Garbled exception when implementing UIPopoverBackgroundView subclass

Question

I've implemented this class as follows:

#import "JKBackgroundView.h"

@implementation JKBackgroundView

static CGFloat jkArrowBase = 26.0;
static CGFloat jkArrowHeight = 16.0;

// Background image insets
static CGFloat jkBackgroundTopInset = 68.0f;
static CGFloat jkBackgroundLeftInset = 16.0f;
static CGFloat jkBackgroundBottomInset = 16.0f;
static CGFloat jkBackgroundRightInset = 34.0f;

// Content view insets
static CGFloat jkContentTopInset = 40.0f;
static CGFloat jkContentLeftInset = 6.0f;
static CGFloat jkContentBottomInset = 8.0f;
static CGFloat jkContentRightInset = 7.0f;

+(CGFloat)arrowBase {
    return jkArrowBase;
}

-(UIPopoverArrowDirection)arrowDirection {
    return UIPopoverArrowDirectionUp;
}

-(CGFloat)arrowOffset {
    return 0.0f;
}

+(CGFloat)arrowHeight {
    return jkArrowHeight;
}

+(UIEdgeInsets)contentViewInsets {
    return UIEdgeInsetsMake(jkContentTopInset, jkContentLeftInset, jkContentBottomInset, jkContentRightInset);
}

-(void)drawRect:(CGRect)rect {
    UIEdgeInsets popoverInsets = UIEdgeInsetsMake(jkBackgroundTopInset, jkBackgroundLeftInset, jkBackgroundBottomInset, jkBackgroundRightInset);
    UIImage *popoverImage = [[UIImage imageNamed:@"popover_stretchable.png"] resizableImageWithCapInsets:popoverInsets];
    [popoverImage drawInRect:rect];
}

-(id)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        self.backgroundColor = [UIColor clearColor];
    }
    return self;
}

-(void)setArrowDirection:(UIPopoverArrowDirection)arrowDirection {
    // Do nothing
}

@end

I add it to my UIPopoverView (not a subclass) using this code:

_logoutPopover.popoverBackgroundViewClass = [JKBackgroundView class];

When I run the project, though, I receive a crazy error message as follows:

* Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[UIPopoverBackgroundView º¯lå] must be implemented by subclassers.'

Does anyone has any idea what method it thinks I didn't implement? It appears to just be a bunch of gibberish. Thanks!

Edit It looks like I forgot to implement setArrowOffset:. It works after adding that. Apple's error message was just garbled.

Answer 1

According to the docs for UIPopoverBackgroundView you are required to also implement setters for the properties in UIPopoverBackgroundView (i.e. arrowDirection and arrowOffset.) You've just got the getters in your implementation.