How we can use Drag and Drop in Android

Ashwani Yadav

26 February 2021

In this blog we will read how we can use Drag and Drop in Android . Drag and Drop allows user to move your data from one view to another.

Drag And Drop process

In Drag and Drop process there are four steps

1.Started

2.Continuing

3.Dropped

4.Ended

1.Started

This step occurred when the user starts dragging into view. when the user starts dragging then startDrag() method will call .

2.Continuing

This step occurs when user continues to drag and shadow intersect on view and ACTION_DRAG_ENTERED event will call

3.Dropped

user can drop view anywhere on the screen . But the thing to be noted here is that you can drop the dragged element in any part of the screen but the dropped event will be called only when if you drop the view in a view that is associated with the drag event and ACTION_DROP event will call

4.Ended

when user drops shadow anywhere and then this event will occur and ACTION_DRAG_ENDED event will call

Now let’s start code for it.

MainActivity

package com.example.myapplication;

import android.content.ClipData;
import android.content.ClipDescription;
import android.os.Bundle;
import android.util.Log;
import android.view.DragEvent;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;

import androidx.appcompat.app.AppCompatActivity;


public class MainActivity extends AppCompatActivity {
    ImageView img;
    String msg ="MainActivity";
    LinearLayout linearLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        img = findViewById(R.id.imageView);
        linearLayout = findViewById(R.id.linearlayout);
        linearLayout.setOnDragListener(new View.OnDragListener() {
            @Override
            public boolean onDrag(View v , DragEvent event) {
                switch (event.getAction()) {
                    case DragEvent.ACTION_DRAG_STARTED:
                        Log.d(msg , "Action is DragEvent.ACTION_DRAG_STARTED");
                        break;

                    case DragEvent.ACTION_DRAG_ENTERED:
                        Log.d(msg , "Action is DragEvent.ACTION_DRAG_ENTERED");
                        break;

                    case DragEvent.ACTION_DRAG_EXITED:
                        Log.d(msg , "Action is DragEvent.ACTION_DRAG_EXITED");

                        break;

                    case DragEvent.ACTION_DRAG_LOCATION:
                        Log.d(msg , "Action is DragEvent.ACTION_DRAG_LOCATION");
                        break;

                    case DragEvent.ACTION_DRAG_ENDED:
                        Log.d(msg , "Action is DragEvent.ACTION_DRAG_ENDED");
                        break;

                    case DragEvent.ACTION_DROP:
                        Log.d(msg , "ACTION_DROP event");
                        View tvState = (View) event.getLocalState();
                        Log.d(msg , "onDrag:viewX" + event.getX() + "viewY" + event.getY());
                        Log.d(msg , "onDrag: Owner-&gt;" + tvState.getParent());
                        ViewGroup tvParent = (ViewGroup) tvState.getParent();
                        tvParent.removeView(tvState);
                        LinearLayout container = (LinearLayout) v;
                        container.addView(tvState);
                        tvParent.removeView(tvState);
                        tvState.setX(event.getX());
                        tvState.setY(event.getY());
                        ((LinearLayout) v).addView(tvState);
                        v.setVisibility(View.VISIBLE);
                        break;
                    default:
                        break;
                }
                return true;
            }
        });

        img.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v , MotionEvent event) {
                if (event.getAction() == MotionEvent.ACTION_DOWN) {
                    ClipData data = ClipData.newPlainText("" , "");
                    View.DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(img);
                    v.startDrag(data , shadowBuilder , v , 0);
                    v.setVisibility(View.VISIBLE);
                    return true;
                } else {
                    return false;
                }
            }
        });
    }
}

package com.example.myapplication;

import android.content.ClipData;

import android.content.ClipDescription;

import android.os.Bundle;

import android.util.Log;

import android.view.DragEvent;

import android.view.MotionEvent;

import android.view.View;

import android.view.ViewGroup;

import android.widget.ImageView;

import android.widget.LinearLayout;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

ImageView img;

String msg ="MainActivity";

LinearLayout linearLayout;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

img = findViewById(R.id.imageView);

linearLayout = findViewById(R.id.linearlayout);

linearLayout.setOnDragListener(new View.OnDragListener() {

@Override

public boolean onDrag(View v , DragEvent event) {

switch (event.getAction()) {

case DragEvent.ACTION_DRAG_STARTED:

Log.d(msg , "Action is DragEvent.ACTION_DRAG_STARTED");

break;

case DragEvent.ACTION_DRAG_ENTERED:

Log.d(msg , "Action is DragEvent.ACTION_DRAG_ENTERED");

break;

case DragEvent.ACTION_DRAG_EXITED:

Log.d(msg , "Action is DragEvent.ACTION_DRAG_EXITED");

break;

case DragEvent.ACTION_DRAG_LOCATION:

Log.d(msg , "Action is DragEvent.ACTION_DRAG_LOCATION");

break;

case DragEvent.ACTION_DRAG_ENDED:

Log.d(msg , "Action is DragEvent.ACTION_DRAG_ENDED");

break;

case DragEvent.ACTION_DROP:

Log.d(msg , "ACTION_DROP event");

View tvState = (View) event.getLocalState();

Log.d(msg , "onDrag:viewX" + event.getX() + "viewY" + event.getY());

Log.d(msg , "onDrag: Owner->" + tvState.getParent());

ViewGroup tvParent = (ViewGroup) tvState.getParent();

tvParent.removeView(tvState);

LinearLayout container = (LinearLayout) v;

container.addView(tvState);

tvParent.removeView(tvState);

tvState.setX(event.getX());

tvState.setY(event.getY());

((LinearLayout) v).addView(tvState);

v.setVisibility(View.VISIBLE);

break;

default:

break;

}

return true;

}

});

img.setOnTouchListener(new View.OnTouchListener() {

@Override

public boolean onTouch(View v , MotionEvent event) {

if (event.getAction() == MotionEvent.ACTION_DOWN) {

ClipData data = ClipData.newPlainText("" , "");

View.DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(img);

v.startDrag(data , shadowBuilder , v , 0);

v.setVisibility(View.VISIBLE);

return true;

} else {

return false;

}

});

}

activity_main

&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:id="@+id/linearlayout"
    android:orientation="vertical"
    android:layout_height="match_parent"
    tools:context=".MainActivity"&gt;


    &lt;TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="Drag and Drop"
        android:id="@+id/textView"
        android:textSize="25sp" /&gt;


    &lt;ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:id="@+id/imageView"
        android:src="@drawable/ic_baseline_drive_eta_24" /&gt;
&lt;/LinearLayout&gt;

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:id="@+id/linearlayout"

android:orientation="vertical"

android:layout_height="match_parent"

tools:context=".MainActivity">

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="center"

android:text="Drag and Drop"

android:id="@+id/textView"

android:textSize="25sp" />

<ImageView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="center"

android:id="@+id/imageView"

android:src="@drawable/ic_baseline_drive_eta_24" />

</LinearLayout>

Now you can see in the screenshot how we drag car from one dimension to another

So here we discussed about How we can use Drag and Drop in Android. Thanks for reading this blog and You can get other blogs from here