add photo viewer

example/lib/example_picker.dart

@@ -69,7 +69,7 @@ class _ExamplePickerState extends State<ExamplePicker> {
             trailing: ASButton(
               title: '图片选择器',
               onPressed: () async {
-                File file = await camView(context);
+                File file = await camView(context, title: '图片选择器');
               },
             ),
           ),

lib/ansu_ui.dart

@@ -1,6 +1,7 @@
 library ansu_ui;
 
 import 'dart:io';
+import 'dart:ui';
 
 import 'package:ansu_ui/bar/as_tab_indicator.dart';
 import 'package:ansu_ui/painters/as_numeric_painter.dart';
@@ -11,7 +12,6 @@ import 'package:flutter_screenutil/flutter_screenutil.dart';
 import 'package:flutter_easyrefresh/easy_refresh.dart';
 import 'package:image_picker/image_picker.dart';
 import 'package:bot_toast/bot_toast.dart';
-
 export 'package:flutter_screenutil/flutter_screenutil.dart';
 export 'package:flutter_easyrefresh/easy_refresh.dart';
 export 'package:bot_toast/bot_toast.dart';
@@ -64,7 +64,9 @@ part 'divider/as_divider.dart';
 part 'text_field/as_search_text_field.dart';
 
 part 'utils/screen_adapter.dart';
-part 'utils/camera_util.dart';part 'utils/camera_view.dart';
+part 'utils/camera_util.dart';
+part 'utils/camera_view.dart';
+part 'utils/photo_viewer.dart';
 
 part 'extension/num_extension.dart';
 part 'extension/list_extension.dart';

lib/utils/camera_view.dart

@@ -23,7 +23,24 @@ class _CameraViewState extends State<CameraView> {
   Widget build(BuildContext context) {
     return ASScaffold(
       title: widget.title,
-      body: Image.file(widget.file, fit: BoxFit.cover),
+      body: BackdropFilter(
+        filter: ImageFilter.blur(sigmaX: 10, sigmaY: 10),
+        child: Container(
+          alignment: Alignment.center,
+          child: GestureDetector(
+            onTap: () {
+              toPhotoViewer(context, tag: widget.title, file: widget.file);
+            },
+            child: Hero(
+              child: Image.file(
+                widget.file,
+                fit: BoxFit.cover,
+              ),
+              tag: widget.title,
+            ),
+          ),
+        ),
+      ),
       bottomNavigationBar: Material(
         color: kForegroundColor,
         child: Column(
@@ -35,7 +52,9 @@ class _CameraViewState extends State<CameraView> {
               title: '重拍',
               onPressed: () async {
                 File file = await camFile();
-                if (file == null) Navigator.pop(context);
+                if (file == null)
+                  Navigator.pop(context);
+                else
                   Navigator.pushReplacement(context, PageRouteBuilder(
                     pageBuilder: (context, animation, secondAnimation) {
                       return FadeTransition(

lib/utils/photo_viewer.dart

@@ -0,0 +1,46 @@
+part of ansu_ui;
+
+class PhotoViewer extends StatefulWidget {
+  final File file;
+  final String tag;
+  PhotoViewer({Key key, this.file, this.tag}) : super(key: key);
+
+  @override
+  _PhotoViewerState createState() => _PhotoViewerState();
+}
+
+class _PhotoViewerState extends State<PhotoViewer> {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      backgroundColor: Colors.black54,
+      body: GestureDetector(
+        onTap: () => Navigator.pop(context),
+        child: Center(
+          child: InteractiveViewer(
+            boundaryMargin: 100.edge,
+            child: Hero(
+              tag: widget.tag,
+              child: Image.file(widget.file),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+toPhotoViewer(BuildContext context, {String tag, File file}) {
+  Navigator.push(
+    context,
+    PageRouteBuilder(
+      pageBuilder: (context, animation, secondAnimation) {
+        return PhotoViewer(file: file, tag: tag);
+      },
+      opaque: false,
+      transitionsBuilder: (context, animation, secondaryAnimation, child) {
+        return FadeTransition(opacity: animation, child: child);
+      },
+    ),
+  );
+}