看起来你可以从Java图形上下文的FontMetrics
中获得更准确的几何信息。
补充说明:在解决这个问题时,区分模型和视图可能会有所帮助。模型是一个String
,是一系列UTF-16代码点,而视图是一系列字形,在某个设备上使用某种字体呈现。
在Java的特定情况下,可以使用SwingUtilities.layoutCompoundLabel()
来实现翻译。下面的示例拦截了BasicLabelUI
中的布局调用,以演示效果。可能可以在其他上下文中使用实用程序方法,但必须经验性地确定相应的FontMetrics
。
![alt text](https://istack.dev59.com/IiqUs.webp)
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.GridLayout;
import java.awt.Rectangle;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import javax.swing.BorderFactory;
import javax.swing.Icon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.border.LineBorder;
import javax.swing.plaf.basic.BasicLabelUI;
public class LayoutTest extends JPanel {
private static final String text =
"A damsel with a dulcimer in a vision once I saw.";
private final JLabel sizeLabel = new JLabel();
private final JLabel textLabel = new JLabel(text);
private final MyLabelUI myUI = new MyLabelUI();
public LayoutTest() {
super(new GridLayout(0, 1));
this.setBorder(BorderFactory.createCompoundBorder(
new LineBorder(Color.blue), new EmptyBorder(5, 5, 5, 5)));
textLabel.setUI(myUI);
textLabel.setFont(new Font("Serif", Font.ITALIC, 24));
this.add(sizeLabel);
this.add(textLabel);
this.addComponentListener(new ComponentAdapter() {
@Override
public void componentResized(ComponentEvent e) {
sizeLabel.setText(
"Before: " + myUI.before + " after: " + myUI.after);
}
});
}
private static class MyLabelUI extends BasicLabelUI {
int before, after;
@Override
protected String layoutCL(
JLabel label, FontMetrics fontMetrics, String text, Icon icon,
Rectangle viewR, Rectangle iconR, Rectangle textR) {
before = text.length();
String s = super.layoutCL(
label, fontMetrics, text, icon, viewR, iconR, textR);
after = s.length();
System.out.println(s);
return s;
}
}
private void display() {
JFrame f = new JFrame("LayoutTest");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(this);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new LayoutTest().display();
}
});
}
}