native_pdf_engine 0.0.7

A high-performance, FFI-based Flutter package to convert HTML and URLs to PDF using native OS webviews (Android, iOS, macOS).

0.0.7

Android PDF Engine Stabilization

• Native Printing Migration: Refactored the Android conversion logic to use the native PrintDocumentAdapter workflow, ensuring high-fidelity rendering for complex and multi-page HTML content.
• Release Mode Reliability: Fixed ClassNotFoundException in release builds by aligning package namespaces and applying comprehensive ProGuard rules.
• WebView Lifecycle Optimization: Improved stability by explicitly attaching the hidden WebView to the Activity context and ensuring proper cleanup via destroy().
• Java SDK Bridge: Implemented PrintCallbackShim in Java to safely access package-private Android printing APIs.
• Native Threading: Enhanced thread safety between the Flutter UI thread and the Android main loop for more predictable PDF generation.

JNI 1.0 Finalization

• Migrated to jni: ^1.0.1 and jnigen: ^0.16.0: Updated all Android bindings and usage patterns to comply with JNI 1.0 standards, including reference counting and new property accessors.

0.0.6

JNI 1.0 Migration & Breaking Changes

• Migrated to jni: ^1.0.0 and jnigen: ^0.16.0: Updated codebase to work with the latest major versions of JNI and JNIgen.
• Added jni_flutter dependency: Now uses jni_flutter for accessing the current Android activity, replacing the deprecated jni.Jni.androidActivity.
• Updated Android Property Accessors: Refactored Android platform code to use new property-style getters/setters (e.g., webView.settings, webView.progress) introduced in jnigen 0.16.0.
• Simplified Binding Casting: Replaced fromReference calls with direct as casting for strongly-typed JNI objects.

Improvements

• Enhanced Android Layout Stability: Increased the settling delay from 200ms to 400ms after a layout change to more reliably capture content height.
• Swift String Extensions: Refactored Java string creation to use the .toJString() extension method for cleaner code.

0.0.5

Stability & Reliability

• Fixed silent hang on callback failure: Added 30-second timeout on all pending PDF generation futures to prevent indefinite hangs when native code fails silently.
• Fixed premature GC of ObjC completion handlers: Introduced _activeCompletionHandler static reference to prevent Dart garbage collection of Objective-C blocks before native callbacks fire (iOS/macOS).
• Fixed use-after-free on native memory: Copied PDF data out of native NSData buffers via Uint8List.fromList() before native memory is deallocated (iOS/macOS).
• Fixed silent exception swallowing: Removed async from _handleMacOSNavigationFinished to prevent exceptions from being silently dropped.
• Added comprehensive try/catch wrappers: All platform setup paths now catch exceptions and properly complete the Completer with an error instead of leaving it pending.

Memory Management

• Arena-based native memory cleanup: Replaced manual calloc/free with Arena for CGRect allocations on iOS/macOS, ensuring memory is freed even on exceptions.
• Arena for native strings: Linux and Windows now use toNativeUtf8(allocator: arena) with arena.releaseAll() in finally blocks for leak-proof string management.
• Android JNI resource cleanup: Added finally block to close PdfDocument, FileOutputStream, and ByteArrayOutputStream even when PDF generation throws.

Tooling

• Fixed ffigen URLSession duplicate symbol error: Added NSURLRequest.h as an explicit entry point header for both iOS and macOS binding generation configs.

Testing

• Added comprehensive integration tests: 18 tests covering all API surfaces — HTML/URL to file/data, concurrent call rejection, sequential cleanup, Unicode content, complex CSS, large documents, and mixed-mode memory safety.

0.0.4

• Fixed clipping issues on Android by implementing dynamic height detection using getContentHeight.
• Improved rendering quality on Android by enabling slowWholeDocumentDraw.
• Enhanced page load detection and layout stability with precise delays.
• Optimized Android conversion logic for better reliability.

0.0.2

• Added convertToData and convertUrlToData to retrieve PDF data directly as Uint8List.
• Added ByteArrayOutputStream to Android bindings to support in-memory PDF generation.

0.0.1

• Initial release.
• Platform implementations for iOS (WKWebView), macOS (WKWebView), and Android (Pure JNI WebView).
• Support for converting HTML strings and URLs to PDF.