<canvas width="600" height="400"> </canvas>
<script>
var tela = document.querySelector("canvas");
var pincel = tela.getContext("2d");
pincel.fillStyle = "grey";
pincel.fillRect(0, 0, 600, 400);
function exiberAlert(evento){
alert("clikei");
console.log(evento);
}
tela.onclick = exiberAlert
</script>
