드래그 해서 뷰 크기 조절하기

구글링을 못하는 건지 아무리 검색해봐도 찾지 못해서 직접 만들었다.

private PointF mCenter;
private float mRadius;
private float mMaxDist;

btn2.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                Rect rect = new Rect();
                v.getGlobalVisibleRect(rect);

                mRadius = btn2.getWidth() / 2;
                mMaxDist = btn2.getHeight() / 2;
                float x = rect.left + mRadius;
                float y = rect.top + mMaxDist;
                mCenter = new PointF(x, y);

                float a = event.getX();
                float b = event.getY();
                float c = event.getRawX();
                float d = event.getRawY();

                if ( mCenter.x > event.getRawX() ) {
                    a = mCenter.x - c + btn2.getWidth() / 2;
                }
                if ( mCenter.y > event.getRawY() ) {
                    b = mCenter.y - d + btn2.getHeight() / 2;
                }

                if ( a > b ){
                    b = a;
                }else {
                    a = b;
                }

                btn2.setLayoutParams(new RelativeLayout.LayoutParams((int)a,(int)b ));

                if (event.getAction() == event.ACTION_UP){
                    btn2.setLayoutParams(new RelativeLayout.LayoutParams(300,300 )); 
                }



                return false;
            }
    });

<RelativeLayout
    android:layout_width="200dp"
    android:layout_height="200dp"
    android:layout_alignTop="@+id/btn3"
    android:layout_centerHorizontal="true">

    <RelativeLayout
        android:id="@+id/abcde"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true">

        <Button
            android:id="@+id/btn2"
            android:layout_width="50dp"
            android:layout_height="50dp" />


    </RelativeLayout>
</RelativeLayout>