WIP: platform dependency refactoring

README.md

@@ -16,7 +16,7 @@ A [demo site](https://espresso3389.github.io/pdfrx/) using Flutter Web
 - Windows
 - macOS
 - Linux (even on Raspberry PI)
-- Web (\*using [PDF.js](https://mozilla.github.io/pdf.js/))
+- Web (\*using [PDF.js](https://mozilla.github.io/pdf.js/)) or Pdfium WASM (\*experimental)
 
 ## Example Code
 
@@ -73,7 +73,7 @@ dependencies:
   pdfrx_wasm: ^1.1.6
 ```
 
-And then, enable Pdfium WASM by adding the following line to somewhere that runs before calling any pdfrx functions:
+And then, enable Pdfium WASM by adding the following line to somewhere that runs before calling any pdfrx functions (typically `main` function):
 
 ```dart
 Pdfrx.webRuntimeType = PdfrxWebRuntimeType.pdfiumWasm;

lib/pdfrx.dart

@@ -1,6 +1,5 @@
 export 'src/pdf_api.dart';
 export 'src/pdf_document_ref.dart';
-export 'src/pdf_file_cache.dart';
 export 'src/web/pdfjs_configuration.dart';
 export 'src/widgets/pdf_page_text_overlay.dart';
 export 'src/widgets/pdf_text_searcher.dart';

lib/src/pdf_file_cache.dart → lib/src/pdfium/pdf_file_cache.dart

@@ -8,91 +8,18 @@ import 'package:http/http.dart' as http;
 import 'package:path/path.dart' as path;
 import 'package:path_provider/path_provider.dart';
 
-import '../pdfrx.dart';
+import '../../pdfrx.dart';
 import 'http_cache_control.dart';
 
-/// PDF file cache for downloading (Non-web).
+/// PDF file cache backed by a file.
 ///
-/// See [PdfFileCacheNative] for actual implementation.
-abstract class PdfFileCache {
-  PdfFileCache();
-
-  /// Size of cache block in bytes.
-  int get blockSize;
-
-  /// File size of the PDF file.
-  int get fileSize;
-
-  /// Number of cache blocks.
-  int get totalBlocks;
-
-  /// Number of bytes cached.
-  int get cachedBytes {
-    if (!isInitialized) return 0;
-    var countCached = 0;
-    for (int i = 0; i < totalBlocks; i++) {
-      if (isCached(i)) {
-        countCached++;
-      }
-    }
-    return min(countCached * blockSize, fileSize);
-  }
-
-  /// The file path.
-  String get filePath;
-
-  HttpCacheControlState get cacheControlState;
-
-  /// Determine if the cache is initialized or not.
-  bool get isInitialized;
-
-  /// Close the cache file.
-  ///
-  /// It does not delete the cache file but just close the file handle.
-  Future<void> close();
-
-  /// Write [bytes] (of the [position]) to the cache.
-  Future<void> write(int position, List<int> bytes);
-
-  /// Read [size] bytes from the cache to [buffer] (from the [position]).
-  Future<void> read(List<int> buffer, int bufferPosition, int position, int size);
-
-  /// Set flag to indicate that the cache block is available.
-  Future<void> setCached(int startBlock, {int? lastBlock});
-
-  /// Check if the cache block is available.
-  bool isCached(int block);
+/// Because the code internally uses `dart:io`'s [File], it is not available on the web.
+class PdfFileCache {
+  PdfFileCache(this.file);
 
   /// Default cache block size is 32KB.
   static const defaultBlockSize = 1024 * 1024;
 
-  /// Set the cache block size.
-  ///
-  /// The block size must be set before [initializeWithFileSize] and it can be called only once.
-  bool setBlockSize(int cacheBlockSize);
-
-  /// Initialize the cache file.
-  Future<void> initializeWithFileSize(int fileSize, {required bool truncateExistingContent});
-
-  Future<void> setCacheControlState(HttpCacheControlState cacheControlState);
-
-  Future<void> invalidateCache();
-
-  /// Clear all the cached data.
-  Future<void> resetAll();
-
-  /// Create [PdfFileCache] object from URI.
-  ///
-  /// You can override the default implementation by setting [fromUri].
-  static Future<PdfFileCache> Function(Uri uri) fromUri = PdfFileCacheNative.fromUri;
-}
-
-/// PDF file cache backed by a file.
-///
-/// Because the code internally uses `dart:io`'s [File], it is not available on the web.
-class PdfFileCacheNative extends PdfFileCache {
-  PdfFileCacheNative(this.file);
-
   /// Cache file.
   final File file;
 
@@ -106,22 +33,30 @@ class PdfFileCacheNative extends PdfFileCache {
   bool _initialized = false;
   RandomAccessFile? _raf;
 
-  @override
   int get blockSize => _cacheBlockSize!;
-  @override
+
   int get totalBlocks => _cacheBlockCount!;
-  @override
+
   int get fileSize => _fileSize!;
-  @override
+
   String get filePath => file.path;
 
-  @override
   HttpCacheControlState get cacheControlState => _cacheControlState;
 
-  @override
+  /// Number of bytes cached.
+  int get cachedBytes {
+    if (!isInitialized) return 0;
+    var countCached = 0;
+    for (int i = 0; i < totalBlocks; i++) {
+      if (isCached(i)) {
+        countCached++;
+      }
+    }
+    return min(countCached * blockSize, fileSize);
+  }
+
   bool get isInitialized => _initialized;
 
-  @override
   Future<void> close() async {
     await _raf?.close();
     _raf = null;
@@ -148,17 +83,13 @@ class PdfFileCacheNative extends PdfFileCache {
     return await _raf!.length();
   }
 
-  @override
   Future<void> read(List<int> buffer, int bufferPosition, int position, int size) =>
       _read(buffer, bufferPosition, _headerSize! + position, size);
 
-  @override
   Future<void> write(int position, List<int> bytes) => _write(_headerSize! + position, bytes);
 
-  @override
   bool isCached(int block) => _cacheState[block >> 3] & (1 << (block & 7)) != 0;
 
-  @override
   Future<void> setCached(int startBlock, {int? lastBlock}) async {
     lastBlock ??= startBlock;
     for (int i = startBlock; i <= lastBlock; i++) {
@@ -173,8 +104,8 @@ class PdfFileCacheNative extends PdfFileCache {
 
   Future<void> _saveCacheState() => _write(_cacheStatePosition!, _cacheState);
 
-  static Future<PdfFileCacheNative> fromFile(File file) async {
-    final cache = PdfFileCacheNative(file);
+  static Future<PdfFileCache> fromFile(File file) async {
+    final cache = PdfFileCache(file);
     await cache._reloadFile();
     return cache;
   }
@@ -221,7 +152,6 @@ class PdfFileCacheNative extends PdfFileCache {
     }
   }
 
-  @override
   Future<void> invalidateCache() async {
     await _ensureFileOpen();
     await _raf!.truncate(0);
@@ -234,20 +164,17 @@ class PdfFileCacheNative extends PdfFileCache {
     _initialized = false;
   }
 
-  @override
   Future<void> resetAll() async {
     await invalidateCache();
     await _reloadFile();
   }
 
-  @override
   bool setBlockSize(int cacheBlockSize) {
     if (_cacheBlockSize != null) return false;
     _cacheBlockSize = cacheBlockSize;
     return true;
   }
 
-  @override
   Future<void> initializeWithFileSize(int fileSize, {required bool truncateExistingContent}) async {
     if (truncateExistingContent) {
       await invalidateCache();
@@ -282,7 +209,6 @@ class PdfFileCacheNative extends PdfFileCache {
     await _write(header1Size, dataStrEncoded);
   }
 
-  @override
   Future<void> setCacheControlState(HttpCacheControlState cacheControlState) async {
     _cacheControlState = cacheControlState;
     await _saveCacheControlState();
@@ -300,7 +226,7 @@ class PdfFileCacheNative extends PdfFileCache {
     return File(path.join(dir.path, '$body.pdf'));
   }
 
-  static Future<PdfFileCacheNative> fromUri(Uri uri) async {
+  static Future<PdfFileCache> fromUri(Uri uri) async {
     return await fromFile(await getCacheFilePathForUri(uri));
   }
 

lib/src/pdfium/pdfrx_pdfium.dart

@@ -10,7 +10,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
 import '../pdf_api.dart';
-import '../pdf_file_cache.dart';
+import 'pdf_file_cache.dart';
 import 'pdfium_bindings.dart' as pdfium_bindings;
 import 'pdfium_interop.dart';
 import 'worker.dart';

lib/src/utils/native/native.dart

@@ -0,0 +1,3 @@
+import 'dart:io';
+
+final isApple = Platform.isMacOS || Platform.isIOS;

lib/src/utils/platform.dart

@@ -0,0 +1,7 @@
+import 'package:flutter/services.dart';
+
+import 'web/web.dart' if (dart.library.io) 'native/native.dart';
+
+/// Key pressing state of ⌘ or Control depending on the platform.
+bool get isCommandKeyPressed =>
+    isApple ? HardwareKeyboard.instance.isMetaPressed : HardwareKeyboard.instance.isControlPressed;

lib/src/utils/web/web.dart

@@ -0,0 +1 @@
+final isApple = false;

lib/src/widgets/pdf_viewer.dart

@@ -1,7 +1,6 @@
 // ignore_for_file: public_member_api_docs
 import 'dart:async';
 import 'dart:collection';
-import 'dart:io';
 import 'dart:math';
 import 'dart:ui' as ui;
 
@@ -15,6 +14,7 @@ import 'package:synchronized/extension.dart';
 import 'package:vector_math/vector_math_64.dart' as vec;
 
 import '../../pdfrx.dart';
+import '../utils/platform.dart';
 import 'interactive_viewer.dart' as iv;
 import 'pdf_error_widget.dart';
 import 'pdf_page_links_overlay.dart';
@@ -496,12 +496,6 @@ class _PdfViewerState extends State<PdfViewer> with SingleTickerProviderStateMix
   /// Last page number that is explicitly requested to go to.
   int? _gotoTargetPageNumber;
 
-  /// Key pressing state of ⌘ or Control depending on the platform.
-  static bool get _isCommandKeyPressed =>
-      Platform.isMacOS || Platform.isIOS
-          ? HardwareKeyboard.instance.isMetaPressed
-          : HardwareKeyboard.instance.isControlPressed;
-
   KeyEventResult _onKeyEvent(FocusNode node, KeyEvent event) {
     final isDown = event is KeyDownEvent;
     switch (event.logicalKey) {
@@ -526,12 +520,12 @@ class _PdfViewerState extends State<PdfViewer> with SingleTickerProviderStateMix
         }
         return KeyEventResult.handled;
       case LogicalKeyboardKey.equal:
-        if (isDown && _isCommandKeyPressed) {
+        if (isDown && isCommandKeyPressed) {
           _zoomUp();
         }
         return KeyEventResult.handled;
       case LogicalKeyboardKey.minus:
-        if (isDown && _isCommandKeyPressed) {
+        if (isDown && isCommandKeyPressed) {
           _zoomDown();
         }
         return KeyEventResult.handled;