feat: v0.5.0 —— 导出 PDF（带预览窗口）

导出 - 文件 → 导出 PDF…（Ctrl+E）先弹出预览窗口，确认后点「保存 PDF…」选路径 - A4 纸、16mm 页边距；预览和导出共用同一个 QTextDocument，页宽一致 - 只用 Qt 自带的 QPrinter / QTextDocument，没有引入外部 PDF 库排版 - 新增 MarkdownRenderer：把 Markdown 解析成排版好的富文本文档 - 支持标题、列表 / 任务列表、引用、围栏代码块、行内代码、粗体 / 斜体 / 删除线、链接；图片输出 alt 文字，表格暂按原文 - 代码块带底色、引用带竖线、分隔线画成横线其它 - 用用户更新后的 logo.png 重新生成了 ico / icns / png - docs/screenshot-export.png 与 README 同步
2026-10-22 17:58:01 +08:00
parent c83b4a239c
commit 8cb0702614
13 changed files with 588 additions and 4 deletions
@@ -0,0 +1,405 @@
+#include "MarkdownRenderer.h"
+
+#include <QColor>
+#include <QFont>
+#include <QRegularExpression>
+#include <QTextBlockFormat>
+#include <QTextCharFormat>
+#include <QTextCursor>
+#include <QTextDocument>
+
+namespace {
+
+QStringList proseFamilies()
+{
+    return {QStringLiteral("Noto Sans CJK SC"), QStringLiteral("Source Han Sans SC"),
+            QStringLiteral("WenQuanYi Micro Hei"), QStringLiteral("Microsoft YaHei"),
+            QStringLiteral("PingFang SC"), QStringLiteral("Segoe UI"),
+            QStringLiteral("DejaVu Sans")};
+}
+
+QStringList monoFamilies()
+{
+    return {QStringLiteral("JetBrains Mono"), QStringLiteral("Cascadia Code"),
+            QStringLiteral("Source Han Mono SC"), QStringLiteral("Noto Sans Mono CJK SC"),
+            QStringLiteral("Sarasa Mono SC"), QStringLiteral("Consolas"),
+            QStringLiteral("DejaVu Sans Mono")};
+}
+
+QColor hex(const char *value)
+{
+    return QColor(QString::fromLatin1(value));
+}
+
+struct Style
+{
+    QColor text = hex("#1f2328");
+    QColor heading = hex("#11151a");
+    QColor muted = hex("#5b6570");
+    QColor rule = hex("#d0d7de");
+    QColor codeText = hex("#b4295a");
+    QColor codeBg = hex("#f3f4f6");
+    QColor link = hex("#0969da");
+    QColor marker = hex("#0969da");
+};
+
+constexpr qreal kBodySize = 11.5;
+constexpr qreal kCodeSize = 10.5;
+
+class Renderer
+{
+public:
+    explicit Renderer(QTextDocument *document)
+        : m_document(document)
+        , m_cursor(document)
+    {
+    }
+
+    void run(const QString &markdown);
+
+private:
+    void beginBlock(const QTextBlockFormat &blockFormat, const QTextCharFormat &charFormat);
+    void renderHeading(int level, const QString &text);
+    void renderParagraph(const QString &text, int quoteDepth);
+    void renderListItem(const QString &marker, const QString &text, int indentLevel);
+    void renderCodeBlock(const QStringList &lines);
+    void renderRule();
+    void renderInline(const QString &text, const QTextCharFormat &base);
+
+    QTextCharFormat bodyFormat(const QColor &color = QColor()) const;
+    QTextCharFormat codeFormat() const;
+
+    QTextDocument *m_document = nullptr;
+    QTextCursor m_cursor;
+    bool m_firstBlock = true;
+    Style m_style;
+};
+
+QTextCharFormat Renderer::bodyFormat(const QColor &color) const
+{
+    QTextCharFormat format;
+    format.setFontFamilies(proseFamilies());
+    format.setFontPointSize(kBodySize);
+    format.setForeground(color.isValid() ? color : m_style.text);
+    return format;
+}
+
+QTextCharFormat Renderer::codeFormat() const
+{
+    QTextCharFormat format;
+    format.setFontFamilies(monoFamilies());
+    format.setFontFixedPitch(true);
+    format.setFontPointSize(kCodeSize);
+    format.setForeground(m_style.codeText);
+    format.setBackground(m_style.codeBg);
+    return format;
+}
+
+void Renderer::beginBlock(const QTextBlockFormat &blockFormat, const QTextCharFormat &charFormat)
+{
+    if (m_firstBlock) {
+        m_cursor.setBlockFormat(blockFormat);
+        m_cursor.setBlockCharFormat(charFormat);
+        m_firstBlock = false;
+    } else {
+        m_cursor.insertBlock(blockFormat, charFormat);
+    }
+    m_cursor.setCharFormat(charFormat);
+}
+
+void Renderer::renderHeading(int level, const QString &text)
+{
+    static const qreal scales[6] = {2.0, 1.55, 1.3, 1.15, 1.05, 1.0};
+    QTextBlockFormat blockFormat;
+    blockFormat.setLineHeight(135, QTextBlockFormat::ProportionalHeight);
+    blockFormat.setTopMargin(level <= 2 ? 20 : 14);
+    blockFormat.setBottomMargin(8);
+
+    QTextCharFormat format;
+    format.setFontFamilies(proseFamilies());
+    format.setFontPointSize(kBodySize * scales[qBound(1, level, 6) - 1]);
+    format.setFontWeight(QFont::Bold);
+    format.setForeground(m_style.heading);
+
+    beginBlock(blockFormat, format);
+    m_cursor.insertText(text, format);
+}
+
+void Renderer::renderParagraph(const QString &text, int quoteDepth)
+{
+    QTextBlockFormat blockFormat;
+    blockFormat.setLineHeight(150, QTextBlockFormat::ProportionalHeight);
+    blockFormat.setBottomMargin(8);
+    if (quoteDepth > 0) {
+        blockFormat.setLeftMargin(18 + (quoteDepth - 1) * 16);
+    }
+    beginBlock(blockFormat, bodyFormat(quoteDepth > 0 ? m_style.muted : QColor()));
+
+    if (quoteDepth > 0) {
+        QTextCharFormat bar = bodyFormat(m_style.rule);
+        bar.setFontWeight(QFont::Bold);
+        m_cursor.insertText(QStringLiteral("│ "), bar);
+    }
+    renderInline(text, bodyFormat(quoteDepth > 0 ? m_style.muted : QColor()));
+}
+
+void Renderer::renderListItem(const QString &marker, const QString &text, int indentLevel)
+{
+    QTextBlockFormat blockFormat;
+    blockFormat.setLineHeight(150, QTextBlockFormat::ProportionalHeight);
+    blockFormat.setBottomMargin(6);
+    blockFormat.setLeftMargin(18 + indentLevel * 18);
+    blockFormat.setTextIndent(-14);
+    beginBlock(blockFormat, bodyFormat());
+
+    QTextCharFormat markerFormat = bodyFormat(m_style.marker);
+    markerFormat.setFontWeight(QFont::DemiBold);
+    m_cursor.insertText(marker + QLatin1Char(' '), markerFormat);
+    renderInline(text, bodyFormat());
+}
+
+void Renderer::renderCodeBlock(const QStringList &lines)
+{
+    QTextBlockFormat blockFormat;
+    blockFormat.setLineHeight(135, QTextBlockFormat::ProportionalHeight);
+    blockFormat.setTopMargin(6);
+    blockFormat.setBottomMargin(10);
+    blockFormat.setLeftMargin(14);
+    blockFormat.setRightMargin(14);
+    blockFormat.setBackground(m_style.codeBg);
+
+    const QTextCharFormat format = codeFormat();
+    QStringList content = lines;
+    if (content.isEmpty())
+        content << QString();
+
+    for (int index = 0; index < content.size(); ++index) {
+        QTextBlockFormat lineFormat = blockFormat;
+        lineFormat.setTopMargin(index == 0 ? 6 : 0);
+        lineFormat.setBottomMargin(index == content.size() - 1 ? 10 : 0);
+        beginBlock(lineFormat, format);
+        const QString line = content.at(index);
+        m_cursor.insertText(line.isEmpty() ? QStringLiteral(" ") : line, format);
+    }
+}
+
+void Renderer::renderRule()
+{
+    QTextBlockFormat blockFormat;
+    blockFormat.setLineHeight(140, QTextBlockFormat::ProportionalHeight);
+    blockFormat.setTopMargin(6);
+    blockFormat.setBottomMargin(12);
+    beginBlock(blockFormat, bodyFormat(m_style.rule));
+
+    QTextCharFormat format = bodyFormat(m_style.rule);
+    format.setFontPointSize(8);
+    m_cursor.insertText(QString(60, QChar(0x2500)), format);
+}
+
+void Renderer::renderInline(const QString &text, const QTextCharFormat &base)
+{
+    struct Rule {
+        QRegularExpression pattern;
+        int kind;
+    };
+
+    static const QVector<Rule> rules = {
+        {QRegularExpression(QStringLiteral("`([^`\\n]+)`")), 0},
+        {QRegularExpression(QStringLiteral("!\\[([^\\]]*)\\]\\(([^)]*)\\)")), 1},
+        {QRegularExpression(QStringLiteral("\\[([^\\]]*)\\]\\(([^)]*)\\)")), 2},
+        {QRegularExpression(QStringLiteral("\\*\\*\\*([^*]+)\\*\\*\\*")), 3},
+        {QRegularExpression(QStringLiteral("\\*\\*([^*]+)\\*\\*")), 4},
+        {QRegularExpression(QStringLiteral("__([^_]+)__")), 4},
+        {QRegularExpression(QStringLiteral("\\*([^*]+)\\*")), 5},
+        {QRegularExpression(QStringLiteral("(?<![_\\w])_([^_]+)_(?![_\\w])")), 5},
+        {QRegularExpression(QStringLiteral("~~([^~]+)~~")), 6},
+        {QRegularExpression(QStringLiteral("<(https?://[^>]+)>")), 7},
+    };
+
+    int position = 0;
+    while (position < text.size()) {
+        int bestStart = -1;
+        int bestKind = -1;
+        QRegularExpressionMatch best;
+        for (const Rule &rule : rules) {
+            const QRegularExpressionMatch match = rule.pattern.match(text, position);
+            if (!match.hasMatch())
+                continue;
+            if (bestStart < 0 || match.capturedStart() < bestStart) {
+                bestStart = match.capturedStart();
+                bestKind = rule.kind;
+                best = match;
+            }
+        }
+
+        if (bestStart < 0) {
+            m_cursor.insertText(text.mid(position), base);
+            break;
+        }
+        if (bestStart > position)
+            m_cursor.insertText(text.mid(position, bestStart - position), base);
+
+        const QString content = best.capturedLength(1) > 0 ? best.captured(1) : best.captured(0);
+        switch (bestKind) {
+        case 0: { // 行内代码
+            m_cursor.insertText(content, codeFormat());
+            break;
+        }
+        case 1: { // 图片：显示 alt
+            QTextCharFormat format = base;
+            format.setForeground(m_style.muted);
+            format.setFontItalic(true);
+            m_cursor.insertText(content.isEmpty() ? QStringLiteral("[图片]") : content, format);
+            break;
+        }
+        case 2: { // 链接
+            QTextCharFormat format = base;
+            format.setForeground(m_style.link);
+            format.setFontUnderline(true);
+            format.setAnchor(true);
+            format.setAnchorHref(best.captured(2));
+            m_cursor.insertText(best.captured(1), format);
+            break;
+        }
+        case 3: { // 粗斜体
+            QTextCharFormat format = base;
+            format.setFontWeight(QFont::Bold);
+            format.setFontItalic(true);
+            m_cursor.insertText(content, format);
+            break;
+        }
+        case 4: { // 粗体
+            QTextCharFormat format = base;
+            format.setFontWeight(QFont::Bold);
+            format.setForeground(m_style.heading);
+            m_cursor.insertText(content, format);
+            break;
+        }
+        case 5: { // 斜体
+            QTextCharFormat format = base;
+            format.setFontItalic(true);
+            m_cursor.insertText(content, format);
+            break;
+        }
+        case 6: { // 删除线
+            QTextCharFormat format = base;
+            format.setFontStrikeOut(true);
+            format.setForeground(m_style.muted);
+            m_cursor.insertText(content, format);
+            break;
+        }
+        default: { // 裸链接
+            QTextCharFormat format = base;
+            format.setForeground(m_style.link);
+            format.setFontUnderline(true);
+            format.setAnchor(true);
+            format.setAnchorHref(best.captured(1));
+            m_cursor.insertText(best.captured(1), format);
+            break;
+        }
+        }
+
+        position = bestStart + best.capturedLength();
+    }
+}
+
+void Renderer::run(const QString &markdown)
+{
+    const QStringList lines = markdown.split(QLatin1Char('\n'));
+
+    static const QRegularExpression headingPattern(QStringLiteral("^(#{1,6})\\s+(.*)$"));
+    static const QRegularExpression fencePattern(QStringLiteral("^\\s{0,3}(?:```|~~~)(.*)$"));
+    static const QRegularExpression quotePattern(QStringLiteral("^\\s{0,3}(>+)\\s?(.*)$"));
+    static const QRegularExpression bulletPattern(
+        QStringLiteral("^(\\s*)[-+*]\\s+\\[([ xX])\\]\\s?(.*)$"));
+    static const QRegularExpression listPattern(
+        QStringLiteral("^(\\s*)([-+*]|\\d{1,9}[.)])\\s+(.*)$"));
+    static const QRegularExpression rulePattern(
+        QStringLiteral("^\\s{0,3}(?:(?:\\*\\s*){3,}|(?:-\\s*){3,}|(?:_\\s*){3,})$"));
+
+    int index = 0;
+    while (index < lines.size()) {
+        const QString line = lines.at(index);
+
+        const QRegularExpressionMatch fence = fencePattern.match(line);
+        if (fence.hasMatch()) {
+            QStringList code;
+            ++index;
+            while (index < lines.size() && !fencePattern.match(lines.at(index)).hasMatch())
+                code << lines.at(index++);
+            if (index < lines.size())
+                ++index; // 跳过闭合围栏
+            renderCodeBlock(code);
+            continue;
+        }
+
+        if (line.trimmed().isEmpty()) {
+            ++index;
+            continue;
+        }
+
+        const QRegularExpressionMatch heading = headingPattern.match(line);
+        if (heading.hasMatch()) {
+            renderHeading(heading.capturedLength(1), heading.captured(2).trimmed());
+            ++index;
+            continue;
+        }
+
+        if (rulePattern.match(line).hasMatch()) {
+            renderRule();
+            ++index;
+            continue;
+        }
+
+        const QRegularExpressionMatch quote = quotePattern.match(line);
+        if (quote.hasMatch()) {
+            renderParagraph(quote.captured(2).trimmed(), quote.capturedLength(1));
+            ++index;
+            continue;
+        }
+
+        const QRegularExpressionMatch task = bulletPattern.match(line);
+        if (task.hasMatch()) {
+            const int indent = task.captured(1).size() / 2;
+            const bool done = task.captured(2).compare(QLatin1String("x"), Qt::CaseInsensitive) == 0;
+            renderListItem(done ? QStringLiteral("☑") : QStringLiteral("☐"),
+                           task.captured(3), indent);
+            ++index;
+            continue;
+        }
+
+        const QRegularExpressionMatch list = listPattern.match(line);
+        if (list.hasMatch()) {
+            const int indent = list.captured(1).size() / 2;
+            QString marker = list.captured(2);
+            if (marker.size() == 1 && (marker == QLatin1String("-") || marker == QLatin1String("+")
+                                       || marker == QLatin1String("*")))
+                marker = QStringLiteral("•");
+            renderListItem(marker, list.captured(3), indent);
+            ++index;
+            continue;
+        }
+
+        renderParagraph(line, 0);
+        ++index;
+    }
+}
+
+} // namespace
+
+void MarkdownRenderer::render(const QString &markdown, QTextDocument *document)
+{
+    if (!document)
+        return;
+
+    document->clear();
+
+    QFont body;
+    body.setFamilies(proseFamilies());
+    body.setPointSizeF(kBodySize);
+    document->setDefaultFont(body);
+    document->setDocumentMargin(0);
+
+    Renderer renderer(document);
+    renderer.run(markdown);
+}