Licenses (#19)

## Purpose

Add licenses attribution.

## Changes

- Added a button for displaying app about page ( + license page), from
the material library.
- Added a script that can check licenses in dependencies.
- Added check to CI that only approved licenses are being used. 

## Checklist

- [x] My code follows the style of this project.
- [x] The code compiles without warnings.
- [x] I have performed a self-review of the changes.
- [x] I have documented my code, in particular the intent of the
      hard-to-understand areas.
- [ ] (If necessary) I have updated the CHANGELOG.

.github/workflows/ci.yml

@@ -14,6 +14,24 @@ env:
     flutter_version: 3.13.6
 
 jobs:
+    check-licenses:
+        runs-on: ubuntu-22.04
+        steps:
+            - name: Checkout repository
+              uses: actions/checkout@v4
+
+            - name: Setup Flutter
+              uses: subosito/flutter-action@v2
+              with:
+                flutter-version: ${{ env.flutter_version }}
+                channel: 'stable'
+                cache: true
+
+            - run: dart pub get
+
+            - name: Check licenses
+              run: dart run scripts/check_license.dart
+
     analyze-format:
         runs-on: ubuntu-22.04
         steps:

README.md

@@ -19,3 +19,12 @@ See for example [`wallet_proxy/model.dart`](./lib/services/wallet_proxy/model.da
 which expands into [`wallet_proxy/model.g.dart`](./lib/services/wallet_proxy/model.g.dart).
 
 The generated class is checked into the repo, but imports always refer to the original one.
+
+## Licenses
+
+To see the allowed licenses, check out `scripts/license.yaml`.
+
+To get a (readable) list of the licenses of dependencies run:
+```
+dart run license_checker check-licenses --config scripts/license.yaml
+```

lib/screens/home/about_button.dart

@@ -0,0 +1,28 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_svg/flutter_svg.dart';
+import 'package:package_info_plus/package_info_plus.dart';
+
+/// Button that when pressed shows the about page for the app, including the license page.
+class AboutButton extends StatelessWidget {
+  const AboutButton({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return ElevatedButton(
+      onPressed: () {
+        PackageInfo.fromPlatform().then((packageInfo) {
+          showAboutDialog(
+            context: context,
+            applicationName: packageInfo.appName,
+            applicationVersion: packageInfo.version,
+            applicationIcon: SvgPicture.asset(
+              'assets/graphics/CCD.svg',
+              semanticsLabel: 'CCD Logo',
+            ),
+          );
+        });
+      },
+      child: const Text('Show About'),
+    );
+  }
+}

lib/screens/home/screen.dart

@@ -1,3 +1,4 @@
+import 'package:concordium_wallet/screens/home/about_button.dart';
 import 'package:concordium_wallet/screens/terms_and_conditions/screen.dart';
 import 'package:concordium_wallet/services/url_launcher.dart';
 import 'package:concordium_wallet/services/wallet_proxy/service.dart';
@@ -79,6 +80,8 @@ class _HomeScreenState extends State<HomeScreen> {
                     ],
                   ),
                 ),
+                const AboutButton(),
+                const SizedBox(height: 8),
                 ElevatedButton(
                   onPressed: () => context.read<TermsAndConditionAcceptance>().testResetValidTime(),
                   child: const Text('Reset update time of valid T&C'),