How do I lerp a double or integer value in Flutter?-CodePudding

I want to lerp the elevation property for a Card upon clicking and holding it on its InkWell.

What I want to do is change its elevation from say 50 to 0, lerping it and reducing the value gradually the longer the InkWell is held, and when it is let go, it lerps back to 50 quickly.

How do I achieve this?

CodePudding user response：

Add a variable

double _updatedElevation = 50.0;
late Timer elevationTimer;

Then in inkwell add onTapDown and call startAnimatingElevation

startAnimatingElevation(){
  _updatedElevation = 50;
  elevationTimer = Timer.periodic(
  const Duration(milliseconds: 1),
  (timer) {
   if(_updatedElevation > 0)
   {
    _updatedElevation--;
    setState((){});
   }
   else{
     timer.cancel();
    }
  },
);
}

assign _updatedElevation as the elevation of the card you wish to animate.

Then add onTapUp in inkwell and reset allvalues.

_updatedElevation = 50;
elevationTimer.cancel();