Question

in a définition of a widget, what is a better practice, and why, use the widget himself or the type “higher”, example, it’s a better practice to do

1) Button myButton;
or
2) Hastext myButton; (and set a button later)

thanks for your answer.

Answer 1

The answer to that lies in the Model-View-Presenter pattern, that was introduced in last years Google IO presentation by Ray Ryan. There’s also an official tutorial/docs – part 1 and part 2. There are also a number of questions here on SO that cover that topic 🙂

And a quick answer to your question (that will make more sense once you get familiar with MVP): use interfaces in the Presenter and their implementations in the View 🙂 That way your Presenter stays oblivious to the underlying implementation/Widget you actually used (was it a Button? Or a Label? It doesn’t matter, they both implement HasText).