Create Annotations ​

// Insert page numbers.
val pageNumber = 0
// Retrieve an instance of the PDF page.
val page = document.pageAtIndex(pageNumber)
val textAnnotation = page.addAnnot(CPDFAnnotation.Type.TEXT) as CPDFTextAnnotation
// Retrieve the actual size of the page to be inserted.
val pageSize = page.size
// Coordinate transformation.
val insertRect = page.convertRectToPage(
  false,
  pageSize.width(),
  pageSize.height(),
  RectF(0f, 0f, 50f, 50f)
)
textAnnotation.setColor(Color.RED)
textAnnotation.alpha = 255
textAnnotation.rect = insertRect
textAnnotation.content = "ComPDFKit"
textAnnotation.updateAp()

// Insert page numbers.
val pageNumber = 1
// Retrieve an instance of the PDF page.
val page = document.pageAtIndex(pageNumber)
val linkAnnotation = page.addAnnot(CPDFAnnotation.Type.LINK) as CPDFLinkAnnotation
val pageSize = readerView.getPageNoZoomSize(pageNumber)
// Coordinate transformation.
linkAnnotation.rect = run {
  var insertRect: RectF? = RectF(0f, 0f, 100f, 100f)
  page.convertRectToPage(readerView.isCropMode, pageSize.width(), pageSize.height(), insertRect)
}

// Navigate to a specified page number.
linkAnnotation.linkAction = CPDFGoToAction().apply { 
  setDestination(document,  CPDFDestination(pageNumber, 0f, pageSize.height(), 1f))
}

// Open a specific webpage.
linkAnnotation.linkAction = CPDFUriAction().apply { 
  uri = "website"
}
// Update the annotations onto the document.
linkAnnotation.updateAp()

val page = document.pageAtIndex(0)
(page.addAnnot(CPDFAnnotation.Type.FREETEXT) as CPDFFreetextAnnotation).apply {
 
// Coordinate transformation.
  val size = page.size
  rect = page.convertRectToPage(false, size.width(), size.height(),  RectF(0f, 0f, 100f, 100f))
  // Set annotation properties
  freetextAlignment = CPDFFreetextAnnotation.Alignment.ALIGNMENT_CENTER
  freetextDa = CPDFTextAttribute(CPDFTextAttribute.FontNameHelper.obtainFontName(
    CPDFTextAttribute.FontNameHelper.FontType.Courier, false, false
  ), 12f, Color.RED)
  alpha = 255
  content = "ComPDFKit Samples"
  // Update the annotations onto the document.
  updateAp()
}

// Insert page numbers.
val pageNumber = 0
// Retrieve an instance of the PDF page.
val page = document.pageAtIndex(pageNumber)

// Create a rectangle annotation object on the page.
val squareAnnotation = page.addAnnot(CPDFAnnotation.Type.SQUARE) as CPDFSquareAnnotation
val pageSize = readerView.getPageNoZoomSize(pageNumber)
// Coordinate transformation.
squareAnnotation.rect = page.convertRectToPage(readerView.isCropMode, pageSize.width(), pageSize.height(), RectF(0F, 0F, 100F, 100F))

squareAnnotation.apply {
// Set annotation properties.
  borderColor = Color.YELLOW
  borderStyle = CPDFBorderStyle(CPDFBorderStyle.Style.Border_Solid, 10F, floatArrayOf(8F, 0F)).apply {
    borderWidth = 10F
  }
  borderAlpha = 255
  fillColor = Color.RED
  fillAlpha = 255
}
// Update the annotations onto the document.
squareAnnotation.updateAp()

// Create a circular annotation object on the page.
val circleAnnotation = page.addAnnot(CPDFAnnotation.Type.CIRCLE) as CPDFCircleAnnotation
val pageSize = readerView.getPageNoZoomSize(pageNumber)
// Coordinate transformation.
circleAnnotation.rect = page.convertRectToPage(readerView.isCropMode, pageSize.width(), pageSize.height(), RectF(0F, 0F, 100F, 100F))
// Set annotation properties.
circleAnnotation.borderColor = Color.YELLOW
circleAnnotation.borderStyle = CPDFBorderStyle(CPDFBorderStyle.Style.Border_Solid, 10F, floatArrayOf(8F, 0F)).apply {
  borderWidth = 10F
}
circleAnnotation.borderAlpha = 255
circleAnnotation.fillColor = Color.RED
circleAnnotation.fillAlpha = 255
// Update the annotations onto the document.
circleAnnotation.updateAp()

// Create a line annotation object on the page.
val lineAnnotation = page.addAnnot(CPDFAnnotation.Type.LINE) as CPDFLineAnnotation
val lineWidth = 10F
val pageSize = readerView.getPageNoZoomSize(pageNumber)
val startPoint = PointF(0F, 0F)
val endPoint = PointF(200F, 200F)

val area = RectF().apply {
  left = min(startPoint.x, endPoint.x) - lineWidth * 2
  top = min(startPoint.y, endPoint.y) - lineWidth * 2
  right = max(startPoint.x, endPoint.x) + lineWidth * 2
  bottom = max(startPoint.y, endPoint.y) + lineWidth * 2
  set(page.convertRectToPage(readerView.isCropMode, pageSize.width(), pageSize.height(), this))
}
// Coordinate transformation.
listOf(startPoint, endPoint).forEach { point ->
  point.set(page.convertPointToPage(
    readerView.isCropMode, 
    pageSize.width(), 
    pageSize.height(), 
    point))
}
// Set annotation properties.
lineAnnotation.rect = area
lineAnnotation.setLinePoints(startPoint, endPoint)
lineAnnotation.setLineType(CPDFLineAnnotation.LineType.LINETYPE_NONE, CPDFLineAnnotation.LineType.LINETYPE_ARROW)
lineAnnotation.borderStyle = CPDFBorderStyle(CPDFBorderStyle.Style.Border_Solid, lineWidth, null)
lineAnnotation.borderWidth = 10F
lineAnnotation.borderAlpha = 255
lineAnnotation.borderColor = Color.RED
// Update the annotations onto the document.
lineAnnotation.updateAp();

// Retrieve the page object for creating annotations.
val pageNumber = 0
val pdfPage = document.pageAtIndex(pageNumber)

// Create a standard signature stamp.
val standardStamp = pdfPage.addAnnot(CPDFAnnotation.Type.STAMP) as CPDFStampAnnotation
standardStamp.setStandardStamp(CPDFStampAnnotation.StandardStamp.COMPLETED)
val pageSize = readerView.getPageNoZoomSize(pageNumber)
val insertRect = standardStamp.rect
insertRect.set(
  pdfPage.convertRectFromPage(readerView.isCropMode, pageSize.width(), pageSize.height(), insertRect)
)
val defaultWidth = 200F
val vertex = PointF(0f, 0F)
insertRect.set(
  vertex.x,
  vertex.y,
  vertex.x + defaultWidth,
  vertex.y + defaultWidth * kotlin.math.abs(insertRect.height() / insertRect.width())
)
standardStamp.rect = pdfPage.convertRectToPage(readerView.isCropMode, pageSize.width(), pageSize.height(), insertRect)
standardStamp.updateAp()

// Create a text signature stamp.
val textStamp = pdfPage.addAnnot(CPDFAnnotation.Type.STAMP) as CPDFStampAnnotation
textStamp.textStamp = CPDFStampAnnotation.TextStamp(
  "Hello world",
  "2022/01/01 12:00:00",
  CPDFStampAnnotation.TextStampShape.TEXTSTAMP_RIGHT_TRIANGLE.id,
  CPDFStampAnnotation.TextStampColor.TEXTSTAMP_GREEN.id
)
val textStampInsertRect = textStamp.rect
textStampInsertRect.set(
  pdfPage.convertRectFromPage(readerView.isCropMode, pageSize.width(), pageSize.height(), textStampInsertRect)
)
textStampInsertRect.set(
  vertex.x,
  vertex.y,
  vertex.x + defaultWidth,
  vertex.y + defaultWidth * kotlin.math.abs(textStampInsertRect.height() / textStampInsertRect.width())
)
textStamp.rect = pdfPage.convertRectToPage(readerView.isCropMode, pageSize.width(), pageSize.height(), textStampInsertRect)
textStamp.updateAp()

// Create an image stamp.
val imageStamp = pdfPage.addAnnot(CPDFAnnotation.Type.STAMP) as CPDFStampAnnotation
val imagePath = "imagePath"
val options = BitmapFactory.Options()
options.inJustDecodeBounds = true
BitmapFactory.decodeFile(imagePath, options)
val imageStampInsertRect = RectF(
  vertex.x,
  vertex.y,
  vertex.x + defaultWidth,
  vertex.y + defaultWidth * options.outHeight / options.outWidth
)
imageStamp.rect = pdfPage.convertRectToPage(readerView.isCropMode, pageSize.width(), pageSize.height(), imageStampInsertRect)

if (imagePath.endsWith("png")) {
  val tmpOptions = BitmapFactory.Options()
  tmpOptions.inMutable = true
  val bitmap = BitmapFactory.decodeFile(imagePath, tmpOptions)
  imageStamp.updateApWithBitmap(bitmap)
  bitmap.recycle()
} else {
  imageStamp.setImageStamp(imagePath)
  imageStamp.updateAp()
}

// Retrieve the page object for creating annotations.
val pageNumber = 0
val pdfPage = document.pageAtIndex(pageNumber)
// Set the path traced by the freehand annotation.
val mDrawing = mutableListOf<MutableList<PointF>>()
val arc1 = mutableListOf(PointF(0f, 0f), PointF(10f, 10f), PointF(20f, 20f))
mDrawing.add(arc1)
val arc2 = mutableListOf(PointF(5f, 5f), PointF(15f, 15f), PointF(25f, 25f))
mDrawing.add(arc2)
// Create a ink annotation on the page.
val inkAnnotation = pdfPage.addAnnot(CPDFAnnotation.Type.INK) as CPDFInkAnnotation
val inkAttr = readerView.readerAttribute.annotAttribute.inkAttr
val scaleValue = pageView.scaleValue
inkAnnotation.color = inkAttr.color
inkAnnotation.alpha = inkAttr.alpha
inkAnnotation.borderWidth = inkAttr.borderWidth / scaleValue

var rect: RectF? = null
val size = readerView.getPageNoZoomSize(pageView.pageNum)
if (size.isEmpty) {
  return
}
val lineCount = mDrawing.size
val path = Array(lineCount) { emptyArray<PointF>() }
for (lineIndex in 0 until lineCount) {
  val line = mDrawing[lineIndex]
  val pointCount = line.size
  val linePath = Array(pointCount) { PointF() }
  for (pointIndex in 0 until pointCount) {
    val point = line[pointIndex]
    /****** Calculate the minimum bounding rectangle for the path ******/
    if (rect == null) {
      rect = RectF(point.x, point.y, point.x, point.y)
    } else {
      rect.union(point.x, point.y)
    }
    /****** Calculate the coordinates transformed to the page and stored in the linePath collection ******/
    linePath[pointIndex] = pdfPage.convertPointToPage(
      readerView.isCropMode,
      size.width(),
      size.height(),
      point
    )
  }
  path[lineIndex] = linePath
}
val dx = inkAttr.borderWidth / scaleValue / 2
rect?.inset(-dx, -dx)
rect?.set(pdfPage.convertRectToPage(readerView.isCropMode, size.width(), size.height(), rect))
inkAnnotation.inkPath = path
inkAnnotation.rect = rect
inkAnnotation.updateAp()

// Retrieve the page object for creating annotations.
val page = document.pageAtIndex(3)
val soundAnnotation = page.addAnnot(CPDFAnnotation.Type.SOUND) as CPDFSoundAnnotation
val insertRect = getConvertRect(page, RectF(50F, 300F, 100F, 350F))
soundAnnotation.rect = insertRect
soundAnnotation.setSoundPath(getAssetsTempFile(context(), "Bird.wav"))
soundAnnotation.updateAp()