initial commit: LeafViewer, LeafZoomable, LeafContextMenu, LeafPopover, LeafImage, misc widgets + tests

example/test/widget_test.dart

@@ -0,0 +1,39 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:example/main.dart';
+import 'package:leaf_widgets/leaf_widgets.dart';
+
+void main() {
+  testWidgets('gallery builds and shows all sections', (tester) async {
+    await tester.pumpWidget(const LeafWidgetsGalleryApp());
+
+    expect(find.text('leaf_widgets gallery'), findsOneWidget);
+    expect(find.byType(AnimatedStar), findsNWidgets(2));
+    expect(find.byType(AnimatedFavoriteButton), findsNWidgets(2));
+    expect(find.byType(LeafPopover), findsOneWidget);
+    expect(find.byType(LeafContextMenu), findsOneWidget);
+    expect(find.byType(LeafImage), findsOneWidget);
+  });
+
+  testWidgets('LeafViewer demo opens and closes', (tester) async {
+    await tester.pumpWidget(const LeafWidgetsGalleryApp());
+
+    // The gallery has perpetual animations, so pumpAndSettle can never settle.
+    await tester.scrollUntilVisible(find.text('Open 3-image viewer'), 200);
+    await tester.ensureVisible(find.text('Open 3-image viewer'));
+    await tester.pump(const Duration(milliseconds: 100));
+    await tester.tap(find.text('Open 3-image viewer'));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 400)); // route transition
+    await tester.pump(); // let image loads fail while the widgets are alive
+
+    expect(find.byType(LeafViewer), findsOneWidget);
+    expect(find.byType(LeafZoomable), findsWidgets);
+
+    await tester.tap(find.byIcon(Icons.close));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 600)); // route pop
+    expect(find.byType(LeafViewer), findsNothing);
+  });
+}