To really demonstrate the use of a custom layout, you need to try building something unusual. In the following example, you'll put together a ViewGroup that arranges its children in a nice circle. It's not a very brilliant layout, nor is it particularly useful, but circles are nice to look at, and it would provide useful negative space in the screen center (which could be filled using a FrameLayout).
Create a new Java source file in the root package of the project named
CircleLayout.java, and open it in your editor or IDE.Declare the
CircleLayoutas extending theViewGroupclass:public class CircleLayout extends ViewGroup
Declare the three
ViewGroupconstructors and have them delegate directly to theViewGroupdefault constructors:public CircleLayout(Context context) { super(context); } // ...We'll need to know the largest number of pixels taken up by a child
Viewobject's width, and the largest number of pixels taken up by a childViewobject...