[a11y] Slider should respect bold text setting (#149053)

Fix #147600

internal GAR issue: b/316933135

reopen from #148435

packages/flutter/lib/src/material/slider.dart

@@ -817,6 +817,11 @@ class _SliderState extends State<Slider> with TickerProviderStateMixin {
  ?? MaterialStateProperty.resolveAs<Color?>(defaults.overlayColor, states);
  }
 
+ TextStyle valueIndicatorTextStyle = sliderTheme.valueIndicatorTextStyle ?? defaults.valueIndicatorTextStyle!;
+ if (MediaQuery.boldTextOf(context)) {
+ valueIndicatorTextStyle = valueIndicatorTextStyle.merge(const TextStyle(fontWeight: FontWeight.bold));
+ }
+
  sliderTheme = sliderTheme.copyWith(
  trackHeight: sliderTheme.trackHeight ?? defaults.trackHeight,
  activeTrackColor: widget.activeColor ?? sliderTheme.activeTrackColor ?? defaults.activeTrackColor,
@@ -839,7 +844,7 @@ class _SliderState extends State<Slider> with TickerProviderStateMixin {
  overlayShape: sliderTheme.overlayShape ?? defaultOverlayShape,
  valueIndicatorShape: valueIndicatorShape,
  showValueIndicator: sliderTheme.showValueIndicator ?? defaultShowValueIndicator,
- valueIndicatorTextStyle: sliderTheme.valueIndicatorTextStyle ?? defaults.valueIndicatorTextStyle,
+ valueIndicatorTextStyle: valueIndicatorTextStyle,
  );
  final MouseCursor effectiveMouseCursor = MaterialStateProperty.resolveAs<MouseCursor?>(widget.mouseCursor, states)
  ?? sliderTheme.mouseCursor?.resolve(states)

packages/flutter/test/material/slider_test.dart

@@ -49,6 +49,36 @@ class LoggingThumbShape extends SliderComponentShape {
  }
 }
 
+// A value indicator shape to log labelPainter text.
+class LoggingValueIndicatorShape extends SliderComponentShape {
+ LoggingValueIndicatorShape(this.logLabel);
+
+ final List<InlineSpan> logLabel;
+
+ @override
+ Size getPreferredSize(bool isEnabled, bool isDiscrete) {
+ return const Size(10.0, 10.0);
+ }
+
+ @override
+ void paint(
+ PaintingContext context,
+ Offset offset, {
+ required Animation<double> activationAnimation,
+ required Animation<double> enableAnimation,
+ required bool isDiscrete,
+ required TextPainter labelPainter,
+ required RenderBox parentBox,
+ required SliderThemeData sliderTheme,
+ required TextDirection textDirection,
+ required double value,
+ required double textScaleFactor,
+ required Size sizeWithOverflow,
+ }) {
+ logLabel.add(labelPainter.text!);
+ }
+}
+
 class TallSliderTickMarkShape extends SliderTickMarkShape {
  @override
  Size getPreferredSize({required SliderThemeData sliderTheme, required bool isEnabled}) {
@@ -975,6 +1005,79 @@ void main() {
  }
  });
 
+ testWidgets('Slider value indicator respects bold text', (WidgetTester tester) async {
+ final Key sliderKey = UniqueKey();
+ double value = 0.0;
+ final List<InlineSpan> log = <InlineSpan>[];
+ final LoggingValueIndicatorShape loggingValueIndicatorShape = LoggingValueIndicatorShape(log);
+
+ Widget buildSlider({ bool boldText = false }) {
+ return MaterialApp(
+ home: Directionality(
+ textDirection: TextDirection.ltr,
+ child: StatefulBuilder(
+ builder: (BuildContext context, StateSetter setState) {
+ return MediaQuery(
+ data: MediaQueryData(boldText: boldText),
+ child: Material(
+ child: Theme(
+ data: Theme.of(context).copyWith(
+ sliderTheme: Theme.of(context).sliderTheme.copyWith(
+ showValueIndicator: ShowValueIndicator.always,
+ valueIndicatorShape: loggingValueIndicatorShape,
+ ),
+ ),
+ child: Center(
+ child: OverflowBox(
+ maxWidth: double.infinity,
+ maxHeight: double.infinity,
+ child: Slider(
+ key: sliderKey,
+ max: 100.0,
+ divisions: 4,
+ label: '${value.round()}',
+ value: value,
+ onChanged: (double newValue) {
+ setState(() {
+ value = newValue;
+ });
+ },
+ ),
+ ),
+ ),
+ ),
+ ),
+ );
+ },
+ ),
+ ),
+ );
+ }
+ // Normal text
+ await tester.pumpWidget(buildSlider());
+ Offset center = tester.getCenter(find.byType(Slider));
+ TestGesture gesture = await tester.startGesture(center);
+ await tester.pumpAndSettle();
+
+ expect(log.last.toPlainText(), '50');
+ expect(log.last.style!.fontWeight, FontWeight.w500);
+
+ await gesture.up();
+ await tester.pumpAndSettle();
+
+ // Bold text
+ await tester.pumpWidget(buildSlider(boldText: true));
+ center = tester.getCenter(find.byType(Slider));
+ gesture = await tester.startGesture(center);
+ await tester.pumpAndSettle();
+
+ expect(log.last.toPlainText(), '50');
+ expect(log.last.style!.fontWeight, FontWeight.w700);
+
+ await gesture.up();
+ await tester.pumpAndSettle();
+ });
+
  testWidgets('Tick marks are skipped when they are too dense', (WidgetTester tester) async {
  Widget buildSlider({
  required int divisions,