Question

I have a wheel, I want to rotate it on its position. my code is rotating this image but its going to change its position. i want to keep this image on fix place.

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    dialImage = (ImageView) findViewById(R.id.inner_dial);

    float rotation = (float) Math.toDegrees(90);
    Matrix matrix = new Matrix();
    matrix.postRotate(rotation);

    bMap = BitmapFactory.decodeResource(getResources(),
            R.drawable.inner_temp);

    dialImage.setBackgroundResource(0);

    Bitmap bMapRotate = Bitmap.createBitmap(bMap, 0, 0, bMap.getWidth(),
            bMap.getHeight(), matrix, true);
    dialImage.setImageBitmap(bMapRotate);

}

my xml file:

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

<ImageView android:background="@drawable/inner_temp"
    android:layout_height="wrap_content" android:id="@+id/inner_dial"
    android:layout_width="wrap_content" android:layout_alignParentLeft="true" />

Answer 1

Save this rotate.xml in the anim folder in res.

<?xml version="1.0" encoding="UTF-8"?>
<rotate
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromDegrees="0"
    android:toDegrees="360"
    android:pivotX="50%"
    android:pivotY="50%"
    android:repeatCount="infinite"
    android:duration="1200"
    android:interpolator="@android:anim/linear_interpolator" />

Start your animation:

dialImage.startAnimation(AnimationUtils.loadAnimation( this, R.anim.rotate ) );

EDIT:

To use rotate animation prgrammatically:

RotateAnimation anim = new RotateAnimation(fromDegrees, toDegrees, pivotXType, pivotXValue, pivotYType, pivotYValue);
dialImage.startAnimation(anim);

Follow this link for detailed description.