如何让 NSTextField 包含在可变行高表中

Question

我需要将文本包装在 NSTable 的行中。我读了： SO How to update row heights...

和： View-based NSTableView with rows that have dynamic height...

我的行高适用于多行文本（带有 eols），但如果我省略 eols 则不行。 （使用精简的测试用例，直到我弄明白为止。）

这是我的演示代码：

class TableCellView: NSTableCellView {
    var title = NSTextField()

    convenience init(_ id: NSUserInterfaceItemIdentifier, itemCount: Int) {
        self.init(frame: .zero)
        identifier = id
        rowSizeStyle = .custom

        addSubview(title)
        var s = "\(itemCount):\n"
        for item in 0...(5 + itemCount) { s += "\(item)) Text written to a scrollable table view " }

        let a = NSAttributedString(string: s, attributes: [NSAttributedString.Key.font : NSFont.systemFont(ofSize: 18.0)] )

        title.attributedStringValue = a
        title.textColor = NSColor.textColor

        title.backgroundColor = NSColor.clear
        title.translatesAutoresizingMaskIntoConstraints = false
        title.isBordered = false

        title.widthAnchor.constraint(equalTo: widthAnchor, constant: 0).isActive = true
        title.topAnchor.constraint(equalTo: topAnchor, constant: 1).isActive = true
        title.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
    }
}

class TableViewManager: NSObject, NSTableViewDataSource, NSTableViewDelegate, Actor {
    weak var actorDelegate: ActorDelegate?

    var identifier: NSUserInterfaceItemIdentifier? = Identifier.View.tableDelegate
    var count = 0

    func numberOfRows(in tableView: NSTableView) -> Int {

        return 10
    }

    func tableView(_ tableView: NSTableView, viewFor tableColumn: NSTableColumn?, row: Int) -> NSView? {
        let id = tableColumn!.identifier
        var view = tableView.makeView(withIdentifier: id, owner: nil) as? TableCellView
        if view == nil {
            view = TableCellView(id, itemCount: count)
        }

        count += 1      
        return view
    }
}

class TableViewController: NSViewController {
    private let tableViewDelegate = TableViewManager()
    var scrollView: ScrollableTableView!
    var tableView: NSTableView { get { return scrollView.tableView } }

    // Initialize the table scroll view
    convenience init(_ identifier: NSUserInterfaceItemIdentifier) {
        self.init()
        self.identifier = identifier
        scrollView = ScrollableTableView(cols: [(500, "Commit")], delegate: tableViewDelegate, source: tableViewDelegate)
        view = scrollView

        tableView.rowSizeStyle = .custom
        tableView.usesAutomaticRowHeights = true
        tableView.rowHeight = 18
        tableView.headerView = nil  // Get rid of header
        tableView.usesAlternatingRowBackgroundColors = true
    }
    // Pass along reload data
    func reloadData() { tableView.reloadData() }
}

Answer 1

终于想出了一个解决方案，但我很想请一位真正的专家告诉我它是否强大。 （直到快速和肮脏的常量）。我覆盖了表格单元格的绘制，对其初始化器进行了一些修改，如下所示：

class TableCellView: NSTableCellView {
    var title = NSTextField()
    var height: NSLayoutConstraint!

    convenience init(_ id: NSUserInterfaceItemIdentifier, itemCount: Int) {
        self.init(frame: .zero)
        identifier = id
        rowSizeStyle = .custom

        addSubview(title)
        var s = "\(itemCount):\n"
        for item in 0...(5 + itemCount) { s += "\(item)) Text written to a scrollable table view " }

        let a = NSAttributedString(string: s, attributes: [NSAttributedString.Key.font : NSFont.systemFont(ofSize: 18.0)] )

        title.attributedStringValue = a
        title.textColor = NSColor.textColor

        title.backgroundColor = NSColor.clear
        title.translatesAutoresizingMaskIntoConstraints = false
        title.isBordered = false
        title.font = NSFont.systemFont(ofSize: 14.0)

        title.widthAnchor.constraint(equalTo: widthAnchor, constant: 1).isActive = true
        title.topAnchor.constraint(equalTo: topAnchor).isActive = true
        title.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
        height = heightAnchor.constraint(equalToConstant: 100)  // Value doesn't matter, gets recalculated by override draw
        height.isActive = true
    }

    override func draw(_ dirtyRect: NSRect) {
        // Will recalculate height, but parameter must be larger than result
        let bound = title.attributedStringValue.boundingRect(with: NSSize(width: frame.width, height: 4096), options: [.usesLineFragmentOrigin, .usesFontLeading])
        height.constant = bound.height + 2.0
        super.draw(dirtyRect)
    }
}

结果如下所示：

并在我调整窗口大小时正确重新换行。

希望这对其他人有所帮助。