exercicio8ano.js

window.onload = function() {
  console.log("carregando arquivo...");
  var canvas = document.getElementById("canvas");
  var boneco = document.getElementById("boneco");
  var ctx = canvas ? canvas.getContext("2d") : null;

  var bonecoCoord = {
    x: 25,
    y: 200
  }
  
  if(ctx) ctx.drawImage(boneco, bonecoCoord.x, bonecoCoord.y);

  function darUmPasso() {
    var arg = [...arguments][0];
    if(arg) {
      if(typeof arg === 'number') {
        bonecoCoord.x += arg;    
      } else {
        switch(arg) {
          case "direita": bonecoCoord.x += 3; break;
          case "esquerda": bonecoCoord.x -= 3; break;
          case "cima": bonecoCoord.y -= 3; break;
          case "baixo": bonecoCoord.y += 3; break;
          default: return;
        }
      }
    } else {
      bonecoCoord.x += 3;
    }
    
    console.log("andando...");
    
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    ctx.drawImage(boneco, bonecoCoord.x, bonecoCoord.y);
  }

  document.addEventListener('keydown', function(e) {
    if(e.keyCode === 39) {darUmPasso();}
  });
  
  window.darUmPasso = darUmPasso;
}