RotatableImageView.java

import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;

public class RotatableImageView extends android.support.v7.widget.AppCompatImageView {

    private float angle = 0f;

    public RotatableImageView(Context context) {
        super(context);
    }

    public RotatableImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public RotatableImageView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public void rotate(float angle) {
        this.angle = angle;
        invalidate();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        int save = canvas.save();
        canvas.rotate(angle, canvas.getWidth() / 2, canvas.getHeight() / 2);
        super.onDraw(canvas);
        canvas.restoreToCount(save);
    }
}