upgrade image picker

lib/src/widgets/check_dialog.dart

@@ -3,7 +3,7 @@ import 'package:flutter/material.dart';
 import 'custom_dialog_template.dart';
 
 class CheckDialog extends StatelessWidget {
-  TextEditingController text = TextEditingController();
+  final TextEditingController text = TextEditingController();
 
   @override
   Widget build(BuildContext context) {

lib/src/widgets/color_picker_dialog.dart

@@ -36,6 +36,7 @@ class _ColorPickerDialogState extends State<ColorPickerDialog> {
           enableAlpha: true,
           displayThumbColor: true,
           showLabel: true,
+          
           paletteType: PaletteType.hsv,
           pickerAreaBorderRadius: const BorderRadius.only(
             topLeft: const Radius.circular(2.0),

lib/src/widgets/font_size_dialog.dart

@@ -3,7 +3,7 @@ import 'package:flutter/material.dart';
 import 'html_text.dart';
 
 class FontSizeDialog extends StatelessWidget {
-  List formats = [
+  final List formats = [
     {'id': '1', 'title': '<small><small><small>Teeny</small></small></small>'},
     {'id': '2', 'title': '<small><small>Very small</small></small>'},
     {'id': '3', 'title': '<small>Small</small>'},

lib/src/widgets/heading_dialog.dart

@@ -3,7 +3,7 @@ import 'package:flutter/material.dart';
 import 'html_text.dart';
 
 class HeadingDialog extends StatelessWidget {
-  List formats = [
+  final List formats = [
     {'id': '1', 'title': '<h1>Heading 1</h1>'},
     {'id': '2', 'title': '<h2>Heading 2</h2>'},
     {'id': '3', 'title': '<h3>Heading 3</h3>'},

lib/src/widgets/insert_link_dialog.dart

@@ -3,8 +3,8 @@ import 'package:flutter/material.dart';
 import 'custom_dialog_template.dart';
 
 class InsertLinkDialog extends StatelessWidget {
-  TextEditingController link = TextEditingController();
-  TextEditingController label = TextEditingController();
+  final TextEditingController link = TextEditingController();
+  final TextEditingController label = TextEditingController();
 
   @override
   Widget build(BuildContext context) {