Android:Rotating LinearLayout leaves a trail

Question

Im rotating a LinearLayout, using an ObjectAnimator. Clicking the button causes the LinearLayout to rotate 360(degrees) with the bottom part as the Pivot.

After the Layout completes the rotation, it leaves back a 'trail'/black mark and the complete view looks odd. How do I avoid this from happening? After the Layout completes the 360 animation, I want the view to look as it did in the beginning (clean basically). Is there a view.refresh or update command im suppose to call somewhere?

1)How do I have a clean looking view at the end?

2)When the image is is in the intermediatestate, why does the back-part appear black? How do I get that to look while(ie,color of the relative layout)?

InitialState>IntermediateState>FinalState:

MainActivity

Button bt1;

float pivotX=0f;
float pivotY=0f;

int a=0;

float width,height;

ViewGroup mContainer=null;

Thread t;

private Handler mHandler = new Handler();

@Override
protected void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    bt1 = (Button) findViewById(R.id.button1);
    mContainer = (ViewGroup) findViewById(R.id.container);

    bt1.setOnClickListener(this);

            t=new Thread()
    {
        @Override
        public void run()
        {
            try {
                while(true)
                {
                    relativeLayout.postInvalidate();
                }
            } catch (Exception e) {
                // TODO: handle exception
            }
        }
    };
}

@Override
public void onWindowFocusChanged(boolean hasFocus) 
{
  super.onWindowFocusChanged(hasFocus);

  //Here you can get the size!

    width = mContainer.getWidth();
    height = mContainer.getHeight();

    pivotX = mContainer.getPivotX()+width; 
    pivotY = mContainer.getPivotY()+height; 

    mContainer.setPivotX(pivotX);
    mContainer.setPivotY(pivotY);
}

private void rotate()
{
    a -=360;

    ObjectAnimator rotate = ObjectAnimator.ofFloat(mContainer, View.ROTATION_X,a);
    rotate.setDuration(2000);

    AnimatorSet aSet = new AnimatorSet();
    aSet.play(rotate);
    aSet.start();

    mHandler.post(new Runnable() 
    {
        @Override
        public void run() 
        {
            b+=1;
            relativeLayout.invalidate();
            relativeLayout.postInvalidate();
            bt1.setText(Integer.toString(b));
        }
    });

    rotate.addListener(new AnimatorListener() 
    {

        @Override
        public void onAnimationStart(Animator animation) {
            // TODO Auto-generated method stub
            //relativeLayout.invalidate();
            t.start();
        }

        @Override
        public void onAnimationRepeat(Animator animation) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onAnimationEnd(Animator animation) {
            // TODO Auto-generated method stub
            //mContainer.invalidate();
            //relativeLayout.invalidate();
            try {
                t.join();
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        @Override
        public void onAnimationCancel(Animator animation) {
            // TODO Auto-generated method stub

        }
    });
}

@Override
public void onClick(View v) 
{
    switch(v.getId())
    {
    case R.id.button1:
        rotate();
        break;

    }
}

}

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
tools:context=".MainActivity" >

<LinearLayout
    android:id="@+id/container"
    android:layout_width="fill_parent"
    android:layout_height="200dp"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:background="#140A1F"
    android:orientation="horizontal" >
</LinearLayout>

<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/container"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="80dp"
    android:text="Rotate" />

</RelativeLayout>

Edit: Added a thread. **Edit2:**** Added a handler and commented out the thread

Answer 1

Adding this to the code fixes the view once the animation is competed, but the intermediate stage still looks the same. Will update this once I figure that out.

        rotate.addListener(new AnimatorListener() 
    {

        @Override
        public void onAnimationStart(Animator animation) {
            // TODO Auto-generated method stub
            relativeLayout.invalidate();
        }

        @Override
        public void onAnimationRepeat(Animator animation) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onAnimationEnd(Animator animation) {
            // TODO Auto-generated method stub
            //mContainer.invalidate();
            relativeLayout.invalidate();
        }

        @Override
        public void onAnimationCancel(Animator animation) {
            // TODO Auto-generated method stub

        }
    });