Interactive Annotations using Java

Interactive annotations in this section focus on link and button-based workflows that respond to user actions inside a PDF viewer.

Add a link annotation

Use this example when you need to place a clickable link over text found on the page.

1. Open the source PDF Document.
2. Locate the target text fragment and create a LinkAnnotation over its rectangle.
3. Assign a GoToURIAction and save the updated document.

public static void linkAdd(Path inputFile, Path outputFile) {
    try (Document document = new Document(inputFile.toString())) {
        TextFragmentAbsorber textFragmentAbsorber = new TextFragmentAbsorber("file");
        document.getPages().get_Item(1).accept(textFragmentAbsorber);

        var phoneNumberFragment = textFragmentAbsorber.getTextFragments().get_Item(1);
        LinkAnnotation linkAnnotation = new LinkAnnotation(
                document.getPages().get_Item(1),
                phoneNumberFragment.getRectangle());
        linkAnnotation.setAction(new GoToURIAction("https://www.aspose.com"));

        document.getPages().get_Item(1).getAnnotations().add(linkAnnotation);
        document.save(outputFile.toString());
    }
}

Get link annotations

This example scans the page annotation collection and reports the location of each link annotation.

1. Open the source PDF Document.
2. Iterate through the annotations on the target page.
3. Filter annotations by AnnotationType.Link and print their rectangles.

public static void linkGet(Path inputFile) {
    try (Document document = new Document(inputFile.toString())) {
        for (Annotation annotation : document.getPages().get_Item(1).getAnnotations()) {
            if (annotation.getAnnotationType() == AnnotationType.Link) {
                System.out.println(annotation.getRect());
            }
        }
    }
}

Delete link annotations

Use this approach when existing link annotations should be removed from the page.

1. Open the source PDF Document.
2. Collect annotations whose type is AnnotationType.Link.
3. Delete the collected annotations and save the output file.

public static void linkDelete(Path inputFile, Path outputFile) {
    try (Document document = new Document(inputFile.toString())) {
        List<Annotation> toDelete = new ArrayList<>();
        for (Annotation annotation : document.getPages().get_Item(1).getAnnotations()) {
            if (annotation.getAnnotationType() == AnnotationType.Link) {
                toDelete.add(annotation);
            }
        }
        for (Annotation annotation : toDelete) {
            document.getPages().get_Item(1).getAnnotations().delete(annotation);
        }
        document.save(outputFile.toString());
    }
}

Add a line annotation

This example creates an interactive line annotation with arrow styles, border settings, and a popup note.

1. Open the source PDF Document.
2. Create a LineAnnotation with start and end points.
3. Configure its appearance and popup annotation, then save the document.

public static void lineAnnotationAdd(Path inputFile, Path outputFile) {
    try (Document document = new Document(inputFile.toString())) {
        LineAnnotation lineAnnotation = new LineAnnotation(
                document.getPages().get_Item(1),
                new Rectangle(550, 93, 562, 439, true),
                new Point(556, 99),
                new Point(556, 443));

        lineAnnotation.setTitle("John Smith");
        lineAnnotation.setColor(Color.getRed());
        lineAnnotation.setStartingStyle(LineEnding.OpenArrow);
        lineAnnotation.setEndingStyle(LineEnding.OpenArrow);

        Border border = new Border(lineAnnotation);
        border.setWidth(3);
        lineAnnotation.setBorder(border);

        PopupAnnotation popup = new PopupAnnotation(
                document.getPages().get_Item(1),
                new Rectangle(842, 124, 1021, 266, true));
        lineAnnotation.setPopup(popup);

        document.getPages().get_Item(1).getAnnotations().add(lineAnnotation);
        document.save(outputFile.toString());
    }
}

Add navigation buttons

Use this example when the PDF should include previous-page and next-page buttons for interactive navigation.

1. Open the source PDF Document and make sure the document has the required pages.
2. Create ButtonField controls with predefined navigation actions.
3. Add the buttons to the form collection and save the updated document.

public static void navigationButtonsAdd(Path inputFile, Path outputFile) {
    try (Document document = new Document(inputFile.toString())) {
        document.getPages().add();

        record ButtonConfig(String name, double xPos, PredefinedAction action) {}
        List<ButtonConfig> buttonConfigs = List.of(
                new ButtonConfig("Previous Page", 120.0, PredefinedAction.PrevPage),
                new ButtonConfig("Next Page", 230.0, PredefinedAction.NextPage));

        for (Page page : document.getPages()) {
            for (ButtonConfig config : buttonConfigs) {
                Rectangle rect = new Rectangle(config.xPos(), 10.0, config.xPos() + 100, 40.0, true);
                ButtonField button = new ButtonField(page, rect);
                button.setPartialName(config.name());
                button.setValue(config.name());
                button.getCharacteristics().setBorder(Color.getRed());
                button.getCharacteristics().setBackground(Color.getOrange().toRgb());
                button.getAnnotationActions().setOnReleaseMouseBtn(new NamedAction(config.action()));
                document.getForm().add(button);
            }
        }
        document.save(outputFile.toString());
    }
}

Add a print button

This example creates a button that triggers the print command when the user clicks it.

1. Create a new PDF Document and add a page.
2. Create a ButtonField and assign the print predefined action.
3. Configure the button border and background, add it to the form, and save the document.

public static void printButtonAdd(Path outputFile) {
    try (Document document = new Document()) {
        Page page = document.getPages().add();

        Rectangle rect = new Rectangle(72, 748, 164, 768, true);
        ButtonField printButton = new ButtonField(page, rect);
        printButton.setAlternateName("Print current document");
        printButton.setColor(Color.getBlack());
        printButton.setPartialName("printBtn1");
        printButton.setValue("Print Document");
        printButton.getAnnotationActions().setOnReleaseMouseBtn(
                new NamedAction(PredefinedAction.File_Print));

        Border border = new Border(printButton);
        border.setStyle(BorderStyle.Solid);
        border.setWidth(2);
        printButton.setBorder(border);

        printButton.getCharacteristics().setBorder(Color.getBlue());
        printButton.getCharacteristics().setBackground(Color.getLightBlue().toRgb());

        document.getForm().add(printButton);
        document.save(outputFile.toString());
    }
}