Move object within canvas boundary limit

canvas.on('object:moving', function (e) {
  var obj = e.target;
  // if object is too big ignore
  if(obj.currentHeight > obj.canvas.height || obj.currentWidth > obj.canvas.width){
    return;
  }
  obj.setCoords();
  // top-left  corner
  if(obj.getBoundingRect().top < 0 || obj.getBoundingRect().left < 0){
    obj.top = Math.max(obj.top, obj.top-obj.getBoundingRect().top);
    obj.left = Math.max(obj.left, obj.left-obj.getBoundingRect().left);
  }
  // bot-right corner
  if(obj.getBoundingRect().top+obj.getBoundingRect().height  > obj.canvas.height || obj.getBoundingRect().left+obj.getBoundingRect().width  > obj.canvas.width){
    obj.top = Math.min(obj.top, obj.canvas.height-obj.getBoundingRect().height+obj.top-obj.getBoundingRect().top);
    obj.left = Math.min(obj.left, obj.canvas.width-obj.getBoundingRect().width+obj.left-obj.getBoundingRect().left);
  }
});