Draggable layer with inertia and boundaries in FramerJS

innertia.coffee

ACCELERATION = 180
INERTIA_CURVE = "spring(140, 30, 0, 0)"

Layer::inertia = ->

  calculateFinalY = =>
    newY = @y + @draggable.calculateVelocity().y * ACCELERATION

    switch
      when newY > 0 then return 0
      when newY + @height < Framer.Device.screen.height then return -@height + Framer.Device.screen.height
      else return newY

  @animate
    properties: y: calculateFinalY()
    curve: INERTIA_CURVE
 
# layerName.on Events.DragEnd, -> @inertia()