A O A O - 4 months ago 38
Objective-C Question

NSPopover with a NSTextField shows the text field with an opaque background as it's opening, and then goes transparent after the popover animation

There's actually a little different behavior across OSs

This is what the popover looks like as it's animating open in 10.10:

enter image description here

If you look closely, you can see a little opaque border around the


Here is what it looks like in 10.11:

enter image description here
There's just a straight up opaque background

And here's what the popover looks like after the animation, fully shown:

enter image description here

Modifying the popover's appearance does not fix the issue:

enter image description here

What we have here is an
, which just has a container
, and a
. The container is so that we can add padding through auto layout constraints

@interface MessageViewController ()
@property (strong) IBOutlet NSTextField *messageLabel;
@property (weak) IBOutlet NSLayoutConstraint *rightPadding;
@property (weak) IBOutlet NSLayoutConstraint *topPadding;
@property (weak) IBOutlet NSLayoutConstraint *bottomPadding;
@property (weak) IBOutlet NSLayoutConstraint *leftPadding;

@implementation MessageViewController

@synthesize message = _message;

- (instancetype)initWithMessage:(NSString *)message andPadding:(CGFloat)padding
self = [super init];
if( self )
[self loadView];
self.rightPadding.constant = padding;
self.topPadding.constant = padding;
self.bottomPadding.constant = padding;
self.leftPadding.constant = padding;
self.message = message;
return self;

- (void)setMessage:(NSString *)message
_message = message;
self.messageLabel.stringValue = message;

- (NSString *)message
return _message;

That's why you can see the border, and only a portion of the popover is opaque. It is that inner
that has the background/border, and the container view keeps the transparent background. It isn't until the popover is fully shown that the background/border goes transparent as well

Also here is the

enter image description here

How could this be?

I have tried setting the background color property, and have tried setting the properties in -awakeFromNib instead of in the init, to no avail


Resolved the issue, in interface builder had to check the view and label in the "View Effects Inspector", which sets wantsLayer = YES

Probably could be done programmatically too