I'm trying to convert my app to the Swift language.
I have this line of code:
[[UIBarButtonItem appearanceWhenContainedIn:[UINavigationBar class], nil]
setTitleTextAttributes:textDictionary
forState:UIControlStateNormal];
How to convert it to Swift?
In Apple's docs, there is no such method.
If you're targeting iOS 9+ (as of Xcode 7 b1), there is a new method in the UIAppearance
protocol which does not use varargs:
static func appearanceWhenContainedInInstancesOfClasses(containerTypes: [AnyObject.Type]) -> Self
Which can be used like so:
UITextField.appearanceWhenContainedInInstancesOfClasses([MyViewController.self]).keyboardAppearance = .Light
If you still need to support iOS 8 or earlier, use the following original answer to this question.
These methods are not available to Swift because Obj-C varargs methods are not compatible with Swift (see http://www.openradar.me/17302764).
I wrote a non-variadic workaround which works in Swift (I repeated the same method for UIBarItem
, which doesn't descend from UIView
):
// UIAppearance+Swift.h
#import <UIKit/UIKit.h>
NS_ASSUME_NONNULL_BEGIN
@interface UIView (UIViewAppearance_Swift)
// appearanceWhenContainedIn: is not available in Swift. This fixes that.
+ (instancetype)my_appearanceWhenContainedIn:(Class<UIAppearanceContainer>)containerClass;
@end
NS_ASSUME_NONNULL_END
—
// UIAppearance+Swift.m
#import "UIAppearance+Swift.h"
@implementation UIView (UIViewAppearance_Swift)
+ (instancetype)my_appearanceWhenContainedIn:(Class<UIAppearanceContainer>)containerClass {
return [self appearanceWhenContainedIn:containerClass, nil];
}
@end
Just be sure to #import "UIAppearance+Swift.h"
in your bridging header.
Then, to call from Swift (for example):
# Swift 2.x:
UITextField.my_appearanceWhenContainedIn(MyViewController.self).keyboardAppearance = .Light
# Swift 3.x:
UITextField.my_appearanceWhenContained(in: MyViewController.self).keyboardAppearance = .light