backup. before shop update

lib/dialog/image_viewer.dart

@@ -0,0 +1,31 @@
+
+import 'package:flutter/material.dart';
+import 'package:photo_view/photo_view.dart';
+
+class ImageViewer extends StatefulWidget {
+  final Key key;
+  final ImageProvider imageProvider;
+
+  ImageViewer(this.imageProvider, {this.key}) :
+      super(key: key);
+
+  @override
+  State<StatefulWidget> createState() {
+    return ImageViewState();
+  }
+
+}
+
+class ImageViewState extends State<ImageViewer> {
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      width: MediaQuery.of(context).size.width - 100.0,
+      height: MediaQuery.of(context).size.height - 120.0,
+      child: PhotoView(
+        imageProvider: widget.imageProvider,
+      ),
+    );
+  }
+
+}