Added basic SourceForge support

lib/app_sources/sourceforge.dart

@@ -0,0 +1,69 @@
+import 'package:html/parser.dart';
+import 'package:http/http.dart';
+import 'package:obtainium/app_sources/github.dart';
+import 'package:obtainium/components/generated_form.dart';
+import 'package:obtainium/providers/source_provider.dart';
+
+class SourceForge implements AppSource {
+  @override
+  late String host = 'sourceforge.net';
+
+  @override
+  String standardizeURL(String url) {
+    RegExp standardUrlRegEx = RegExp('^https?://$host/projects/[^/]+');
+    RegExpMatch? match = standardUrlRegEx.firstMatch(url.toLowerCase());
+    if (match == null) {
+      throw notValidURL(runtimeType.toString());
+    }
+    return url.substring(0, match.end);
+  }
+
+  @override
+  Future<APKDetails> getLatestAPKDetails(
+      String standardUrl, List<String> additionalData) async {
+    Response res = await get(Uri.parse('$standardUrl/rss?path=/'));
+    if (res.statusCode == 200) {
+      var parsedHtml = parse(res.body);
+      var allDownloadLinks =
+          parsedHtml.querySelectorAll('guid').map((e) => e.innerHtml).toList();
+      getVersion(String url) {
+        try {
+          var tokens = url.split('/');
+          return tokens[tokens.length - 3];
+        } catch (e) {
+          return null;
+        }
+      }
+
+      String? version = getVersion(allDownloadLinks[0]);
+      if (version == null) {
+        throw couldNotFindLatestVersion;
+      }
+      var apkUrlListAllReleases = allDownloadLinks
+          .where((element) => element.toLowerCase().endsWith('.apk/download'))
+          .toList();
+      var apkUrlList =
+          apkUrlListAllReleases // This can be used skipped for fallback support later
+              .where((element) => getVersion(element) == version)
+              .toList();
+      if (apkUrlList.isEmpty) {
+        throw noAPKFound;
+      }
+      return APKDetails(version, apkUrlList);
+    } else {
+      throw couldNotFindReleases;
+    }
+  }
+
+  @override
+  AppNames getAppNames(String standardUrl) {
+    return AppNames(runtimeType.toString(),
+        standardUrl.substring(standardUrl.lastIndexOf('/') + 1));
+  }
+
+  @override
+  List<List<GeneratedFormItem>> additionalDataFormItems = [];
+
+  @override
+  List<String> additionalDataDefaults = [];
+}

lib/pages/add_app.dart

@@ -142,8 +142,7 @@ class _AddAppPageState extends State<AddAppPage> {
                               child: const Text('Add'))
                         ],
                       ),
-                      if (pickedSource != null &&
-                          (pickedSource!.additionalDataFormItems.isNotEmpty))
+                      if (pickedSource != null)
                         Column(
                           crossAxisAlignment: CrossAxisAlignment.stretch,
                           children: [
@@ -158,6 +157,8 @@ class _AddAppPageState extends State<AddAppPage> {
                             const SizedBox(
                               height: 16,
                             ),
+                            if (pickedSource!
+                                .additionalDataFormItems.isNotEmpty)
                               GeneratedForm(
                                   items: pickedSource!.additionalDataFormItems,
                                   onValueChanges: (values, valid) {
@@ -168,14 +169,12 @@ class _AddAppPageState extends State<AddAppPage> {
                                   },
                                   defaultValues:
                                       pickedSource!.additionalDataDefaults),
-                            if (pickedSource != null)
-                              Column(
-                                  crossAxisAlignment:
-                                      CrossAxisAlignment.stretch,
-                                  children: [
+                            if (pickedSource!
+                                .additionalDataFormItems.isNotEmpty)
                               const SizedBox(
                                 height: 8,
                               ),
+                            if (pickedSource != null)
                               GeneratedForm(
                                   items: [
                                     [
@@ -190,7 +189,6 @@ class _AddAppPageState extends State<AddAppPage> {
                                     });
                                   },
                                   defaultValues: [customName])
-                                  ]),
                           ],
                         )
                       else

lib/providers/source_provider.dart

@@ -10,6 +10,7 @@ import 'package:obtainium/app_sources/gitlab.dart';
 import 'package:obtainium/app_sources/izzyondroid.dart';
 import 'package:obtainium/app_sources/mullvad.dart';
 import 'package:obtainium/app_sources/signal.dart';
+import 'package:obtainium/app_sources/sourceforge.dart';
 import 'package:obtainium/components/generated_form.dart';
 import 'package:obtainium/mass_app_sources/githubstars.dart';
 
@@ -144,7 +145,8 @@ class SourceProvider {
     FDroid(),
     IzzyOnDroid(),
     Mullvad(),
-    Signal()
+    Signal(),
+    SourceForge()
   ];
 
   // Add more mass source classes here so they are available via the service