def setup 
  c = createCanvas(100, 100)
  background(200)
  textAlign(CENTER)
  text('drag & drop file', width / 2, height / 2)
  c.dragOver do
    background(240)
    text('Dragged over', width / 2, height / 2)
  end
  c.dragLeave do
    background(200)
    text('Dragged off', width / 2, height / 2)
  end
  c.drop do |file|
    background(200)
    text('dropped file:', width / 2, height / 2)
    text("[#{file.type}]", width / 2, height / 2 + 30)
  end
end