DropDown on swift

First you have to create an IBOutlet for the button that will have its title changed: (Do not forget to connect it to the button on the storyboard)

@IBOutlet var botao: UIButton!

There in the "func createPicker ()" add the following line in the loop where you create the popup options:

button.addTarget(self, action: "clicado:", forControlEvents: .TouchUpInside)

The above line tells the button being created, which method it should call when it is clicked.

Then you create the method:

func clicado(sender : UIButton){
   // acha o titulo de acordo com a tag do botão clicado
   let feeling = properties.moods[sender.tag].first!
   // atribui o titulo achado ao botão do IBOutlet criado
   self.botao.setTitle(feeling.1, forState: .Normal)
   // fecha o picker
   self.closePicker()
}