Pointer Events

You can listen for pointer events inside any script that implements pointerDown, pointerMove, pointerUp, or pointerExit. These functions can be defined in Node Scripts and Layout Scripts.

-- Pointer event callbacks have parameters of `self` and a `PointerEvent`.
function handlePointerDown(self: MyNode, event: PointerEvent)
  -- Pointer location in local coordinates relative to the script.
  print(event.position.x, event.position.y)

  -- the pointer identifier (useful for multi-touch)
  print(event.id)

  -- Marks the event as handled and prevents propagation.
  event:hit()
  -- event:hit(true) -- handled, but allowed to pass through translucent elements
end

-- Register your pointer handlers by assigning functions to pointerDown,
-- pointerUp, pointerMove, or pointerExit in the script’s returned table.
return function(): Node<MyScript>
  return {
    init = init,
    draw = draw,
    advance = advance,
    pointerDown = myPointerDownFunction,
  }
end

Multi-touch

Using event.id, you can track multiple active pointers.

type ActiveId = {
  position: Vec2D,
}

export type TrackPointers = {
  -- Keep track of the position for each of the pointers
  activePointers: { ActiveId },
}

function onPointerDown(self: TrackPointers, event: PointerEvent)
  -- Save an item in the table for each pointer down
  self.activePointers[event.id] = {
    position = event.position,
  }

  print('New pointer down: ' .. event.id)
  print('Position: ' .. event.position.x .. event.position.y)

  event:hit()
end

function onPointerMove(self: TrackPointers, event: PointerEvent)
  if self.activePointers[event.id] then
    self.activePointers[event.id].position = event.position

    -- Print all currently active pointer IDs
    print('Active pointer IDs:')
    for id, pointer in self.activePointers do
      print('  id: ', id)
      print('    x:', pointer.position.x)
      print('    y:', pointer.position.y)
    end
  end

  event:hit()
end

function onPointerUp(self: TrackPointers, event: PointerEvent)
  self.activePointers[event.id] = nil

  print('Pointer up: ' .. event.id)
  print('Position: ' .. event.position.x .. event.position.y)

  event:hit()
end

return function(): Node<TrackPointers>
  return {
    init = init,
    advance = advance,
    draw = draw,
    pointerDown = onPointerDown,
    pointerMove = onPointerMove,
    pointerUp = onPointerUp,
    activePointers = {},
  }
end

Nested Pointer Events

Rive only listens for Pointer Events on the main artboard. If you need to listen for Pointer Events in your instantiated artboards, you must forward them manually.

-- Handle pointer events in the main script
function handlePointerDown(self: MyScript, event: PointerEvent)
  -- self.enemy.pointerDown(self.enemy, event)
  for _, enemy in self.enemies do
    -- Convert the incoming pointer position into the enemy's local space.
    -- This example assumes enemy.position is in the same coordinate system.
    local localEvent = PointerEvent.new(
      event.id,
      Vec2D.xy(
        -- Normalize the pointer position based on the artboard's position
        event.position.x - enemy.position.x,
        event.position.y - enemy.position.y
      )
    )

    -- Forward the event into the instantiated artboard
    self.enemy:pointerDown(localEvent)
  end
end