Why is NSCollectionView cut off?

Question

I have a NSCollectionView inside of NSScrollView inside of a NSSplitView. The CollectionView contains NSImageViews. Everything works fine, but the CollectionView is clipped (but without scroll bars).

This is the result:

(There are 5 sections. Section 1 has one image. Section 2 (clipped) has two images. Section 3 (not visible) has three images and so on).

I can't understand why some of the CollectionView's content is cut off. When I select the CollectionView, there are "resize squares" (what is the name of this little squares?), but they are inactive:

When I select the CollectionViewFlowLayout I can see exactly the area that is visible in the running app:

I can't unterstand that behaviour:

• Why is the CollectionView smaller than the Area of the ScrollView?
• And why are there no scroll bars?

How can I get the CollectionView to display all the images completely?

Answer 1

According to https://stackoverflow.com/a/62973012/4213887 I've added the following Code to the ViewController that owns the CollectionView:

override func viewDidAppear() {
    self.view.setFrameSize(NSSize(width: self.view.frame.size.width, height: self.view.frame.size.height + 1))
}

Now everything is OK:

Some say it could be an issue only in macOS 10.13 and 10.14, but at the moment I am not able to test other versions.