Basic UIView overlay (for tutorials etc.). Inserts itself under all other subviews and uses drawRect: to cover the canvas with a colour and then cut out collection of view frames using drawRect:. Based on CXOverlay.

Observes when subviews move by performing KVO on the center selector.

✓ UIView category convenience methods

self.view.focusView = [[CXFocusView alloc] init];
self.view.focusView.backgroundColor = [UIColor orangeColor];
self.view.focusView = nil;

✓ Supports animation with a crossfade effect.

[self.view.overlay focusOnView:someView withDuration:1.0];

Full API:

CXFocusView

@property (nonatomic, strong) NSArray *views;

- (instancetype)initWithView:(UIView *)view;
- (instancetype)initWithViews:(NSArray *)views;

- (void)focusOnView:(UIView *)view;
- (void)focusOnView:(UIView *)view withDuration:(NSTimeInterval)duration;
- (void)focusOnView:(UIView *)view withDuration:(NSTimeInterval)duration andDelay:(NSTimeInterval)delay;
- (void)focusOnView:(UIView *)view withDuration:(NSTimeInterval)duration andDelay:(NSTimeInterval)delay andCompletion:(void (^)(BOOL finished))completion;

- (void)focusOnViews:(NSArray *)views;
- (void)focusOnViews:(NSArray *)views withDuration:(NSTimeInterval)duration;
- (void)focusOnViews:(NSArray *)views withDuration:(NSTimeInterval)duration andDelay:(NSTimeInterval)delay;
- (void)focusOnViews:(NSArray *)views withDuration:(NSTimeInterval)duration andDelay:(NSTimeInterval)delay andCompletion:(void (^)(BOOL finished))completion;

- (void)clearFocus;
- (void)clearFocusWithDuration:(NSTimeInterval)duration;
- (void)clearFocusWithDuration:(NSTimeInterval)duration andDelay:(NSTimeInterval)delay;
- (void)clearFocusWithDuration:(NSTimeInterval)duration andDelay:(NSTimeInterval)delay andCompletion:(void (^)(BOOL finished))completion;

UIView (CXFocusView)

@property (readwrite) CXFocusView *focusView;