Guides

Update a Watermark

Use updateWatermark() with the watermark index and a new CPDFWatermark value. Read the original watermark first, then use copyWith() to change only the properties you need.

final CPDFWatermark? watermark = await document.getWatermark(
  0,
  exportImage: true,
);

if (watermark != null) {
  final bool success = await document.updateWatermark(
    watermark.index,
    watermark.copyWith(
      textContent: 'Updated Confidential',
      textColor: Colors.blue,
      fontSize: 36,
      opacity: 0.75,
    ),
  );

  print('Update watermark result: $success');
}

When updating an image watermark, pass a new imagePath only if you want to replace the image. If imagePath is empty, the SDK keeps the existing image and updates the other watermark properties.