One line of ios code does the screen rotation

.h files:

#import <UIKit/UIKit.h>

@interface LSLRotationManager : NSObject 

@property (nonatomic, readonly) UIInterfaceOrientationMask interfaceOrientationMask; @property (nonatomic) UIDeviceOrientation orientation; 

 + (instancetype)defaultManager;

 @end 

.m files

#import “LSLRotationManager.h”

#import <objc/message.h>

static LSLRotationManager *INSTANCE = nil;

@interface LSLRotationManager ()

@property (nonatomic, readwrite) UIInterfaceOrientationMask interfaceOrientationMask;

@end

@implementation LSLRotationManager

#pragma mark – singleton

+ (instancetype)defaultManager {

static dispatch_once_t onceToken;

dispatch_once(&onceToken, ^{

INSTANCE = [[super allocWithZone:nil] init];

INSTANCE.interfaceOrientationMask = UIInterfaceOrientationMaskPortrait;

});

return INSTANCE;

}

+ (instancetype)allocWithZone:(struct _NSZone *)zone {

return [self defaultManager];

}

#pragma mark – setter methods

– (void)setOrientation:(UIDeviceOrientation)orientation {

if (_orientation == orientation) return;

if ([UIDevice currentDevice].orientation == orientation) {

// Force the rotation to be different than before

[[UIDevice currentDevice] setValue:@(_orientation) forKey:@”orientation”];

}

_orientation = orientation;

UIInterfaceOrientationMask interfaceOrientationMask = UIInterfaceOrientationMaskPortrait;

switch (orientation) {

case UIDeviceOrientationPortrait:

interfaceOrientationMask = UIInterfaceOrientationMaskPortrait;

break;

case UIDeviceOrientationPortraitUpsideDown:

interfaceOrientationMask = UIInterfaceOrientationMaskPortraitUpsideDown;

break;

case UIDeviceOrientationLandscapeRight:

interfaceOrientationMask = UIInterfaceOrientationMaskLandscapeLeft;

break;

case UIDeviceOrientationLandscapeLeft:

interfaceOrientationMask = UIInterfaceOrientationMaskLandscapeRight;

break;

default:

interfaceOrientationMask = UIInterfaceOrientationMaskPortrait;

break;

}

[LSLRotationManager defaultManager].interfaceOrientationMask = interfaceOrientationMask;

// Force rotation to full screen

[[UIDevice currentDevice] setValue:@(orientation) forKey:@”orientation”];

}