[iOS] Fix: Converting from WebP causes app crash (#222)

Author: novikov-studio

example/img/icon.webp

@@ -10,4 +10,6 @@ class R {
 
   static const String IMG_TRANSPARENT_BACKGROUND_PNG =
       'img/transparent-background.png';
+
+  static const String IMG_ICON_WEBP = 'img/icon.webp';
 }

example/lib/const/resource.dart

@@ -287,6 +287,18 @@ class _MyAppState extends State<MyApp> {
     });
   }
 
+  void _compressFromWebPImage() async {
+    // Converting webp to jpeg
+    final result = await FlutterImageCompress.compressAssetImage(
+      R.IMG_ICON_WEBP,
+    );
+    if (result == null) return;
+    // Show result image
+    safeSetState(() {
+      provider = MemoryImage(typed_data.Uint8List.fromList(result));
+    });
+  }
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
@@ -372,6 +384,12 @@ class _MyAppState extends State<MyApp> {
                 onPressed: _compressAndroidWebpExample,
               ),
             ),
+            SliverToBoxAdapter(
+              child: TextButton(
+                child: Text('Convert from webp format'),
+                onPressed: _compressFromWebPImage,
+              ),
+            ),
           ],
         ),
         floatingActionButton: FloatingActionButton(

example/lib/main.dart

@@ -4,6 +4,7 @@
 
 #import "CompressHandler.h"
 #import "UIImage+scale.h"
+#import "UIImage+WebP.h"
 #import "ImageCompressPlugin.h"
 #import <SDWebImageWebPCoder/SDImageWebPCoder.h>
 
@@ -13,7 +14,7 @@ @implementation CompressHandler {
 
 + (NSData *)compressWithData:(NSData *)data minWidth:(int)minWidth minHeight:(int)minHeight quality:(int)quality
                       rotate:(int)rotate format:(int)format {
-    UIImage *img = [[UIImage alloc] initWithData:data];
+    UIImage *img = [self isWebP:data] ? [UIImage sd_imageWithWebPData:data] : [[UIImage alloc] initWithData:data];
     return [CompressHandler compressWithUIImage:img minWidth:minWidth minHeight:minHeight quality:quality rotate:rotate format:format];
 }
 
@@ -80,4 +81,13 @@ + (NSData *)compressDataWithImage:(UIImage *)image quality:(float)quality format
     return data;
 }
 
++ (BOOL)isWebP:(NSData *)data {
+    if (data.length < 12) return false;
+
+    NSData *riff = [data subdataWithRange:NSMakeRange(8, 4)];
+    NSString* format = [[NSString alloc] initWithData:riff encoding:(NSASCIIStringEncoding)];
+
+    return [format isEqualToString:@"WEBP"];
+}
+
 @end