refactor: ImageConversionException

lib/platform_image_converter.dart

@@ -10,6 +10,7 @@ import 'package:platform_image_converter/src/output_format.dart';
 import 'package:platform_image_converter/src/output_resize.dart';
 import 'package:platform_image_converter/src/web/shared.dart';
 
+export 'src/image_conversion_exception.dart';
 export 'src/output_format.dart';
 export 'src/output_resize.dart';
 
@@ -42,8 +43,9 @@ class ImageConverter {
   ///
   /// **Throws:**
   /// - [UnsupportedError]: If the platform or output format is not supported.
-  /// - [Exception]: If the image decoding or encoding fails.
+  /// - [ImageDecodingException]: If the input image data cannot be decoded.
-  ///
+  /// - [ImageEncodingException]: If the image cannot be encoded to the target format.
+  /// - [ImageConversionException]: For other general errors during the conversion process.  ///
   /// **Example - Convert HEIC to JPEG:**
   /// ```dart
   /// final jpegData = await ImageConverter.convert(

lib/src/android/native.dart

@@ -2,6 +2,7 @@ import 'dart:typed_data';
 
 import 'package:jni/jni.dart';
 import 'package:platform_image_converter/src/android/bindings.g.dart';
+import 'package:platform_image_converter/src/image_conversion_exception.dart';
 import 'package:platform_image_converter/src/image_converter_platform_interface.dart';
 import 'package:platform_image_converter/src/output_format.dart';
 import 'package:platform_image_converter/src/output_resize.dart';
@@ -54,7 +55,7 @@ final class ImageConverterAndroid implements ImageConverterPlatform {
         inputData.length,
       );
       if (originalBitmap == null) {
-        throw Exception('Failed to decode image. Invalid image data.');
+        throw const ImageDecodingException('Invalid image data.');
       }
 
       final originalWidth = originalBitmap.getWidth();
@@ -78,7 +79,9 @@ final class ImageConverterAndroid implements ImageConverterPlatform {
 
       if (bitmapToCompress == null) {
         // This should not happen if originalBitmap is valid
-        throw Exception('Bitmap could not be prepared for compression.');
+        throw const ImageConversionException(
+          'Bitmap could not be prepared for compression.',
+        );
       }
 
       compressFormat = switch (format) {
@@ -98,12 +101,15 @@ final class ImageConverterAndroid implements ImageConverterPlatform {
         outputStream,
       );
       if (!success) {
-        throw Exception('Failed to compress bitmap.');
+        throw ImageEncodingException(format, 'Failed to compress bitmap.');
       }
 
       outputJBytes = outputStream.toByteArray();
       if (outputJBytes == null) {
-        throw Exception('Failed to get byte array from output stream.');
+        throw ImageEncodingException(
+          format,
+          'Failed to get byte array from output stream.',
+        );
       }
 
       return Uint8List.fromList(outputJBytes.toList());

lib/src/darwin/native.dart

@@ -4,6 +4,7 @@ import 'dart:typed_data';
 import 'package:ffi/ffi.dart';
 import 'package:objective_c/objective_c.dart';
 import 'package:platform_image_converter/src/darwin/bindings.g.dart';
+import 'package:platform_image_converter/src/image_conversion_exception.dart';
 import 'package:platform_image_converter/src/image_converter_platform_interface.dart';
 import 'package:platform_image_converter/src/output_format.dart';
 import 'package:platform_image_converter/src/output_resize.dart';
@@ -60,17 +61,19 @@ final class ImageConverterDarwin implements ImageConverterPlatform {
         inputData.length,
       );
       if (cfData == nullptr) {
-        throw Exception('Failed to create CFData from input data.');
+        throw const ImageConversionException(
+          'Failed to create CFData from input data.',
+        );
       }
 
       imageSource = CGImageSourceCreateWithData(cfData, nullptr);
       if (imageSource == nullptr) {
-        throw Exception('Failed to create CGImageSource. Invalid image data.');
+        throw const ImageDecodingException('Invalid image data.');
       }
 
       originalImage = CGImageSourceCreateImageAtIndex(imageSource, 0, nullptr);
       if (originalImage == nullptr) {
-        throw Exception('Failed to decode image.');
+        throw const ImageDecodingException();
       }
 
       final originalWidth = CGImageGetWidth(originalImage);
@@ -87,12 +90,14 @@ final class ImageConverterDarwin implements ImageConverterPlatform {
       }
 
       if (imageToEncode == nullptr) {
-        throw Exception('Failed to prepare image for encoding.');
+        throw const ImageConversionException(
+          'Failed to prepare image for encoding. Resizing may have failed.',
+        );
       }
 
       outputData = CFDataCreateMutable(kCFAllocatorDefault, 0);
       if (outputData == nullptr) {
-        throw Exception('Failed to create output CFData.');
+        throw ImageEncodingException(format, 'Failed to create output CFData.');
       }
 
       final utiStr = switch (format) {
@@ -120,7 +125,10 @@ final class ImageConverterDarwin implements ImageConverterPlatform {
         nullptr,
       );
       if (destination == nullptr) {
-        throw Exception('Failed to create CGImageDestination.');
+        throw ImageEncodingException(
+          format,
+          'Failed to create CGImageDestination.',
+        );
       }
 
       properties = _createPropertiesForFormat(format, quality);
@@ -132,13 +140,19 @@ final class ImageConverterDarwin implements ImageConverterPlatform {
 
       final success = CGImageDestinationFinalize(destination);
       if (!success) {
-        throw Exception('Failed to finalize image encoding.');
+        throw ImageEncodingException(
+          format,
+          'Failed to finalize image encoding.',
+        );
       }
 
       final length = CFDataGetLength(outputData);
       final bytePtr = CFDataGetBytePtr(outputData);
       if (bytePtr == nullptr) {
-        throw Exception('Failed to get output data bytes.');
+        throw ImageEncodingException(
+          format,
+          'Failed to get output data bytes.',
+        );
       }
 
       return Uint8List.fromList(bytePtr.cast<Uint8>().asTypedList(length));
@@ -193,7 +207,9 @@ final class ImageConverterDarwin implements ImageConverterPlatform {
     try {
       final colorSpace = CGImageGetColorSpace(originalImage);
       if (colorSpace == nullptr) {
-        throw Exception('Failed to get color space from image.');
+        throw const ImageConversionException(
+          'Failed to get color space from image for resizing.',
+        );
       }
 
       final bitsPerComponent = CGImageGetBitsPerComponent(originalImage);
@@ -209,7 +225,9 @@ final class ImageConverterDarwin implements ImageConverterPlatform {
         bitmapInfo,
       );
       if (context == nullptr) {
-        throw Exception('Failed to create bitmap context for resizing.');
+        throw const ImageConversionException(
+          'Failed to create bitmap context for resizing.',
+        );
       }
 
       CGContextSetInterpolationQuality(
@@ -227,7 +245,9 @@ final class ImageConverterDarwin implements ImageConverterPlatform {
 
       final resizedImage = CGBitmapContextCreateImage(context);
       if (resizedImage == nullptr) {
-        throw Exception('Failed to create resized image from context.');
+        throw const ImageConversionException(
+          'Failed to create resized image from context.',
+        );
       }
       return resizedImage;
     } finally {

lib/src/image_conversion_exception.dart

@@ -0,0 +1,30 @@
+import 'package:platform_image_converter/src/output_format.dart';
+
+/// Base exception for image conversion errors.
+class ImageConversionException implements Exception {
+  /// Creates an [ImageConversionException] with the given [message].
+  const ImageConversionException(this.message);
+
+  /// Error message describing the exception.
+  final String message;
+
+  @override
+  String toString() => 'ImageConversionException: $message';
+}
+
+/// Thrown when the input image data cannot be decoded.
+class ImageDecodingException extends ImageConversionException {
+  /// Creates an [ImageDecodingException] with the given [message].
+  const ImageDecodingException([
+    super.message = 'Failed to decode image data.',
+  ]);
+}
+
+/// Thrown when the image cannot be encoded to the target format.
+class ImageEncodingException extends ImageConversionException {
+  /// Creates an [ImageEncodingException] with the given [message].
+  ImageEncodingException(this.format, [String? message])
+      : super(message ?? 'Failed to encode image to ${format.name}');
+
+  final OutputFormat format;
+}

lib/src/image_converter_platform_interface.dart

@@ -1,7 +1,7 @@
 import 'dart:typed_data';
 
-import 'output_format.dart';
+import 'package:platform_image_converter/src/output_format.dart';
-import 'output_resize.dart';
+import 'package:platform_image_converter/src/output_resize.dart';
 
 /// Platform-specific image converter interface.
 ///
@@ -27,7 +27,9 @@ abstract interface class ImageConverterPlatform {
   /// **Throws:**
   /// - [UnimplementedError]: If not implemented by platform subclass
   /// - [UnsupportedError]: If format is not supported
-  /// - [Exception]: If conversion fails
+  /// - [ImageDecodingException]: If the input image data cannot be decoded.
+  /// - [ImageEncodingException]: If the image cannot be encoded to the target format.
+  /// - [ImageConversionException]: For other general errors during the conversion process.
   Future<Uint8List> convert({
     required Uint8List inputData,
     OutputFormat format = OutputFormat.jpeg,

lib/src/web/web.dart

@@ -2,6 +2,7 @@ import 'dart:async';
 import 'dart:js_interop';
 import 'dart:typed_data';
 
+import 'package:platform_image_converter/src/image_conversion_exception.dart';
 import 'package:platform_image_converter/src/image_converter_platform_interface.dart';
 import 'package:platform_image_converter/src/output_format.dart';
 import 'package:platform_image_converter/src/output_resize.dart';
@@ -45,17 +46,24 @@ final class ImageConverterWeb implements ImageConverterPlatform {
   }) async {
     final img = HTMLImageElement();
     final decodeCompleter = Completer<void>();
-
     final blob = Blob([inputData.toJS].toJS);
     final url = URL.createObjectURL(blob);
-    img.onLoad.listen((_) => decodeCompleter.complete());
+    img
-    img.onError.listen((e) {
+      ..onLoad.listen((_) {
-      URL.revokeObjectURL(url);
+        decodeCompleter.complete();
-      decodeCompleter.completeError('Failed to load image: $e');
+      })
+      ..onError.listen((event) {
+        decodeCompleter.completeError(
+          const ImageDecodingException('Failed to load image from data.'),
+        );
       });
     img.src = url;
+
+    try {
       await decodeCompleter.future;
+    } finally {
       URL.revokeObjectURL(url);
+    }
 
     final canvas = HTMLCanvasElement();
 
@@ -86,7 +94,7 @@ final class ImageConverterWeb implements ImageConverterPlatform {
           encodeCompleter.complete(blob);
         } else {
           encodeCompleter.completeError(
-            'Failed to convert canvas to JPEG Blob.',
+            ImageEncodingException(format, 'Canvas toBlob returned null.'),
           );
         }
       }.toJS,