Added support for stroking text

lottie-swift/src/Private/LayerContainers/CompLayers/TextCompositionLayer.swift

@@ -56,6 +56,7 @@ class TextCompositionLayer: CompositionLayer {
  let interpolatableScale: KeyframeInterpolator<Vector3D>?
 
  let textLayer: DisabledTextLayer = DisabledTextLayer()
+ let textStrokeLayer: DisabledTextLayer = DisabledTextLayer()
  var textProvider: AnimationTextProvider
 
  init(textLayer: TextLayerModel, textProvider: AnimationTextProvider) {
@@ -65,18 +66,19 @@ class TextCompositionLayer: CompositionLayer {
  }
  self.rootNode = rootNode
  self.textDocument = KeyframeInterpolator(keyframes: textLayer.text.keyframes)
-
+ 
  self.textProvider = textProvider
-
+ 
  // TODO: this has to be somewhere that can be interpolated
  // TODO: look for inspiration from other composite layer
  self.interpolatableAnchorPoint = KeyframeInterpolator(keyframes: textLayer.transform.anchorPoint.keyframes)
  self.interpolatableScale = KeyframeInterpolator(keyframes: textLayer.transform.scale.keyframes)
 
  super.init(layer: textLayer, size: .zero)
  contentsLayer.addSublayer(self.textLayer)
+ contentsLayer.addSublayer(self.textStrokeLayer)
  self.textLayer.masksToBounds = false
-
+ self.textStrokeLayer.masksToBounds = false
  }
 
  required init?(coder aDecoder: NSCoder) {
@@ -90,19 +92,21 @@ class TextCompositionLayer: CompositionLayer {
  }
  self.rootNode = nil
  self.textDocument = nil
-
+ 
  self.textProvider = DefaultTextProvider()
-
+ 
  self.interpolatableAnchorPoint = nil
  self.interpolatableScale = nil
-
+ 
  super.init(layer: layer)
  }
-
+ 
  override func displayContentsWithFrame(frame: CGFloat, forceUpdates: Bool) {
  guard let textDocument = textDocument else { return }
 
  textLayer.contentsScale = self.renderScale
+ textStrokeLayer.contentsScale = self.renderScale
+
  let documentUpdate = textDocument.hasUpdate(frame: frame)
  let animatorUpdate = rootNode?.updateContents(frame, forceLocalUpdate: forceUpdates) ?? false
  guard documentUpdate == true || animatorUpdate == true else { return }
@@ -116,31 +120,34 @@ class TextCompositionLayer: CompositionLayer {
  let strokeColor = rootNode?.textOutputNode.strokeColor ?? text.strokeColorData?.cgColorValue
  let strokeWidth = rootNode?.textOutputNode.strokeWidth ?? CGFloat(text.strokeWidth ?? 0)
  let tracking = (CGFloat(text.fontSize) * (rootNode?.textOutputNode.tracking ?? CGFloat(text.tracking))) / 1000.0
- // TODO LINE HEIGHT
 
  let matrix = rootNode?.textOutputNode.xform ?? CATransform3DIdentity
  let ctFont = CTFontCreateWithName(text.fontFamily as CFString, CGFloat(text.fontSize), nil)
 
+ let textString = textProvider.textFor(keypathName: self.keypathName, sourceText: text.text)
+
  var attributes: [NSAttributedString.Key : Any] = [
  NSAttributedString.Key.font: ctFont,
  NSAttributedString.Key.foregroundColor: fillColor,
  NSAttributedString.Key.kern: tracking,
- ]
-
- if let strokeColor = strokeColor {
- attributes[NSAttributedString.Key.strokeColor] = strokeColor
- attributes[NSAttributedString.Key.strokeWidth] = strokeWidth
- }
-
-
- let textString = textProvider.textFor(keypathName: self.keypathName, sourceText: text.text)
+ ]
 
  let paragraphStyle = NSMutableParagraphStyle()
  paragraphStyle.lineSpacing = CGFloat(text.lineHeight)
  paragraphStyle.alignment = text.justification.textAlignment
  attributes[NSAttributedString.Key.paragraphStyle] = paragraphStyle
 
- let attributedString = NSAttributedString(string: textString, attributes: attributes )
+ let baseAttributedString = NSAttributedString(string: textString, attributes: attributes )
+
+ if let strokeColor = strokeColor {
+ textStrokeLayer.isHidden = false
+ attributes[NSAttributedString.Key.strokeColor] = strokeColor
+ attributes[NSAttributedString.Key.strokeWidth] = strokeWidth
+ } else {
+ textStrokeLayer.isHidden = true
+ }
+
+ let attributedString: NSAttributedString = NSAttributedString(string: textString, attributes: attributes )
 
  let framesetter = CTFramesetterCreateWithAttributedString(attributedString)
 
@@ -162,15 +169,34 @@ class TextCompositionLayer: CompositionLayer {
  textAnchor = CGPoint(x: size.width * 0.5, y: baselinePosition)
  }
  let anchor = textAnchor + anchorPoint.pointValue
-
- textLayer.anchorPoint = CGPoint(x: anchor.x.remap(fromLow: 0, fromHigh: size.width, toLow: 0, toHigh: 1),
- y: anchor.y.remap(fromLow: 0, fromHigh: size.height, toLow: 0, toHigh: 1))
+ let normalizedAnchor = CGPoint(x: anchor.x.remap(fromLow: 0, fromHigh: size.width, toLow: 0, toHigh: 1),
+ y: anchor.y.remap(fromLow: 0, fromHigh: size.height, toLow: 0, toHigh: 1))
+
+ if textStrokeLayer.isHidden == false {
+ if text.strokeOverFill ?? false {
+ textStrokeLayer.removeFromSuperlayer()
+ contentsLayer.addSublayer(textStrokeLayer)
+ } else {
+ textLayer.removeFromSuperlayer()
+ contentsLayer.addSublayer(textLayer)
+ }
+ textStrokeLayer.anchorPoint = normalizedAnchor
+ textStrokeLayer.opacity = Float(rootNode?.textOutputNode.opacity ?? 1)
+ textStrokeLayer.transform = CATransform3DIdentity
+ textStrokeLayer.frame = CGRect(origin: .zero, size: size)
+ textStrokeLayer.position = CGPoint.zero
+ textStrokeLayer.transform = matrix
+ textStrokeLayer.string = attributedString
+ textStrokeLayer.alignmentMode = text.justification.caTextAlignement
+ }
+
+ textLayer.anchorPoint = normalizedAnchor
  textLayer.opacity = Float(rootNode?.textOutputNode.opacity ?? 1)
  textLayer.transform = CATransform3DIdentity
  textLayer.frame = CGRect(origin: .zero, size: size)
  textLayer.position = CGPoint.zero
  textLayer.transform = matrix
- textLayer.string = attributedString
+ textLayer.string = baseAttributedString
  textLayer.alignmentMode = text.justification.caTextAlignement
  }
 }