A O A O - 10 months ago 76
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

Answer Source

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