getY()到底是什么意思呢？和getHeight()有什么区别呢？
我看getY()的解释是返回组件原点的当前 y 坐标。但是组件原点又是什么呢？
一个书上的例子：
class FontPanel extends JPanel {
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D) g;
        
        String message = "Hello , World!";
        
        Font f = new Font("Serif", Font.BOLD, 36);
        g2.setFont(f);
        
        FontRenderContext context = g2.getFontRenderContext();
        Rectangle2D bounds = f.getStringBounds(message, context);
        double x = (getWidth() - bounds.getWidth())/2;
        double y = (getHeight() - bounds.getHeight())/2;
        double ascent = -bounds.getY();
        double baseY = y + ascent;
        
        g2.drawString(message, (int)x, (int) baseY);
        
        g2.setPaint(Color.GRAY);
        
        g2.draw(new Line2D.Double(x, baseY, x+bounds.getWidth(), baseY));
        
        Rectangle2D rect = new Rectangle2D.Double(x, y, bounds.getWidth(), bounds.getHeight());
        g2.draw(rect);
    }
}

请问那根线（基线）的位置是如何算出来的？
谢谢

请问该Y座标是以什么为原点的？而组件的高度又是从哪里开始算的？谢谢

哦，明白了，谢谢，呵呵