feat: v0.8.1 —— 代码框左上角加语言下拉菜单

- 编辑模式下每个代码框左上角显示当前语言（纯文本 / C++ / Python …），
  点开是一个带勾选标记的语言菜单
- 选中后改写围栏上的语言标记（例如 ```cpp → ```python），
  高亮立即跟着变；选「纯文本」则去掉语言标记
- 下拉与复制按钮都是画在编辑器视口里的，跟着滚动重算，源码模式下都不显示
- 「纯文本」加入中英文翻译
- 截图与 README 同步

README.md

@@ -2,7 +2,7 @@
 
 一个轻量的跨平台 Markdown 编辑器，基于 **Qt 5 / C++17** 构建。
 
-当前版本 **0.8.0**。
+当前版本 **0.8.1**。
 
 ## 界面
 
@@ -29,6 +29,8 @@
 - 代码块按语言做语法高亮：C / C++ / Python / JavaScript / TypeScript /
   Java / Rust / Go / JSON / Bash / SQL / YAML，关键字、字符串、数字、
   注释、预处理指令分色；不认识的标记语言就按等宽纯文本显示
+- 代码框**左上角**是语言下拉菜单，选一下就会改写围栏上的语言标记，
+  高亮立刻跟着变（选「纯文本」则去掉语言）
 - `Tab` / `Shift+Tab` 整行缩进，选中多行时批量缩进
 - 自动换行（`Alt+Z`）、`Ctrl+滚轮` 或 `Ctrl++` / `Ctrl+-` 缩放字号
 - 撤销 / 重做、剪切 / 复制 / 粘贴，菜单项会跟随可用状态自动灰显

VoiletMark.pro

@@ -1,6 +1,6 @@
 TEMPLATE = app
 TARGET   = VoiletMark
-VERSION  = 0.8.0
+VERSION  = 0.8.1
 
 QT += core gui widgets printsupport
 

src/CodeHighlight.cpp

@@ -163,6 +163,34 @@ const LanguageDef *definition(Language language)
 
 } // namespace
 
+const QVector<LanguageEntry> &languageEntries()
+{
+    static const QVector<LanguageEntry> entries = {
+        {Language::C, QStringLiteral("c"), QStringLiteral("C")},
+        {Language::Cpp, QStringLiteral("cpp"), QStringLiteral("C++")},
+        {Language::Python, QStringLiteral("python"), QStringLiteral("Python")},
+        {Language::JavaScript, QStringLiteral("js"), QStringLiteral("JavaScript")},
+        {Language::TypeScript, QStringLiteral("ts"), QStringLiteral("TypeScript")},
+        {Language::Java, QStringLiteral("java"), QStringLiteral("Java")},
+        {Language::Rust, QStringLiteral("rust"), QStringLiteral("Rust")},
+        {Language::Go, QStringLiteral("go"), QStringLiteral("Go")},
+        {Language::Json, QStringLiteral("json"), QStringLiteral("JSON")},
+        {Language::Bash, QStringLiteral("bash"), QStringLiteral("Bash")},
+        {Language::Sql, QStringLiteral("sql"), QStringLiteral("SQL")},
+        {Language::Yaml, QStringLiteral("yaml"), QStringLiteral("YAML")},
+    };
+    return entries;
+}
+
+QString displayName(Language language)
+{
+    for (const LanguageEntry &entry : languageEntries()) {
+        if (entry.language == language)
+            return entry.name;
+    }
+    return QString();
+}
+
 Language fromInfoString(const QString &info)
 {
     QString name = info.trimmed().toLower();

src/CodeHighlight.h

@@ -34,6 +34,17 @@ struct Span {
     Token token = Token::Keyword;
 };
 
+struct LanguageEntry {
+    Language language;
+    QString info;  // 写进围栏里的标记，例如 cpp
+    QString name;  // 显示名，例如 C++
+};
+
+/// 供语言下拉菜单使用（顺序即菜单顺序）。
+const QVector<LanguageEntry> &languageEntries();
+
+QString displayName(Language language);
+
 /// 从 ```cpp 这类 info string 里识别语言（大小写不敏感）。
 Language fromInfoString(const QString &info);
 

src/MarkdownEditor.cpp

@@ -12,6 +12,7 @@
 #include <QFontMetricsF>
 #include <QGuiApplication>
 #include <QKeyEvent>
+#include <QMenu>
 #include <QMouseEvent>
 #include <QMimeData>
 #include <QPainter>
@@ -56,6 +57,14 @@ bool isFenceLine(const QTextBlock &block)
     return block.isValid() && block.text().trimmed().startsWith(fenceMarker());
 }
 
+QString fenceInfo(const QString &line)
+{
+    QString info = line.trimmed();
+    static const QRegularExpression marker(QStringLiteral("^(?:```+|~~~+)"));
+    info.remove(marker);
+    return info.trimmed();
+}
+
 class LineNumberArea : public QWidget
 {
 public:
@@ -519,10 +528,23 @@ void MarkdownEditor::paintEvent(QPaintEvent *event)
         return;
     }
 
-    // 编辑模式：代码块套一个圆角框，右上角给个复制按钮。
+    // 编辑模式：代码块套圆角框，左上角选语言，右上角复制。
     const ThemeColors &colors = ThemeManager::instance()->colors();
     const QRectF visible(event->rect());
 
+    auto drawBadge = [&](const QRectF &badge, const QString &label, bool hovered, bool emphasized) {
+        if (!badge.isValid())
+            return;
+        QFont small = font();
+        small.setPointSizeF(qMax(7.0, font().pointSizeF() - 2.0));
+        painter.setFont(small);
+        painter.setPen(QPen(hovered ? colors.accent : colors.border, 1));
+        painter.setBrush(colors.editorBase);
+        painter.drawRoundedRect(badge, 4, 4);
+        painter.setPen(emphasized ? colors.accent : colors.placeholder);
+        painter.drawText(badge, Qt::AlignCenter, label);
+    };
+
     for (int index = 0; index < m_codeFences.size(); ++index) {
         const QRectF rect = codeFenceRect(index);
         if (!rect.isValid() || !rect.intersects(visible))
@@ -532,21 +554,12 @@ void MarkdownEditor::paintEvent(QPaintEvent *event)
         painter.setPen(QPen(colors.border, 1));
         painter.drawRoundedRect(rect.adjusted(0.5, 0.5, -0.5, -0.5), 6, 6);
 
-        const QRectF button = copyButtonRect(index);
+        drawBadge(languageRect(index), languageLabel(index) + QStringLiteral(" \u25be"),
-        if (!button.isValid())
+                  m_hoveredLanguage == index, false);
-            continue;
 
-        QFont small = font();
-        small.setPointSizeF(qMax(7.0, font().pointSizeF() - 2.0));
-        painter.setFont(small);
-
-        const bool hovered = (m_hoveredFence == index);
         const bool copied = (m_copiedFence == index);
-        painter.setPen(QPen(hovered ? colors.accent : colors.border, 1));
+        drawBadge(copyButtonRect(index), copied ? tr("已复制") : tr("复制"),
-        painter.setBrush(colors.editorBase);
+                  m_hoveredFence == index, copied);
-        painter.drawRoundedRect(button, 4, 4);
-        painter.setPen(copied ? colors.accent : colors.placeholder);
-        painter.drawText(button, Qt::AlignCenter, copied ? tr("已复制") : tr("复制"));
     }
 }
 
@@ -569,6 +582,87 @@ QRectF MarkdownEditor::codeFenceRect(int index) const
     return QRectF(3, top, viewport()->width() - 6, bottom - top);
 }
 
+QRectF MarkdownEditor::languageRect(int index) const
+{
+    const QRectF rect = codeFenceRect(index);
+    if (!rect.isValid())
+        return QRectF();
+
+    QFont small = font();
+    small.setPointSizeF(qMax(7.0, font().pointSizeF() - 2.0));
+    const QFontMetricsF metrics(small);
+    const QString label = languageLabel(index) + QStringLiteral(" \u25be");
+    const qreal width = metrics.horizontalAdvance(label) + 16;
+    const qreal height = metrics.height() + 6;
+    return QRectF(rect.left() + 8, rect.top() + 6, width, height);
+}
+
+QString MarkdownEditor::languageLabel(int index) const
+{
+    if (index < 0 || index >= m_codeFences.size())
+        return QString();
+    const CodeHighlight::Language language = m_codeFences.at(index).language;
+    if (language == CodeHighlight::Language::None)
+        return tr("纯文本");
+    return CodeHighlight::displayName(language);
+}
+
+void MarkdownEditor::showLanguageMenu(int index)
+{
+    if (index < 0 || index >= m_codeFences.size())
+        return;
+
+    QMenu menu(this);
+
+    QAction *plain = menu.addAction(tr("纯文本"));
+    plain->setData(QString());
+    plain->setCheckable(true);
+    plain->setChecked(m_codeFences.at(index).language == CodeHighlight::Language::None);
+    menu.addSeparator();
+
+    for (const CodeHighlight::LanguageEntry &entry : CodeHighlight::languageEntries()) {
+        QAction *action = menu.addAction(entry.name);
+        action->setData(entry.info);
+        action->setCheckable(true);
+        action->setChecked(entry.language == m_codeFences.at(index).language);
+    }
+
+    const QRectF badge = languageRect(index);
+    const QPoint origin = viewport()->mapToGlobal(badge.bottomLeft().toPoint());
+    QAction *chosen = menu.exec(origin);
+    if (!chosen)
+        return;
+
+    setCodeFenceLanguage(index, chosen->data().toString());
+}
+
+void MarkdownEditor::setCodeFenceLanguage(int index, const QString &info)
+{
+    if (index < 0 || index >= m_codeFences.size())
+        return;
+
+    const int blockNumber = m_codeFences.at(index).open;
+    QTextBlock block = document()->findBlockByNumber(blockNumber);
+    if (!block.isValid())
+        return;
+
+    static const QRegularExpression marker(QStringLiteral("^\\s{0,3}(?:```+|~~~+)"));
+    const QRegularExpressionMatch match = marker.match(block.text());
+    if (!match.hasMatch())
+        return;
+
+    const QString newText = match.captured(0) + info;
+    if (newText == block.text())
+        return;
+
+    QTextCursor cursor(block);
+    cursor.beginEditBlock();
+    cursor.setPosition(block.position());
+    cursor.setPosition(block.position() + block.text().length(), QTextCursor::KeepAnchor);
+    cursor.insertText(newText);
+    cursor.endEditBlock();
+}
+
 QRectF MarkdownEditor::copyButtonRect(int index) const
 {
     const QRectF rect = codeFenceRect(index);
@@ -606,6 +700,7 @@ void MarkdownEditor::rebuildCodeFences()
     static const QRegularExpression fencePattern(QStringLiteral("^\\s{0,3}(?:```|~~~)"));
     bool inFence = false;
     int open = -1;
+    QString openInfo;
 
     for (QTextBlock block = document()->firstBlock(); block.isValid(); block = block.next()) {
         if (!fencePattern.match(block.text()).hasMatch())
@@ -613,10 +708,13 @@ void MarkdownEditor::rebuildCodeFences()
         if (!inFence) {
             inFence = true;
             open = block.blockNumber();
+            openInfo = fenceInfo(block.text());
         } else {
             CodeFence fence;
             fence.open = open;
             fence.close = block.blockNumber();
+            fence.info = openInfo;
+            fence.language = CodeHighlight::fromInfoString(openInfo);
             m_codeFences.append(fence);
             inFence = false;
             open = -1;
@@ -625,6 +723,8 @@ void MarkdownEditor::rebuildCodeFences()
     if (inFence && open >= 0) {
         CodeFence fence;
         fence.open = open;
+        fence.info = openInfo;
+        fence.language = CodeHighlight::fromInfoString(openInfo);
         m_codeFences.append(fence);
     }
 
@@ -637,17 +737,25 @@ void MarkdownEditor::mouseMoveEvent(QMouseEvent *event)
     if (m_sourceMode)
         return;
 
-    int hovered = -1;
+    int hoveredCopy = -1;
+    int hoveredLanguage = -1;
     for (int index = 0; index < m_codeFences.size(); ++index) {
+        if (languageRect(index).contains(event->pos())) {
+            hoveredLanguage = index;
+            break;
+        }
         if (copyButtonRect(index).contains(event->pos())) {
-            hovered = index;
+            hoveredCopy = index;
             break;
         }
     }
 
-    if (hovered != m_hoveredFence) {
+    if (hoveredCopy != m_hoveredFence || hoveredLanguage != m_hoveredLanguage) {
-        m_hoveredFence = hovered;
+        m_hoveredFence = hoveredCopy;
-        viewport()->setCursor(hovered >= 0 ? Qt::PointingHandCursor : Qt::IBeamCursor);
+        m_hoveredLanguage = hoveredLanguage;
+        viewport()->setCursor((hoveredCopy >= 0 || hoveredLanguage >= 0)
+                                  ? Qt::PointingHandCursor
+                                  : Qt::IBeamCursor);
         viewport()->update();
     }
 }
@@ -655,6 +763,12 @@ void MarkdownEditor::mouseMoveEvent(QMouseEvent *event)
 void MarkdownEditor::mousePressEvent(QMouseEvent *event)
 {
     if (!m_sourceMode && event->button() == Qt::LeftButton) {
+        for (int index = 0; index < m_codeFences.size(); ++index) {
+            if (languageRect(index).contains(event->pos())) {
+                showLanguageMenu(index);
+                return;
+            }
+        }
         for (int index = 0; index < m_codeFences.size(); ++index) {
             if (!copyButtonRect(index).contains(event->pos()))
                 continue;

src/MarkdownEditor.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "CodeHighlight.h"
+
 #include <QPlainTextEdit>
 #include <QVector>
 
@@ -66,7 +68,11 @@ private:
     void indentSelection(bool outdent);
     QRectF codeFenceRect(int index) const;
     QRectF copyButtonRect(int index) const;
+    QRectF languageRect(int index) const;
     QString codeFenceText(int index) const;
+    QString languageLabel(int index) const;
+    void showLanguageMenu(int index);
+    void setCodeFenceLanguage(int index, const QString &info);
     bool acceptsLocalFiles(const QMimeData *mime) const;
     void selectedBlockRange(int *firstBlock, int *lastBlock) const;
     void selectBlocks(int firstBlock, int lastBlock);
@@ -76,6 +82,8 @@ private:
     struct CodeFence {
         int open = -1;   // 开围栏所在行
         int close = -1;  // 闭围栏所在行，未闭合时为 -1
+        QString info;    // 围栏上的语言标记
+        CodeHighlight::Language language = CodeHighlight::Language::None;
     };
 
     QWidget *m_lineNumberArea = nullptr;
@@ -87,5 +95,6 @@ private:
     QVector<CodeFence> m_codeFences;
     QTimer *m_fenceTimer = nullptr;
     int m_hoveredFence = -1;
+    int m_hoveredLanguage = -1;
     int m_copiedFence = -1;
 };

translations/voiletmark_en.ts

@@ -372,37 +372,43 @@
 <context>
     <name>MarkdownEditor</name>
     <message>
-        <location filename="../src/MarkdownEditor.cpp" line="549" />
+        <location filename="../src/MarkdownEditor.cpp" line="561" />
-        <location filename="../src/MarkdownEditor.cpp" line="581" />
+        <location filename="../src/MarkdownEditor.cpp" line="675" />
         <source>已复制</source>
         <translation>Copied</translation>
     </message>
     <message>
-        <location filename="../src/MarkdownEditor.cpp" line="549" />
+        <location filename="../src/MarkdownEditor.cpp" line="561" />
-        <location filename="../src/MarkdownEditor.cpp" line="581" />
+        <location filename="../src/MarkdownEditor.cpp" line="675" />
         <source>复制</source>
         <translation>Copy</translation>
     </message>
+    <message>
+        <location filename="../src/MarkdownEditor.cpp" line="606" />
+        <location filename="../src/MarkdownEditor.cpp" line="617" />
+        <source>纯文本</source>
+        <translation>Plain text</translation>
+    </message>
 </context>
 <context>
     <name>QObject</name>
     <message>
-        <location filename="../src/ThemeManager.cpp" line="354" />
+        <location filename="../src/ThemeManager.cpp" line="364" />
         <source>浅色</source>
         <translation>Light</translation>
     </message>
     <message>
-        <location filename="../src/ThemeManager.cpp" line="355" />
+        <location filename="../src/ThemeManager.cpp" line="365" />
         <source>深色</source>
         <translation>Dark</translation>
     </message>
     <message>
-        <location filename="../src/ThemeManager.cpp" line="356" />
+        <location filename="../src/ThemeManager.cpp" line="366" />
         <source>按时段自动</source>
         <translation>Scheduled</translation>
     </message>
     <message>
-        <location filename="../src/ThemeManager.cpp" line="359" />
+        <location filename="../src/ThemeManager.cpp" line="369" />
         <source>跟随系统</source>
         <translation>Follow System</translation>
     </message>