FTGPopoverController, a popover that works on both iOS 7 and iOS 8

FTGPopoverController

//FTGPopoverController.h
@interface FTGPopoverController : NSObject

- (instancetype)initWithContentVC:(UIViewController *)contentVC contentSize:(CGSize)contentSize;
- (void)presentInVC:(UIViewController *)vc fromButton:(UIButton *)button;
- (void)dismiss;
- (BOOL)isVisible;

@end

//FTGPopoverController.m
#import "FTGPopoverController.h"
#import <WYPopoverController/WYPopoverController.h>

@interface FTGPopoverController () <UIPopoverPresentationControllerDelegate>

@property (nonatomic, strong) UIViewController *contentVC;
@property (nonatomic, assign) CGSize contentSize;
@property (nonatomic, strong) WYPopoverController *wyPopoverController;

@end

@implementation FTGPopoverController

- (instancetype)initWithContentVC:(UIViewController *)contentVC contentSize:(CGSize)contentSize
{
    self = [super init];
    if (self) {
        _contentVC = contentVC;
        _contentSize = contentSize;
        if (IOS8_OR_ABOVE) {
            contentVC.modalPresentationStyle = UIModalPresentationPopover;
            contentVC.preferredContentSize = contentSize;
        } else {
            _wyPopoverController = [[WYPopoverController alloc] initWithContentViewController:contentVC];
            contentVC.contentSizeForViewInPopover = contentSize;
        }
    }

    return self;
}

#pragma mark - Public Interface
- (void)presentInVC:(UIViewController *)vc fromButton:(UIButton *)button
{
    if (IOS8_OR_ABOVE) {
        UIPopoverPresentationController *popoverController = self.contentVC.popoverPresentationController;
        popoverController.delegate = self;

        popoverController.sourceRect = button.bounds;
        popoverController.sourceView = button;
        popoverController.permittedArrowDirections = UIPopoverArrowDirectionAny;

        [vc presentViewController:self.contentVC animated:YES completion:nil];
    } else {
        [self.wyPopoverController presentPopoverFromRect:button.bounds
                                                  inView:button
                                permittedArrowDirections:WYPopoverArrowDirectionAny
                                                animated:YES];
    }
}

- (void)dismiss
{
    if (IOS8_OR_ABOVE) {
        [self.contentVC dismissViewControllerAnimated:YES completion:nil];
    } else {
        [self.wyPopoverController dismissPopoverAnimated:YES];
    }
}

- (BOOL)isVisible
{
    if (IOS8_OR_ABOVE) {
        return self.contentVC.presentingViewController ? YES : NO;
    } else {
        return self.wyPopoverController.isPopoverVisible;
    }
}

#pragma mark - UIPopoverPresentationControllerDelegate
-(UIModalPresentationStyle)adaptivePresentationStyleForPresentationController:(UIPresentationController *)controller
{
    return UIModalPresentationNone;
}


@end