RecyclerView

RecyclerView for displaying lists of data:

As the name implies, RecyclerView recycles those individual elements. When an item scrolls off the screen, RecyclerView doesn’t destroy its view. Instead, RecyclerView reuses the view for new items that have scrolled onscreen. This reuse vastly improves performance, improving your app’s responsiveness and reducing power consumption.

Key classes

Several different classes work together to build your dynamic list.

• RecyclerView is the ViewGroup that contains the views corresponding to your data. It’s a view itself, so you add RecyclerView into your layout the way you would add any other UI element.

• Each individual element in the list is defined by a view holder object. When the view holder is created, it doesn’t have any data associated with it. After the view holder is created, the RecyclerView binds it to its data. You define the view holder by extending RecyclerView.ViewHolder.

• The RecyclerView requests those views, and binds the views to their data, by calling methods in the adapter. You define the adapter by extending RecyclerView.Adapter.

• The layout manager arranges the individual elements in your list. You can use one of the layout managers provided by the RecyclerView library, or you can define your own. Layout managers are all based on the library’s LayoutManager abstract class.

Steps for implementing your RecyclerView

• First of all, decide what the list or grid is going to look like. Ordinarily you’ll be able to use one of the RecyclerView library’s standard layout managers.

• Design how each element in the list is going to look and behave. Based on this design, extend the ViewHolder class. Your version of ViewHolder provides all the functionality for your list items. Your view holder is a wrapper around a View, and that view is managed by RecyclerView.

• Define the Adapter that associates your data with the ViewHolder views.

resources:

https://developer.android.com/guide/topics/ui/layout/recyclerview#java