Friday, July 10, 2015

Add and remove items to RecyclerView, with default animation

Last example show how to Place RecyclerView in layout XML. Here we add user editable EditText and Button to add items to RecyclerView, and also when user click on the item in RecyclerView, the item will be removed. Refer to the video, it also show the default animation effect when notifyItemInserted() and notifyItemRemoved() of RecyclerView.Adapter are called.



com.example.androidrecyclerview.MainActivity
package com.example.androidrecyclerview;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends ActionBarActivity implements RecyclerViewAdapter.OnItemClickListener{

    private RecyclerView myRecyclerView;
    private LinearLayoutManager linearLayoutManager;
    private RecyclerViewAdapter myRecyclerViewAdapter;

    EditText nameField;
    Button btnAdd;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        myRecyclerView = (RecyclerView)findViewById(R.id.myrecyclerview);

        linearLayoutManager =
                new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
        /*
        linearLayoutManager =
                new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
        */

        myRecyclerViewAdapter = new RecyclerViewAdapter(this);
        myRecyclerViewAdapter.setOnItemClickListener(this);
        myRecyclerView.setAdapter(myRecyclerViewAdapter);
        myRecyclerView.setLayoutManager(linearLayoutManager);

        nameField = (EditText)findViewById(R.id.namefield);
        btnAdd = (Button)findViewById(R.id.addbutton);
        btnAdd.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                String newName = nameField.getText().toString();

                if(!newName.equals("")){
                    if(myRecyclerViewAdapter.getItemCount()>1){
                        myRecyclerViewAdapter.add(1, newName);
                    }else{
                        myRecyclerViewAdapter.add(0, newName);
                    }
                }
            }
        });
    }

    @Override
    public void onItemClick(RecyclerViewAdapter.ItemHolder item, int position) {
        Toast.makeText(this,
                "Remove " + position + " : " + item.getItemName(),
                Toast.LENGTH_SHORT).show();
        myRecyclerViewAdapter.remove(position);
    }
}


layout/activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
        <EditText
            android:id="@+id/namefield"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"/>
        <Button
            android:id="@+id/addbutton"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="Add"/>
    </LinearLayout>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/myrecyclerview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</LinearLayout>


Keep using the files RecyclerViewAdapter.java and layout_item.xmlin the exercise of Simple RecyclerView example.

Next:
Implement custom ItemDecoration for RecyclerView

3 comments:

Obie Aja said...

how about with button delete? and extends RecyclerView.Adapter ?
thx before

Vishal Bhimani said...

Where is your RecycleViewAdapter?
give Adapter code to understand..

Andr.oid Eric said...

hello Vishal Bhimani,

Keep using the files RecyclerViewAdapter.java and layout_item.xmlin the exercise of Simple RecyclerView example. http://android-er.blogspot.com/2015/07/simple-recyclerview-example.html