NSCollectionView自定义布局启用滚动

Question

我无法纵向和横向滚动以使用NSCollectionView的自定义布局.根据文档,在我的子类中,我返回`collectionViewContentSize',如果它太大,则在集合视图的封闭滚动视图中自动启用滚动.但是,即使我在水平行中排序所有元素,也只启用垂直滚动.

这是一个截图:http: //i.stack.imgur.com/tMbCN.png

这是我的布局代码:

import Cocoa 
class Layout: NSCollectionViewLayout {

var cellSize = CGSize(width: 100, height: 30)

var cellSpacing: CGFloat = 10
var sectionSpacing: CGFloat = 20

private var contentSize = CGSize.zero
private var layoutAttributes = [NSIndexPath: NSCollectionViewLayoutAttributes]()


override func prepareLayout() {
    guard let collectionView = collectionView else { return }

    let sections = collectionView.numberOfSections
    guard sections > 0 else { return }

    contentSize.height = cellSize.height

    for section in 0..<sections {
        let items = collectionView.numberOfItemsInSection(section)
        guard items > 0 else { break }

        for item in 0..<items {
            let origin = CGPoint(x: contentSize.width, y: 0)
            let indexPath = NSIndexPath(forItem: item, inSection: section)
            let attributes = NSCollectionViewLayoutAttributes(forItemWithIndexPath: indexPath)
            attributes.frame = CGRect(origin: origin, size: cellSize)
            layoutAttributes[indexPath] = attributes

            contentSize.width += cellSize.width + cellSpacing
        }
        contentSize.width += sectionSpacing
    }
}

override var collectionViewContentSize: NSSize {
    return contentSize
}

override func layoutAttributesForElementsInRect(rect: NSRect) -> [NSCollectionViewLayoutAttributes] {

    return layoutAttributes.values.filter { $0.frame.intersects(rect) }
}

override func layoutAttributesForItemAtIndexPath(indexPath: NSIndexPath) -> NSCollectionViewLayoutAttributes? {
    return layoutAttributes[indexPath]
}

override func shouldInvalidateLayoutForBoundsChange(newBounds: NSRect) -> Bool {
    return false
}
}

Answer 1

这个bug仍在继续.我把Bo Yuan讨厌的黑客改成了Swift.(没有冒犯,博远,这不是你的错,我们必须做这个可怕的解决办法!我仍然会在有正式修复的情况下尽快删除这些代码.暂时这只是为了让我的开发工作继续下去.)

class HackedCollectionView: NSCollectionView {
    override func setFrameSize(_ newSize: NSSize) {
        let size = collectionViewLayout?.collectionViewContentSize ?? newSize
        super.setFrameSize(size)
        if let scrollView = enclosingScrollView {
            scrollView.hasHorizontalScroller = size.width > scrollView.frame.width
        }
    }
}

请注意,这肯定需要尽快,因为在滚动时会为每一帧动画调用它.不太好.请,请有人解决此问题或找到合适的解决方案.不能水平滚动是荒谬的.

Answer 2

这基本上是 NSCollectionView 中的一个错误。作为解决方法，您可以实现scrollDirection方法（来自NSCollectionViewFlowLayout）并返回NSCollectionViewScrollDirectionHorizo​​ntal。