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//
//  UIViewController.h
//  UIKit
//
//  Copyright (c) 2007-2013, Apple Inc. All rights reserved.
//

#import <Foundation/Foundation.h>
#import <UIKit/UIKitDefines.h>
#import <UIKit/UIApplication.h>
#import <UIKit/UIStateRestoration.h>

/*
  UIViewController is a generic controller base class that manages a view.  It has methods that are called
  when a view appears or disappears.
 
  Subclasses can override -loadView to create their custom view hierarchy, or specify a nib name to be loaded
  automatically.  This class is also a good place for delegate & datasource methods, and other controller
  stuff.
*/

@class UIView;
@class UINavigationItem, UIBarButtonItem, UITabBarItem;
@class UISearchDisplayController;
@class UIPopoverController;
@class UIStoryboard, UIStoryboardSegue;
@class UIScrollView;

typedef NS_ENUM(NSInteger, UIModalTransitionStyle) {
    UIModalTransitionStyleCoverVertical = 0,
    UIModalTransitionStyleFlipHorizontal,
    UIModalTransitionStyleCrossDissolve,
#if __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_3_2
    UIModalTransitionStylePartialCurl,
#endif
};

typedef NS_ENUM(NSInteger, UIModalPresentationStyle) {
    UIModalPresentationFullScreen = 0,
#if __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_3_2
    UIModalPresentationPageSheet,
    UIModalPresentationFormSheet,
    UIModalPresentationCurrentContext,
#endif
#if __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_7_0
    UIModalPresentationCustom,
    UIModalPresentationNone = -1,        
#endif        
};

NS_CLASS_AVAILABLE_IOS(2_0) @interface UIViewController : UIResponder <NSCoding, UIAppearanceContainer> {
    @package
    UIView           *_view;
    UITabBarItem     *_tabBarItem;
    UINavigationItem *_navigationItem;
    NSArray          *_toolbarItems;
    NSString         *_title;
    
    NSString         *_nibName;
    NSBundle         *_nibBundle;
    
    UIViewController *_parentViewController; // Nonretained
    
    UIViewController *_childModalViewController;
    UIViewController *_parentModalViewController; // Nonretained
    UIViewController *_previousRootViewController; // Nonretained    
    UIView           *_modalTransitionView;
    UIResponder	     *_modalPreservedFirstResponder;
    id               _dimmingView;
    id               _dropShadowView;
    
    id                _currentAction;
    UIStoryboard     *_storyboard;
    NSArray          *_storyboardSegueTemplates;
    NSDictionary     *_externalObjectsTableForViewLoading;
    NSArray          *_topLevelObjectsToKeepAliveFromStoryboard;
    
    UIView           *_savedHeaderSuperview;
    UIView           *_savedFooterSuperview;
    
    UIBarButtonItem  *_editButtonItem;
    
    UISearchDisplayController *_searchDisplayController;
    
    UIModalTransitionStyle _modalTransitionStyle;
    UIModalPresentationStyle _modalPresentationStyle;
    
    UIInterfaceOrientation _lastKnownInterfaceOrientation;

    UIPopoverController*    _popoverController;
    UIView *_containerViewInSheet;
    CGSize _contentSizeForViewInPopover;
    CGSize _formSheetSize;

    UIScrollView *_recordedContentScrollView;

    void (^_afterAppearance)(void);
    NSInteger _explicitAppearanceTransitionLevel;
    
    NSArray *_keyCommands;

    struct {
        unsigned int appearState:2;
        unsigned int isEditing:1;
        unsigned int isPerformingModalTransition:1;
        unsigned int hidesBottomBarWhenPushed:1;
        unsigned int autoresizesArchivedViewToFullSize:1;
        unsigned int viewLoadedFromControllerNib:1;
        unsigned int isRootViewController:1;
        unsigned int customizesForPresentationInPopover:1;
        unsigned int isSuspended:1;
        unsigned int wasApplicationFrameAtSuspend:1;
        unsigned int wantsFullScreenLayout:1;
        unsigned int shouldUseFullScreenLayout:1;
        unsigned int allowsAutorotation:1;
        unsigned int searchControllerRetained:1;
        unsigned int oldModalInPopover:1;
        unsigned int isModalInPopover:1;
        unsigned int isInWillRotateCallback:1;
        unsigned int disallowMixedOrientationPresentations:1;
        unsigned int isFinishingModalTransition:1;
        unsigned int definesPresentationContext:1;
        unsigned int providesPresentationContextTransitionStyle:1;        
        unsigned int containmentSupport:1;
        unsigned int isSettingAppearState:1;
        unsigned int isInAnimatedVCTransition:1;
        unsigned int presentationIsChanging:1;
        unsigned int isBeingPresented:1;        
        unsigned int containmentIsChanging:1;
        unsigned int explicitTransitionIsAppearing:1;
        unsigned int disableAppearanceTransitions:1;
        unsigned int needsDidMoveCleanup:1;        
        unsigned int suppressesBottomBar:1;
        unsigned int disableRootPromotion:1;
        unsigned int interfaceOrientationReentranceGuard:1;
        unsigned int isExecutingAfterAppearance:1;
        unsigned int rootResignationNeeded:1;
        unsigned int shouldSynthesizeSupportedOrientations:1;
        unsigned int viewConstraintsNeedUpdateOnAppearance:1;
        unsigned int shouldForceNonAnimatedTransition:1;
        unsigned int isInCustomTransition:1;
        unsigned int usesSharedView:1;
        unsigned int extendedLayoutIncludesOpaqueBars:1;
        unsigned int automaticallyAdjustInsets:1;
        unsigned int previousShouldUnderlapUnderStatusBar:1;
        unsigned int freezeShouldUnderlapUnderStatusBar:1;
        unsigned int neverResizeRoot:1;
    } _viewControllerFlags;
}

/*
  The designated initializer. If you subclass UIViewController, you must call the super implementation of this
  method, even if you aren't using a NIB.  (As a convenience, the default init method will do this for you,
  and specify nil for both of this methods arguments.) In the specified NIB, the File's Owner proxy should
  have its class set to your view controller subclass, with the view outlet connected to the main view. If you
  invoke this method with a nil nib name, then this class' -loadView method will attempt to load a NIB whose
  name is the same as your view controller's class. If no such NIB in fact exists then you must either call
  -setView: before -view is invoked, or override the -loadView method to set up your views programatically.
*/
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil;

@property(nonatomic,retain) UIView *view; // The getter first invokes [self loadView] if the view hasn't been set yet. Subclasses must call super if they override the setter or getter.
- (void)loadView; // This is where subclasses should create their custom view hierarchy if they aren't using a nib. Should never be called directly.

- (void)viewWillUnload NS_DEPRECATED_IOS(5_0,6_0);
- (void)viewDidUnload NS_DEPRECATED_IOS(3_0,6_0); // Called after the view controller's view is released and set to nil. For example, a memory warning which causes the view to be purged. Not invoked as a result of -dealloc.

- (void)viewDidLoad; // Called after the view has been loaded. For view controllers created in code, this is after -loadView. For view controllers unarchived from a nib, this is after the view is set.
- (BOOL)isViewLoaded NS_AVAILABLE_IOS(3_0);

@property(nonatomic, readonly, copy) NSString *nibName;     // The name of the nib to be loaded to instantiate the view.
@property(nonatomic, readonly, retain) NSBundle *nibBundle; // The bundle from which to load the nib.
@property(nonatomic, readonly, retain) UIStoryboard *storyboard NS_AVAILABLE_IOS(5_0);

- (void)performSegueWithIdentifier:(NSString *)identifier sender:(id)sender NS_AVAILABLE_IOS(5_0);
- (BOOL)shouldPerformSegueWithIdentifier:(NSString *)identifier sender:(id)sender NS_AVAILABLE_IOS(6_0); // Invoked immediately prior to initiating a segue. Return NO to prevent the segue from firing. The default implementation returns YES. This method is not invoked when -performSegueWithIdentifier:sender: is used.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender NS_AVAILABLE_IOS(5_0);

// View controllers will receive this message during segue unwinding. The default implementation returns the result of -respondsToSelector: - controllers can override this to perform any ancillary checks, if necessary.
- (BOOL)canPerformUnwindSegueAction:(SEL)action fromViewController:(UIViewController *)fromViewController withSender:(id)sender NS_AVAILABLE_IOS(6_0);

// Custom containers should override this method and search their children for an action handler (using -canPerformUnwindSegueAction:fromViewController:sender:). If a handler is found, the controller should return it. Otherwise, the result of invoking super's implementation should be returned.
- (UIViewController *)viewControllerForUnwindSegueAction:(SEL)action fromViewController:(UIViewController *)fromViewController withSender:(id)sender NS_AVAILABLE_IOS(6_0);

// Custom container view controllers should override this method and return segue instances that will perform the navigation portion of segue unwinding.
- (UIStoryboardSegue *)segueForUnwindingToViewController:(UIViewController *)toViewController fromViewController:(UIViewController *)fromViewController identifier:(NSString *)identifier NS_AVAILABLE_IOS(6_0);

- (void)viewWillAppear:(BOOL)animated;    // Called when the view is about to made visible. Default does nothing
- (void)viewDidAppear:(BOOL)animated;     // Called when the view has been fully transitioned onto the screen. Default does nothing
- (void)viewWillDisappear:(BOOL)animated; // Called when the view is dismissed, covered or otherwise hidden. Default does nothing
- (void)viewDidDisappear:(BOOL)animated;  // Called after the view was dismissed, covered or otherwise hidden. Default does nothing

// Called just before the view controller's view's layoutSubviews method is invoked. Subclasses can implement as necessary. The default is a nop.
- (void)viewWillLayoutSubviews NS_AVAILABLE_IOS(5_0);
// Called just after the view controller's view's layoutSubviews method is invoked. Subclasses can implement as necessary. The default is a nop.
- (void)viewDidLayoutSubviews NS_AVAILABLE_IOS(5_0);

@property(nonatomic,copy) NSString *title;  // Localized title for use by a parent controller.

- (void)didReceiveMemoryWarning; // Called when the parent application receives a memory warning. On iOS 6.0 it will no longer clear the view by default.

/*
  If this view controller is a child of a containing view controller (e.g. a navigation controller or tab bar
  controller,) this is the containing view controller.  Note that as of 5.0 this no longer will return the
  presenting view controller.
*/
@property(nonatomic,readonly) UIViewController *parentViewController;

// This property has been replaced by presentedViewController.
@property(nonatomic,readonly) UIViewController *modalViewController NS_DEPRECATED_IOS(2_0, 6_0);

// The view controller that was presented by this view controller or its nearest ancestor.
@property(nonatomic,readonly) UIViewController *presentedViewController  NS_AVAILABLE_IOS(5_0);

// The view controller that presented this view controller (or its farthest ancestor.)
@property(nonatomic,readonly) UIViewController *presentingViewController NS_AVAILABLE_IOS(5_0);

/*
  Determines which parent view controller's view should be presented over for presentations of type
  UIModalPresentationCurrentContext.  If no ancestor view controller has this flag set, then the presenter
  will be the root view controller.
*/
@property(nonatomic,assign) BOOL definesPresentationContext NS_AVAILABLE_IOS(5_0);

// A controller that defines the presentation context can also specify the modal transition style if this property is true.
@property(nonatomic,assign) BOOL providesPresentationContextTransitionStyle NS_AVAILABLE_IOS(5_0);

/*
  These four methods can be used in a view controller's appearance callbacks to determine if it is being
  presented, dismissed, or added or removed as a child view controller. For example, a view controller can
  check if it is disappearing because it was dismissed or popped by asking itself in its viewWillDisappear:
  method by checking the expression ([self isBeingDismissed] || [self isMovingFromParentViewController]).
*/

- (BOOL)isBeingPresented NS_AVAILABLE_IOS(5_0);
- (BOOL)isBeingDismissed NS_AVAILABLE_IOS(5_0);

- (BOOL)isMovingToParentViewController NS_AVAILABLE_IOS(5_0);
- (BOOL)isMovingFromParentViewController NS_AVAILABLE_IOS(5_0);

/*
  The next two methods are replacements for presentModalViewController:animated and
  dismissModalViewControllerAnimated: The completion handler, if provided, will be invoked after the presented
  controllers viewDidAppear: callback is invoked.
*/
- (void)presentViewController:(UIViewController *)viewControllerToPresent animated: (BOOL)flag completion:(void (^)(void))completion NS_AVAILABLE_IOS(5_0);
// The completion handler, if provided, will be invoked after the dismissed controller's viewDidDisappear: callback is invoked.
- (void)dismissViewControllerAnimated: (BOOL)flag completion: (void (^)(void))completion NS_AVAILABLE_IOS(5_0);

// Display another view controller as a modal child. Uses a vertical sheet transition if animated.This method has been replaced by presentViewController:animated:completion:
- (void)presentModalViewController:(UIViewController *)modalViewController animated:(BOOL)animated NS_DEPRECATED_IOS(2_0, 6_0);

// Dismiss the current modal child. Uses a vertical sheet transition if animated. This method has been replaced by dismissViewControllerAnimated:completion:
- (void)dismissModalViewControllerAnimated:(BOOL)animated NS_DEPRECATED_IOS(2_0, 6_0);

/*
  Defines the transition style that will be used for this view controller when it is presented modally. Set
  this property on the view controller to be presented, not the presenter.  Defaults to
  UIModalTransitionStyleCoverVertical.
*/
@property(nonatomic,assign) UIModalTransitionStyle modalTransitionStyle NS_AVAILABLE_IOS(3_0);
@property(nonatomic,assign) UIModalPresentationStyle modalPresentationStyle NS_AVAILABLE_IOS(3_2);
// This controls whether this view controller takes over control of the status bar's appearance when presented non-full screen on another view controller. Defaults to NO.
@property(nonatomic,assign) BOOL modalPresentationCapturesStatusBarAppearance NS_AVAILABLE_IOS(7_0);

// Presentation modes may keep the keyboard visible when not required. Default implementation affects UIModalPresentationFormSheet visibility.
- (BOOL)disablesAutomaticKeyboardDismissal NS_AVAILABLE_IOS(4_3);

@property(nonatomic,assign) BOOL wantsFullScreenLayout NS_DEPRECATED_IOS(3_0, 7_0); // Deprecated in 7_0, Replaced by the following:

@property(nonatomic,assign) UIRectEdge edgesForExtendedLayout NS_AVAILABLE_IOS(7_0); // Defaults to UIRectEdgeAll
@property(nonatomic,assign) BOOL extendedLayoutIncludesOpaqueBars NS_AVAILABLE_IOS(7_0); // Defaults to NO, but bars are translucent by default on 7_0.  
@property(nonatomic,assign) BOOL automaticallyAdjustsScrollViewInsets NS_AVAILABLE_IOS(7_0); // Defaults to YES

/* The preferredContentSize is used for any container laying out a child view controller.
 */
@property (nonatomic) CGSize preferredContentSize NS_AVAILABLE_IOS(7_0);

// These methods control the attributes of the status bar when this view controller is shown. They can be overridden in view controller subclasses to return the desired status bar attributes.
- (UIStatusBarStyle)preferredStatusBarStyle NS_AVAILABLE_IOS(7_0); // Defaults to UIStatusBarStyleDefault
- (BOOL)prefersStatusBarHidden NS_AVAILABLE_IOS(7_0); // Defaults to NO
// Override to return the type of animation that should be used for status bar changes for this view controller. This currently only affects changes to prefersStatusBarHidden.
- (UIStatusBarAnimation)preferredStatusBarUpdateAnimation NS_AVAILABLE_IOS(7_0); // Defaults to UIStatusBarAnimationFade

// This should be called whenever the return values for the view controller's status bar attributes have changed. If it is called from within an animation block, the changes will be animated along with the rest of the animation block.
- (void)setNeedsStatusBarAppearanceUpdate NS_AVAILABLE_IOS(7_0);

@end

// To make it more convenient for applications to adopt rotation, a view controller may implement the below methods. Your UIWindow's frame should use [UIScreen mainScreen].bounds as its frame.
@interface UIViewController (UIViewControllerRotation)

// call this method when your return value from shouldAutorotateToInterfaceOrientation: changes
// if the current interface orientation does not match the current device orientation, a rotation may occur provided all relevant view controllers now return YES from shouldAutorotateToInterfaceOrientation:
+ (void)attemptRotationToDeviceOrientation NS_AVAILABLE_IOS(5_0);

// Applications should use supportedInterfaceOrientations and/or shouldAutorotate..
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation NS_DEPRECATED_IOS(2_0, 6_0);

// New Autorotation support.
- (BOOL)shouldAutorotate NS_AVAILABLE_IOS(6_0);
- (NSUInteger)supportedInterfaceOrientations NS_AVAILABLE_IOS(6_0);
// Returns interface orientation masks.
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation NS_AVAILABLE_IOS(6_0);

// The rotating header and footer views will slide out during the rotation and back in once it has completed.
- (UIView *)rotatingHeaderView;     // Must be in the view hierarchy. Default returns nil.
- (UIView *)rotatingFooterView;     // Must be in the view hierarchy. Default returns nil.

@property(nonatomic,readonly) UIInterfaceOrientation interfaceOrientation;

// Notifies when rotation begins, reaches halfway point and ends.
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration;
- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation;

// Faster one-part variant, called from within a rotating animation block, for additional animations during rotation.
// A subclass may override this method, or the two-part variants below, but not both.
- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration NS_AVAILABLE_IOS(3_0);

// Slower two-part variant, called from within a rotating animation block, for additional animations during rotation.
// A subclass may override these methods, or the one-part variant above, but not both.
- (void)willAnimateFirstHalfOfRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration NS_DEPRECATED_IOS(2_0, 5_0);
- (void)didAnimateFirstHalfOfRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation NS_DEPRECATED_IOS(2_0, 5_0); // The rotating header and footer views are offscreen.
- (void)willAnimateSecondHalfOfRotationFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation duration:(NSTimeInterval)duration NS_DEPRECATED_IOS(2_0, 5_0); // A this point, our view orientation is set to the new orientation.

@end

// Many view controllers have a view that may be in an editing state or not- for example, a UITableView.  These view
// controllers can track the editing state, and generate an Edit|Done button to be used in a navigation bar.
@interface UIViewController (UIViewControllerEditing)

@property(nonatomic,getter=isEditing) BOOL editing;
- (void)setEditing:(BOOL)editing animated:(BOOL)animated; // Updates the appearance of the Edit|Done button item as necessary. Clients who override it must call super first.

- (UIBarButtonItem *)editButtonItem; // Return an Edit|Done button that can be used as a navigation item's custom view. Default action toggles the editing state with animation.

@end

@interface UIViewController (UISearchDisplayControllerSupport)

@property(nonatomic, readonly, retain) UISearchDisplayController *searchDisplayController;

@end


/*
  This exception is raised when a child view controller's view is added into the view hierarchy and the first
  superview of the child view controller's view that has a view controller is NOT the child view controller's
  parent.
*/
UIKIT_EXTERN NSString *const UIViewControllerHierarchyInconsistencyException NS_AVAILABLE_IOS(5_0);

/*
  The methods in the UIContainerViewControllerProtectedMethods and the UIContainerViewControllerCallbacks
  categories typically should only be called by subclasses which are implementing new container view
  controllers. They may be overridden but must call super.
*/
@interface UIViewController (UIContainerViewControllerProtectedMethods)

// An array of children view controllers. This array does not include any presented view controllers.
@property(nonatomic,readonly) NSArray *childViewControllers NS_AVAILABLE_IOS(5_0);

/*
  If the child controller has a different parent controller, it will first be removed from its current parent
  by calling removeFromParentViewController. If this method is overridden then the super implementation must
  be called.
*/
- (void)addChildViewController:(UIViewController *)childController NS_AVAILABLE_IOS(5_0);

/*
  Removes the the receiver from its parent's children controllers array. If this method is overridden then
  the super implementation must be called.
*/
- (void) removeFromParentViewController NS_AVAILABLE_IOS(5_0);

/*
  This method can be used to transition between sibling child view controllers. The receiver of this method is
  their common parent view controller. (Use [UIViewController addChildViewController:] to create the
  parent/child relationship.) This method will add the toViewController's view to the superview of the
  fromViewController's view and the fromViewController's view will be removed from its superview after the
  transition completes. It is important to allow this method to add and remove the views. The arguments to
  this method are the same as those defined by UIView's block animation API. This method will fail with an
  NSInvalidArgumentException if the parent view controllers are not the same as the receiver, or if the
  receiver explicitly forwards its appearance and rotation callbacks to its children. Finally, the receiver
  should not be a subclass of an iOS container view controller. Note also that it is possible to use the
  UIView APIs directly. If they are used it is important to ensure that the toViewController's view is added
  to the visible view hierarchy while the fromViewController's view is removed.
*/
- (void)transitionFromViewController:(UIViewController *)fromViewController toViewController:(UIViewController *)toViewController duration:(NSTimeInterval)duration options:(UIViewAnimationOptions)options animations:(void (^)(void))animations completion:(void (^)(BOOL finished))completion NS_AVAILABLE_IOS(5_0);

// If a custom container controller manually forwards its appearance callbacks, then rather than calling
// viewWillAppear:, viewDidAppear: viewWillDisappear:, or viewDidDisappear: on the children these methods
// should be used instead. This will ensure that descendent child controllers appearance methods will be
// invoked. It also enables more complex custom transitions to be implemented since the appearance callbacks are
// now tied to the final matching invocation of endAppearanceTransition.
- (void)beginAppearanceTransition:(BOOL)isAppearing animated:(BOOL)animated __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_5_0);
- (void)endAppearanceTransition __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_5_0);

// Override to return a child view controller or nil. If non-nil, that view controller's status bar appearance attributes will be use. If nil, self is used. Whenever the return values from these methods change, -setNeedsUpdatedStatusBarAttributes should be called.
- (UIViewController *)childViewControllerForStatusBarStyle NS_AVAILABLE_IOS(7_0);
- (UIViewController *)childViewControllerForStatusBarHidden NS_AVAILABLE_IOS(7_0);

@end

@interface UIViewController (UIContainerViewControllerCallbacks)

/*
  This method is consulted to determine if a view controller manually forwards its containment callbacks to
  any children view controllers. Subclasses of UIViewController that implement containment logic may override
  this method. The default implementation returns YES. If it is overridden and returns NO, then the subclass is
  responsible for forwarding the following methods as appropriate - viewWillAppear: viewDidAppear: viewWillDisappear:
  viewDidDisappear: willRotateToInterfaceOrientation:duration:
  willAnimateRotationToInterfaceOrientation:duration: didRotateFromInterfaceOrientation:
*/

// This soon to be deprecated method
- (BOOL)automaticallyForwardAppearanceAndRotationMethodsToChildViewControllers NS_DEPRECATED_IOS(5_0,6_0);
// is being replaced by these two methods.
- (BOOL)shouldAutomaticallyForwardRotationMethods NS_AVAILABLE_IOS(6_0);
- (BOOL)shouldAutomaticallyForwardAppearanceMethods NS_AVAILABLE_IOS(6_0);


/*
  These two methods are public for container subclasses to call when transitioning between child
  controllers. If they are overridden, the overrides should ensure to call the super. The parent argument in
  both of these methods is nil when a child is being removed from its parent; otherwise it is equal to the new
  parent view controller.

  addChildViewController: will call [child willMoveToParentViewController:self] before adding the
  child. However, it will not call didMoveToParentViewController:. It is expected that a container view
  controller subclass will make this call after a transition to the new child has completed or, in the
  case of no transition, immediately after the call to addChildViewController:. Similarly
  removeFromParentViewController: does not call [self willMoveToParentViewController:nil] before removing the
  child. This is also the responsibilty of the container subclass. Container subclasses will typically define
  a method that transitions to a new child by first calling addChildViewController:, then executing a
  transition which will add the new child's view into the view hierarchy of its parent, and finally will call
  didMoveToParentViewController:. Similarly, subclasses will typically define a method that removes a child in
  the reverse manner by first calling [child willMoveToParentViewController:nil].
*/
- (void)willMoveToParentViewController:(UIViewController *)parent NS_AVAILABLE_IOS(5_0);
- (void)didMoveToParentViewController:(UIViewController *)parent NS_AVAILABLE_IOS(5_0);

@end

@interface UIViewController (UIStateRestoration) <UIStateRestoring>
@property (nonatomic, copy) NSString *restorationIdentifier NS_AVAILABLE_IOS(6_0);
@property (nonatomic, readwrite, assign) Class<UIViewControllerRestoration> restorationClass NS_AVAILABLE_IOS(6_0);
- (void) encodeRestorableStateWithCoder:(NSCoder *)coder NS_AVAILABLE_IOS(6_0);
- (void) decodeRestorableStateWithCoder:(NSCoder *)coder NS_AVAILABLE_IOS(6_0);
- (void) applicationFinishedRestoringState NS_AVAILABLE_IOS(7_0);
@end

@interface UIViewController (UIConstraintBasedLayoutCoreMethods)
/* Base implementation sends -updateConstraints to the view.
    When a view has a view controller, this message is sent to the view controller during 
     the autolayout updateConstraints pass in lieu of sending updateConstraints directly
     to the view.
    You may override this method in a UIViewController subclass for updating custom 
     constraints instead of subclassing your view and overriding -[UIView updateConstraints].
    Overrides must call super or send -updateConstraints to the view.
 */
- (void)updateViewConstraints NS_AVAILABLE_IOS(6_0);
@end

@protocol UIViewControllerTransitioningDelegate;

@interface UIViewController(CustomTransitioning)

@property (nonatomic,assign) id <UIViewControllerTransitioningDelegate> transitioningDelegate NS_AVAILABLE_IOS(7_0);

@end

@interface UIViewController (UILayoutSupport)
// These objects may be used as layout items in the NSLayoutConstraint API
@property(nonatomic,readonly,retain) id<UILayoutSupport> topLayoutGuide NS_AVAILABLE_IOS(7_0);
@property(nonatomic,readonly,retain) id<UILayoutSupport> bottomLayoutGuide NS_AVAILABLE_IOS(7_0);
@end