Fabricjs -如何通过键盘移动选定的对象

<canvas id="canvas" width="800" height="600"></canvas>
<script>
  var canvas = new fabric.Canvas('canvas');
</script>

var rect = new fabric.Rect({
  left: 100,
  top: 100,
  width: 200,
  height: 100,
  fill: 'red'
});

canvas.add(rect);

document.addEventListener('keydown', function(event) {
  var selectedObject = canvas.getActiveObject();
  
  if (selectedObject) {
    var moveDistance = 10; // 移动的距离
    
    switch (event.keyCode) {
      case 37: // 左箭头键
        selectedObject.set('left', selectedObject.left - moveDistance);
        break;
      case 38: // 上箭头键
        selectedObject.set('top', selectedObject.top - moveDistance);
        break;
      case 39: // 右箭头键
        selectedObject.set('left', selectedObject.left + moveDistance);
        break;
      case 40: // 下箭头键
        selectedObject.set('top', selectedObject.top + moveDistance);
        break;
    }
    
    canvas.renderAll();
  }
});