fix: Image viewer routing

lib/pages/image_viewer.dart

@@ -25,7 +25,7 @@ class ImageViewerController extends State<ImageViewer> {
   }
 
   /// Open this file with a system call.
-  void openFileAction() => widget.event.openFile(context, downloadOnly: true);
+  void openFileAction() => widget.event.openFile(context);
 
   /// Go back if user swiped it away
   void onInteractionEnds(ScaleEndDetails endDetails) {

lib/utils/matrix_sdk_extensions.dart/event_extension.dart

@@ -4,18 +4,9 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_cache_manager/flutter_cache_manager.dart';
 import 'matrix_file_extension.dart';
-import '../../pages/image_viewer.dart';
-import '../../widgets/matrix.dart';
 
 extension LocalizedBody on Event {
-  void openFile(BuildContext context, {bool downloadOnly = false}) async {
-    if (!downloadOnly &&
-        [MessageTypes.Image, MessageTypes.Sticker].contains(messageType)) {
-      await Navigator.of(Matrix.of(context).navigatorContext).push(
-        MaterialPageRoute(builder: (_) => ImageViewer(this)),
-      );
-      return;
-    }
+  void openFile(BuildContext context) async {
     final matrixFile = await showFutureLoadingDialog(
       context: context,
       future: () => downloadAndDecryptAttachmentCached(),

lib/widgets/event_content/image_bubble.dart

@@ -7,7 +7,6 @@ import 'package:cached_network_image/cached_network_image.dart';
 import 'package:flutter_svg/flutter_svg.dart';
 
 import '../../utils/matrix_sdk_extensions.dart/event_extension.dart';
-import '../matrix.dart';
 
 class ImageBubble extends StatefulWidget {
   final Event event;
@@ -238,22 +237,21 @@ class _ImageBubbleState extends State<ImageBubble> {
       child: InkWell(
         onTap: () {
           if (!widget.tapToView) return;
-          Navigator.of(Matrix.of(context).navigatorContext).push(
-            MaterialPageRoute(
-              builder: (_) => ImageViewer(widget.event, onLoaded: () {
-                // If the original file didn't load yet, we want to do that now.
-                // This is so that the original file displays after going on the image viewer,
-                // waiting for it to load, and then hitting back. This ensures that we always
-                // display the best image available, with requiring as little network as possible
-                if (_file == null) {
-                  widget.event.isAttachmentCached().then((cached) {
-                    if (cached) {
-                      _requestFile();
-                    }
-                  });
-                }
-              }),
-            ),
+          showDialog(
+            context: context,
+            builder: (_) => ImageViewer(widget.event, onLoaded: () {
+              // If the original file didn't load yet, we want to do that now.
+              // This is so that the original file displays after going on the image viewer,
+              // waiting for it to load, and then hitting back. This ensures that we always
+              // display the best image available, with requiring as little network as possible
+              if (_file == null) {
+                widget.event.isAttachmentCached().then((cached) {
+                  if (cached) {
+                    _requestFile();
+                  }
+                });
+              }
+            }),
           );
         },
         child: Hero(