Added 'See Changes' button in app list (GitHub only)

lib/app_sources/fdroid.dart

@@ -23,6 +23,9 @@ class FDroid implements AppSource {
     return url.substring(0, match.end);
   }
 
+  @override
+  String? changeLogPageFromStandardUrl(String standardUrl) => null;
+
   @override
   Future<APKDetails> getLatestAPKDetails(
       String standardUrl, List<String> additionalData) async {

lib/app_sources/github.dart

@@ -29,6 +29,11 @@ class GitHub implements AppSource {
     return creds != null && creds.isNotEmpty ? '$creds@' : '';
   }
 
+  @override
+  String? changeLogPageFromStandardUrl(String standardUrl) {
+    return '$standardUrl/releases';
+  }
+
   @override
   Future<APKDetails> getLatestAPKDetails(
       String standardUrl, List<String> additionalData) async {

lib/app_sources/gitlab.dart

@@ -18,6 +18,9 @@ class GitLab implements AppSource {
     return url.substring(0, match.end);
   }
 
+  @override
+  String? changeLogPageFromStandardUrl(String standardUrl) => null;
+
   @override
   Future<APKDetails> getLatestAPKDetails(
       String standardUrl, List<String> additionalData) async {

lib/app_sources/izzyondroid.dart

@@ -17,6 +17,9 @@ class IzzyOnDroid implements AppSource {
     return url.substring(0, match.end);
   }
 
+  @override
+  String? changeLogPageFromStandardUrl(String standardUrl) => null;
+
   @override
   Future<APKDetails> getLatestAPKDetails(
       String standardUrl, List<String> additionalData) async {

lib/app_sources/mullvad.dart

@@ -17,6 +17,9 @@ class Mullvad implements AppSource {
     return url.substring(0, match.end);
   }
 
+  @override
+  String? changeLogPageFromStandardUrl(String standardUrl) => null;
+
   @override
   Future<APKDetails> getLatestAPKDetails(
       String standardUrl, List<String> additionalData) async {

lib/app_sources/signal.dart

@@ -12,6 +12,9 @@ class Signal implements AppSource {
     return 'https://$host';
   }
 
+  @override
+  String? changeLogPageFromStandardUrl(String standardUrl) => null;
+
   @override
   Future<APKDetails> getLatestAPKDetails(
       String standardUrl, List<String> additionalData) async {

lib/app_sources/sourceforge.dart

@@ -17,6 +17,9 @@ class SourceForge implements AppSource {
     return url.substring(0, match.end);
   }
 
+  @override
+  String? changeLogPageFromStandardUrl(String standardUrl) => null;
+
   @override
   Future<APKDetails> getLatestAPKDetails(
       String standardUrl, List<String> additionalData) async {

lib/pages/apps.dart

@@ -6,8 +6,10 @@ import 'package:obtainium/components/generated_form_modal.dart';
 import 'package:obtainium/pages/app.dart';
 import 'package:obtainium/providers/apps_provider.dart';
 import 'package:obtainium/providers/settings_provider.dart';
+import 'package:obtainium/providers/source_provider.dart';
 import 'package:provider/provider.dart';
 import 'package:share_plus/share_plus.dart';
+import 'package:url_launcher/url_launcher_string.dart';
 
 class AppsPage extends StatefulWidget {
   const AppsPage({super.key});
@@ -172,7 +174,43 @@ class AppsPageState extends State<AppsPage> {
                     : (sortedApps[index].app.installedVersion != null &&
                             sortedApps[index].app.installedVersion !=
                                 sortedApps[index].app.latestVersion
-                        ? const Text('Update Available')
+                        ? Column(
+                            mainAxisAlignment: SourceProvider()
+                                        .getSource(sortedApps[index].app.url)
+                                        .changeLogPageFromStandardUrl(
+                                            sortedApps[index].app.url) ==
+                                    null
+                                ? MainAxisAlignment.center
+                                : MainAxisAlignment.spaceEvenly,
+                            crossAxisAlignment: CrossAxisAlignment.end,
+                            children: [
+                              const Text('Update Available'),
+                              SourceProvider()
+                                          .getSource(sortedApps[index].app.url)
+                                          .changeLogPageFromStandardUrl(
+                                              sortedApps[index].app.url) ==
+                                      null
+                                  ? const SizedBox()
+                                  : GestureDetector(
+                                      onTap: () {
+                                        launchUrlString(
+                                            SourceProvider()
+                                                .getSource(
+                                                    sortedApps[index].app.url)
+                                                .changeLogPageFromStandardUrl(
+                                                    sortedApps[index].app.url)!,
+                                            mode:
+                                                LaunchMode.externalApplication);
+                                      },
+                                      child: const Text(
+                                        'See Changes',
+                                        style: TextStyle(
+                                            fontStyle: FontStyle.italic,
+                                            decoration:
+                                                TextDecoration.underline),
+                                      )),
+                            ],
+                          )
                         : Text(sortedApps[index].app.installedVersion ??
                             'Not Installed')),
                 onTap: () {

lib/providers/source_provider.dart

@@ -136,6 +136,7 @@ abstract class AppSource {
   late List<List<GeneratedFormItem>> additionalDataFormItems;
   late List<String> additionalDataDefaults;
   late List<GeneratedFormItem> moreSourceSettingsFormItems;
+  String? changeLogPageFromStandardUrl(String standardUrl);
 }
 
 abstract class MassAppSource {