This library contains a few core classes that are often used alongside a RecyclerView, and are intended to remove some of the tedious boilerplate code from being written many times.

Usage

To have access to the library, add the dependency to your build.gradle:

    compile 'com.adammcneilly:recyclerviewutils:2.0.2'

CoreViewHolder

At the heart of these classes is CoreViewHolder which is a RecyclerView.ViewHolder class used to display an object of a specific type. It has one abstract method for binding an object of that type.

Below is a sample of a CoreViewHolder for Account objects:

public class AccountViewHolder extends CoreViewHolder<Account> {
    private TextView tvName;
    private TextView tvBalance;

    public AccountViewHolder(View view) {
        super(view);

        this.tvName = (TextView) view.findViewById(R.id.account_name);
        this.tvBalance = (TextView) view.findViewById(R.id.account_balance);
    }

    @Override
    protected void bindItem(Account item) {
        this.tvName.setText(item.getName());
        this.tvBalance.setText(String.valueOf(item.getBalance()));
    }
}

Or in Kotlin:

internal inner class AccountViewHolder(view: View) : CoreViewHolder<Account>(view) {
    private val tvName: TextView = view.findViewById(R.id.account_name) as TextView
    private val tvBalance: TextView = view.findViewById(R.id.account_balance) as TextView

    override fun bindItem(item: Account) {
        this.tvName.text = item.name
        this.tvBalance.text = item.balance.toString()
    }
}

This class also implements the View.OnClickListener interface. If you want to handle clicks in your ReyclerView, just ovveride the onClick() method in your ViewHolder class.

CoreRecyclerViewAdapter

Using the CoreViewHolder class from above, the CoreRecyclerViewAdapter is an abstract base class for using an adapter of objects with a given type. By using a generic type, we were able to override many boilerplate methods such as:

• add
• remove
• swapItems
• onBindViewHolder

Thanks to this handy utils class, it cuts down on a ton of boilerplate code inside your adapter, and makes it very simple:

public class AccountAdapter extends CoreRecyclerViewAdapter<Account, AccountAdapter.AccountViewHolder>{
    public AccountAdapter(Context context, List<Account> accounts) {
        super(context, accounts);
    }

    @Override
    public AccountViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return new AccountViewHolder(LayoutInflater.from(context).inflate(R.layout.list_item_account, parent, false));
    }

    public class AccountViewHolder extends CoreViewHolder<Account> {
        ...
    }
}

Or in Kotlin:

internal class AccountAdapter(accounts: MutableList<Account>) : CoreRecyclerViewAdapter<Account, AccountAdapter.AccountViewHolder>(accounts) {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): AccountViewHolder {
        return AccountViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.list_item_account, parent, false))
    }

    internal inner class AccountViewHolder(view: View) : CoreViewHolder<Account>(view) {
        ...
    }
}

CoreDividerItemDecoration

The CoreDividerItemDecoration class is used to display a simple line divider between list items in your RecyclerView.

Credits & Contact

This library was created by Adam McNeilly.

And reviewed by Maurício Pessoa.

Version History

2.0.2

• Added long click listener to CoreViewHolder.

2.0.1

• Made a number of parameters nullable.

2.0.0

• Converted library to Kotlin.

1.0.5

• Updated support library version.

1.0.4

• Updated support library version.

1.0.3

• Minor update that made the items field protected, so sub classes could make use of it.

1.0.2

• Added a default constructor and removed adapter's dependency on a Context.
• Added the List interface to the adapter to allow easier addition/removal of items.

1.0.1

• Added View.OnClickListener interface to the CoreViewHolder.
• Code cleanup and removed deprecated methods.

1.0.0

• Initial release.

License

The RecyclerViewUtils library is available under the MIT License. You are free to modify and enhance it in any way. If you submit a pull request, please add your name into the credits section! :)