Halkyon's shared packages

A pub workspace of the Dart packages Halkyon's apps share: halkyon_ui,
Halkyon's look (the theme, fonts, layout and shared widgets, with texts
in English and German), halkyon_core's low-level primitives and
halkyon_interop's cross-app contracts. Dart 3.13 with LeanCode's lints,
configured once at the root; apps take a package by git, pinned to a
signed commit.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

packages/halkyon_ui/test/widget/scroll_hiding_fab_test.dart

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+import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_ui/halkyon_ui.dart';
+import 'package:material_ui/material_ui.dart';
+
+void main() {
+  /// A list of [lines] with a button that hides while reading onwards.
+  Future<void> show(WidgetTester tester, {int lines = 100}) async {
+    tester.view.physicalSize = const Size(400, 800);
+    tester.view.devicePixelRatio = 1;
+    addTearDown(tester.view.reset);
+    await tester.pumpWidget(
+      MaterialApp(
+        home: ScrollHidingFab(
+          builder: (context, fab) => Scaffold(
+            floatingActionButton: fab,
+            body: ListView(
+              children: [
+                for (var i = 0; i < lines; i++)
+                  SizedBox(height: 48, child: Text('Line $i')),
+              ],
+            ),
+          ),
+          fab: FloatingActionButton(
+            tooltip: 'New studyset',
+            onPressed: () {},
+            child: const Icon(Icons.add),
+          ),
+        ),
+      ),
+    );
+  }
+
+  Finder fab() => find.byTooltip('New studyset').hitTestable();
+
+  testWidgets('hides while scrolling down and returns when scrolling up', (
+    tester,
+  ) async {
+    await show(tester);
+    expect(fab(), findsOneWidget);
+
+    await tester.drag(find.byType(ListView), const Offset(0, -300));
+    await tester.pumpAndSettle();
+    expect(fab(), findsNothing);
+
+    await tester.drag(find.byType(ListView), const Offset(0, 100));
+    await tester.pumpAndSettle();
+    expect(fab(), findsOneWidget);
+  });
+
+  testWidgets('stays when the list fits without scrolling', (tester) async {
+    await show(tester, lines: 3);
+
+    await tester.drag(find.byType(ListView), const Offset(0, -300));
+    await tester.pumpAndSettle();
+
+    expect(fab(), findsOneWidget);
+  });
+}