null safety

lib/pages/widgets/multi_img_file.dart

@@ -8,7 +8,7 @@ import 'package:fcs/pages/widgets/show_img.dart';
 import 'package:fcs/pages/widgets/show_multiple_img.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:image_picker/image_picker.dart';
 
@@ -18,13 +18,13 @@ import 'multi_img_controller.dart';
 typedef OnFile = void Function(File);
 
 class MultiImageFile extends StatefulWidget {
-  final String title;
+  final String? title;
   final bool enabled;
   final ImageSource imageSource;
-  final MultiImgController controller;
+  final MultiImgController? controller;
 
   const MultiImageFile(
-      {Key key,
+      {Key? key,
       this.title,
       this.enabled = true,
       this.controller,
@@ -39,10 +39,10 @@ class _MultiImageFileState extends State<MultiImageFile> {
   @override
   void initState() {
     super.initState();
-    fileContainers = widget.controller.fileContainers;
-    widget.controller.onChange(() {
+    fileContainers = widget.controller!.fileContainers;
+    widget.controller!.onChange(() {
       setState(() {
-        this.fileContainers = widget.controller.fileContainers;
+        this.fileContainers = widget.controller!.fileContainers;
       });
     });
   }
@@ -133,7 +133,7 @@ class _MultiImageFileState extends State<MultiImageFile> {
                               fit: BoxFit.cover,
                               width: 50,
                               height: 50,
-                              imageUrl: fileContainers[index].url,
+                              imageUrl: fileContainers[index].url!,
                               placeholder: (context, url) => Column(
                                 mainAxisAlignment: MainAxisAlignment.center,
                                 mainAxisSize: MainAxisSize.min,
@@ -150,7 +150,7 @@ class _MultiImageFileState extends State<MultiImageFile> {
                           : FittedBox(
                               fit: BoxFit.cover,
                               child: Image.file(
-                                fileContainers[index].file,
+                                fileContainers[index].file!,
                               ),
                             ),
                     ),
@@ -189,13 +189,13 @@ class _MultiImageFileState extends State<MultiImageFile> {
     fileContainer.file = selectedFile;
     setState(() {
       fileContainers.add(fileContainer);
-      widget.controller.addFile = fileContainer;
+      widget.controller!.addFile = fileContainer;
     });
   }
 
   _fileRemove(DisplayImageSource fileContainer) {
     setState(() {
-      widget.controller.removeFile = fileContainer;
+      widget.controller!.removeFile = fileContainer;
     });
   }
 
@@ -232,11 +232,11 @@ class _MultiImageFileState extends State<MultiImageFile> {
                     context,
                     MaterialPageRoute(
                         builder: (context) => ShowImage(
-                            imageFile: fileContainer.file,
+                            imageFile: fileContainer.file!,
                             url: fileContainer.file == null
-                                ? fileContainer.url
-                                : null,
-                            fileName: widget.title)),
+                                ? fileContainer.url!
+                                : '',
+                            fileName: widget.title!)),
                   )
                 },
                 child: Chip(
@@ -249,7 +249,7 @@ class _MultiImageFileState extends State<MultiImageFile> {
                   deleteIcon: Icon(
                     Icons.close,
                   ),
-                  label: Text(widget.title + " - ${index + 1}"),
+                  label: Text("${widget.title}" + " - ${index + 1}"),
                 ),
               ),
             ),
@@ -308,7 +308,7 @@ class _MultiImageFileState extends State<MultiImageFile> {
     );
   }
 
-  Widget actionIcon({OnTap onTap, Color color, IconData iconData}) {
+  Widget actionIcon({OnTap? onTap, Color? color, IconData? iconData}) {
     return InkWell(
       onTap: onTap,
       child: ClipOval(