Adds in SNBT Editing support

lib/pages/SNBTEditor.dart

@@ -0,0 +1,66 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_code_editor/flutter_code_editor.dart';
+import 'package:flutter_highlight/themes/vs.dart';
+import 'package:libac_dart/nbt/SnbtIo.dart';
+import 'package:libac_dart/nbt/impl/CompoundTag.dart';
+import 'package:nbteditor/Constants.dart';
+import 'package:nbteditor/SessionData.dart';
+
+class SnbtEdit extends StatefulWidget {
+  @override
+  State<StatefulWidget> createState() {
+    return SnbtState();
+  }
+}
+
+class SnbtState extends State<SnbtEdit> {
+  CodeController snbt = CodeController();
+
+  @override
+  void didChangeDependencies() {
+    snbt.text = SnbtIo.writeToString(SessionData.ROOT_TAG);
+
+    setState(() {});
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text("SNBT Editor"),
+        backgroundColor: Constants.TITLEBAR_COLOR,
+      ),
+      floatingActionButton: ElevatedButton(
+        onPressed: () async {
+          try {
+            CompoundTag ct =
+                (await SnbtIo.readFromString(snbt.text)).asCompoundTag();
+            snbt.text = SnbtIo.writeToString(ct);
+
+            setState(() {
+              SessionData.ROOT_TAG = ct;
+            });
+
+            ScaffoldMessenger.of(context).showSnackBar(
+                SnackBar(content: Text("Successfully edited NBT data")));
+          } catch (E) {
+            ScaffoldMessenger.of(context).showSnackBar(SnackBar(
+                content: Text("FATAL ERROR: Your SNBT Syntax is not valid")));
+          }
+        },
+        child: Text("Compile"),
+      ),
+      body: Padding(
+        padding: EdgeInsets.all(8),
+        child: CodeTheme(
+          data: CodeThemeData(styles: vsTheme),
+          child: SingleChildScrollView(
+            child: CodeField(
+              controller: snbt,
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}