Adjust vertical position of UIBarButtonItem title inside UIToolbar

Question

Is it possible to adjust the title of a UIBarButtonItem inside an UIToolbar?

I've tried the following lines of code without success:

UIBarButtonItem.appearance().setTitlePositionAdjustment(UIOffset(horizontal: 30, vertical: 30), forBarMetrics: UIBarMetrics.Default)

And this one:

self.setTitlePositionAdjustment(UIOffset(horizontal: 30, vertical: 30), forBarMetrics: UIBarMetrics.Compact)

Answer 1

Offset an UIBarButtonItem (Text!) inside a UIToolBar vertically seems not to work with Xcode 7 (Beta 6).

You are right, according to the docs, this should do it: UIBarButtonItem.appearance().setTitlePositionAdjustment

either globally in AppDelegate:

UIBarButtonItem.appearance().setTitlePositionAdjustment(UIOffset(horizontal: 30, vertical: 30), forBarMetrics: UIBarMetrics.Default)

or locally with the item outlet itself:

(Swift)

self.myBarItem.setTitlePositionAdjustment(UIOffset(horizontal: 30, vertical: 30), forBarMetrics: UIBarMetrics.Default)

(Obj C)

[self.myBarItem setTitlePositionAdjustment:UIOffsetMake(30, 30) forBarMetrics: UIBarMetricsDefault];

Is this a bug with Appearance?

Answer 2

Change the baselineOffset of the text.

let doneButton = UIBarButtonItem(title: "Done", style: .plain, target: self, action: #selector(self.someFunction))
let attributes = [NSAttributedString.Key.baselineOffset: NSNumber(value: -3)]
doneButton.setTitleTextAttributes(attributes, for: .normal)

A negative baselineOffset will shift the title text down, a positive value will shift it up. 0 is the default value.

I tested this on iOS 11.

Answer 3

I was frustrated with this too so I subclassed UIBarButtonItem to work as expected. Taking from this answer I came up with this:

@interface TitleAdjustingBarButtonItem(){
    UIView*   _parentView;
    UIButton* _button;
}

@end

@implementation TitleAdjustingBarButtonItem

-(id) initWithTitle:(NSString *)title style:(UIBarButtonItemStyle)style target:(id)target action:(SEL)action{
    _button = [[UIButton alloc] init];
    [_button setTitle:title forState:UIControlStateNormal];

    [_button addTarget:target action:action forControlEvents:UIControlEventTouchUpInside];

    [_button sizeToFit];

    _parentView = [[UIView alloc] initWithFrame:_button.bounds];

    [_parentView addSubview:_button];

    return [super initWithCustomView:_parentView];
}

#pragma mark - property setters -

-(void) setTitlePositionAdjustment:(UIOffset)adjustment forBarMetrics:(UIBarMetrics)barMetrics{
    [_button sizeToFit];
    _parentView.bounds = CGRectMake(0.0, 0.0, _button.bounds.size.width - (adjustment.horizontal * 2.0), _button.bounds.size.height - (adjustment.vertical * 2.0));
}

Admittedly it does not account for the different bar metrics but for default metrics I've gotten this to work pretty well.