fix: 🚑 Enable dart 3 support in example app

- Fix action data access in showcase_controller.dart.

Author: aditya-css

example/pubspec.yaml

@@ -3,7 +3,7 @@ description: An example application to demonstrate showcaseview package.
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.18.0 <4.0.0"
+  sdk: ">=3.0.0 <4.0.0"
 
 publish_to: none
 
@@ -21,4 +21,4 @@ dev_dependencies:
 flutter:
   uses-material-design: true
   assets:
-    - assets/
+    - assets/

lib/src/showcase/showcase_controller.dart

@@ -399,7 +399,7 @@ class ShowcaseController {
         ? config.tooltipActions!
         : showcaseView.globalTooltipActions ?? [];
     final actionDataLength = actionData.length;
-    final lastAction = actionData.last;
+    final lastAction = actionData.lastOrNull;
     final actionGap = _getTooltipActionConfig().actionGap;
 
     return [

lib/src/showcase/showcase_view.dart

@@ -22,11 +22,11 @@
 import 'dart:async';
 
 import 'package:flutter/material.dart';
-import 'package:showcaseview/src/utils/enum.dart';
 
 import '../models/tooltip_action_button.dart';
 import '../models/tooltip_action_config.dart';
 import '../utils/constants.dart';
+import '../utils/enum.dart';
 import '../utils/overlay_manager.dart';
 import '../widget/floating_action_widget.dart';
 import 'showcase_controller.dart';