Flutter: Disabling Multi-Touch/Drag with Gesture Detector

Question

Im currently building a Slider widget which multiple handle and am currently implementing the Gesture Detector. I am having an issue where if you touch/drag the screen with a se

Answer 1

According to the class reference:

Attempts to recognize gestures that correspond to its non-null callbacks.

So if you write it like this:

GestureDetector(
  onDragUpdate: (updateDetails) {
    // Single finger drag, update your handlers
  },
  onPanDown: (_){}, 
  onPanStart: (_){}, 
  onPanUpdate: (_){}, 
  onPanEnd: (_){}, 
  onPanCancel: (){},
  child: Container(
    color: Colors.yellow,
    child: Text('TURN LIGHTS ON'),
  ),
)

It won't react on multi-touch, so you don't have to disable anything

UPD: according to question edit, you should set empty but non-null callbacks for all multi-touch events, so two fingers drag will be handled by empty callback, but single finger not

Answer 2

Whilst I was working on another separate problem I happened to have also solved this problem by using the solution here