PDF splitting with Syncfusion truncates pages

[aliboy007]

Bug description

When splitting a PDF into individual pages using the Syncfusion PDF library in Flutter, the output pages are truncated or incomplete. This issue occurs regardless of the PDF size or complexity and affects the integrity of the resulting pages.

Steps to reproduce

Set up a Flutter project and include the Syncfusion PDF library (syncfusion_flutter_pdf).

Implement a workflow to split a multi-page PDF into individual pages using the createTemplate method.

Use the following code to load a PDF, split it into individual pages, and save them:

Load the resulting split pages using a PDF viewer (e.g., Syncfusion PDF Viewer or similar tools).

Code sample

Code sample

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:syncfusion_flutter_pdf/pdf.dart';
import 'package:syncfusion_flutter_pdfviewer/pdfviewer.dart';
import 'package:file_picker/file_picker.dart';
import 'package:path_provider/path_provider.dart';

class PdfSamplePage extends StatefulWidget {
  const PdfSamplePage({Key? key}) : super(key: key);

  @override
  State<PdfSamplePage> createState() => _PdfSamplePageState();
}

class _PdfSamplePageState extends State<PdfSamplePage> {
  List<String> _splitPagePaths = [];

  Future<void> _pickAndSplitPdf() async {
    try {
      FilePickerResult? result = await FilePicker.platform.pickFiles(
        type: FileType.custom,
        allowedExtensions: ['pdf'], // Restrict to PDF files
      );

      if (result != null && result.files.single.path != null) {
        File pdfFile = File(result.files.single.path!);

        // Split the PDF into pages
        List<File> splitFiles = await _splitPdfIntoPages(pdfFile);

        setState(() {
          _splitPagePaths = splitFiles.map((file) => file.path).toList();
        });
      } else {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('No file selected')),
        );
      }
    } catch (e) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('Error picking or splitting file: $e')),
      );
    }
  }

  Future<List<File>> _splitPdfIntoPages(File pdfFile) async {
    final pdfBytes = await pdfFile.readAsBytes();
    final document = PdfDocument(inputBytes: pdfBytes);

    List<File> pageFiles = [];
    final appDir = await getApplicationDocumentsDirectory();

    for (int i = 0; i < document.pages.count; i++) {
      final page = PdfDocument();
      page.pages.add().graphics.drawPdfTemplate(
            document.pages[i].createTemplate(),
            Offset(0, 0),
          );

      final pageBytes = page.saveSync();
      final pageFile = File('${appDir.path}/page_${i + 1}.pdf');
      await pageFile.writeAsBytes(pageBytes);

      pageFiles.add(pageFile);
      page.dispose();
    }

    document.dispose();
    return pageFiles;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('PDF Split and Viewer'),
      ),
      body: Column(
        children: [
          ElevatedButton(
            onPressed: _pickAndSplitPdf,
            child: const Text('Pick and Split PDF File'),
          ),
          const SizedBox(height: 10),
          Expanded(
            child: _splitPagePaths.isNotEmpty
                ? ListView.builder(
                    itemCount: _splitPagePaths.length,
                    itemBuilder: (context, index) {
                      return Padding(
                        padding: const EdgeInsets.symmetric(vertical: 8.0),
                        child: SizedBox(
                          height: 400, // Fixed height for each page preview
                          child: SfPdfViewer.file(
                            File(_splitPagePaths[index]),
                            pageSpacing: 0,
                            enableDoubleTapZooming: false,
                            enableTextSelection: false,
                            pageLayoutMode: PdfPageLayoutMode.single,
                            canShowPaginationDialog: false,
                            canShowScrollHead: false,
                            canShowScrollStatus: false,
                            initialZoomLevel: 1.0,
                          ),
                        ),
                      );
                    },
                  )
                : const Center(
                    child: Text('No PDF selected or split yet.'),
                  ),
          ),
        ],
      ),
    );
  }
}

Screenshots or Video

Screenshots / Video demonstration

The margin ones are split PDFs and without margin are original pages.

Stack Traces

No specific stack trace, but the issue is evident in the truncated output files.

On which target platforms have you observed this bug?

Android, iOS

Flutter Doctor output

Doctor output

[✓] Flutter (Channel stable, 3.27.0, on macOS 15.2 24C101 darwin-arm64, locale en-AU)
    • Flutter version 3.27.0 on channel stable at /Users/<username>/Developer/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 8495dee1fd (4 weeks ago), 2024-12-10 14:23:39 -0800
    • Engine revision 83bacfc525
    • Dart version 3.6.0
    • DevTools version 2.40.2

[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
    • Android SDK at /Users/<username>/Library/Android/sdk
    • Platform android-35, build-tools 35.0.0
    • ANDROID_HOME = /Users/<username>/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 21.0.3+-79915917-b509.11)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 16.2)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 16C5032a
    • CocoaPods version 1.16.2

[✓] Android Studio (version 2024.2)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 21.0.3+-79915917-b509.11)

[✓] VS Code (version 1.92.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.102.0

[✓] Connected device (2 available)
    • iPhone (mobile)                 • <device-id>               • ios    • iOS 17.7.1
    • Mac Designed for iPad (desktop) • mac-designed-for-ipad     • darwin • macOS 15.2

[✓] Network resources
    • All expected network resources are available.

• No issues found!

[aliboy007]

I found the issue - it is to with the margins.

`Future<List> _splitPdfIntoPages(File pdfFile) async {
final pdfBytes = await pdfFile.readAsBytes();
final document = PdfDocument(inputBytes: pdfBytes);

List pageFiles = [];
final appDir = await getApplicationDocumentsDirectory();

for (int i = 0; i < document.pages.count; i++) {
final originalPage = document.pages[i];
final originalSize = originalPage.size; // Get original page size (width, height)

final newDocument = PdfDocument();

// Explicitly set margins to zero
newDocument.pageSettings.margins.all = 0;

final newPage = newDocument.pages.add();
final graphics = newPage.graphics;

// Draw the content of the original page to the new page
graphics.drawPdfTemplate(
  originalPage.createTemplate(),
  Offset.zero, // No offset
);

// Save the new page as a file
final pageBytes = newDocument.saveSync();
final pageFile = File('${appDir.path}/page_${i + 1}.pdf');
await pageFile.writeAsBytes(pageBytes);

pageFiles.add(pageFile);
newDocument.dispose();

}

document.dispose();
return pageFiles;
}
`