swift - Collapsing NSSplitViewItem does not call splitViewDidResizeSubviews

Question

I have a class that inherits from NSSplitViewController and overrides the splitViewDidResizeSubviews function.

When I call collapse on a NSSplitViewItem inside the NSSplitViewController and I see the NSSplitViewItem visibly resize the splitViewDidResizeSubviews function isn't called.

If I resize the window the splitViewDidResizeSubviews function is called so I know it is implemented correctly.

Can I expect the splitViewDidResizeSubviews function to be called on a collapse and if so what might I be doing wrong?

Answer 1

因为折叠 splitViewItem 不会调整其实际帧大小，而只是切换项目的可见性。isCollapsed如果您只是切换状态，则 splitViewItem 会保存帧大小。

（一个例外是当 item 向外扩展时。即splitViewItem.collapseBehavior = .preferResizingSplitViewWithFixedSiblings。正如我测试的那样，它调用splitViewDidResizeSubviews。）

因此，对于这种用法，我更喜欢覆盖 NSSplitViewController 的另一种方法，例如：

func splitView(_ splitView: NSSplitView, shouldCollapseSubview subview: NSView, forDoubleClickOnDividerAt dividerIndex: Int