Flutter - Remove default padding in Slider

Question

I am wondering how I can remove the default padding in Flutter Slider

Current output is like this, default padding of Slider is clearly visible

Here's my code::

                    Positioned(
                      child: Align(
                        alignment: Alignment.bottomLeft,
                        child: SliderTheme(
                            data: SliderTheme.of(context).copyWith(
                              trackHeight: 2.0,
                              thumbColor: Colors.transparent,
                              thumbShape: RoundSliderThumbShape(enabledThumbRadius: 0.0),
                            ),
                            child: Container(
                                width: 380.0,
                                height: 20.0,
                                padding: EdgeInsets.all(0.0),
                                decoration: BoxDecoration(
                                  border: Border.all(color: Colors.blueAccent)
                                ),
                                child: Slider(
                                  value: 50,
                                  min: 1,
                                  max: 100,
                                  divisions: 100,
                                  activeColor: colors.primaryRed,
                                  inactiveColor: Colors.white,
                                  onChanged: (double newValue) {
                                    print(newValue);
                                  },
                                )
                            )
                        ),
                      ),
                    )

user_15517013 · Answer

SliderThemeData(overlayShape: SliderComponentShape.noOverlay)

or

overlayShape: SliderComponentShape.noThumb

Default padding is caused by thumb painting and overlay painting, by specifying these properties you will remove them, but you will get zero padding

https://api.flutter.dev/flutter/material/SliderThemeData-class.html

user_11631758 · Answer

you can fix it with custom trackShape like this:

add this line to SliderTheme data:

trackShape: CustomTrackShape(),

then inside CustomTrackShape() you must write this code:

class CustomTrackShape extends RoundedRectSliderTrackShape {
  Rect getPreferredRect({
    @required RenderBox parentBox,
    Offset offset = Offset.zero,
    @required SliderThemeData sliderTheme,
    bool isEnabled = false,
    bool isDiscrete = false,
    }) {
      final double trackHeight = sliderTheme.trackHeight;
      final double trackLeft = offset.dx;
      final double trackTop = offset.dy + (parentBox.size.height - trackHeight) / 2;
      final double trackWidth = parentBox.size.width;
      return Rect.fromLTWH(trackLeft, trackTop, trackWidth, trackHeight);
    }
}

Flutter - Remove default padding in Slider

2 Answers