以编程方式在 NSScrollView 中设置 NSTextView

Question

我正在尝试以编程方式在NSScrollView 中设置NSTextView，但遇到了问题。

具体来说，我无法滚动文本视图；滚动视图似乎认为“这就是全部”。当您尝试向下滚动查看其余内容（不释放）时，结果如下：

一旦你释放，滚动视图就会反弹回来，所以这不是图形故障；它只是在框架高度处剪辑文本视图。

我尝试过使用the Apple 'Text In ScrollView' docs 和setVerticallyResizable: 等进行试验。

代码：

- (void)configureValueTextView
{
    NSScrollView *vfContainer = [[NSScrollView alloc] initWithFrame:(NSRect){0,0,50,50}];
    vfContainer.hasVerticalScroller = YES;
    vfContainer.hasHorizontalScroller = NO;
    vfContainer.translatesAutoresizingMaskIntoConstraints = NO;
    _valueFieldContainer = vfContainer;
    vfContainer.borderType = NSLineBorder;

    NSTextView *valueField = _valueField = [[NSTextView alloc] initWithFrame:(NSRect){0,0,vfContainer.contentSize}];
    valueField.delegate = self;
    valueField.minSize = (NSSize){0,0};
    valueField.maxSize = (NSSize){FLT_MAX, FLT_MAX};
    [valueField setVerticallyResizable:YES];
    [valueField setHorizontallyResizable:YES];

    valueField.translatesAutoresizingMaskIntoConstraints = NO;
    valueField.string = _value ? _value : @"";
    valueField.editable = YES;
    valueField.textContainer.containerSize = (NSSize) { vfContainer.contentSize.width, FLT_MAX };
    valueField.textContainer.heightTracksTextView = NO;

    vfContainer.documentView = valueField;
    [vfContainer addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-(0)-[_valueField]-(0)-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(_valueField)]];
    [vfContainer addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-(0)-[_valueField]-(0)-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(_valueField)]];
}

框架稍后会调整为正确的值，

[_valueFieldContainer setFrame:(NSRect){kKEFormFieldViewKeyWidth + 10, 0, valueFieldWidth, h}];
[_valueField setFrame:(NSRect){0, 0, valueFieldWidth, h}];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-(0)-[_valueFieldContainer]-(5)-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(_valueFieldContainer)]];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-(0)-[_keyField]-(10)-[_valueFieldContainer]-(0)-|" options:0 metrics:nil views:@{@"_keyField": _keyField, @"_valueFieldContainer": _valueFieldContainer}]];

就是这样。欢迎提示！

Answer 1

Swift 4 示例。

class ViewController: NSViewController {

   fileprivate lazy var textStorage = NSTextStorage()
   fileprivate lazy var layoutManager = NSLayoutManager()
   fileprivate lazy var textContainer = NSTextContainer()
   fileprivate lazy var textView: NSTextView = NSTextView(frame: CGRect(), textContainer: textContainer)
   fileprivate lazy var scrollview = NSScrollView()

   override func viewDidLoad() {
      super.viewDidLoad()
      view.addSubview(scrollview)
      // Set `true` to enable horizontal scrolling.
      setupUI(isHorizontalScrollingEnabled: false) 
      setupLayout()
      setupTextStack()
   }
}

extension ViewController {

   fileprivate func setupTextStack() {
      textStorage.addLayoutManager(layoutManager)
      layoutManager.addTextContainer(textContainer)
   }

   fileprivate func setupUI(isHorizontalScrollingEnabled: Bool) {

      let contentSize = scrollview.contentSize

      if isHorizontalScrollingEnabled {
         textContainer.containerSize = CGSize(width: CGFloat.greatestFiniteMagnitude, height: CGFloat.greatestFiniteMagnitude)
         textContainer.widthTracksTextView = false
      } else {
         textContainer.containerSize = CGSize(width: contentSize.width, height: CGFloat.greatestFiniteMagnitude)
         textContainer.widthTracksTextView = true
      }

      textView.minSize = CGSize(width: 0, height: 0)
      textView.maxSize = CGSize(width: CGFloat.greatestFiniteMagnitude, height: CGFloat.greatestFiniteMagnitude)
      textView.isVerticallyResizable = true
      textView.isHorizontallyResizable = isHorizontalScrollingEnabled
      textView.frame = CGRect(width: contentSize.width, height: contentSize.height)
      if isHorizontalScrollingEnabled {
         textView.autoresizingMask = [.width, .height]
      } else {
         textView.autoresizingMask = [.width]
      }

      scrollview.borderType = .noBorder
      scrollview.hasVerticalScroller = true
      scrollview.hasHorizontalScroller = isHorizontalScrollingEnabled
      scrollview.documentView = textView
   }

   fileprivate func setupLayout() {
      scrollview.translatesAutoresizingMaskIntoConstraints = false

      var customConstraints = [NSLayoutConstraint]()
      // `LayoutConstraint` - custom type with convenience methods. 
      customConstraints += LayoutConstraint.pinInSuperview(scrollview)
      view.addConstraints(customConstraints)
   }
}

Answer 2

您设置了垂直约束，使文本视图与其父视图（滚动视图的剪辑视图）的高度相匹配。我认为这就是问题所在。如果您只是完全删除它，那么您在垂直方向上就会完全模棱两可，并且文本视图可以在任何地方结束。我认为您只需将其顶部边缘固定到超级视图的顶部即可逃脱 - 即@"V:|[_valueField]"。如果文本视图提供固有高度，那将起作用，但我不确定它是否有效。为文本视图的高度设置一个约束，使其与文本布局管理器生成的内容相匹配，这是非常重要的。

鉴于您真的不需要布局中的任何特殊内容，您可以只使用旧式自动调整大小掩码而不是自动布局。