背景
用一个 java 文件做出能翻页的《論語·學而》中英对照本 那篇文章用 GUI 来展示《論語·學而》的内容：中间繁体原文，右边英译，点按钮时两栏一起换。ctext.org 上的《孫子兵法·始計篇》按七个小节排布，还带有 Giles 1910 年的英译，很适合用同样的骨架。我用 trae 给《孫子兵法·始計篇》也生成了类似的 GUI。
界面与功能
- 左栏"段落"下方是
7个段号按钮，点击直达；当前段朱砂底高亮，同时禁用 ‹ 上一段在第1段自动变灰下一段 ›在第7段自动变灰- 中间繁体原文、右侧 Lionel Giles（1910）英译，均自动换行；切换段落时两侧滚动位置复位
- 键盘：← / → 切换段落，Home / End 跳到首尾
- 页脚显示"第 n 段 / 共 7 段"以及快捷键提示
- 页脚右侧"資料來源 · ctext.org ↗"是可点击链接，悬停变朱红；点击调系统浏览器打开 ctext.org 的《始計》页，若当前环境不支持浏览（如 headless）则弹窗展示 URL
--preview模式不弹窗，直接把界面画成 PNG——本文配图就是这么生成的
界面文案统一用繁体中文；标题、栏目、按钮的字族按 Kaiti SC → Noto Serif CJK TC → Songti SC 的顺序回退，保证不同系统上都能落到一款中文衬线字体。
如何运行
请将 完整代码 保存为 SunziReaderGui.java，使用下列命令可以编译、运行。
javac -d /tmp/sunzi-build SunziReaderGui.java
java -cp /tmp/sunzi-build SunziReaderGui
java -cp /tmp/sunzi-build SunziReaderGui --section 6
java -Djava.awt.headless=true -cp /tmp/sunzi-build SunziReaderGui --preview out.png 1
需要 JDK 15+（用到了文本块与 switch 表达式），我在本地 JDK 21 环境上验证过。
实现说明
- 布局：
BorderLayout三栏，左栏固定 212px、右栏固定 430px，中间原文栏吃掉剩余宽度 - 数据：原文与英译各是一个 7 元素的
String[]，下标即"段号减一" - 联动：所有状态变化都收在
showSection()一个方法里——正文、栏目标题、按钮态、翻页边界、页脚进度一次刷新完，不会出现切了一半的中间态 - 自绘：卡片、段号按钮、翻页胶囊、印章都用
paintComponent画的，外观不随系统主题变；当前段「高亮且禁用」靠选中态优先于禁用态来保留 - 字体：
chooseFont()传入候选字族列表，按可用字体名逐个匹配，全都不存在时回落到Font.SERIF - 来源链接：
JLabel加下划线字型与手型光标，点击走Desktop.browse()；不支持时用JOptionPane展示地址，避免静默失效 - 离屏出图：
buildPanel()后手工doLayout整棵组件树，再printAll()到BufferedImage，所以不依赖真实窗口
说明：这个工具的代码是我借助 trae 生成的，我在本机 JDK 21 上核对过。
参考资料
- 风格参考：用一个 java 文件做出能翻页的《論語·學而》中英对照本
- 原文与译文来源：ctext.org《孫子兵法·始計》；Lionel Giles, The Art of War（1910）
完整代码
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Cursor;
import java.awt.Desktop;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsEnvironment;
import java.awt.GridLayout;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.font.TextAttribute;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URI;
import java.nio.file.Path;
import java.util.List;
import java.util.Map;
import javax.imageio.ImageIO;
import javax.swing.AbstractAction;
import javax.swing.BoxLayout;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextPane;
import javax.swing.JToggleButton;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;
import javax.swing.border.EmptyBorder;
import javax.swing.text.SimpleAttributeSet;
import javax.swing.text.StyleConstants;
import javax.swing.text.StyledDocument;
/**
* A simple reader for the first chapter of The Art of War (《孫子·始計》), built with
* plain Swing - modeled on the Analects reader from
* <a href="https://juejin.cn/post/7702637146160758826">this article</a>.
* <p>
* Layout: the left column holds the seven section buttons plus prev/next pills,
* the center column shows the traditional Chinese original, and the right column
* shows Lionel Giles's English translation (both texts from
* <a href="https://ctext.org/art-of-war/laying-plans/zh">ctext.org</a>).
* The current section button is selected and disabled, prev/next are disabled at
* the ends, and arrow keys move between sections as well.
* <p>
* Run with:
* javac SunziReaderGui.java
* java SunziReaderGui
* <p>
* Options:
* java SunziReaderGui --section 5 open at section 5
* java SunziReaderGui --preview out.png render the window offscreen
* java SunziReaderGui --preview out.png 5 render section 5 offscreen
*/
public class SunziReaderGui {
private static final int SECTION_COUNT = 7;
private static final String SOURCE_URL = "https://ctext.org/art-of-war/laying-plans/zh";
// ---- text: traditional Chinese original + Giles translation (ctext.org) --
private static final String[] CHINESE = {
"孫子曰：兵者，國之大事，死生之地，存亡之道，不可不察也。",
"故經之以五事，校之以計，而索其情，一曰道，二曰天，三曰地，四曰將，五曰法。",
"道者，令民與上同意也，可與之死，可與之生，而不畏危。天者，陰陽，寒暑，時制也。"
+ "地者，遠近，險易，廣狹，死生也。將者，智，信，仁，勇，嚴也。法者，曲制，"
+ "官道，主用也。凡此五者，將莫不聞，知之者勝，不知者不勝。",
"故校之以計，而索其情。曰：主孰有道，將孰有能，天地孰得，法令孰行，兵眾孰強，"
+ "士卒孰練，賞罰孰明，吾以此知勝負矣。將聽吾計，用之必勝，留之；"
+ "將不聽吾計，用之必敗，去之。",
"計利以聽，乃為之勢，以佐其外；勢者，因利而制權也。",
"兵者，詭道也。故能而示之不能，用而示之不用，近而示之遠，遠而示之近。"
+ "利而誘之，亂而取之，實而備之，強而避之，怒而撓之，卑而驕之，佚而勞之，"
+ "親而離之。攻其無備，出其不意，此兵家之勝，不可先傳也。",
"夫未戰而廟算勝者，得算多也；未戰而廟算不勝者，得算少也；多算勝，少算不勝，"
+ "而況於無算乎？吾以此觀之，勝負見矣。",
};
private static final String[] ENGLISH = {
"""
Sunzi said: The art of war is of vital importance to the State. \
It is a matter of life and death, a road either to safety or to ruin. \
Hence it is a subject of inquiry which can on no account be neglected.""",
"""
The art of war, then, is governed by five constant factors, to be taken \
into account in one's deliberations, when seeking to determine the \
conditions obtaining in the field. These are: (1) The Moral Law; \
(2) Heaven; (3) Earth; (4) The Commander; (5) Method and discipline.""",
"""
The Moral Law causes the people to be in complete accord with their \
ruler, so that they will follow him regardless of their lives, \
undismayed by any danger. Heaven signifies night and day, cold and heat, \
times and seasons. Earth comprises distances, great and small; danger \
and security; open ground and narrow passes; the chances of life and \
death. The Commander stands for the virtues of wisdom, sincerity, \
benevolence, courage and strictness. By method and discipline are to be \
understood the marshaling of the army in its proper subdivisions, the \
graduations of rank among the officers, the maintenance of roads by \
which supplies may reach the army, and the control of military \
expenditure. These five heads should be familiar to every general: he \
who knows them will be victorious; he who knows them not will fail.""",
"""
Therefore, in your deliberations, when seeking to determine the military \
conditions, let them be made the basis of a comparison, in this wise: \
(1) Which of the two sovereigns is imbued with the Moral law? \
(2) Which of the two generals has most ability? (3) With whom lie the \
advantages derived from Heaven and Earth? (4) On which side is \
discipline most rigorously enforced? (5) Which army is stronger? \
(6) On which side are officers and men more highly trained? (7) In \
which army is there the greater constancy both in reward and punishment? \
By means of these seven considerations I can forecast victory or defeat. \
The general that hearkens to my counsel and acts upon it, will conquer: \
let such a one be retained in command! The general that hearkens not to \
my counsel nor acts upon it, will suffer defeat - let such a one be \
dismissed!""",
"""
While heading the profit of my counsel, avail yourself also of any \
helpful circumstances over and beyond the ordinary rules. According as \
circumstances are favorable, one should modify one's plans.""",
"""
All warfare is based on deception. Hence, when able to attack, we must \
seem unable; when using our forces, we must seem inactive; when we are \
near, we must make the enemy believe we are far away; when far away, we \
must make him believe we are near. Hold out baits to entice the enemy. \
Feign disorder, and crush him. If he is secure at all points, be \
prepared for him. If he is in superior strength, evade him. If your \
opponent is of choleric temper, seek to irritate him. Pretend to be \
weak, that he may grow arrogant. If he is taking his ease, give him no \
rest. If his forces are united, separate them. Attack him where he is \
unprepared, appear where you are not expected. These military devices, \
leading to victory, must not be divulged beforehand.""",
"""
Now the general who wins a battle makes many calculations in his temple \
ere the battle is fought. The general who loses a battle makes but few \
calculations beforehand. Thus do many calculations lead to victory, and \
few calculations to defeat: how much more no calculation at all! It is \
by attention to this point that I can foresee who is likely to win or \
lose.""",
};
// ---- palette: warm paper, ink text, cinnabar accent -----------------------
private static final Color PAPER = new Color(0xF5, 0xF0, 0xE6);
private static final Color CARD = new Color(0xFF, 0xFC, 0xF5);
private static final Color INK = new Color(0x2B, 0x23, 0x20);
private static final Color SOFT_INK = new Color(0x7A, 0x6E, 0x64);
private static final Color BODY_ENGLISH = new Color(0x3A, 0x33, 0x2E);
private static final Color ACCENT = new Color(0x9E, 0x2B, 0x22);
private static final Color CREAM = new Color(0xFA, 0xF6, 0xEC);
private static final Color LINE = new Color(0xD8, 0xCF, 0xC0);
private static final Color BUTTON_IDLE = new Color(0xEF, 0xE8, 0xDA);
private static final Color BUTTON_HOVER = new Color(0xE3, 0xD5, 0xC0);
private static final Color PILL_BORDER = new Color(0xC9, 0xA7, 0x9F);
private static final Color PILL_HOVER = new Color(0xF7, 0xE9, 0xE4);
private static final Color DISABLED_INK = new Color(0xB8, 0xAE, 0xA2);
// ---- fonts: candidate families with automatic fallback --------------------
private static final List<String> CJK_FAMILIES = List.of(
"Kaiti SC", "STKaiti", "KaiTi", "LXGW WenKai",
"Noto Serif CJK TC", "Noto Serif CJK SC", "Songti SC", "SimSun");
private static final List<String> SERIF_FAMILIES = List.of(
"Georgia", "Times New Roman", "Palatino");
private static final Font CHINESE_FONT = chooseFont(CJK_FAMILIES, Font.PLAIN, 21);
private static final Font ENGLISH_FONT = chooseFont(SERIF_FAMILIES, Font.PLAIN, 15);
private static final Font TITLE_FONT = chooseFont(CJK_FAMILIES, Font.BOLD, 24);
private static final Font SUBTITLE_FONT = chooseFont(CJK_FAMILIES, Font.PLAIN, 13);
private static final Font HEADING_FONT = chooseFont(CJK_FAMILIES, Font.BOLD, 14);
private static final Font FOOTER_FONT = chooseFont(CJK_FAMILIES, Font.PLAIN, 12);
private static final Font BUTTON_FONT = chooseFont(SERIF_FAMILIES, Font.BOLD, 15);
private static final Font PILL_FONT = chooseFont(CJK_FAMILIES, Font.BOLD, 13);
private static final Font SEAL_FONT = chooseFont(CJK_FAMILIES, Font.BOLD, 17);
private static final Font LINK_FONT = chooseFont(CJK_FAMILIES, Font.PLAIN, 12)
.deriveFont(Map.of(TextAttribute.UNDERLINE, TextAttribute.UNDERLINE_ON));
// ---- state ----------------------------------------------------------------
private int section;
private final SectionButton[] sectionButtons = new SectionButton[SECTION_COUNT];
private PillButton previousButton;
private PillButton nextButton;
private JTextPane chinesePane;
private JTextPane englishPane;
private JScrollPane chineseScroll;
private JScrollPane englishScroll;
private JLabel chineseHeading;
private JLabel englishHeading;
private JLabel progressLabel;
private JFrame frame; // created lazily so headless preview never touches it
public SunziReaderGui(int startSection) {
this.section = clamp(startSection);
}
public static void main(String[] args) throws Exception {
int startSection = 1;
String previewOutput = null;
for (int i = 0; i < args.length; i++) {
switch (args[i]) {
case "--section" -> startSection = Integer.parseInt(args[++i]);
case "--preview" -> {
previewOutput = args[++i];
if (i + 1 < args.length && !args[i + 1].startsWith("--")) {
startSection = Integer.parseInt(args[++i]);
}
}
default -> {
System.err.println("Unknown argument: " + args[i]);
printUsage();
return;
}
}
}
if (previewOutput != null) {
renderPreview(previewOutput, startSection);
System.out.println("Wrote " + previewOutput);
return;
}
final int initial = startSection;
SwingUtilities.invokeLater(() -> new SunziReaderGui(initial).show());
}
private static void printUsage() {
System.err.println("""
Usage:
java SunziReaderGui open the reader
java SunziReaderGui --section 5 open at section 5
java SunziReaderGui --preview out.png render the window offscreen
java SunziReaderGui --preview out.png 5 render section 5 offscreen
""");
}
// ---- window ---------------------------------------------------------------
private void show() {
frame = new JFrame("孫子兵法 · 始計篇");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = buildPanel();
bindKeys(panel);
showSection(section);
frame.setContentPane(panel);
frame.setMinimumSize(new Dimension(1040, 640));
frame.setSize(1240, 760);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
JPanel buildPanel() {
JPanel panel = new JPanel(new BorderLayout());
panel.setBackground(PAPER);
panel.setBorder(new EmptyBorder(20, 24, 16, 24));
panel.add(buildHeader(), BorderLayout.NORTH);
JPanel body = new JPanel(new BorderLayout(16, 0));
body.setOpaque(false);
body.add(buildNavigator(), BorderLayout.WEST);
body.add(buildChineseCard(), BorderLayout.CENTER);
body.add(buildEnglishCard(), BorderLayout.EAST);
panel.add(body, BorderLayout.CENTER);
panel.add(buildFooter(), BorderLayout.SOUTH);
return panel;
}
private JComponent buildHeader() {
JPanel header = new JPanel(new BorderLayout());
header.setOpaque(false);
header.setBorder(new EmptyBorder(0, 4, 16, 4));
JPanel titles = new JPanel();
titles.setOpaque(false);
titles.setLayout(new BoxLayout(titles, BoxLayout.Y_AXIS));
JLabel title = new JLabel("孫子兵法 · 始計篇");
title.setFont(TITLE_FONT);
title.setForeground(INK);
JLabel subtitle = new JLabel("第一篇 — 英譯：Lionel Giles（1910）");
subtitle.setFont(SUBTITLE_FONT);
subtitle.setForeground(SOFT_INK);
subtitle.setBorder(new EmptyBorder(6, 0, 0, 0));
titles.add(title);
titles.add(subtitle);
header.add(titles, BorderLayout.WEST);
header.add(new SealLabel("始", "計"), BorderLayout.EAST);
return header;
}
private JComponent buildNavigator() {
JPanel navigator = new JPanel(new BorderLayout(0, 12));
navigator.setOpaque(false);
navigator.setPreferredSize(new Dimension(212, 0));
JLabel heading = new JLabel("段落");
heading.setFont(HEADING_FONT);
heading.setForeground(SOFT_INK);
navigator.add(heading, BorderLayout.NORTH);
JPanel grid = new JPanel(new GridLayout(SECTION_COUNT, 1, 8, 8));
grid.setOpaque(false);
ButtonGroup group = new ButtonGroup();
for (int i = 0; i < SECTION_COUNT; i++) {
final int number = i + 1;
SectionButton button = new SectionButton(number);
button.addActionListener(e -> showSection(number));
group.add(button);
sectionButtons[i] = button;
grid.add(button);
}
// keep the grid top-aligned so the buttons stay 44px high
JPanel gridHolder = new JPanel(new BorderLayout());
gridHolder.setOpaque(false);
gridHolder.add(grid, BorderLayout.NORTH);
navigator.add(gridHolder, BorderLayout.CENTER);
JPanel pager = new JPanel(new GridLayout(1, 2, 8, 0));
pager.setOpaque(false);
pager.setBorder(new EmptyBorder(12, 0, 0, 0));
previousButton = new PillButton("‹ 上一段");
previousButton.addActionListener(e -> showSection(section - 1));
nextButton = new PillButton("下一段 ›");
nextButton.addActionListener(e -> showSection(section + 1));
pager.add(previousButton);
pager.add(nextButton);
navigator.add(pager, BorderLayout.SOUTH);
return navigator;
}
private JComponent buildChineseCard() {
Card card = new Card();
card.setLayout(new BorderLayout(0, 10));
card.setBorder(new EmptyBorder(18, 22, 18, 22));
chineseHeading = new JLabel();
chineseHeading.setFont(HEADING_FONT);
chineseHeading.setForeground(ACCENT);
card.add(chineseHeading, BorderLayout.NORTH);
chinesePane = createPane();
chineseScroll = wrapScroll(chinesePane);
card.add(chineseScroll, BorderLayout.CENTER);
return card;
}
private JComponent buildEnglishCard() {
Card card = new Card();
card.setLayout(new BorderLayout(0, 10));
card.setBorder(new EmptyBorder(18, 22, 18, 22));
card.setPreferredSize(new Dimension(430, 0));
englishHeading = new JLabel();
englishHeading.setFont(HEADING_FONT);
englishHeading.setForeground(ACCENT);
card.add(englishHeading, BorderLayout.NORTH);
englishPane = createPane();
englishScroll = wrapScroll(englishPane);
card.add(englishScroll, BorderLayout.CENTER);
return card;
}
private JComponent buildFooter() {
JPanel footer = new JPanel(new BorderLayout());
footer.setOpaque(false);
footer.setBorder(new EmptyBorder(12, 4, 0, 4));
JPanel separator = new JPanel();
separator.setBackground(LINE);
separator.setPreferredSize(new Dimension(0, 1));
footer.add(separator, BorderLayout.NORTH);
progressLabel = new JLabel();
progressLabel.setFont(FOOTER_FONT);
progressLabel.setForeground(SOFT_INK);
progressLabel.setBorder(new EmptyBorder(8, 0, 0, 0));
footer.add(progressLabel, BorderLayout.CENTER);
footer.add(buildSourceLink(), BorderLayout.EAST);
return footer;
}
private JComponent buildSourceLink() {
JLabel link = new JLabel("資料來源 · ctext.org ↗");
link.setFont(LINK_FONT);
link.setForeground(SOFT_INK);
link.setBorder(new EmptyBorder(8, 0, 0, 0));
link.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
link.setToolTipText("在瀏覽器中開啟 " + SOURCE_URL);
link.addMouseListener(new MouseAdapter() {
@Override
public void mouseEntered(MouseEvent e) {
link.setForeground(ACCENT);
}
@Override
public void mouseExited(MouseEvent e) {
link.setForeground(SOFT_INK);
}
@Override
public void mouseClicked(MouseEvent e) {
openSourceUrl();
}
});
return link;
}
private static void openSourceUrl() {
try {
if (Desktop.isDesktopSupported()
&& Desktop.getDesktop().isSupported(Desktop.Action.BROWSE)) {
Desktop.getDesktop().browse(URI.create(SOURCE_URL));
return;
}
} catch (IOException | RuntimeException ex) {
// fall back to showing the URL below
}
JOptionPane.showMessageDialog(null, SOURCE_URL, "資料來源",
JOptionPane.INFORMATION_MESSAGE);
}
private static JTextPane createPane() {
JTextPane pane = new JTextPane();
pane.setEditable(false);
pane.setFocusable(false);
pane.setOpaque(false);
pane.setBorder(null);
return pane;
}
private static JScrollPane wrapScroll(JTextPane pane) {
JScrollPane scroll = new JScrollPane(pane);
scroll.setBorder(null);
scroll.setOpaque(false);
scroll.getViewport().setOpaque(false);
scroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
scroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
return scroll;
}
// ---- state changes --------------------------------------------------------
private void showSection(int number) {
section = clamp(number);
int index = section - 1;
fillPane(chinesePane, CHINESE[index], CHINESE_FONT, 0.42f, INK);
fillPane(englishPane, ENGLISH[index], ENGLISH_FONT, 0.28f, BODY_ENGLISH);
chineseHeading.setText("原文 · 第 " + section + " 段");
englishHeading.setText("英譯 · 第 " + section + " 段");
for (int i = 0; i < SECTION_COUNT; i++) {
sectionButtons[i].setSelected(i + 1 == section);
sectionButtons[i].setEnabled(i + 1 != section);
}
previousButton.setEnabled(section > 1);
nextButton.setEnabled(section < SECTION_COUNT);
progressLabel.setText(String.format(
"第 %d 段 / 共 %d 段 — ← → 切換段落，Home/End 跳至首尾",
section, SECTION_COUNT));
resetScroll();
}
private void resetScroll() {
chineseScroll.getViewport().setViewPosition(new Point(0, 0));
englishScroll.getViewport().setViewPosition(new Point(0, 0));
}
private void bindKeys(JComponent target) {
bind(target, "LEFT", () -> showSection(section - 1));
bind(target, "RIGHT", () -> showSection(section + 1));
bind(target, "HOME", () -> showSection(1));
bind(target, "END", () -> showSection(SECTION_COUNT));
}
private static void bind(JComponent target, String keyStroke, Runnable action) {
target.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(
KeyStroke.getKeyStroke(keyStroke), keyStroke);
target.getActionMap().put(keyStroke, new AbstractAction() {
@Override
public void actionPerformed(ActionEvent e) {
action.run();
}
});
}
// ---- text rendering ---------------------------------------------------------
private static void fillPane(JTextPane pane, String text, Font font,
float lineSpacing, Color color) {
pane.setText(text);
StyledDocument document = pane.getStyledDocument();
SimpleAttributeSet attributes = new SimpleAttributeSet();
StyleConstants.setFontFamily(attributes, font.getFamily());
StyleConstants.setFontSize(attributes, font.getSize());
StyleConstants.setForeground(attributes, color);
StyleConstants.setLineSpacing(attributes, lineSpacing);
int length = document.getLength();
document.setParagraphAttributes(0, length, attributes, false);
document.setCharacterAttributes(0, length, attributes, false);
pane.setCaretPosition(0);
}
private static Font chooseFont(List<String> families, int style, int size) {
String[] available = GraphicsEnvironment.getLocalGraphicsEnvironment()
.getAvailableFontFamilyNames();
for (String family : families) {
for (String name : available) {
if (name.equalsIgnoreCase(family)) {
return new Font(name, style, size);
}
}
}
return new Font(Font.SERIF, style, size);
}
private static int clamp(int number) {
return Math.max(1, Math.min(SECTION_COUNT, number));
}
// ---- offscreen preview ------------------------------------------------------
private static void renderPreview(String output, int startSection) throws IOException {
int width = 1240;
int height = 760;
SunziReaderGui reader = new SunziReaderGui(startSection);
JPanel panel = reader.buildPanel();
reader.showSection(startSection);
panel.setSize(new Dimension(width, height));
layoutAll(panel);
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics2D g = image.createGraphics();
g.setColor(PAPER);
g.fillRect(0, 0, width, height);
panel.printAll(g);
g.dispose();
ImageIO.write(image, "png", Path.of(output).toFile());
}
private static void layoutAll(Container container) {
container.doLayout();
for (Component child : container.getComponents()) {
if (child instanceof Container nested) {
layoutAll(nested);
}
}
}
// ---- custom controls --------------------------------------------------------
/** Rounded "book page" card with a 1px outline. */
private static final class Card extends JPanel {
private static final long serialVersionUID = 1L;
Card() {
setOpaque(false);
}
@Override
protected void paintComponent(Graphics graphics) {
Graphics2D g = (Graphics2D) graphics.create();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g.setColor(CARD);
g.fillRoundRect(0, 0, getWidth() - 1, getHeight() - 1, 16, 16);
g.setColor(LINE);
g.setStroke(new BasicStroke(1f));
g.drawRoundRect(0, 0, getWidth() - 1, getHeight() - 1, 16, 16);
g.dispose();
super.paintComponent(graphics);
}
}
/** Numbered section button; the current section stays selected and disabled. */
private static final class SectionButton extends JToggleButton {
private static final long serialVersionUID = 1L;
private boolean hover;
SectionButton(int number) {
super(String.valueOf(number));
setFont(BUTTON_FONT);
setFocusPainted(false);
setContentAreaFilled(false);
setBorderPainted(false);
setOpaque(false);
setRolloverEnabled(false);
setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
addMouseListener(new MouseAdapter() {
@Override
public void mouseEntered(MouseEvent e) {
hover = true;
repaint();
}
@Override
public void mouseExited(MouseEvent e) {
hover = false;
repaint();
}
});
}
@Override
public Dimension getPreferredSize() {
return new Dimension(44, 44);
}
@Override
protected void paintComponent(Graphics graphics) {
Graphics2D g = (Graphics2D) graphics.create();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
Color fill;
Color ink;
if (isSelected()) {
fill = ACCENT;
ink = CREAM;
} else if (hover && isEnabled()) {
fill = BUTTON_HOVER;
ink = INK;
} else {
fill = BUTTON_IDLE;
ink = INK;
}
g.setColor(fill);
g.fillRoundRect(0, 0, getWidth() - 1, getHeight() - 1, 10, 10);
g.setColor(ink);
g.setFont(getFont());
FontMetrics metrics = g.getFontMetrics();
String text = getText();
int x = (getWidth() - metrics.stringWidth(text)) / 2;
int y = (getHeight() - metrics.getHeight()) / 2 + metrics.getAscent();
g.drawString(text, x, y);
g.dispose();
}
}
/** Capsule-shaped prev/next button; border and label fade when disabled. */
private static final class PillButton extends JButton {
private static final long serialVersionUID = 1L;
private boolean hover;
PillButton(String text) {
super(text);
setFont(PILL_FONT);
setFocusPainted(false);
setContentAreaFilled(false);
setBorderPainted(false);
setOpaque(false);
setRolloverEnabled(false);
setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
addMouseListener(new MouseAdapter() {
@Override
public void mouseEntered(MouseEvent e) {
hover = true;
repaint();
}
@Override
public void mouseExited(MouseEvent e) {
hover = false;
repaint();
}
});
}
@Override
public Dimension getPreferredSize() {
return new Dimension(90, 38);
}
@Override
protected void paintComponent(Graphics graphics) {
Graphics2D g = (Graphics2D) graphics.create();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
boolean enabled = isEnabled();
Color fill = enabled && hover ? PILL_HOVER : CARD;
Color border = enabled ? (hover ? ACCENT : PILL_BORDER) : LINE;
Color ink = enabled ? ACCENT : DISABLED_INK;
g.setColor(fill);
g.fillRoundRect(0, 0, getWidth() - 1, getHeight() - 1,
getHeight() - 1, getHeight() - 1);
g.setColor(border);
g.setStroke(new BasicStroke(1f));
g.drawRoundRect(0, 0, getWidth() - 1, getHeight() - 1,
getHeight() - 1, getHeight() - 1);
g.setColor(ink);
g.setFont(getFont());
FontMetrics metrics = g.getFontMetrics();
String text = getText();
int x = (getWidth() - metrics.stringWidth(text)) / 2;
int y = (getHeight() - metrics.getHeight()) / 2 + metrics.getAscent();
g.drawString(text, x, y);
g.dispose();
}
}
/** Small cinnabar seal with two characters set vertically. */
private static final class SealLabel extends JComponent {
private static final long serialVersionUID = 1L;
private final String top;
private final String bottom;
SealLabel(String top, String bottom) {
this.top = top;
this.bottom = bottom;
}
@Override
public Dimension getPreferredSize() {
return new Dimension(52, 52);
}
@Override
protected void paintComponent(Graphics graphics) {
Graphics2D g = (Graphics2D) graphics.create();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int width = getWidth();
int height = getHeight();
g.setColor(ACCENT);
g.fillRoundRect(0, 0, width - 1, height - 1, 8, 8);
g.setColor(CREAM);
g.setStroke(new BasicStroke(1f));
g.drawRoundRect(3, 3, width - 8, height - 8, 5, 5);
g.setFont(SEAL_FONT);
FontMetrics metrics = g.getFontMetrics();
int lineHeight = metrics.getAscent() + metrics.getDescent();
int startY = (height - lineHeight * 2) / 2 + metrics.getAscent();
g.drawString(top, (width - metrics.stringWidth(top)) / 2, startY);
g.drawString(bottom, (width - metrics.stringWidth(bottom)) / 2,
startY + lineHeight);
g.dispose();
}
}
}
