Fix copy Image to Clipboard not works on web

lib/components/image.dart

@@ -1,16 +1,27 @@
-import 'dart:typed_data';
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:logging/logging.dart';
 import 'package:super_clipboard/super_clipboard.dart';
 import 'package:super_context_menu/super_context_menu.dart';
+import '../platform/to_png_none.dart'
+    if (dart.library.html) '../platform/to_png.dart';
 
 final _log = Logger("ImageWithContextMenu");
 
+enum ImageFmt {
+  jpg,
+  png,
+  gif,
+}
+
 class ImageWithContextMenu extends StatelessWidget {
-  const ImageWithContextMenu(this.data, {Key? key, this.uri}) : super(key: key);
+  const ImageWithContextMenu(this.data,
+      {Key? key, this.uri, this.fmt = ImageFmt.jpg})
+      : super(key: key);
   final Uint8List data;
   final String? uri;
+  final ImageFmt fmt;
   @override
   Widget build(BuildContext context) {
     return ContextMenuWidget(
@@ -18,12 +29,21 @@ class ImageWithContextMenu extends StatelessWidget {
           var list = [
             MenuAction(
                 title: AppLocalizations.of(context)!.copyImage,
-                callback: () {
+                callback: () async {
-                  final item = DataWriterItem();
+                  try {
-                  item.add(Formats.jpeg(data));
+                    final item = DataWriterItem();
-                  ClipboardWriter.instance.write([item]).catchError((err) {
+                    if (!kIsWeb) {
+                      item.add(fmt == ImageFmt.jpg
+                          ? Formats.jpeg(data)
+                          : Formats.png(data));
+                    } else {
+                      item.add(Formats.png(
+                          fmt == ImageFmt.jpg ? await jpgToPng(data) : data));
+                    }
+                    await ClipboardWriter.instance.write([item]);
+                  } catch (err) {
                     _log.warning("Failed to copy image to clipboard:", err);
-                  });
+                  }
                 })
           ];
           if (uri != null) {

lib/platform/to_png.dart

@@ -0,0 +1,6 @@
+import 'dart:typed_data';
+import 'package:image/image.dart';
+
+Future<Uint8List> jpgToPng(Uint8List data) async {
+  return  encodePng(decodeJpg(data)!);
+}

lib/platform/to_png_none.dart

@@ -0,0 +1,5 @@
+import 'dart:typed_data';
+
+Future<Uint8List> jpgToPng(Uint8List data) async {
+  throw UnimplementedError();
+}

pubspec.lock

@@ -17,6 +17,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "6.2.0"
+  archive:
+    dependency: transitive
+    description:
+      name: archive
+      sha256: "49b1fad315e57ab0bbc15bcbb874e83116a1d78f77ebd500a4af6c9407d6b28e"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.3.8"
   args:
     dependency: transitive
     description:
@@ -382,6 +390,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "4.0.2"
+  image:
+    dependency: "direct main"
+    description:
+      name: image
+      sha256: a72242c9a0ffb65d03de1b7113bc4e189686fc07c7147b8b41811d0dd0e0d9bf
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.0.17"
   infinite_scroll_pagination:
     dependency: "direct main"
     description:
@@ -558,6 +574,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.2.1"
+  petitparser:
+    dependency: transitive
+    description:
+      name: petitparser
+      sha256: cb3798bef7fc021ac45b308f4b51208a152792445cce0448c9a4ba5879dd8750
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.4.0"
   pixel_snap:
     dependency: transitive
     description:
@@ -582,6 +606,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.1.6"
+  pointycastle:
+    dependency: transitive
+    description:
+      name: pointycastle
+      sha256: "7c1e5f0d23c9016c5bbd8b1473d0d3fb3fc851b876046039509e18e0c7485f2c"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.7.3"
   pool:
     dependency: transitive
     description:
@@ -915,6 +947,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.0.3"
+  xml:
+    dependency: transitive
+    description:
+      name: xml
+      sha256: "5bc72e1e45e941d825fd7468b9b4cc3b9327942649aeb6fc5cdbf135f0a86e84"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.0"
   yaml:
     dependency: transitive
     description:

pubspec.yaml

@@ -23,6 +23,7 @@ dependencies:
   flutter_web_plugins:
     sdk: flutter
   go_router: ^10.1.0
+  image: ^4.0.17
   infinite_scroll_pagination: ^4.0.0
   intl: any
   json_annotation: ^4.8.1