//
// UILayoutGuide.h
// UIKit
//
// Copyright © 2015 Apple Inc. All rights reserved.
//



#import <CoreGraphics/CoreGraphics.h>

#import <Foundation/Foundation.h>



@class NSLayoutXAxisAnchor, NSLayoutYAxisAnchor, NSLayoutDimension;



NS_ASSUME_NONNULL_BEGIN

@class UIView;

/* UILayoutGuides will not show up in the view hierarchy, but may be used as items in

 an NSLayoutConstraint and represent a rectangle in the layout engine.

 Create a UILayoutGuide with -init, and add to a view with -[UIView addLayoutGuide:]
 before using it in a constraint.

 */

NS_CLASS_AVAILABLE_IOS(9_0)

@interface UILayoutGuide : NSObject <NSCoding>



/* The frame of the UILayoutGuide in its owningView's coordinate system.
 Valid by the time the owningView receives -layoutSubviews.
 */

@property(nonatomic,readonly) CGRect layoutFrame;



/* The guide must be added to a view with -[UIView addLayoutGuide:] before being used in a constraint.
 Do not use this property directly to change the owningView of a layout guide. Instead, use
 -[UIView addLayoutGuide:] and -[UIView removeLayoutGuide:], which will use this property to
 change the owningView.
 */

@property(nonatomic,weak,nullable) UIView *owningView;



/* For ease of debugging.

 'UI' prefix is reserved for UIKit-created layout guides.

 */

@property(nonatomic,copy) NSString *identifier;





/* Constraint creation conveniences. See NSLayoutAnchor.h for details.

 */

@property(readonly, strong) NSLayoutXAxisAnchor *leadingAnchor;

@property(readonly, strong) NSLayoutXAxisAnchor *trailingAnchor;

@property(readonly, strong) NSLayoutXAxisAnchor *leftAnchor;

@property(readonly, strong) NSLayoutXAxisAnchor *rightAnchor;

@property(readonly, strong) NSLayoutYAxisAnchor *topAnchor;

@property(readonly, strong) NSLayoutYAxisAnchor *bottomAnchor;

@property(readonly, strong) NSLayoutDimension *widthAnchor;

@property(readonly, strong) NSLayoutDimension *heightAnchor;

@property(readonly, strong) NSLayoutXAxisAnchor *centerXAnchor;

@property(readonly, strong) NSLayoutYAxisAnchor *centerYAnchor;



@end

NS_ASSUME_NONNULL_END