我用popoverPresentationController来展示我的府绸.用于显示为popover的UITableViewController是通过编程创建的，通常包含1到5行.如何设置此popover以根据tableview的内容调整大小？
我的popover的代码:
if recognizer.state == .Began {
let translation = recognizer.locationInView(view)
// Create popoverViewController
var popoverViewController = UITableViewController()
popoverViewController.modalPresentationStyle = UIModalPresentationStyle.Popover
popoverViewController.tableView.backgroundColor = UIColor.popupColor()
// Settings for the popover
let popover = popoverViewController.popoverPresentationController!
popover.delegate = self
popover.sourceView = self.view
popover.sourceRect = CGRect(x: translation.x, y: translation.y, width: 0, height: 0)
popover.backgroundColor = UIColor.popupColor()
presentViewController(popoverViewController, animated: true, completion: nil)
}