feat: Navigate in image viewer with keyboard keys

lib/pages/image_viewer/image_viewer.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 
 import 'package:matrix/matrix.dart';
 
@@ -26,6 +27,8 @@ class ImageViewer extends StatefulWidget {
 }
 
 class ImageViewerController extends State<ImageViewer> {
+  final FocusNode focusNode = FocusNode();
+
   @override
   void initState() {
     super.initState();
@@ -45,6 +48,17 @@ class ImageViewerController extends State<ImageViewer> {
 
   late final List<Event> allEvents;
 
+  void onKeyEvent(KeyEvent event) {
+    switch (event.logicalKey) {
+      case LogicalKeyboardKey.arrowLeft:
+        if (canGoBack) prevImage();
+        break;
+      case LogicalKeyboardKey.arrowRight:
+        if (canGoNext) nextImage();
+        break;
+    }
+  }
+
   void prevImage() async {
     await pageController.previousPage(
       duration: FluffyThemes.animationDuration,

lib/pages/image_viewer/image_viewer_view.dart

@@ -69,7 +69,10 @@ class ImageViewerView extends StatelessWidget {
         body: HoverBuilder(
           builder: (context, hovered) => Stack(
             children: [
-              PageView.builder(
+              KeyboardListener(
+                focusNode: controller.focusNode,
+                onKeyEvent: controller.onKeyEvent,
+                child: PageView.builder(
                   controller: controller.pageController,
                   itemCount: controller.allEvents.length,
                   itemBuilder: (context, i) => InteractiveViewer(
@@ -94,6 +97,7 @@ class ImageViewerView extends StatelessWidget {
                     ),
                   ),
                 ),
+              ),
               if (hovered && controller.canGoBack)
                 Align(
                   alignment: Alignment.centerLeft,