraLarge: @19,
UIContentSizeCategoryAccessibilityLarge: @19,
UIContentSizeCategoryAccessibilityMedium: @18,
UIContentSizeCategoryExtraExtraExtraLarge: @18,
UIContentSizeCategoryExtraExtraLarge: @17,
UIContentSizeCategoryExtraLarge: @16,
UIContentSizeCategoryLarge: @15,
UIContentSizeCategoryMedium: @14,
UIContentSizeCategorySmall: @13,
UIContentSizeCategoryExtraSmall: @12,},
UIFontTextStyleCaption1: @{
UIContentSizeCategoryAccessibilityExtraExtraExtraLarge: @19,
UIContentSizeCategoryAccessibilityExtraExtraLarge: @18,
UIContentSizeCategoryAccessibilityExtraLarge: @17,
UIContentSizeCategoryAccessibilityLarge: @17,
UIContentSizeCategoryAccessibilityMedium: @16,
UIContentSizeCategoryExtraExtraExtraLarge: @16,
UIContentSizeCategoryExtraExtraLarge: @16,
UIContentSizeCategoryExtraLarge: @15,
UIContentSizeCategoryLarge: @14,
UIContentSizeCategoryMedium: @13,
UIContentSizeCategorySmall: @12,
UIContentSizeCategoryExtraSmall: @12,},
UIFontTextStyleCaption2: @{
UIContentSizeCategoryAccessibilityExtraExtraExtraLarge: @18,
UIContentSizeCategoryAccessibilityExtraExtraLarge: @17,
UIContentSizeCategoryAccessibilityExtraLarge: @16,
UIContentSizeCategoryAccessibilityLarge: @16,
UIContentSizeCategoryAccessibilityMedium: @15,
UIContentSizeCategoryExtraExtraExtraLarge: @15,
UIContentSizeCategoryExtraExtraLarge: @14,
UIContentSizeCategoryExtraLarge: @14,
UIContentSizeCategoryLarge: @13,
UIContentSizeCategoryMedium: @12,
UIContentSizeCategorySmall: @12,
UIContentSizeCategoryExtraSmall: @11,},
ANUIFontTextStyleCaption3: @{
UIContentSizeCategoryAccessibilityExtraExtraExtraLarge: @17,
UIContentSizeCategoryAccessibilityExtraExtraLarge: @16,
UIContentSizeCategoryAccessibilityExtraLarge: @15,
UIContentSizeCategoryAccessibilityLarge: @15,
UIContentSizeCategoryAccessibilityMedium: @14,
UIContentSizeCategoryExtraExtraExtraLarge: @14,
UIContentSizeCategoryExtraExtraLarge: @13,
UIContentSizeCategoryExtraLarge: @12,
UIContentSizeCategoryLarge: @12,
UIContentSizeCategoryMedium: @12,
UIContentSizeCategorySmall: @11,
UIContentSizeCategoryExtraSmall: @10,},
UIFontTextStyleFootnote: @{
UIContentSizeCategoryAccessibilityExtraExtraExtraLarge: @16,
UIContentSizeCategoryAccessibilityExtraExtraLarge: @15,
UIContentSizeCategoryAccessibilityExtraLarge: @14,
UIContentSizeCategoryAccessibilityLarge: @14,
UIContentSizeCategoryAccessibilityMedium: @13,
UIContentSizeCategoryExtraExtraExtraLarge: @13,
UIContentSizeCategoryExtraExtraLarge: @12,
UIContentSizeCategoryExtraLarge: @12,
UIContentSizeCategoryLarge: @11,
UIContentSizeCategoryMedium: @11,
UIContentSizeCategorySmall: @10,
UIContentSizeCategoryExtraSmall: @10,},
ANUIFontTextStyleCaption4: @{
UIContentSizeCategoryAccessibilityExtraExtraExtraLarge: @15,
UIContentSizeCategoryAccessibilityExtraExtraLarge: @14,
UIContentSizeCategoryAccessibilityExtraLarge: @13,
UIContentSizeCategoryAccessibilityLarge: @13,
UIContentSizeCategoryAccessibilityMedium: @12,
UIContentSizeCategoryExtraExtraExtraLarge: @12,
UIContentSizeCategoryExtraExtraLarge: @11,
UIContentSizeCategoryExtraLarge: @11,
UIContentSizeCategoryLarge: @10,
UIContentSizeCategoryMedium: @10,
UIContentSizeCategorySmall: @9,
UIContentSizeCategoryExtraSmall: @9,},
};
});
NSString *contentSize = [UIApplication sharedApplication].preferredContentSizeCategory;
return [UIFontDescriptor fontDescriptorWithName:[self preferredFontName] size:((NSNumber *)fontSizeTable[style][contentSize]).floatValue];
}
+(UIFontDescriptor *)preferredAvenirNextDemiBoldFontDescriptorWithTextStyle:(NSString *)style {
return [[self preferredAvenirNextFontDescriptorWithTextStyle:style] fontDescriptorWithSymbolicTraits:UIFontDescriptorTraitBold];
}
+(UIFontDescriptor *)preferredAvenirNextBoldFontDescriptorWithTextStyle:(NSString *)style {
return [UIFontDescriptor fontDescriptorWithName:[self preferredBoldFontName] size:[self preferredAvenirNextFontDescriptorWithTextStyle:style].pointSize];
}
+(NSString *)preferredFontName {
return @"AvenirNext-Medium";
}
+(NSString *)preferredBoldFontName {
return @"AvenirNext-Bold";
}
@end
我们选择使用相同的基本字体 AvenirNext-Medium，然后通过符号特征使用粗体等，但您可能会很疯狂，在您的字体上指定不同的粗细变体作为查找表的一部分如果您愿意，也可以，例如 AvenirNext-ExtraBold.
We chose to use the same base font AvenirNext-Medium, and then bold and such via symbolic traits, but you could get crazy and specify different weight variants on your font as part of your lookup table as well if you wanted, like AvenirNext-ExtraBold.
[UIFont fontWithDescriptor:[UIFontDescriptor preferredAvenirNextFontDescriptorWithTextStyle:UIFontTextStyleHeadline] size: 0]
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