Drag and Drop Example

Drag and Drop is useful in canvas or drawing application.Here is full description,just follow it.

• Modify the code in activity_main.xml file.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>

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

    android:id="@+id/LinearLayout01"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:gravity="center" >

    <Button

        android:id="@+id/btn"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="Drag Me" >

    </Button>

</FrameLayout>

• Add below code in MainActivity.java file.

MainActivity.java

public class Home extends Activity implements OnTouchListener {

private final static int START_DRAGGING = 0;

private final static int STOP_DRAGGING = 1;

private Button btn;

private FrameLayout layout;

private int status;

private LayoutParams params;

private ImageView image;

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

layout = (FrameLayout) findViewById(R.id.LinearLayout01);

// layout.setOnTouchListener(this);

btn = (Button) findViewById(R.id.btn);

btn.setDrawingCacheEnabled(true);

btn.setOnTouchListener(this);

params = new LayoutParams(LayoutParams.WRAP_CONTENT,

LayoutParams.WRAP_CONTENT);

}

@Override

public boolean onTouch(View view, MotionEvent me) 

{

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

status = START_DRAGGING;

image = new ImageView(this);

image.setImageBitmap(btn.getDrawingCache());

layout.addView(image, params);

}

if (me.getAction() == MotionEvent.ACTION_UP) {

status = STOP_DRAGGING;

Log.i("Drag", "Stopped Dragging");

} else if (me.getAction() == MotionEvent.ACTION_MOVE) {

if (status == START_DRAGGING) {

System.out.println("Dragging");

image.setPadding((int) me.getRawX(), (int) me.getRawY(), 0, 0);

image.invalidate();

}

}

return false;

}

}

• Done ! Now Run the Project.Try to drag button.