Guides

Copy Pages

ComPDF Flutter SDK provides a page copy API for duplicating a page in the current PDF document and inserting the copied page at a target position. This is useful for page reordering, template reuse, and quickly creating similar pages.

API Overview

The page copy API is available on CPDFDocument:

Future<bool> copyPage({
  required int pageIndex,
  required int insertIndex,
});

Parameter description:

Parameter	Description
pageIndex	The zero-based index of the source page to copy
insertIndex	The zero-based insertion index for the copied page; use -1 to append to the end of the document

Return value:

• true: the page was copied and inserted successfully.
• false: the page index is invalid, the insertion index is invalid, or the native platform failed to copy the page.

Copy a Specific Page

Use copyPage(pageIndex, insertIndex) to duplicate a page in the current document and insert the copy at the desired position.

final CPDFDocument document = await CPDFDocument.createInstance();
await document.open('/path/to/sample.pdf');

final bool result = await document.copyPage(
  pageIndex: 0,
  insertIndex: 1,
);

print('Copy page result: $result');

This example copies the first page and inserts the copy before the second page.

If insertIndex is set to -1, the copied page is appended to the end of the document:

final bool result = await document.copyPage(
  pageIndex: 0,
  insertIndex: -1,
);

Use in CPDFReaderWidget

When you use CPDFReaderWidget, you can call the same API through CPDFReaderWidgetController.document. After a successful copy, refresh the reader view so the new page count is reflected.

Future<void> copyCurrentPage(CPDFReaderWidgetController controller) async {
  final int pageIndex = await controller.getCurrentPageIndex();

  final bool result = await controller.document.copyPage(
    pageIndex: pageIndex,
    insertIndex: -1,
  );

  if (result) {
    controller.reloadPages();
  }
}

This is a good fit for custom toolbars, page menus, or batch page operations.

Complete Example

The following example opens a PDF, duplicates the first page, and appends the copy to the end of the document.

import 'package:compdfkit_flutter/document/cpdf_document.dart';

Future<void> duplicateFirstPage(String filePath) async {
  final CPDFDocument document = await CPDFDocument.createInstance();
  await document.open(filePath);

  final bool result = await document.copyPage(
    pageIndex: 0,
    insertIndex: -1,
  );

  if (!result) {
    throw Exception('Copy page failed.');
  }

  print('Page copied successfully.');
}

Notes

• pageIndex must point to an existing page in the current document, otherwise the API returns false.
• insertIndex supports 0..pageCount; -1 means append to the end of the document.
• Page copy changes the document page count, so refresh the reader state if you use this API in a reader view.
• If the document is empty, the page index is invalid, or the native SDK rejects the current document state, the API returns false.
• If you need to duplicate multiple pages, call copyPage multiple times in the order required by your business logic.