Drag And Drop feature is very helpful. It is very simple and easy to implement. It is used in many apps that are famous, and if we’re doing some project it is very convenient to implement it. You should know the RecyclerAdapter Class. A sample video is given below to get an idea about what we are going to do in this article.
Step-by-Step Implementation
Step 1: Create a New Project in Android Studio
To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.
Step 2:
Create One Recycler View in activity_main.xml and give an id of your recycler view as your choice. We are using RecyclerView Id as recyclerView.
XML
<?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.ConstraintLayout android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <androidx.recyclerview.widget.RecyclerView android:id="@+id/recyclerView" android:layout_width="0dp" android:layout_height="0dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"/> </androidx.constraintlayout.widget.ConstraintLayout> |
Step 3:
Create one xml file res > layout > name of the activity you want. We are using the name row_item.xml for displaying the list that we created with the image and we can use that in RecycleAdapter Class.
XML
<?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.ConstraintLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:background="@android:color/white" android:foreground="?attr/selectableItemBackground"> <ImageView android:id="@+id/imageView" android:layout_width="48dp" android:layout_height="48dp" android:layout_marginStart="16dp" android:layout_marginTop="16dp" android:layout_marginBottom="16dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:srcCompat="@mipmap/ic_launcher" /> <TextView android:id="@+id/textView" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginStart="16dp" android:layout_marginEnd="8dp" android:text="TextView" android:textAppearance="@style/TextAppearance.AppCompat.Large" app:layout_constraintBottom_toTopOf="@+id/rowCountTextView" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toEndOf="@+id/imageView" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/rowCountTextView" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginEnd="8dp" android:text="TextView" android:textAppearance="@style/TextAppearance.AppCompat.Small" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="@+id/textView" app:layout_constraintTop_toBottomOf="@+id/textView" /> </androidx.constraintlayout.widget.ConstraintLayout> |
Step 4:
It is the RecyclerAdapter.java class that is used to implement the RecyclerView. To add the implementation Of the View Holder Right click after adding RecyclerView.Adapter<RecyclerAdapter.ViewHolder> And implement all three methods.
Java
package com.android.gfgapp; import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import android.widget.TextView;import android.widget.Toast; import androidx.annotation.NonNull;import androidx.recyclerview.widget.RecyclerView; import java.util.List; public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> { private static final String TAG = "RecyclerAdapter"; List<String> citiesList; // create constructor by right clicking public RecyclerAdapter(List<String> citiesList) { this.citiesList = citiesList; } @NonNull @Override public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) { LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext()); // Make Sure the Activity You Created in Step3 you // use that only inplace of row_item View view = layoutInflater.inflate(R.layout.row_item, parent, false); ViewHolder viewHolder = new ViewHolder(view); return viewHolder; } @Override public void onBindViewHolder(@NonNull ViewHolder holder, int position) { holder.rowCountTextView.setText(String.valueOf(position)); holder.textView.setText(citiesList.get(position)); } @Override public int getItemCount() { return citiesList.size(); } class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { ImageView imageView; TextView textView, rowCountTextView; public ViewHolder(@NonNull View itemView) { super(itemView); imageView = itemView.findViewById(R.id.imageView); textView = itemView.findViewById(R.id.textView); rowCountTextView = itemView.findViewById(R.id.rowCountTextView); itemView.setOnClickListener(this); } @Override public void onClick(View view) { Toast.makeText(view.getContext(), citiesList.get(getAdapterPosition()), Toast.LENGTH_SHORT).show(); } }} |
Step 5:
In this step A Basic Main Activity That Implements the Recycler view and A list of various cities around the world and then implemented the RecyclerView and we also have RecyclerAapterClass which is used to implement Recycler view we don’t have to do anything in the RecyclerAdapter class And then we have to create a simple Callable that was created using ItemTouchHelper class
MainActivity.java
Java
package com.android.gfgapp; import androidx.annotation.NonNull;import androidx.appcompat.app.AppCompatActivity;import androidx.recyclerview.widget.DividerItemDecoration;import androidx.recyclerview.widget.ItemTouchHelper;import androidx.recyclerview.widget.RecyclerView;import android.os.Bundle; import java.util.ArrayList;import java.util.Collections;import java.util.List; public class MainActivity extends AppCompatActivity { RecyclerView recyclerView; RecyclerAdapter recyclerAdapter; List<String> citiesList; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); citiesList = new ArrayList<>(); citiesList.add("Tokyo"); citiesList.add("New York City"); citiesList.add("Paris"); citiesList.add("London"); citiesList.add("Dubai"); citiesList.add("Singapore"); citiesList.add("Hong Kong"); citiesList.add("Shanghai"); citiesList.add("Los Angeles"); citiesList.add("Chicago"); citiesList.add("Miami"); citiesList.add("Sydney"); citiesList.add("Rio de Janeiro"); citiesList.add("Cape Town"); citiesList.add("Mumbai"); citiesList.add("Bangkok"); citiesList.add("Moscow"); citiesList.add("Rome"); citiesList.add("Barcelona"); citiesList.add("Toronto"); citiesList.add("Berlin"); citiesList.add("Istanbul"); citiesList.add("Tokyo"); citiesList.add("Vancouver"); recyclerView = findViewById(R.id.recyclerView); recyclerAdapter = new RecyclerAdapter(citiesList); recyclerView.setAdapter(recyclerAdapter); DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(this, DividerItemDecoration.VERTICAL); recyclerView.addItemDecoration(dividerItemDecoration); ItemTouchHelper itemTouchHelper = new ItemTouchHelper(simpleCallback); itemTouchHelper.attachToRecyclerView(recyclerView); } ItemTouchHelper.SimpleCallback simpleCallback = new ItemTouchHelper.SimpleCallback(ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.START | ItemTouchHelper.END, 0) { @Override public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) { int fromPosition = viewHolder.getAdapterPosition(); int toPosition = target.getAdapterPosition(); Collections.swap(citiesList, fromPosition, toPosition); recyclerView.getAdapter().notifyItemMoved(fromPosition, toPosition); return false; } @Override public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int direction) { } }; } |
Output:
