1 files changed, 147 insertions, 0 deletions
diff --git a/modules/react-native-ui-text-view/ios/RNUITextViewShadow.swift b/modules/react-native-ui-text-view/ios/RNUITextViewShadow.swift
new file mode 100644
index 000000000..4f3eda43c
--- /dev/null
+++ b/modules/react-native-ui-text-view/ios/RNUITextViewShadow.swift
@@ -0,0 +1,147 @@
+class RNUITextViewShadow: RCTShadowView {
+  // Props
+  @objc var numberOfLines: Int = 0 {
+    didSet {
+      if !YGNodeIsDirty(self.yogaNode) {
+        self.setAttributedText()
+      }
+    }
+  }
+  @objc var allowsFontScaling: Bool = true
+
+  var attributedText: NSAttributedString = NSAttributedString()
+  var frameSize: CGSize = CGSize()
+
+  var lineHeight: CGFloat = 0
+
+  var bridge: RCTBridge
+
+  init(bridge: RCTBridge) {
+    self.bridge = bridge
+    super.init()
+
+    // We need to set a custom measure func here to calculate the height correctly
+    YGNodeSetMeasureFunc(self.yogaNode) { node, width, widthMode, height, heightMode in
+      // Get the shadowview and determine the needed size to set
+      let shadowView = Unmanaged<RNUITextViewShadow>.fromOpaque(YGNodeGetContext(node)).takeUnretainedValue()
+      return shadowView.getNeededSize(maxWidth: width)
+    }
+
+    // Subscribe to ynamic type size changes
+    NotificationCenter.default.addObserver(
+      self,
+      selector: #selector(preferredContentSizeChanged(_:)),
+      name: UIContentSizeCategory.didChangeNotification,
+      object: nil
+    )
+  }
+
+  @objc func preferredContentSizeChanged(_ notification: Notification) {
+    self.setAttributedText()
+  }
+
+  // Tell yoga not to use flexbox
+  override func isYogaLeafNode() -> Bool {
+    return true
+  }
+
+  // We only need to insert text children
+  override func insertReactSubview(_ subview: RCTShadowView!, at atIndex: Int) {
+    if subview.isKind(of: RNUITextViewChildShadow.self) {
+      super.insertReactSubview(subview, at: atIndex)
+    }
+  }
+
+  // Whenever the subvies update, set the text
+  override func didUpdateReactSubviews() {
+    self.setAttributedText()
+  }
+
+  // Whenever we layout, update the UI
+  override func layoutSubviews(with layoutContext: RCTLayoutContext) {
+    // Don't do anything if the layout is dirty
+    if(YGNodeIsDirty(self.yogaNode)) {
+      return
+    }
+
+    // Update the text
+    self.bridge.uiManager.addUIBlock { uiManager, viewRegistry in
+      guard let textView = viewRegistry?[self.reactTag] as? RNUITextView else {
+        return
+      }
+      textView.setText(string: self.attributedText, size: self.frameSize, numberOfLines: self.numberOfLines)
+    }
+  }
+
+  override func dirtyLayout() {
+    super.dirtyLayout()
+    YGNodeMarkDirty(self.yogaNode)
+  }
+
+  // Update the attributed text whenever changes are made to the subviews.
+  func setAttributedText() -> Void {
+    // Create an attributed string to store each of the segments
+    let finalAttributedString = NSMutableAttributedString()
+
+    self.reactSubviews().forEach { child in
+      guard let child = child as? RNUITextViewChildShadow else {
+        return
+      }
+      let scaledFontSize = self.allowsFontScaling ?
+        UIFontMetrics.default.scaledValue(for: child.fontSize) : child.fontSize
+      let font = UIFont.systemFont(ofSize: scaledFontSize, weight: child.getFontWeight())
+
+      // Set some generic attributes that don't need ranges
+      let attributes: [NSAttributedString.Key:Any] = [
+        .font: font,
+        .foregroundColor: child.color,
+      ]
+
+      // Create the attributed string with the generic attributes
+      let string = NSMutableAttributedString(string: child.text, attributes: attributes)
+
+      // Set the paragraph style attributes if necessary
+      let paragraphStyle = NSMutableParagraphStyle()
+      if child.lineHeight != 0.0 {
+        paragraphStyle.minimumLineHeight = child.lineHeight
+        paragraphStyle.maximumLineHeight = child.lineHeight
+        string.addAttribute(
+          NSAttributedString.Key.paragraphStyle,
+          value: paragraphStyle,
+          range: NSMakeRange(0, string.length)
+        )
+
+        // Store that height
+        self.lineHeight = child.lineHeight
+      } else {
+        self.lineHeight = font.lineHeight
+      }
+
+      finalAttributedString.append(string)
+    }
+
+    self.attributedText = finalAttributedString
+    self.dirtyLayout()
+  }
+
+  // Create a YGSize based on the max width
+  func getNeededSize(maxWidth: Float) -> YGSize {
+    // Create the max size and figure out the size of the entire text
+    let maxSize = CGSize(width: CGFloat(maxWidth), height: CGFloat(MAXFLOAT))
+    let textSize = self.attributedText.boundingRect(with: maxSize, options: .usesLineFragmentOrigin, context: nil)
+
+    // Figure out how many total lines there are
+    let totalLines = Int(ceil(textSize.height / self.lineHeight))
+
+    // Default to the text size
+    var neededSize: CGSize = textSize.size
+
+    // If the total lines > max number, return size with the max
+    if self.numberOfLines != 0, totalLines > self.numberOfLines {
+      neededSize = CGSize(width: CGFloat(maxWidth), height: CGFloat(CGFloat(self.numberOfLines) * self.lineHeight))
+    }
+
+    self.frameSize = neededSize
+    return YGSize(width: Float(neededSize.width), height: Float(neededSize.height))
+  }
+}