如何在自定义视图中定义相对触摸大小？

public class CustomView extends View {
    private Rect touchArea; // 定义触摸区域的矩形

    public CustomView(Context context) {
        super(context);
        init();
    }

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

    private void init() {
        // 初始化触摸区域的矩形，这里以视图的宽度和高度的一半为中心点
        int centerX = getWidth() / 2;
        int centerY = getHeight() / 2;
        int halfWidth = getWidth() / 4;
        int halfHeight = getHeight() / 4;
        touchArea = new Rect(centerX - halfWidth, centerY - halfHeight, centerX + halfWidth, centerY + halfHeight);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int x = (int) event.getX();
        int y = (int) event.getY();

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                if (touchArea.contains(x, y)) {
                    // 触摸点在定义的触摸区域内，执行相应的逻辑
                    // TODO: 处理触摸事件
                    return true;
                }
                break;
            case MotionEvent.ACTION_MOVE:
                // 处理移动事件
                break;
            case MotionEvent.ACTION_UP:
                // 处理抬起事件
                break;
        }

        return super.onTouchEvent(event);
    }
}