Merge branch 'main' into 16_create-theme-for-scenes

Author: matthew-carroll

lib/flutter_test_goldens.dart

@@ -1,5 +1,6 @@
 export 'src/flutter/flutter_test_extensions.dart';
 export 'src/fonts/fonts.dart';
+export 'src/fonts/icons.dart';
 export 'src/goldens/golden_camera.dart';
 export 'src/goldens/golden_collections.dart';
 export 'src/goldens/golden_comparisons.dart';

lib/src/fonts/icons.dart

@@ -0,0 +1,40 @@
+import 'dart:io';
+
+import 'package:file/file.dart' show FileSystem;
+import 'package:file/local.dart' show LocalFileSystem;
+import 'package:flutter/services.dart';
+import 'package:path/path.dart';
+import 'package:platform/platform.dart';
+
+/// Loads the Material icons font into the [FontLoader], which doesn't happen by
+/// default in widget tests.
+///
+/// In widget tests. icons render as empty squares. This is because in widget tests
+/// the Material icons font isn't loaded by default. Unfortunately, Flutter doesn't
+/// provide a first-class ability to load the font, so this method was copied from
+/// Flutter to dig into implementation details and load it.
+///
+/// After loading this font into a widget test, Material icons should render normally.
+Future<void> loadMaterialIconsFont() async {
+  const FileSystem fs = LocalFileSystem();
+  const Platform platform = LocalPlatform();
+  final Directory flutterRoot = fs.directory(platform.environment['FLUTTER_ROOT']);
+
+  final File iconFont = flutterRoot.childFile(
+    fs.path.join(
+      'bin',
+      'cache',
+      'artifacts',
+      'material_fonts',
+      'MaterialIcons-Regular.otf',
+    ),
+  );
+
+  final Future<ByteData> bytes = Future<ByteData>.value(iconFont.readAsBytesSync().buffer.asByteData());
+
+  await (FontLoader('MaterialIcons')..addFont(bytes)).load();
+}
+
+extension on Directory {
+  File childFile(String basename) => File("$path$separator$basename");
+}

lib/src/goldens/golden_camera.dart

@@ -16,42 +16,35 @@ class GoldenCamera {
   /// along with its [description].
   ///
   /// {@macro golden_image_bounds_default_finder}
+  ///
+  /// The photo captures a screenshot of the entire widget tree, and then extracts the pixels
+  /// within the [finder] region. This requires moving more pixel data, but this is done so
+  /// that the photo captures widgets that sit in the app overlay, such as the mobile drag
+  /// handles, magnifier, or popover toolbar for a text field.
   Future<void> takePhoto(String description, [Finder? finder]) async {
     finder = finder ?? find.byType(GoldenImageBounds);
 
     expect(finder, findsOne);
 
     final renderObject = finder.evaluate().first.findRenderObject();
     late final Image photo;
-    if (renderObject!.isRepaintBoundary) {
-      // The render object that we want to screenshot is already a repaint boundary,
-      // so we can directly request an image from it.
-      final repaintBoundary = finder.evaluate().first.renderObject! as RenderRepaintBoundary;
-      photo = await repaintBoundary.toImage(pixelRatio: 1.0);
-    } else {
-      // The render object that we want to screenshot is NOT a repaint boundary, so we need
-      // to screenshot the entire UI and then extract the region belonging to this widget.
-      if (renderObject is! RenderBox) {
-        throw Exception(
-          "Can't take screenshot because the root of the widget tree isn't a RenderBox. It's a ${renderObject.runtimeType}",
-        );
-      }
+    if (renderObject is! RenderBox) {
+      throw Exception(
+        "Can't take screenshot because the root of the widget tree isn't a RenderBox. It's a ${renderObject.runtimeType}",
+      );
+    }
 
-      // TODO: Try the following approach. It probably doesn't work because we're
-      //       using a TestRecordingPaintingContext with a non-test version of Canvas.
-      //       But maybe it will work out.
-      final pictureRecorder = PictureRecorder();
-      final canvas = Canvas(pictureRecorder);
-      final screenSize = renderObject.size;
+    final pictureRecorder = PictureRecorder();
+    final canvas = Canvas(pictureRecorder);
+    final screenSize = renderObject.size;
 
-      final paintingContext = TestRecordingPaintingContext(canvas);
-      renderObject.paint(paintingContext, Offset.zero);
+    final paintingContext = TestRecordingPaintingContext(canvas);
+    renderObject.paint(paintingContext, Offset.zero);
 
-      photo = await pictureRecorder.endRecording().toImage(
-            screenSize.width.round(),
-            screenSize.height.round(),
-          );
-    }
+    photo = await pictureRecorder.endRecording().toImage(
+          screenSize.width.round(),
+          screenSize.height.round(),
+        );
 
     _photos.add(
       GoldenPhoto(description, photo),