The widget exploration app

We have just discussed six widgets – EditText, ImageView, RadioButton (and RadioGroup), Switch, CheckBox, and TextClock. Let's make a working app and do something practical with each of them. We will also use a Button widget and a TextView widget again as well.

In this layout, we will use LinearLayout as the layout type that holds everything, and within LinearLayout, we will use multiple RelativeLayout instances.

RelativeLayout has been superseded by ConstraintLayout, but they are still commonly used and are worth playing around with. You will see as you build layouts within RelativeLayout that the UI elements behave very much the same as ConstraintLayout, but that the underlying XML is different. It is not necessary to learn this XML in detail, rather, using RelativeLayout will allow us to show the interesting way that Android Studio enables you to convert these layouts to ConstraintLayout.

Remember that you can refer to the completed code in the...