Drag view in activity

We can use service to drag view on screen. But we can do it in activity too.

To drag view vertical a layout, we do like this.

Create a file name keoview.xml in folder layout.

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

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

    xmlns:ads="http://schemas.android.com/apk/res-auto"

    android:layout_width="wrap_content"

    android:layout_height="fill_parent"

    android:layout_gravity="center"

    android:orientation="vertical" >

    <TextView

        android:layout_width="130dp"

        android:layout_height="30dp"

        android:layout_gravity="center"

        android:text="Đây là view kéo được"

        android:textColor="#FF0000" />

    <RelativeLayout

        android:id="@+id/root"

        android:layout_width="wrap_content"

        android:layout_height="match_parent"     android:layout_gravity="center" >

        <TextView

         android:id="@+id/te"

         android:layout_width="wrap_content"

         android:layout_height="40dp"

         android:layout_centerVertical="true"

         android:background="#2292CB"

         android:text="Chạm để kéo" />

    </RelativeLayout>

</LinearLayout>

Here is the class to control.

public class keo extends Activity implements View.OnTouchListener {

     private int _yDelta;

     LayoutParams params;

     @Override

     protected void onCreate(Bundle savedInstanceState) {

          super.onCreate(savedInstanceState);

          setContentView(R.layout.keoview);

          findViewById(R.id.te).setOnTouchListener(this);

          params = new WindowManager.LayoutParams(LayoutParams.WRAP_CONTENT,

                     LayoutParams.WRAP_CONTENT, LayoutParams.TYPE_PHONE,

                     LayoutParams.FLAG_NOT_FOCUSABLE, PixelFormat.TRANSLUCENT);   

}

@Override

public boolean onTouch(View view, MotionEvent event) {

final int Y = (int) event.getRawY();

switch (event.getAction() & MotionEvent.ACTION_MASK) {

          case MotionEvent.ACTION_DOWN:

               RelativeLayout.LayoutParams lParams = (RelativeLayout.LayoutParams) view

                          .getLayoutParams();

               _yDelta = Y - lParams.bottomMargin;

               break;

          case MotionEvent.ACTION_UP:

               break;

          case MotionEvent.ACTION_POINTER_DOWN:

               break;

          case MotionEvent.ACTION_POINTER_UP:

               break;

          case MotionEvent.ACTION_MOVE:

               RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) view

                          .getLayoutParams();

               layoutParams.bottomMargin = (Y - _yDelta);

               layoutParams.topMargin = -layoutParams.bottomMargin;

               view.setLayoutParams(layoutParams);

               view.animate().translationY(Y - _yDelta).setDuration(0);

               break;

          }

     findViewById(R.id.root).invalidate();

          return true;

     }

}

To drag view horizontal screen, in file keoview.xml change the layout_width of Linearlayout and RelativeLayout to android:layout_width="match_parent"

In class, declare one more variable.

private int _xDelta;

Command onTouch now like this.

@Override

public boolean onTouch(View view, MotionEvent event) {

          final int X = (int) event.getRawX();

switch (event.getAction() & MotionEvent.ACTION_MASK) {

          case MotionEvent.ACTION_DOWN:

               RelativeLayout.LayoutParams lParams = (RelativeLayout.LayoutParams) view

                          .getLayoutParams();

               _xDelta = X - lParams.leftMargin;

              

               break;

          case MotionEvent.ACTION_UP:

               break;

          case MotionEvent.ACTION_POINTER_DOWN:

               break;

          case MotionEvent.ACTION_POINTER_UP:

               break;

          case MotionEvent.ACTION_MOVE:

               RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) view

                          .getLayoutParams();

              

               layoutParams.leftMargin = (X - _xDelta);

               layoutParams.rightMargin = -layoutParams.leftMargin;

               view.setLayoutParams(layoutParams);

               view.animate().translationX(X - _xDelta).setDuration(0);

               break;

          }

          findViewById(R.id.root).invalidate();

          return true;

   }

If want to drag free anywhere, we combine them like this.

@Override

public boolean onTouch(View view, MotionEvent event) {

     final int X = (int) event.getRawX();

     final int Y = (int) event.getRawY();

     switch (event.getAction() & MotionEvent.ACTION_MASK) {

     case MotionEvent.ACTION_DOWN:

          RelativeLayout.LayoutParams lParams = (RelativeLayout.LayoutParams) view

                          .getLayoutParams();

               _xDelta = X - lParams.leftMargin;

               _yDelta = Y - lParams.bottomMargin;

               break;

          case MotionEvent.ACTION_UP:

               dem=dem+1;

               if(dem==2){

Toast.makeText(getApplicationContext(), "Touch view", Toast.LENGTH_LONG).show();

               dem=0;

               }

               break;

          case MotionEvent.ACTION_POINTER_DOWN:

               break;

          case MotionEvent.ACTION_POINTER_UP:

               break;

          case MotionEvent.ACTION_MOVE:

               RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) view

                          .getLayoutParams();

               layoutParams.bottomMargin = (Y - _yDelta);

               layoutParams.topMargin = -layoutParams.bottomMargin;

              

               layoutParams.leftMargin = (X - _xDelta);

               layoutParams.rightMargin = -layoutParams.leftMargin;

               view.setLayoutParams(layoutParams);

               view.animate().translationX(X - _xDelta).setDuration(0);

               view.animate().translationY(Y - _yDelta).setDuration(0);

               break;

          }

          findViewById(R.id.root).invalidate();

          return true;

   }

Command in case MotionEvent.ACTION_UP: to detect when user touch screen two times.

You must add count variable name dem.

If you want to save new position of view, use SharedPreferences like this post.