Question

Xcode 9.1，Swift 4

我正在尝试创建一个随着用户输入文本而增长的NSTextField。就像在Mac上的iMessage中那样。以下是视频示例：http://d.pr/v/zWRA6w

我已将NSViews设置为这样，以便我可以在NSTextField周围设置自定义设计，并保留其默认边框和背景：

这是我的约束。聊天对话在聊天环绕下滚动。

我尝试关注this answer并创建了以下Swift版本：

class ResizingTextField: NSTextField{
  var isEditing = false
  override func textDidBeginEditing(_ notification: Notification) {
    super.textDidBeginEditing(notification)
    isEditing = true
  }
  override func textDidEndEditing(_ notification: Notification) {
    super.textDidEndEditing(notification)
    isEditing = false
  }
  override func textDidChange(_ notification: Notification) {
    super.textDidChange(notification)
    self.invalidateIntrinsicContentSize()
  }
  override public var intrinsicContentSize: CGSize {
    if isEditing{
      let fieldEditor = self.window?.fieldEditor(false, for: self)
      if fieldEditor != nil{
        if let cellCopy = self.cell?.copy() as? NSTextFieldCell{
          cellCopy.stringValue = fieldEditor!.string
          return cellCopy.cellSize
        }
      }
    }
    return self.cell!.cellSize
  }
}

但是我的约束和/或代码肯定有问题，因为当我在框中输入时没有任何反应。

有什么建议吗？

Answer 1

我偶然发现了这个：https://gist.github.com/entotsu/ddc136832a87a0fd2f9a0a6d4cf754ea

我必须稍微更新代码才能使用 Swift 4 ：

class AutoGrowingTextField: NSTextField {

  var minHeight: CGFloat? = 22
  let bottomSpace: CGFloat = 7
  // magic number! (the field editor TextView is offset within the NSTextField. It’s easy to get the space above (it’s origin), but it’s difficult to get the default spacing for the bottom, as we may be changing the height

  var heightLimit: CGFloat?
  var lastSize: NSSize?
  var isEditing = false

  override func textDidBeginEditing(_ notification: Notification) {
    super.textDidBeginEditing(notification)
    isEditing = true
  }
  override func textDidEndEditing(_ notification: Notification) {
    super.textDidEndEditing(notification)
    isEditing = false
  }
  override func textDidChange(_ notification: Notification) {
    super.textDidChange(notification)
    self.invalidateIntrinsicContentSize()
  }

  override var intrinsicContentSize: NSSize {
    var minSize: NSSize {
      var size = super.intrinsicContentSize
      size.height = minHeight ?? 0
      return size
    }
    // Only update the size if we’re editing the text, or if we’ve not set it yet
    // If we try and update it while another text field is selected, it may shrink back down to only the size of one line (for some reason?)
    if isEditing || lastSize == nil {

      //If we’re being edited, get the shared NSTextView field editor, so we can get more info
      guard let textView = self.window?.fieldEditor(false, for: self) as? NSTextView, let container = textView.textContainer, let newHeight = container.layoutManager?.usedRect(for: container).height
      else {
          return lastSize ?? minSize
      }
      var newSize = super.intrinsicContentSize
      newSize.height = newHeight + bottomSpace

      if let heightLimit = heightLimit, let lastSize = lastSize, newSize.height > heightLimit {
        newSize = lastSize
      }

      if let minHeight = minHeight, newSize.height < minHeight {
        newSize.height = minHeight
      }

      lastSize = newSize
      return newSize
    }
    else {
      return lastSize ?? minSize
    }
  }
}

使用Swift和自动布局增加更高级别的NSTextField

1 个答案: