fix hero tag duplicated

lib/src/giphy_attachment.dart

@@ -48,9 +48,8 @@ class GiphyAttachment extends StatelessWidget {
                 }));
               },
               child: Hero(
-                tag: attachment.imageUrl ??
-                    attachment.assetUrl ??
-                    attachment.thumbUrl,
+                tag:
+                    '${message.id} - ${attachment.imageUrl ?? attachment.assetUrl ?? attachment.thumbUrl}',
                 child: CachedNetworkImage(
                   height: size?.height,
                   width: size?.width,

lib/src/image_attachment.dart

@@ -9,12 +9,14 @@ import 'utils.dart';
 
 class ImageAttachment extends StatelessWidget {
   final Attachment attachment;
+  final Message message;
   final MessageTheme messageTheme;
   final Size size;
 
   const ImageAttachment({
     Key key,
-    this.attachment,
+    @required this.attachment,
+    @required this.message,
     this.messageTheme,
     this.size,
   }) : super(key: key);
@@ -36,9 +38,8 @@ class ImageAttachment extends StatelessWidget {
             children: <Widget>[
               Expanded(
                 child: Hero(
-                  tag: attachment.imageUrl ??
-                      attachment.assetUrl ??
-                      attachment.thumbUrl,
+                  tag:
+                      '${message.id} - ${attachment.imageUrl ?? attachment.assetUrl ?? attachment.thumbUrl}',
                   child: GestureDetector(
                     onTap: () {
                       Navigator.push(context, MaterialPageRoute(builder: (_) {

lib/src/message_widget.dart

@@ -137,6 +137,7 @@ class MessageWidget extends StatefulWidget {
           'image': (context, message, attachment) {
             return ImageAttachment(
               attachment: attachment,
+              message: message,
               messageTheme: messageTheme,
               size: Size(
                 MediaQuery.of(context).size.width * 0.8,

pubspec.yaml

@@ -10,7 +10,7 @@ dependencies:
   flutter:
     sdk: flutter
   photo_view: ^0.9.2
-  rxdart: ^0.24.0
+  rxdart: ^0.24.1
   jiffy: ^3.0.1
   flutter_portal: ^0.1.0
   cached_network_image: ^2.2.0+1