Android ImageView rotate around pivot point

ArrowTouchListener.java

package gram.ua.robinzon.listener.interaction.protractor;

import android.view.MotionEvent;
import android.view.View;
import android.view.animation.RotateAnimation;
import android.widget.ImageView;
import android.widget.TextView;

/**
 * @author Gram <gram7gram@gmail.com>
 */
public class ArrowTouchListener implements View.OnTouchListener {

    private final String tag = getClass().getSimpleName();
    private final int NONE = 0;
    private final int DRAG = 1;
    private final TextView rotationLbl;
    private int mode = NONE;
    private int prevRotation;

    public ArrowTouchListener(TextView rotationLbl) {
        this.rotationLbl = rotationLbl;
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        final ImageView view = (ImageView) v;

        switch (event.getAction() & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN:
                onActionDown(event);
                break;
            case MotionEvent.ACTION_UP:
                onActionUp(event);
                break;
            case MotionEvent.ACTION_POINTER_UP:
                onPointerUp(event);
                break;
            case MotionEvent.ACTION_MOVE:
                switch (mode) {
                    case DRAG:
                        onActionMoveDrag(view, event);
                        break;
                }
                break;
        }

        return true;
    }

    private void onActionDown(MotionEvent event) {
        mode = DRAG;
    }

    private void onActionUp(MotionEvent event) {
    }

    private void onActionMoveDrag(ImageView view, MotionEvent event) {
        view.setPivotY((view.getY() + view.getHeight()) * .98f);
        int angle = getAngle(view.getPivotX(), view.getPivotY(), event.getX(), event.getY());

        if (angle < 0) angle = 0;
        if (angle > 90) angle = 90;
        int currentRotation = 90 - angle;

        RotateAnimation rotate = new RotateAnimation(prevRotation, currentRotation,
                RotateAnimation.RELATIVE_TO_SELF, 0.5f,
                RotateAnimation.RELATIVE_TO_SELF, 0.98f);

        rotate.setFillAfter(true);
        rotate.setDuration(100);

        view.startAnimation(rotate);

        prevRotation = currentRotation;

        rotationLbl.setText(angle + "*");
    }

    private void onPointerUp(MotionEvent event) {
        mode = NONE;
    }

    private int getAngle(float xt, float yt, float x, float y) {
        float dx = x - xt;
        float dy = yt - y;

        double inRads = Math.atan2(dy, dx);

        return (int) Math.toDegrees(inRads);
    }
}

How can I change the axis of rotation(the pivot point)? I want it to rotate upside down. Please help

Welcome! I suppose you need to update these numbers to achieve a needed angle:

if (angle < 0) angle = 0;
if (angle > 90) angle = 90;
int currentRotation = 90 - angle;

Use values like 360/270/180/90/0/-90/-180/-270 until you succeed :)

Thanks man.