How to create Watermarks using Foxit PDF SDK (Objective-C)

A watermark is a type of PDF annotation and is widely used in PDF documents. A watermark is a visible embedded overlay on a document consisting of text, a logo, or a copyright notice. The purpose of a watermark is to brand your work and discourage its unauthorized use. Foxit PDF SDK provides APIs to work with watermarks, allowing applications to create, insert, release and remove watermarks.

Example:

How to create a text watermark and insert it into the first page

import com.foxit.sdk.common.Font;
import com.foxit.sdk.pdf.*;
import com.foxit.sdk.pdf.Watermark;
import com.foxit.sdk.pdf.WatermarkSettings;
import com.foxit.sdk.pdf.WatermarkTextProperties;
import com.foxit.sdk.common.Constants;
import static com.foxit.sdk.common.Constants.e_AlignmentCenter;
import static com.foxit.sdk.common.Font.e_StdIDTimesB;
import static com.foxit.sdk.pdf.WatermarkSettings.*;
import static com.foxit.sdk.pdf.WatermarkTextProperties.e_FontStyleNormal;
...
// Assuming PDFDoc doc has been loaded.
WatermarkSettings settings = new WatermarkSettings();
settings.setFlags(e_FlagASPageContents | e_FlagOnTop);
settings.setOffset_x(0);
settings.setOffset_y(0);
settings.setOpacity(90);
settings.setPosition(Constants.e_PosTopRight);
settings.setRotation(-45.f);
settings.setScale_x(1.f);
settings.setScale_y(1.f);
WatermarkTextProperties text_properties = new WatermarkTextProperties();
text_properties.setAlignment(e_AlignmentCenter);
text_properties.setColor(0xF68C21);
text_properties.setFont_size(e_FontStyleNormal);
text_properties.setLine_space(1);
text_properties.setFont_size(12.f);
text_properties.setFont(new Font(e_StdIDTimesB));
Watermark watermark = new Watermark(doc, "Foxit PDF SDK\nwww.foxit.com", text_properties, settings);
watermark.insertToPage(page);
// Save document to file
...

How to create an image watermark and insert it into the first page

import com.foxit.sdk.common.Bitmap;
import com.foxit.sdk.common.Image;
import com.foxit.sdk.pdf.*;
import com.foxit.sdk.pdf.Watermark;
import com.foxit.sdk.pdf.WatermarkSettings;
import com.foxit.sdk.common.Constants;
import static com.foxit.sdk.common.Constants.e_AlignmentCenter;
import static com.foxit.sdk.common.Font.e_StdIDTimesB;
import static com.foxit.sdk.pdf.WatermarkSettings.*;
import static com.foxit.sdk.pdf.WatermarkTextProperties.e_FontStyleNormal;
...
// Assuming PDFDoc doc has been loaded.
WatermarkSettings settings = new WatermarkSettings();
settings.setFlags(e_FlagASPageContents | e_FlagOnTop);
settings.setOffset_x(0.f);
settings.setOffset_y(0.f);
settings.setOpacity(20);
settings.setPosition(Constants.e_PosCenter);
settings.setRotation(0.0f);
Image image = new Image(image_file);
Bitmap bitmap = image.getFrameBitmap(0);
settings.setScale_x(page.getWidth() * 0.618f / bitmap.getWidth());
settings.setScale_y(settings.getScale_x());
Watermark watermark = new Watermark(doc, image, 0, settings);
watermark.insertToPage(page);
// Save document to file.
...

How to remove all watermarks from a page

import com.foxit.sdk.pdf.PDFPage;
...
// Assuming PDFPage page has been loaded and parsed.
...
page.removeAllWatermarks();
...
// Save document to file
...