// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:ui' show window;

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:flutter/painting.dart';

import '../rendering/mock_canvas.dart';

void main() {
  testWidgets('Slider theme is built by ThemeData', (WidgetTester tester) async {
    final ThemeData theme = ThemeData(
      platform: TargetPlatform.android,
      primarySwatch: Colors.red,
    );
    final SliderThemeData sliderTheme = theme.sliderTheme;

    expect(sliderTheme.activeTrackColor.value, equals(Colors.red.value));
    expect(sliderTheme.inactiveTrackColor.value, equals(Colors.red.withAlpha(0x3d).value));
  });

  testWidgets('Slider uses ThemeData slider theme if present', (WidgetTester tester) async {
    final ThemeData theme = ThemeData(
      platform: TargetPlatform.android,
      primarySwatch: Colors.red,
    );
    final SliderThemeData sliderTheme = theme.sliderTheme;

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.5, enabled: false));
    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    expect(
      sliderBox,
      paints
        ..rect(color: sliderTheme.disabledActiveTrackColor)
        ..rect(color: sliderTheme.disabledInactiveTrackColor),
    );
  });

  testWidgets('Slider overrides ThemeData theme if SliderTheme present', (WidgetTester tester) async {
    final ThemeData theme = ThemeData(
      platform: TargetPlatform.android,
      primarySwatch: Colors.red,
    );
    final SliderThemeData sliderTheme = theme.sliderTheme;
    final SliderThemeData customTheme = sliderTheme.copyWith(
      activeTrackColor: Colors.purple,
      inactiveTrackColor: Colors.purple.withAlpha(0x3d),
    );

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.5, enabled: false));
    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    expect(
      sliderBox,
      paints
        ..rect(color: customTheme.disabledActiveTrackColor)
        ..rect(color: customTheme.disabledInactiveTrackColor),
    );
  });

  testWidgets('SliderThemeData assigns the correct default shapes', (WidgetTester tester) async {
    final SliderThemeData sliderTheme = ThemeData().sliderTheme;
    expect(sliderTheme.trackShape, equals(isInstanceOf<RectangularSliderTrackShape>()));
    expect(sliderTheme.tickMarkShape, equals(isInstanceOf<RoundSliderTickMarkShape>()));
    expect(sliderTheme.thumbShape, equals(isInstanceOf<RoundSliderThumbShape>()));
    expect(sliderTheme.valueIndicatorShape, equals(isInstanceOf<PaddleSliderValueIndicatorShape>()));
    expect(sliderTheme.overlayShape, equals(isInstanceOf<RoundSliderOverlayShape>()));
  });

  testWidgets('SliderThemeData assigns the correct default flags', (WidgetTester tester) async {
    final SliderThemeData sliderTheme = ThemeData().sliderTheme;
    expect(sliderTheme.showValueIndicator, equals(ShowValueIndicator.onlyForDiscrete));
  });

  testWidgets('SliderThemeData generates correct opacities for fromPrimaryColors', (WidgetTester tester) async {
    const Color customColor1 = Color(0xcafefeed);
    const Color customColor2 = Color(0xdeadbeef);
    const Color customColor3 = Color(0xdecaface);
    const Color customColor4 = Color(0xfeedcafe);

    final SliderThemeData sliderTheme = SliderThemeData.fromPrimaryColors(
      primaryColor: customColor1,
      primaryColorDark: customColor2,
      primaryColorLight: customColor3,
      valueIndicatorTextStyle: ThemeData.fallback().accentTextTheme.body2.copyWith(color: customColor4),
    );

    expect(sliderTheme.activeTrackColor, equals(customColor1.withAlpha(0xff)));
    expect(sliderTheme.inactiveTrackColor, equals(customColor1.withAlpha(0x3d)));
    expect(sliderTheme.disabledActiveTrackColor, equals(customColor2.withAlpha(0x52)));
    expect(sliderTheme.disabledInactiveTrackColor, equals(customColor2.withAlpha(0x1f)));
    expect(sliderTheme.activeTickMarkColor, equals(customColor3.withAlpha(0x8a)));
    expect(sliderTheme.inactiveTickMarkColor, equals(customColor1.withAlpha(0x8a)));
    expect(sliderTheme.disabledActiveTickMarkColor, equals(customColor3.withAlpha(0x1f)));
    expect(sliderTheme.disabledInactiveTickMarkColor, equals(customColor2.withAlpha(0x1f)));
    expect(sliderTheme.thumbColor, equals(customColor1.withAlpha(0xff)));
    expect(sliderTheme.disabledThumbColor, equals(customColor2.withAlpha(0x52)));
    expect(sliderTheme.overlayColor, equals(customColor1.withAlpha(0x29)));
    expect(sliderTheme.valueIndicatorColor, equals(customColor1.withAlpha(0xff)));
    expect(sliderTheme.valueIndicatorTextStyle.color, equals(customColor4));
  });

  testWidgets('SliderThemeData lerps correctly', (WidgetTester tester) async {
    final SliderThemeData sliderThemeBlack = SliderThemeData.fromPrimaryColors(
      primaryColor: Colors.black,
      primaryColorDark: Colors.black,
      primaryColorLight: Colors.black,
      valueIndicatorTextStyle: ThemeData.fallback().accentTextTheme.body2.copyWith(color: Colors.black),
    ).copyWith(trackHeight: 2.0);
    final SliderThemeData sliderThemeWhite = SliderThemeData.fromPrimaryColors(
      primaryColor: Colors.white,
      primaryColorDark: Colors.white,
      primaryColorLight: Colors.white,
      valueIndicatorTextStyle: ThemeData.fallback().accentTextTheme.body2.copyWith(color: Colors.white),
    ).copyWith(trackHeight: 6.0);
    final SliderThemeData lerp = SliderThemeData.lerp(sliderThemeBlack, sliderThemeWhite, 0.5);
    const Color middleGrey = Color(0xff7f7f7f);

    expect(lerp.trackHeight, equals(4.0));
    expect(lerp.activeTrackColor, equals(middleGrey.withAlpha(0xff)));
    expect(lerp.inactiveTrackColor, equals(middleGrey.withAlpha(0x3d)));
    expect(lerp.disabledActiveTrackColor, equals(middleGrey.withAlpha(0x52)));
    expect(lerp.disabledInactiveTrackColor, equals(middleGrey.withAlpha(0x1f)));
    expect(lerp.activeTickMarkColor, equals(middleGrey.withAlpha(0x8a)));
    expect(lerp.inactiveTickMarkColor, equals(middleGrey.withAlpha(0x8a)));
    expect(lerp.disabledActiveTickMarkColor, equals(middleGrey.withAlpha(0x1f)));
    expect(lerp.disabledInactiveTickMarkColor, equals(middleGrey.withAlpha(0x1f)));
    expect(lerp.thumbColor, equals(middleGrey.withAlpha(0xff)));
    expect(lerp.disabledThumbColor, equals(middleGrey.withAlpha(0x52)));
    expect(lerp.overlayColor, equals(middleGrey.withAlpha(0x29)));
    expect(lerp.valueIndicatorColor, equals(middleGrey.withAlpha(0xff)));
    expect(lerp.valueIndicatorTextStyle.color, equals(middleGrey.withAlpha(0xff)));
  });

  testWidgets('Default slider track draws correctly', (WidgetTester tester) async {
    final ThemeData theme = ThemeData(
      platform: TargetPlatform.android,
      primarySwatch: Colors.blue,
    );
    final SliderThemeData sliderTheme = theme.sliderTheme.copyWith(thumbColor: Colors.red.shade500);

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.25));
    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    // The enabled slider thumb has track segments that extend to and from
    // the center of the thumb.
    expect(
      sliderBox,
      paints
        ..rect(rect: Rect.fromLTRB(16.0, 299.0, 208.0, 301.0), color: sliderTheme.activeTrackColor)
        ..rect(rect: Rect.fromLTRB(208.0, 299.0, 784.0, 301.0), color: sliderTheme.inactiveTrackColor),
    );

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.25, enabled: false));
    await tester.pumpAndSettle(); // wait for disable animation

    // The disabled slider thumb has a horizontal gap between itself and the
    // track segments. Therefore, the track segments are shorter since they do
    // not extend to the center of the thumb, but rather the outer edge of th
    // gap. As a result, the `right` value of the first segment is less than it
    // is above, and the `left` value of the second segment is more than it is
    // above.
    expect(
      sliderBox,
      paints
        ..rect(rect: Rect.fromLTRB(16.0, 299.0, 202.0, 301.0), color: sliderTheme.disabledActiveTrackColor)
        ..rect(rect: Rect.fromLTRB(214.0, 299.0, 784.0, 301.0), color: sliderTheme.disabledInactiveTrackColor),
    );
  });

  testWidgets('Default slider overlay draws correctly', (WidgetTester tester) async {
    final ThemeData theme = ThemeData(
      platform: TargetPlatform.android,
      primarySwatch: Colors.blue,
    );
    final SliderThemeData sliderTheme = theme.sliderTheme.copyWith(thumbColor: Colors.red.shade500);

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.25));
    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    // With no touch, paints only the thumb.
    expect(
      sliderBox,
      paints
        ..circle(
          color: sliderTheme.thumbColor,
          x: 208.0,
          y: 300.0,
          radius: 6.0,
        ),
    );

    final Offset center = tester.getCenter(find.byType(Slider));
    final TestGesture gesture = await tester.startGesture(center);
    // Wait for overlay animation to finish.
    await tester.pumpAndSettle();

    // After touch, paints thumb and overlay.
    expect(
      sliderBox,
      paints
        ..circle(
          color: sliderTheme.overlayColor,
          x: 208.0,
          y: 300.0,
          radius: 16.0,
        )
        ..circle(
          color: sliderTheme.thumbColor,
          x: 208.0,
          y: 300.0,
          radius: 6.0,
        ),
    );

    await gesture.up();
    await tester.pumpAndSettle();

    // After the gesture is up and complete, it again paints only the thumb.
    expect(
      sliderBox,
      paints
        ..circle(
          color: sliderTheme.thumbColor,
          x: 208.0,
          y: 300.0,
          radius: 6.0,
        ),
    );
  });

  testWidgets('Default slider ticker and thumb shape draw correctly', (WidgetTester tester) async {
    final ThemeData theme = ThemeData(
      platform: TargetPlatform.android,
      primarySwatch: Colors.blue,
    );
    final SliderThemeData sliderTheme = theme.sliderTheme.copyWith(thumbColor: Colors.red.shade500);

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.45));
    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    expect(sliderBox, paints..circle(color: sliderTheme.thumbColor, radius: 6.0));

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.45, enabled: false));
    await tester.pumpAndSettle(); // wait for disable animation

    expect(sliderBox, paints..circle(color: sliderTheme.disabledThumbColor, radius: 4.0));

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.45, divisions: 3));
    await tester.pumpAndSettle(); // wait for enable animation

    expect(
      sliderBox,
      paints
        ..circle(color: sliderTheme.activeTickMarkColor)
        ..circle(color: sliderTheme.activeTickMarkColor)
        ..circle(color: sliderTheme.inactiveTickMarkColor)
        ..circle(color: sliderTheme.inactiveTickMarkColor)
        ..circle(color: sliderTheme.thumbColor, radius: 6.0),
    );

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.45, divisions: 3, enabled: false));
    await tester.pumpAndSettle(); // wait for disable animation

    expect(
      sliderBox,
      paints
        ..circle(color: sliderTheme.disabledActiveTickMarkColor)
        ..circle(color: sliderTheme.disabledInactiveTickMarkColor)
        ..circle(color: sliderTheme.disabledInactiveTickMarkColor)
        ..circle(color: sliderTheme.disabledInactiveTickMarkColor)
        ..circle(color: sliderTheme.disabledThumbColor, radius: 4.0),
    );
  });

  testWidgets('Default slider value indicator shape draws correctly', (WidgetTester tester) async {
    final ThemeData theme = ThemeData(
      platform: TargetPlatform.android,
      primarySwatch: Colors.blue,
    );
    final SliderThemeData sliderTheme = theme.sliderTheme.copyWith(thumbColor: Colors.red.shade500, showValueIndicator: ShowValueIndicator.always);
    Widget buildApp(String value, { double sliderValue = 0.5, double textScale = 1.0 }) {
      return Directionality(
        textDirection: TextDirection.ltr,
        child: MediaQuery(
          data: MediaQueryData.fromWindow(window).copyWith(textScaleFactor: textScale),
          child: Material(
            child: Row(
              children: <Widget>[
                Expanded(
                  child: SliderTheme(
                    data: sliderTheme,
                    child: Slider(
                      value: sliderValue,
                      label: '$value',
                      divisions: 3,
                      onChanged: (double d) { },
                    ),
                  ),
                ),
              ],
            ),
          ),
        ),
      );
    }

    await tester.pumpWidget(buildApp('1'));

    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    Offset center = tester.getCenter(find.byType(Slider));
    TestGesture gesture = await tester.startGesture(center);
    // Wait for value indicator animation to finish.
    await tester.pumpAndSettle();
    expect(
      sliderBox,
      paints
        ..path(
          color: sliderTheme.valueIndicatorColor,
          includes: <Offset>[
            const Offset(0.0, -40.0),
            const Offset(15.9, -40.0),
            const Offset(-15.9, -40.0),
          ],
          excludes: <Offset>[const Offset(16.1, -40.0), const Offset(-16.1, -40.0)],
        ),
    );

    await gesture.up();

    // Test that it expands with a larger label.
    await tester.pumpWidget(buildApp('1000'));
    center = tester.getCenter(find.byType(Slider));
    gesture = await tester.startGesture(center);
    // Wait for value indicator animation to finish.
    await tester.pumpAndSettle();
    expect(
      sliderBox,
      paints
        ..path(
          color: sliderTheme.valueIndicatorColor,
          includes: <Offset>[
            const Offset(0.0, -40.0),
            const Offset(35.9, -40.0),
            const Offset(-35.9, -40.0),
          ],
          excludes: <Offset>[const Offset(36.1, -40.0), const Offset(-36.1, -40.0)],
        ),
    );
    await gesture.up();

    // Test that it avoids the left edge of the screen.
    await tester.pumpWidget(buildApp('1000000', sliderValue: 0.0));
    center = tester.getCenter(find.byType(Slider));
    gesture = await tester.startGesture(center);
    // Wait for value indicator animation to finish.
    await tester.pumpAndSettle();
    expect(
      sliderBox,
      paints
        ..path(
          color: sliderTheme.valueIndicatorColor,
          includes: <Offset>[
            const Offset(0.0, -40.0),
            const Offset(98.0, -40.0),
            const Offset(-16.0, -40.0),
          ],
          excludes: <Offset>[const Offset(98.1, -40.0), const Offset(-16.1, -40.0)],
        ),
    );
    await gesture.up();

    // Test that it avoids the right edge of the screen.
    await tester.pumpWidget(buildApp('1000000', sliderValue: 1.0));
    center = tester.getCenter(find.byType(Slider));
    gesture = await tester.startGesture(center);
    // Wait for value indicator animation to finish.
    await tester.pumpAndSettle();
    expect(
      sliderBox,
      paints
        ..path(
          color: sliderTheme.valueIndicatorColor,
          includes: <Offset>[
            const Offset(0.0, -40.0),
            const Offset(16.0, -40.0),
            const Offset(-98.0, -40.0),
          ],
          excludes: <Offset>[const Offset(16.1, -40.0), const Offset(-98.1, -40.0)],
        ),
    );
    await gesture.up();

    // Test that the neck stretches when the text scale gets smaller.
    await tester.pumpWidget(buildApp('1000000', sliderValue: 0.0, textScale: 0.5));
    center = tester.getCenter(find.byType(Slider));
    gesture = await tester.startGesture(center);
    // Wait for value indicator animation to finish.
    await tester.pumpAndSettle();
    expect(
      sliderBox,
      paints
        ..path(
          color: sliderTheme.valueIndicatorColor,
          includes: <Offset>[
            const Offset(0.0, -49.0),
            const Offset(90.0, -49.0),
            const Offset(-24.0, -49.0),
          ],
          excludes: <Offset>[
            const Offset(98.0, -32.0),  // inside full size, outside small
            const Offset(-16.0, -32.0),  // inside full size, outside small
            const Offset(90.1, -49.0),
            const Offset(-24.1, -49.0),
          ],
        ),
    );
    await gesture.up();

    // Test that the neck shrinks when the text scale gets larger.
    await tester.pumpWidget(buildApp('1000000', sliderValue: 0.0, textScale: 2.5));
    center = tester.getCenter(find.byType(Slider));
    gesture = await tester.startGesture(center);
    // Wait for value indicator animation to finish.
    await tester.pumpAndSettle();
    expect(
      sliderBox,
      paints
        ..path(
          color: sliderTheme.valueIndicatorColor,
          includes: <Offset>[
            const Offset(0.0, -38.8),
            const Offset(98.0, -38.8),
            const Offset(-16.0, -38.8),
            const Offset(10.0, -23.0), // Inside large, outside scale=1.0
            const Offset(-4.0, -23.0), // Inside large, outside scale=1.0
          ],
          excludes: <Offset>[
            const Offset(98.5, -38.8),
            const Offset(-16.1, -38.8),
          ],
        ),
    );
    await gesture.up();
  });

  testWidgets('The slider track height can be overridden', (WidgetTester tester) async {
    final SliderThemeData sliderTheme = ThemeData().sliderTheme.copyWith(trackHeight: 16);

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.25));

    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    // Top and bottom are centerY (300) + and - trackRadius (8).
    expect(
      sliderBox,
      paints
        ..rect(rect: Rect.fromLTRB(16.0, 292.0, 208.0, 308.0), color: sliderTheme.activeTrackColor)
        ..rect(rect: Rect.fromLTRB(208.0, 292.0, 784.0, 308.0), color: sliderTheme.inactiveTrackColor),
    );

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.25, enabled: false));
    await tester.pumpAndSettle(); // wait for disable animation

    // The disabled thumb is smaller so the active track has to paint longer to
    // get to the edge.
    expect(
      sliderBox,
      paints
        ..rect(rect: Rect.fromLTRB(16.0, 292.0, 202.0, 308.0), color: sliderTheme.disabledActiveTrackColor)
        ..rect(rect: Rect.fromLTRB(214.0, 292.0, 784.0, 308.0), color: sliderTheme.disabledInactiveTrackColor),
    );
  });

  testWidgets('The default slider thumb shape sizes can be overridden', (WidgetTester tester) async {
    final SliderThemeData sliderTheme = ThemeData().sliderTheme.copyWith(
        thumbShape: const RoundSliderThumbShape(
          enabledThumbRadius: 7,
          disabledThumbRadius: 11,
        ),
    );

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.25));
    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    expect(
      sliderBox,
      paints..circle(x: 208, y: 300, radius: 7, color: sliderTheme.thumbColor),
    );

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.25, enabled: false));
    await tester.pumpAndSettle(); // wait for disable animation

    expect(
      sliderBox,
      paints..circle(x: 208, y: 300, radius: 11, color: sliderTheme.disabledThumbColor),
    );
  });

  testWidgets('The default slider thumb shape disabled size can be inferred from the enabled size', (WidgetTester tester) async {
    final SliderThemeData sliderTheme = ThemeData().sliderTheme.copyWith(
      thumbShape: const RoundSliderThumbShape(
        enabledThumbRadius: 9,
      ),
    );

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.25));
    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    expect(
      sliderBox,
      paints..circle(x: 208, y: 300, radius: 9, color: sliderTheme.thumbColor),
    );

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.25, enabled: false));
    await tester.pumpAndSettle(); // wait for disable animation
    // Radius should be 6, or 2/3 of 9. 2/3 because the default disabled thumb
    // radius is 4 and the default enabled thumb radius is 6.
    // TODO(clocksmith): This ratio will change once thumb sizes are updated to spec.
    expect(
      sliderBox,
      paints..circle(x: 208, y: 300, radius: 6, color: sliderTheme.disabledThumbColor),
    );
  });


  testWidgets('The default slider tick mark shape size can be overridden', (WidgetTester tester) async {
    final SliderThemeData sliderTheme = ThemeData().sliderTheme.copyWith(
      tickMarkShape: const RoundSliderTickMarkShape(
        tickMarkRadius: 5
      ),
      activeTickMarkColor: const Color(0xfadedead),
      inactiveTickMarkColor: const Color(0xfadebeef),
      disabledActiveTickMarkColor: const Color(0xfadecafe),
      disabledInactiveTickMarkColor: const Color(0xfadeface),
    );

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.5, divisions: 2));

    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    expect(
      sliderBox,
      paints
        ..circle(x: 21, y: 300, radius: 5, color: sliderTheme.activeTickMarkColor)
        ..circle(x: 400, y: 300, radius: 5, color: sliderTheme.activeTickMarkColor)
        ..circle(x: 779, y: 300, radius: 5, color: sliderTheme.inactiveTickMarkColor),
    );

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.5, divisions: 2,  enabled: false));
    await tester.pumpAndSettle();

    expect(
      sliderBox,
      paints
        ..circle(x: 21, y: 300, radius: 5, color: sliderTheme.disabledActiveTickMarkColor)
        ..circle(x: 400, y: 300, radius: 5, color: sliderTheme.disabledActiveTickMarkColor)
        ..circle(x: 779, y: 300, radius: 5, color: sliderTheme.disabledInactiveTickMarkColor),
    );
  });

  testWidgets('The default slider overlay shape size can be overridden', (WidgetTester tester) async {
    const double uniqueOverlayRadius = 23;
    final SliderThemeData sliderTheme = ThemeData().sliderTheme.copyWith(
      overlayShape: const RoundSliderOverlayShape(
        overlayRadius: uniqueOverlayRadius,
      ),
    );

    await tester.pumpWidget(_buildApp(sliderTheme, value: 0.5));
    // Tap center and wait for animation.
    final Offset center = tester.getCenter(find.byType(Slider));
    await tester.startGesture(center);
    await tester.pumpAndSettle();

    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));
    expect(
      sliderBox,
      paints..circle(
        x: center.dx,
        y: center.dy,
        radius: uniqueOverlayRadius,
        color: sliderTheme.overlayColor,
      ),
    );
  });

  // Only the thumb, overlay, and tick mark have special shortcuts to provide
  // no-op or empty shapes.
  //
  // The track can also be skipped by providing 0 height.
  //
  // The value indicator can be skipped by passing the appropriate
  // [ShowValueIndicator].
  testWidgets('The slider can skip all of its comoponent painting', (WidgetTester tester) async {
    // Pump a slider with all shapes skipped.
    await tester.pumpWidget(_buildApp(
      ThemeData().sliderTheme.copyWith(
        trackHeight: 0,
        overlayShape: SliderComponentShape.noOverlay,
        thumbShape: SliderComponentShape.noThumb,
        tickMarkShape: SliderTickMarkShape.noTickMark,
        showValueIndicator: ShowValueIndicator.never,
      ),
      value: 0.5,
      divisions: 4,
    ));

    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    expect(sliderBox, paintsNothing);
  });

  testWidgets('The slider can skip all component painting except the track', (WidgetTester tester) async {
    // Pump a slider with just a track.
    await tester.pumpWidget(_buildApp(
      ThemeData().sliderTheme.copyWith(
        overlayShape: SliderComponentShape.noOverlay,
        thumbShape: SliderComponentShape.noThumb,
        tickMarkShape: SliderTickMarkShape.noTickMark,
        showValueIndicator: ShowValueIndicator.never,
      ),
      value: 0.5,
      divisions: 4,
    ));

    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    // Only 2 track segments.
    expect(sliderBox, paintsExactlyCountTimes(#drawRect, 2));
    expect(sliderBox, paintsExactlyCountTimes(#drawCircle, 0));
    expect(sliderBox, paintsExactlyCountTimes(#drawPath, 0));
  });

  testWidgets('The slider can skip all component painting except the tick marks', (WidgetTester tester) async {
    // Pump a slider with just tick marks.
    await tester.pumpWidget(_buildApp(
      ThemeData().sliderTheme.copyWith(
        trackHeight: 0,
        overlayShape: SliderComponentShape.noOverlay,
        thumbShape: SliderComponentShape.noThumb,
        showValueIndicator: ShowValueIndicator.never,
      ),
      value: 0.5,
      divisions: 4,
    ));

    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    // Only 5 tick marks.
    expect(sliderBox, paintsExactlyCountTimes(#drawRect, 0));
    expect(sliderBox, paintsExactlyCountTimes(#drawCircle, 5));
    expect(sliderBox, paintsExactlyCountTimes(#drawPath, 0));
  });

  testWidgets('The slider can skip all component painting except the thumb', (WidgetTester tester) async {
    // Pump a slider with just a thumb.
    await tester.pumpWidget(_buildApp(
      ThemeData().sliderTheme.copyWith(
        trackHeight: 0,
        overlayShape: SliderComponentShape.noOverlay,
        tickMarkShape: SliderTickMarkShape.noTickMark,
        showValueIndicator: ShowValueIndicator.never,
      ),
      value: 0.5,
      divisions: 4,
    ));

    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    // Only 1 thumb.
    expect(sliderBox, paintsExactlyCountTimes(#drawRect, 0));
    expect(sliderBox, paintsExactlyCountTimes(#drawCircle, 1));
    expect(sliderBox, paintsExactlyCountTimes(#drawPath, 0));
  });

  testWidgets('The slider can skip all component painting except the overlay', (WidgetTester tester) async {
    // Pump a slider with just an overlay.
    await tester.pumpWidget(_buildApp(
      ThemeData().sliderTheme.copyWith(
        trackHeight: 0,
        thumbShape: SliderComponentShape.noThumb,
        tickMarkShape: SliderTickMarkShape.noTickMark,
        showValueIndicator: ShowValueIndicator.never,
      ),
      value: 0.5,
      divisions: 4,
    ));

    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    // Tap the center of the track and wait for animations to finish.
    final Offset center = tester.getCenter(find.byType(Slider));
    final TestGesture gesture = await tester.startGesture(center);
    await tester.pumpAndSettle();

    // Only 1 overlay.
    expect(sliderBox, paintsExactlyCountTimes(#drawRect, 0));
    expect(sliderBox, paintsExactlyCountTimes(#drawCircle, 1));
    expect(sliderBox, paintsExactlyCountTimes(#drawPath, 0));

    await gesture.up();
  });

  testWidgets('The slider can skip all component painting except the value indicator', (WidgetTester tester) async {
    // Pump a slider with just a value indicator.
    await tester.pumpWidget(_buildApp(
      ThemeData().sliderTheme.copyWith(
        trackHeight: 0,
        overlayShape: SliderComponentShape.noOverlay,
        thumbShape: SliderComponentShape.noThumb,
        tickMarkShape: SliderTickMarkShape.noTickMark,
        showValueIndicator: ShowValueIndicator.always,
      ),
      value: 0.5,
      divisions: 4,
    ));

    final RenderBox sliderBox = tester.firstRenderObject<RenderBox>(find.byType(Slider));

    // Tap the center of the track and wait for animations to finish.
    final Offset center = tester.getCenter(find.byType(Slider));
    final TestGesture gesture = await tester.startGesture(center);
    await tester.pumpAndSettle();

    // Only 1 value indicator.
    expect(sliderBox, paintsExactlyCountTimes(#drawRect, 0));
    expect(sliderBox, paintsExactlyCountTimes(#drawCircle, 0));
    expect(sliderBox, paintsExactlyCountTimes(#drawPath, 1));

    await gesture.up();
  });
}

Widget _buildApp(
  SliderThemeData sliderTheme, {
  double value = 0.0,
  bool enabled = true,
  int divisions,
}) {
  final ValueChanged<double> onChanged = enabled ? (double d) => value = d : null;
  return MaterialApp(
    home: Scaffold(
      body: Center(
        child: SliderTheme(
          data: sliderTheme,
          child: Slider(
            value: value,
            label: '$value',
            onChanged: onChanged,
            divisions: divisions,
          ),
        ),
      ),
    ),
  );
}