BareBonesRecyclerView

Simple implementation of a recycler view to expose all the components necessary in a straight forward manner and facilitate learning/recall. Each instruction below has a matching commit to show a simple implementation of the instructions.

#Step 1: Gradle dependency

• add to Gradle app file: compile 'com.android.support:recyclerview-v7:25.0.1'
• replace the version with something that fits your app

#Step 2: Create MainActivity.java

• add global references
  • RecyclerView (import it)
  • RecyclerAdapter (you'll write this class later)
  • LinearLayoutManger (import it)
  • Data (list of whatever you're trying to display, this project uses a simple array)
• in MainActivity.onCreate()
  • set recyclerView reference to a view with findViewById(R.id.list) (you'll add the recycler view with id list to xml later)
  • set RecyclerAdapter reference to a new RecyclerAdapter whose constructor takes in the data array
  • set linearLayoutManger to new LinearLayoutManager
  • set recyclerView adapter
  • set recyclerView layout manager

#Step 3: Add missing parts

• write recycler adapter class in new file (that extends RecyclerView.Adapter<CustomHolder>) (you'll write CustomHolder later)
  • add a global reference to a data array
  • implement methods
  • write constructor and set data to the constructor's input
  • update getItemCount() to return size of data array
  • in onBindViewHolder() set the fields of the holder with holder.bindData(position) (you'll write this method in the holder below)
  • in onCreateViewHolder() inflate the item layout with an xml id that will be defined later and pass to CustomHolder's constructor to return it

@Override
public CustomHolder onCreateViewHolder(ViewGroup parent, int viewType) {
   View inflatedView = LayoutInflater.from(parent.getContext())
           .inflate(R.layout.item_layout, parent, false);
   return new CustomHolder(inflatedView);
}

• write CustomHolder class inside the adapter class (extends RecyclerView.ViewHolder implements OnClickListener)
  • implement methods
  • write refs to what you want to display in each row of recycler view (defined in the xml file for the layout of each row, which we'll write later)
  • write method bindData(args) to bind args to the refs above; setting the values directly from the holder will return an error
  • in constructor, set refs to fields in the xml we'll write later, findById() with future ids, and set the view's click listener to this
• write missing xml
  • add a RecyclerView widget to the xml of the main activity with the right id used in MainActivity
  • add a item xml layout file for the item to be displayed in each row of the recycler view, this will contain all the views that the CustomHolder requires