RangeThumbSelector typedef Null safety

RangeThumbSelector = Thumb? Function(TextDirection textDirection, RangeValues values, double tapValue, Size thumbSize, Size trackSize, double dx)

Decides which thumbs (if any) should be selected.

The default finds the closest thumb, but if the thumbs are close to each other, it waits for movement defined by dx to determine the selected thumb.

Override SliderThemeData.thumbSelector for custom thumb selection.

Implementation

typedef RangeThumbSelector = Thumb? Function(
  TextDirection textDirection,
  RangeValues values,
  double tapValue,
  Size thumbSize,
  Size trackSize,
  double dx,
);