Subscribe in a readerAndroid comes with a wide variety of widgets, small visual construction blocks you can glue together to present the users with complex and useful interfaces. However applications often need higher level visual components. A component can be seen as a complex widget made of several simple stock widgets. You could for instance reuse a panel containing a progress bar and a cancel button, a panel containing two buttons (positive and negative actions), a panel with an icon, a title and a description, etc. Creating new components can be done easily by writing a custom View but it can be done even more easily using only XML.
In Android XML layout files, each tag is mapped to an actual class instance (the class is always a subclass of View.) The UI toolkit lets you also use three special tags that are not mapped to a View instance:
The
