feat: v0.2.0 —— 文件夹侧栏、源代码模式、按时段主题与格式快捷键

主题
- 新增「按时段自动」模式：6:00–18:00 浅色，其余时间深色
- 主题菜单改为四种模式，默认仍为跟随系统

侧栏
- 左侧文件夹侧栏（Ctrl+B 开关），递归扫描 *.md / *.markdown / *.mdown / *.mkd
- 文件 → 打开文件夹…（Ctrl+Shift+O），记住上次打开的目录
- 点击文件名即打开，当前文件在列表中高亮，支持手动刷新

编辑
- 左下角 <src> 按钮 / Ctrl+Shift+M 切换源代码模式（关高亮、行号、当前行）
- Ctrl+1~6 设置标题级别，再按一次取消
- Ctrl+/ 把选中内容包成围栏代码块，再按一次拆掉（含光标在块内的情况）

其他
- 模板回归脚本验证了标题与代码块的文本变换
- README 与截图更新

src/MainWindow.cpp

@@ -8,21 +8,32 @@
 #include <QApplication>
 #include <QCloseEvent>
 #include <QDir>
+#include <QDirIterator>
+#include <QDockWidget>
 #include <QFile>
 #include <QFileDialog>
 #include <QFileInfo>
+#include <QFrame>
+#include <QHBoxLayout>
 #include <QLabel>
+#include <QListWidget>
 #include <QMenu>
 #include <QMenuBar>
 #include <QMessageBox>
 #include <QSaveFile>
 #include <QSettings>
+#include <QSignalBlocker>
 #include <QStandardPaths>
 #include <QStatusBar>
 #include <QTextBlock>
 #include <QTextCursor>
 #include <QTextDocument>
 #include <QTimer>
+#include <QToolButton>
+#include <QVBoxLayout>
+#include <QWidget>
+
+#include <algorithm>
 
 namespace {
 
@@ -82,6 +93,7 @@ MainWindow::MainWindow(QWidget *parent)
     setCentralWidget(m_editor);
 
     createActions();
+    createSidebar();
     createMenus();
     createStatusBar();
     loadSettings();
@@ -169,6 +181,79 @@ void MainWindow::createActions()
     connect(m_editor, &QPlainTextEdit::redoAvailable, m_redoAction, &QAction::setEnabled);
     connect(m_editor, &QPlainTextEdit::copyAvailable, m_cutAction, &QAction::setEnabled);
     connect(m_editor, &QPlainTextEdit::copyAvailable, m_copyAction, &QAction::setEnabled);
+
+    m_openFolderAction = new QAction(tr("打开文件夹…"), this);
+    m_openFolderAction->setShortcut(QKeySequence(QStringLiteral("Ctrl+Shift+O")));
+    connect(m_openFolderAction, &QAction::triggered, this, &MainWindow::chooseFolder);
+
+    m_sidebarAction = new QAction(tr("侧栏"), this);
+    m_sidebarAction->setCheckable(true);
+    m_sidebarAction->setChecked(true);
+    m_sidebarAction->setShortcut(QKeySequence(QStringLiteral("Ctrl+B")));
+    connect(m_sidebarAction, &QAction::toggled, this, [this](bool visible) {
+        if (m_sidebar)
+            m_sidebar->setVisible(visible);
+        QSettings().setValue(QStringLiteral("window/sidebarVisible"), visible);
+    });
+
+    m_sourceModeAction = new QAction(tr("源代码模式"), this);
+    m_sourceModeAction->setCheckable(true);
+    m_sourceModeAction->setShortcut(QKeySequence(QStringLiteral("Ctrl+Shift+M")));
+    connect(m_sourceModeAction, &QAction::toggled, this, &MainWindow::setSourceModeEnabled);
+
+    m_codeBlockAction = new QAction(tr("代码块"), this);
+    m_codeBlockAction->setShortcut(QKeySequence(QStringLiteral("Ctrl+/")));
+    connect(m_codeBlockAction, &QAction::triggered, this, [this] {
+        m_editor->toggleCodeBlock();
+    });
+
+    for (int level = 1; level <= 6; ++level) {
+        QAction *action = new QAction(tr("标题 %1").arg(level), this);
+        action->setShortcut(QKeySequence(QStringLiteral("Ctrl+%1").arg(level)));
+        connect(action, &QAction::triggered, this, [this, level] {
+            m_editor->setHeadingLevel(level);
+        });
+        m_headingActions[level - 1] = action;
+    }
+}
+
+void MainWindow::createSidebar()
+{
+    m_sidebar = new QDockWidget(tr("文件夹"), this);
+    m_sidebar->setObjectName(QStringLiteral("folderDock"));
+    m_sidebar->setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea);
+    m_sidebar->setFeatures(QDockWidget::NoDockWidgetFeatures);
+    m_sidebar->setTitleBarWidget(new QWidget(m_sidebar));
+
+    QWidget *content = new QWidget(m_sidebar);
+    QVBoxLayout *layout = new QVBoxLayout(content);
+    layout->setContentsMargins(8, 8, 8, 8);
+    layout->setSpacing(6);
+
+    QHBoxLayout *header = new QHBoxLayout();
+    header->setSpacing(4);
+    m_folderLabel = new QLabel(tr("未打开文件夹"), content);
+    m_folderLabel->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Preferred);
+    QToolButton *refreshButton = new QToolButton(content);
+    refreshButton->setText(tr("刷新"));
+    refreshButton->setToolTip(tr("重新扫描文件夹里的 Markdown 文件"));
+    header->addWidget(m_folderLabel, 1);
+    header->addWidget(refreshButton);
+    layout->addLayout(header);
+
+    m_fileList = new QListWidget(content);
+    m_fileList->setFrameShape(QFrame::NoFrame);
+    m_fileList->setUniformItemSizes(true);
+    m_fileList->setTextElideMode(Qt::ElideMiddle);
+    m_fileList->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    layout->addWidget(m_fileList, 1);
+
+    m_sidebar->setWidget(content);
+    addDockWidget(Qt::LeftDockWidgetArea, m_sidebar);
+    resizeDocks({m_sidebar}, {250}, Qt::Horizontal);
+
+    connect(refreshButton, &QToolButton::clicked, this, &MainWindow::refreshFolder);
+    connect(m_fileList, &QListWidget::itemClicked, this, &MainWindow::openSidebarItem);
 }
 
 void MainWindow::createMenus()
@@ -176,6 +261,7 @@ void MainWindow::createMenus()
     QMenu *fileMenu = menuBar()->addMenu(tr("文件"));
     fileMenu->addAction(m_newAction);
     fileMenu->addAction(m_openAction);
+    fileMenu->addAction(m_openFolderAction);
     m_recentMenu = fileMenu->addMenu(tr("最近打开"));
     fileMenu->addSeparator();
     fileMenu->addAction(m_saveAction);
@@ -194,6 +280,9 @@ void MainWindow::createMenus()
     editMenu->addAction(m_selectAllAction);
 
     QMenu *viewMenu = menuBar()->addMenu(tr("视图"));
+    viewMenu->addAction(m_sidebarAction);
+    viewMenu->addAction(m_sourceModeAction);
+    viewMenu->addSeparator();
     viewMenu->addAction(m_wrapAction);
     viewMenu->addSeparator();
     viewMenu->addAction(m_zoomInAction);
@@ -208,7 +297,10 @@ void MainWindow::createMenus()
     m_themeSystemAction = new QAction(ThemeManager::modeLabel(ThemeManager::Mode::System), this);
     m_themeLightAction = new QAction(ThemeManager::modeLabel(ThemeManager::Mode::Light), this);
     m_themeDarkAction = new QAction(ThemeManager::modeLabel(ThemeManager::Mode::Dark), this);
-    for (QAction *action : {m_themeSystemAction, m_themeLightAction, m_themeDarkAction}) {
+    m_themeScheduleAction = new QAction(ThemeManager::modeLabel(ThemeManager::Mode::Schedule), this);
+    m_themeScheduleAction->setToolTip(tr("6:00–18:00 使用浅色，其余时间使用深色"));
+    for (QAction *action : {m_themeSystemAction, m_themeLightAction, m_themeDarkAction,
+                            m_themeScheduleAction}) {
         action->setCheckable(true);
         themeGroup->addAction(action);
         themeMenu->addAction(action);
@@ -221,6 +313,16 @@ void MainWindow::createMenus()
             [this] { applyThemeMode(static_cast<int>(ThemeManager::Mode::Light)); });
     connect(m_themeDarkAction, &QAction::triggered, this,
             [this] { applyThemeMode(static_cast<int>(ThemeManager::Mode::Dark)); });
+    connect(m_themeScheduleAction, &QAction::triggered, this,
+            [this] { applyThemeMode(static_cast<int>(ThemeManager::Mode::Schedule)); });
+
+    QMenu *formatMenu = menuBar()->addMenu(tr("格式"));
+    QMenu *headingMenu = formatMenu->addMenu(tr("标题"));
+    for (QAction *headingAction : m_headingActions) {
+        if (headingAction)
+            headingMenu->addAction(headingAction);
+    }
+    formatMenu->addAction(m_codeBlockAction);
 
     QMenu *helpMenu = menuBar()->addMenu(tr("帮助"));
     helpMenu->addAction(tr("关于 VoiletMark"), this, &MainWindow::showAbout);
@@ -228,10 +330,20 @@ void MainWindow::createMenus()
 
 void MainWindow::createStatusBar()
 {
+    // 左下角的 <src> 开关：切到源代码模式。
+    m_sourceButton = new QToolButton(this);
+    m_sourceButton->setText(QStringLiteral("<src>"));
+    m_sourceButton->setCheckable(true);
+    m_sourceButton->setCursor(Qt::PointingHandCursor);
+    m_sourceButton->setToolTip(tr("源代码模式：关闭语法高亮与行号（Ctrl+Shift+M）"));
+    statusBar()->addWidget(m_sourceButton);
+
     m_statusLabel = new QLabel(this);
     m_statusLabel->setContentsMargins(8, 0, 10, 0);
     statusBar()->addPermanentWidget(m_statusLabel);
     statusBar()->setSizeGripEnabled(false);
+
+    connect(m_sourceButton, &QToolButton::toggled, this, &MainWindow::setSourceModeEnabled);
 }
 
 void MainWindow::loadSettings()
@@ -259,6 +371,21 @@ void MainWindow::loadSettings()
     m_themeSystemAction->setChecked(mode == ThemeManager::Mode::System);
     m_themeLightAction->setChecked(mode == ThemeManager::Mode::Light);
     m_themeDarkAction->setChecked(mode == ThemeManager::Mode::Dark);
+    m_themeScheduleAction->setChecked(mode == ThemeManager::Mode::Schedule);
+
+    m_folderPath = settings.value(QStringLiteral("files/folder")).toString();
+    if (!m_folderPath.isEmpty() && QFileInfo(m_folderPath).isDir())
+        refreshFolder();
+    else
+        m_folderPath.clear();
+
+    const bool sidebarVisible =
+        settings.value(QStringLiteral("window/sidebarVisible"), true).toBool();
+    m_sidebar->setVisible(sidebarVisible);
+    m_sidebarAction->setChecked(sidebarVisible);
+
+    const bool sourceMode = settings.value(QStringLiteral("editor/sourceMode"), false).toBool();
+    setSourceModeEnabled(sourceMode);
 }
 
 void MainWindow::saveSettings()
@@ -269,6 +396,8 @@ void MainWindow::saveSettings()
     settings.setValue(QStringLiteral("editor/wordWrap"), m_wrapAction->isChecked());
     settings.setValue(QStringLiteral("files/lastDirectory"), m_lastDirectory);
     settings.setValue(QStringLiteral("files/recent"), m_recentFiles);
+    settings.setValue(QStringLiteral("files/folder"), m_folderPath);
+    settings.setValue(QStringLiteral("window/sidebarVisible"), m_sidebar->isVisible());
 }
 
 void MainWindow::closeEvent(QCloseEvent *event)
@@ -455,6 +584,7 @@ void MainWindow::setCurrentFile(const QString &path)
         setWindowFilePath(QString());
     }
     updateWindowTitle();
+    selectInSidebar(path);
 }
 
 void MainWindow::updateWindowTitle()
@@ -565,3 +695,133 @@ void MainWindow::refreshRecentMenu()
         refreshRecentMenu();
     });
 }
+
+void MainWindow::chooseFolder()
+{
+    const QString directory = QFileDialog::getExistingDirectory(
+        this, tr("打开文件夹"), startDirectory(), QFileDialog::ShowDirsOnly);
+    if (!directory.isEmpty())
+        openFolder(directory);
+}
+
+void MainWindow::openFolder(const QString &path)
+{
+    const QFileInfo info(path);
+    if (!info.isDir())
+        return;
+
+    m_folderPath = info.absoluteFilePath();
+    m_lastDirectory = m_folderPath;
+    QSettings().setValue(QStringLiteral("files/folder"), m_folderPath);
+    refreshFolder();
+
+    m_sidebar->setVisible(true);
+    m_sidebarAction->setChecked(true);
+}
+
+void MainWindow::refreshFolder()
+{
+    if (!m_fileList)
+        return;
+
+    m_fileList->clear();
+
+    if (m_folderPath.isEmpty() || !QFileInfo(m_folderPath).isDir()) {
+        m_folderLabel->setText(tr("未打开文件夹"));
+        m_folderLabel->setToolTip(tr("文件 → 打开文件夹…"));
+        return;
+    }
+
+    const QDir root(m_folderPath);
+    m_folderLabel->setText(root.dirName().isEmpty() ? m_folderPath : root.dirName());
+    m_folderLabel->setToolTip(QDir::toNativeSeparators(m_folderPath));
+
+    QStringList files;
+    QDirIterator iterator(m_folderPath,
+                          {QStringLiteral("*.md"), QStringLiteral("*.markdown"),
+                           QStringLiteral("*.mdown"), QStringLiteral("*.mkd")},
+                          QDir::Files, QDirIterator::Subdirectories);
+    while (iterator.hasNext()) {
+        const QString filePath = iterator.next();
+        const QString relative = root.relativeFilePath(filePath);
+        if (relative.startsWith(QLatin1Char('.')) || relative.contains(QLatin1String("/.")))
+            continue;
+        files.append(filePath);
+    }
+
+    std::sort(files.begin(), files.end(), [&root](const QString &left, const QString &right) {
+        return root.relativeFilePath(left).compare(root.relativeFilePath(right),
+                                                   Qt::CaseInsensitive) < 0;
+    });
+
+    for (const QString &filePath : files) {
+        QListWidgetItem *item = new QListWidgetItem(root.relativeFilePath(filePath), m_fileList);
+        item->setData(Qt::UserRole, filePath);
+        item->setToolTip(QDir::toNativeSeparators(filePath));
+    }
+
+    if (files.isEmpty()) {
+        QListWidgetItem *empty = new QListWidgetItem(tr("（没有 Markdown 文件）"), m_fileList);
+        empty->setFlags(Qt::NoItemFlags);
+    }
+
+    selectInSidebar(m_currentPath);
+}
+
+void MainWindow::openSidebarItem(QListWidgetItem *item)
+{
+    if (!item)
+        return;
+
+    const QString path = item->data(Qt::UserRole).toString();
+    if (path.isEmpty())
+        return;
+
+    if (!m_currentPath.isEmpty()
+        && QFileInfo(path).absoluteFilePath() == QFileInfo(m_currentPath).absoluteFilePath()
+        && !m_editor->document()->isModified()) {
+        return;
+    }
+    openPath(path);
+}
+
+void MainWindow::selectInSidebar(const QString &path)
+{
+    if (!m_fileList || m_fileList->count() == 0)
+        return;
+
+    const QString absolute = path.isEmpty() ? QString() : QFileInfo(path).absoluteFilePath();
+    if (!absolute.isEmpty()) {
+        for (int index = 0; index < m_fileList->count(); ++index) {
+            QListWidgetItem *item = m_fileList->item(index);
+            const QString itemPath = item->data(Qt::UserRole).toString();
+            if (itemPath.isEmpty())
+                continue;
+            if (QFileInfo(itemPath).absoluteFilePath() == absolute) {
+                m_fileList->setCurrentItem(item);
+                m_fileList->scrollToItem(item);
+                return;
+            }
+        }
+    }
+
+    m_fileList->clearSelection();
+    m_fileList->setCurrentItem(nullptr);
+}
+
+void MainWindow::setSourceModeEnabled(bool enabled)
+{
+    m_editor->setSourceMode(enabled);
+
+    if (m_sourceButton) {
+        const QSignalBlocker blocker(m_sourceButton);
+        m_sourceButton->setChecked(enabled);
+        m_sourceButton->setText(enabled ? QStringLiteral("</src>") : QStringLiteral("<src>"));
+    }
+    if (m_sourceModeAction) {
+        const QSignalBlocker blocker(m_sourceModeAction);
+        m_sourceModeAction->setChecked(enabled);
+    }
+
+    QSettings().setValue(QStringLiteral("editor/sourceMode"), enabled);
+}

src/MainWindow.h

@@ -5,9 +5,13 @@
 
 class QAction;
 class QActionGroup;
+class QDockWidget;
 class QLabel;
+class QListWidget;
+class QListWidgetItem;
 class QMenu;
 class QTextDocument;
+class QToolButton;
 class MarkdownEditor;
 
 class MainWindow : public QMainWindow
@@ -26,6 +30,7 @@ private:
     enum class Eol { Lf, Crlf };
 
     void createActions();
+    void createSidebar();
     void createMenus();
     void createStatusBar();
     void loadSettings();
@@ -44,6 +49,13 @@ private:
     void refreshRecentMenu();
     void loadRecentFiles();
 
+    void chooseFolder();
+    void openFolder(const QString &path);
+    void refreshFolder();
+    void openSidebarItem(QListWidgetItem *item);
+    void selectInSidebar(const QString &path);
+    void setSourceModeEnabled(bool enabled);
+
     void changeZoom(int direction);
     void resetZoom();
     void setWordWrapEnabled(bool enabled);
@@ -60,6 +72,12 @@ private:
     MarkdownEditor *m_editor = nullptr;
     QLabel *m_statusLabel = nullptr;
 
+    QDockWidget *m_sidebar = nullptr;
+    QListWidget *m_fileList = nullptr;
+    QLabel *m_folderLabel = nullptr;
+    QToolButton *m_sourceButton = nullptr;
+    QString m_folderPath;
+
     QString m_currentPath;
     Eol m_eol = Eol::Lf;
     bool m_hasBom = false;
@@ -87,6 +105,13 @@ private:
     QAction *m_themeSystemAction = nullptr;
     QAction *m_themeLightAction = nullptr;
     QAction *m_themeDarkAction = nullptr;
+    QAction *m_themeScheduleAction = nullptr;
+
+    QAction *m_openFolderAction = nullptr;
+    QAction *m_sidebarAction = nullptr;
+    QAction *m_sourceModeAction = nullptr;
+    QAction *m_codeBlockAction = nullptr;
+    QAction *m_headingActions[6] = {nullptr, nullptr, nullptr, nullptr, nullptr, nullptr};
 
     QMenu *m_recentMenu = nullptr;
 };

src/MarkdownEditor.cpp

@@ -12,7 +12,9 @@
 #include <QKeyEvent>
 #include <QMimeData>
 #include <QPainter>
+#include <QRegularExpression>
 #include <QTextBlock>
+#include <QTextCursor>
 #include <QTextOption>
 #include <QUrl>
 #include <QWheelEvent>
@@ -21,6 +23,17 @@ namespace {
 
 constexpr int kLineNumberRightPadding = 14;
 
+const QString &fenceMarker()
+{
+    static const QString marker = QString(QChar(96)).repeated(3);
+    return marker;
+}
+
+bool isFenceLine(const QTextBlock &block)
+{
+    return block.isValid() && block.text().trimmed().startsWith(fenceMarker());
+}
+
 class LineNumberArea : public QWidget
 {
 public:
@@ -150,7 +163,7 @@ void MarkdownEditor::applyEditorFont()
 
 void MarkdownEditor::updateLineNumberAreaWidth(int)
 {
-    setViewportMargins(lineNumberAreaWidth(), 0, 0, 0);
+    setViewportMargins(m_sourceMode ? 0 : lineNumberAreaWidth(), 0, 0, 0);
 }
 
 void MarkdownEditor::updateLineNumberArea(const QRect &rect, int dy)
@@ -166,6 +179,11 @@ void MarkdownEditor::updateLineNumberArea(const QRect &rect, int dy)
 
 void MarkdownEditor::updateCurrentLineHighlight()
 {
+    if (m_sourceMode) {
+        setExtraSelections({});
+        return;
+    }
+
     QTextEdit::ExtraSelection selection;
     selection.format.setBackground(ThemeManager::instance()->colors().currentLine);
     selection.format.setProperty(QTextFormat::FullWidthSelection, true);
@@ -181,6 +199,206 @@ void MarkdownEditor::applyTheme()
     viewport()->update();
 }
 
+void MarkdownEditor::setSourceMode(bool enabled)
+{
+    if (m_sourceMode == enabled)
+        return;
+
+    m_sourceMode = enabled;
+    m_highlighter->setHighlightingEnabled(!enabled);
+
+    if (enabled)
+        setExtraSelections({});
+    else
+        updateCurrentLineHighlight();
+
+    m_lineNumberArea->setVisible(!enabled);
+    updateLineNumberAreaWidth(0);
+
+    const QRect rect = contentsRect();
+    m_lineNumberArea->setGeometry(QRect(rect.left(), rect.top(),
+                                        lineNumberAreaWidth(), rect.height()));
+
+    viewport()->update();
+    emit sourceModeChanged(enabled);
+}
+
+void MarkdownEditor::selectedBlockRange(int *firstBlock, int *lastBlock) const
+{
+    const QTextCursor cursor = textCursor();
+    int first = cursor.blockNumber();
+    int last = first;
+
+    if (cursor.hasSelection()) {
+        QTextCursor start(document());
+        start.setPosition(cursor.selectionStart());
+        QTextCursor end(document());
+        end.setPosition(cursor.selectionEnd());
+        first = start.blockNumber();
+        last = end.blockNumber();
+        // 选区正好停在下一行行首时，不要把那一行算进来。
+        if (end.positionInBlock() == 0 && last > first)
+            --last;
+    }
+
+    if (firstBlock) *firstBlock = first;
+    if (lastBlock) *lastBlock = last;
+}
+
+void MarkdownEditor::selectBlocks(int firstBlock, int lastBlock)
+{
+    const QTextBlock first = document()->findBlockByNumber(firstBlock);
+    const QTextBlock last = document()->findBlockByNumber(lastBlock);
+    if (!first.isValid() || !last.isValid())
+        return;
+
+    QTextCursor cursor(document());
+    cursor.setPosition(first.position());
+    cursor.setPosition(last.position() + last.text().length(), QTextCursor::KeepAnchor);
+    setTextCursor(cursor);
+}
+
+void MarkdownEditor::setHeadingLevel(int level)
+{
+    level = qBound(0, level, 6);
+
+    int firstBlock = 0;
+    int lastBlock = 0;
+    selectedBlockRange(&firstBlock, &lastBlock);
+
+    static const QRegularExpression headingPattern(QStringLiteral("^\\s{0,3}#{1,6}\\s+"));
+
+    bool alreadySame = level > 0;
+    if (alreadySame) {
+        const QString prefix = QString(level, QChar('#')).append(QLatin1Char(' '));
+        for (int index = firstBlock; index <= lastBlock; ++index) {
+            if (!document()->findBlockByNumber(index).text().startsWith(prefix)) {
+                alreadySame = false;
+                break;
+            }
+        }
+    }
+
+    const int target = alreadySame ? 0 : level;
+    const QString newPrefix = target > 0
+                                  ? QString(target, QChar('#')).append(QLatin1Char(' '))
+                                  : QString();
+
+    QTextCursor edit(document());
+    edit.beginEditBlock();
+    for (int index = firstBlock; index <= lastBlock; ++index) {
+        const QTextBlock block = document()->findBlockByNumber(index);
+        const QString original = block.text();
+        QString text = original;
+        text.remove(headingPattern);
+        if (!newPrefix.isEmpty())
+            text.prepend(newPrefix);
+
+        QTextCursor blockCursor(block);
+        blockCursor.setPosition(block.position());
+        blockCursor.setPosition(block.position() + original.length(), QTextCursor::KeepAnchor);
+        blockCursor.insertText(text);
+    }
+    edit.endEditBlock();
+
+    selectBlocks(firstBlock, lastBlock);
+}
+
+void MarkdownEditor::toggleCodeBlock()
+{
+    int firstBlockNumber = 0;
+    int lastBlockNumber = 0;
+    selectedBlockRange(&firstBlockNumber, &lastBlockNumber);
+
+    const QTextBlock first = document()->findBlockByNumber(firstBlockNumber);
+    const QTextBlock last = document()->findBlockByNumber(lastBlockNumber);
+    if (!first.isValid() || !last.isValid())
+        return;
+
+    // 整块删掉一行（含行尾换行）。
+    const auto removeBlock = [this](const QTextBlock &block) {
+        QTextCursor cursor(block);
+        cursor.setPosition(block.position());
+        const int end = qMin(block.position() + block.length(), document()->characterCount() - 1);
+        cursor.setPosition(end, QTextCursor::KeepAnchor);
+        cursor.removeSelectedText();
+    };
+
+    QTextCursor edit(document());
+
+    // 1) 选中的首尾行本身就是围栏 → 拆掉这两行。
+    if (lastBlockNumber > firstBlockNumber && isFenceLine(first) && isFenceLine(last)) {
+        edit.beginEditBlock();
+        removeBlock(last);
+        removeBlock(first);
+        edit.endEditBlock();
+        return;
+    }
+
+    // 2) 选中内容整体落在某个围栏块内部 → 拆掉外层围栏。
+    QTextBlock opener;
+    QTextBlock closer;
+    if (enclosingFence(firstBlockNumber, lastBlockNumber, &opener, &closer)) {
+        edit.beginEditBlock();
+        removeBlock(closer);
+        removeBlock(opener);
+        edit.endEditBlock();
+        return;
+    }
+
+    // 3) 包成围栏代码块。
+    const int startPosition = first.position();
+    const int endPosition = last.position() + last.text().length();
+
+    edit.beginEditBlock();
+    QTextCursor tail(document());
+    tail.setPosition(endPosition);
+    tail.insertText(QLatin1Char('\n') + fenceMarker());
+    QTextCursor head(document());
+    head.setPosition(startPosition);
+    head.insertText(fenceMarker() + QLatin1Char('\n'));
+    edit.endEditBlock();
+
+    QTextCursor selection(document());
+    selection.setPosition(startPosition);
+    selection.setPosition(endPosition + 8, QTextCursor::KeepAnchor);
+    setTextCursor(selection);
+}
+
+bool MarkdownEditor::enclosingFence(int firstBlockNumber, int lastBlockNumber,
+                                    QTextBlock *opener, QTextBlock *closer) const
+{
+    bool inFence = false;
+    bool captured = false;
+    QTextBlock candidate;
+
+    for (QTextBlock block = document()->firstBlock(); block.isValid(); block = block.next()) {
+        const int number = block.blockNumber();
+        const bool fenceLine = isFenceLine(block);
+
+        if (number == firstBlockNumber) {
+            captured = inFence;
+            if (opener)
+                *opener = candidate;
+        }
+        if (captured && number > lastBlockNumber && fenceLine) {
+            if (closer)
+                *closer = block;
+            return true;
+        }
+        if (fenceLine) {
+            if (!inFence) {
+                inFence = true;
+                candidate = block;
+            } else {
+                inFence = false;
+                candidate = QTextBlock();
+            }
+        }
+    }
+    return false;
+}
+
 void MarkdownEditor::resizeEvent(QResizeEvent *event)
 {
     QPlainTextEdit::resizeEvent(event);

src/MarkdownEditor.h

@@ -3,6 +3,7 @@
 #include <QPlainTextEdit>
 
 class MarkdownHighlighter;
+class QTextBlock;
 
 /// 编辑器本体：等宽字体、行号栏、当前行高亮、Tab 缩进、
 /// Ctrl+滚轮缩放，以及把拖入的文件转交给主窗口打开。
@@ -21,9 +22,19 @@ public:
 
     MarkdownHighlighter *highlighter() const { return m_highlighter; }
 
+    bool isSourceMode() const { return m_sourceMode; }
+    /// 源代码模式：关掉语法高亮、行号与当前行高亮，只看文件原始内容。
+    void setSourceMode(bool enabled);
+
+    /// 把选中的行设为 N 级标题（1–6）；整段已经是这一级时改回正文。
+    void setHeadingLevel(int level);
+    /// 把选中内容包成围栏代码块；如果已经围起来了则拆掉。
+    void toggleCodeBlock();
+
 signals:
     void zoomStepRequested(int direction);
     void fileDropped(const QString &path);
+    void sourceModeChanged(bool enabled);
 
 protected:
     void resizeEvent(QResizeEvent *event) override;
@@ -43,8 +54,13 @@ private:
     void applyEditorFont();
     void indentSelection(bool outdent);
     bool acceptsLocalFiles(const QMimeData *mime) const;
+    void selectedBlockRange(int *firstBlock, int *lastBlock) const;
+    void selectBlocks(int firstBlock, int lastBlock);
+    bool enclosingFence(int firstBlock, int lastBlock,
+                        QTextBlock *opener, QTextBlock *closer) const;
 
     QWidget *m_lineNumberArea = nullptr;
     MarkdownHighlighter *m_highlighter = nullptr;
     int m_fontPointSize = 12;
+    bool m_sourceMode = false;
 };

src/MarkdownHighlighter.cpp

@@ -90,10 +90,18 @@ void MarkdownHighlighter::applyPattern(const QRegularExpression &pattern, const
     }
 }
 
+void MarkdownHighlighter::setHighlightingEnabled(bool enabled)
+{
+    if (m_enabled == enabled)
+        return;
+    m_enabled = enabled;
+    rehighlight();
+}
+
 void MarkdownHighlighter::highlightBlock(const QString &text)
 {
     setCurrentBlockState(StateNormal);
-    if (text.isEmpty())
+    if (!m_enabled || text.isEmpty())
         return;
 
     static const QRegularExpression fencePattern(QStringLiteral("^\\s{0,3}(?:```|~~~)"));

src/MarkdownHighlighter.h

@@ -16,6 +16,9 @@ class MarkdownHighlighter : public QSyntaxHighlighter
 public:
     explicit MarkdownHighlighter(QTextDocument *document = nullptr);
 
+    /// 源代码模式会关掉着色，但不改文档内容（rehighlight 会清掉旧格式）。
+    void setHighlightingEnabled(bool enabled);
+
 protected:
     void highlightBlock(const QString &text) override;
 
@@ -38,4 +41,5 @@ private:
     QTextCharFormat m_ruleFormat;
     QTextCharFormat m_taskDoneFormat;
     QTextCharFormat m_strikeFormat;
+    bool m_enabled = true;
 };

src/ThemeManager.cpp

@@ -9,6 +9,7 @@
 #include <QProcess>
 #include <QSettings>
 #include <QStandardPaths>
+#include <QTime>
 #include <QTimer>
 #include <QXmlStreamReader>
 
@@ -76,6 +77,8 @@ ThemeColors lightColors()
     c.menuBackground      = hex("#ffffff");
     c.scrollHandle        = hex("#c9ced6");
     c.scrollHandleHover   = hex("#aeb5bf");
+    c.sidebarBackground   = hex("#f8f9fb");
+    c.hoverBackground     = hex("#eaedf1");
 
     c.editorBase          = hex("#ffffff");
     c.editorText          = hex("#24292f");
@@ -119,6 +122,8 @@ ThemeColors darkColors()
     c.menuBackground      = hex("#242730");
     c.scrollHandle        = hex("#3a3f47");
     c.scrollHandleHover   = hex("#4d535d");
+    c.sidebarBackground   = hex("#1a1c20");
+    c.hoverBackground     = hex("#272b31");
 
     c.editorBase          = hex("#1e2024");
     c.editorText          = hex("#d7dade");
@@ -171,10 +176,7 @@ void ThemeManager::initialize(Mode forcedMode, bool persist)
     } else {
         const QString saved = QSettings().value(QStringLiteral("theme/mode")).toString();
         m_mode = modeFromString(saved, nullptr);
-        const Scheme scheme = (m_mode == Mode::Dark)   ? Scheme::Dark
-                            : (m_mode == Mode::Light)  ? Scheme::Light
-                                                       : detectSystemScheme();
-        applyScheme(scheme, true);
+        applyScheme(schemeForMode(m_mode), true);
     }
     m_pollTimer->start();
 }
@@ -185,20 +187,35 @@ void ThemeManager::setMode(Mode mode, bool persist)
     if (persist)
         QSettings().setValue(QStringLiteral("theme/mode"), modeToString(mode));
 
-    if (m_mode == Mode::System)
-        applyScheme(detectSystemScheme(), true);
-    else
-        applyScheme(m_mode == Mode::Dark ? Scheme::Dark : Scheme::Light, true);
+    applyScheme(schemeForMode(m_mode), true);
 }
 
 void ThemeManager::pollSystemTheme()
 {
-    if (m_mode != Mode::System)
+    if (m_mode == Mode::Light || m_mode == Mode::Dark)
         return;
 
-    const Scheme detected = detectSystemScheme();
-    if (detected != m_scheme)
-        applyScheme(detected, false);
+    // 跟随系统：读桌面设置；按时段：到 6:00 / 18:00 自动翻转。
+    const Scheme target = schemeForMode(m_mode);
+    if (target != m_scheme)
+        applyScheme(target, false);
+}
+
+ThemeManager::Scheme ThemeManager::schemeForMode(Mode mode) const
+{
+    switch (mode) {
+    case Mode::Light:    return Scheme::Light;
+    case Mode::Dark:     return Scheme::Dark;
+    case Mode::Schedule: return scheduleScheme();
+    case Mode::System:   break;
+    }
+    return detectSystemScheme();
+}
+
+ThemeManager::Scheme ThemeManager::scheduleScheme() const
+{
+    const int hour = QTime::currentTime().hour();
+    return (hour >= 6 && hour < 18) ? Scheme::Light : Scheme::Dark;
 }
 
 void ThemeManager::applyScheme(Scheme scheme, bool force)
@@ -276,6 +293,16 @@ QPushButton { background-color: @button; color: @buttonText; border: 1px solid @
 QPushButton:hover { background-color: @highlight; color: @highlightedText; }
 QPushButton:default { background-color: @accent; color: #ffffff; border-color: @accent; }
 QToolTip { background-color: @menuBackground; color: @text; border: 1px solid @border; padding: 4px; }
+QToolButton { border: none; border-radius: 5px; padding: 3px 8px; color: @text; background: transparent; }
+QToolButton:hover { background-color: @hoverBackground; }
+QToolButton:checked { background-color: @highlight; color: @highlightedText; }
+QDockWidget { color: @text; }
+QDockWidget::title { background-color: @window; padding: 6px 8px; }
+QListWidget { background-color: @sidebarBackground; border: 1px solid @border; border-radius: 6px;
+              padding: 3px; outline: 0; }
+QListWidget::item { padding: 4px 6px; border-radius: 4px; }
+QListWidget::item:hover { background-color: @hoverBackground; }
+QListWidget::item:selected { background-color: @highlight; color: @highlightedText; }
 )");
 
     // 先替换长 token，避免 @window 吃掉 @windowText 这类前缀冲突。
@@ -290,6 +317,8 @@ QToolTip { background-color: @menuBackground; color: @text; border: 1px solid @b
     qss.replace(QLatin1String("@placeholder"), m_colors.placeholder.name());
     qss.replace(QLatin1String("@disabled"), m_colors.disabled.name());
     qss.replace(QLatin1String("@border"), m_colors.border.name());
+    qss.replace(QLatin1String("@hoverBackground"), m_colors.hoverBackground.name());
+    qss.replace(QLatin1String("@sidebarBackground"), m_colors.sidebarBackground.name());
     qss.replace(QLatin1String("@accent"), m_colors.accent.name());
     qss.replace(QLatin1String("@highlight"), m_colors.highlight.name());
     qss.replace(QLatin1String("@button"), m_colors.button.name());
@@ -301,9 +330,10 @@ QToolTip { background-color: @menuBackground; color: @text; border: 1px solid @b
 QString ThemeManager::modeToString(Mode mode)
 {
     switch (mode) {
-    case Mode::Light: return QStringLiteral("light");
-    case Mode::Dark:  return QStringLiteral("dark");
-    case Mode::System: break;
+    case Mode::Light:    return QStringLiteral("light");
+    case Mode::Dark:     return QStringLiteral("dark");
+    case Mode::Schedule: return QStringLiteral("schedule");
+    case Mode::System:   break;
     }
     return QStringLiteral("system");
 }
@@ -311,8 +341,9 @@ QString ThemeManager::modeToString(Mode mode)
 ThemeManager::Mode ThemeManager::modeFromString(const QString &value, bool *ok)
 {
     const QString normalized = value.trimmed().toLower();
-    if (normalized == QLatin1String("light")) { if (ok) *ok = true; return Mode::Light; }
-    if (normalized == QLatin1String("dark"))  { if (ok) *ok = true; return Mode::Dark; }
+    if (normalized == QLatin1String("light"))    { if (ok) *ok = true; return Mode::Light; }
+    if (normalized == QLatin1String("dark"))     { if (ok) *ok = true; return Mode::Dark; }
+    if (normalized == QLatin1String("schedule")) { if (ok) *ok = true; return Mode::Schedule; }
     if (ok) *ok = (normalized == QLatin1String("system") || normalized.isEmpty());
     return Mode::System;
 }
@@ -320,9 +351,10 @@ ThemeManager::Mode ThemeManager::modeFromString(const QString &value, bool *ok)
 QString ThemeManager::modeLabel(Mode mode)
 {
     switch (mode) {
-    case Mode::Light: return QObject::tr("浅色");
-    case Mode::Dark:  return QObject::tr("深色");
-    case Mode::System: break;
+    case Mode::Light:    return QObject::tr("浅色");
+    case Mode::Dark:     return QObject::tr("深色");
+    case Mode::Schedule: return QObject::tr("按时段自动");
+    case Mode::System:   break;
     }
     return QObject::tr("跟随系统");
 }

src/ThemeManager.h

@@ -26,6 +26,8 @@ struct ThemeColors
     QColor menuBackground;
     QColor scrollHandle;
     QColor scrollHandleHover;
+    QColor sidebarBackground;
+    QColor hoverBackground;
 
     // 编辑器
     QColor editorBase;
@@ -53,16 +55,17 @@ struct ThemeColors
 
 /// 负责“跟随系统自动切换浅色 / 深色主题”。
 ///
-/// 检测顺序：显式覆盖（环境变量 / 命令行）→ 平台自身设置
+/// 四种模式：跟随系统 / 浅色 / 深色 / 按时段自动（6:00 起浅色、18:00 起深色）。
+/// 跟随系统时的检测顺序：显式覆盖（环境变量 / 命令行）→ 平台自身设置
 /// （Windows 注册表、macOS defaults、Linux 的 KDE / GTK / XFCE / gsettings）
 /// → 启动时的调色板亮度兜底。
-/// 每 2 秒轮询一次系统设置，变化后立即重绘整个界面。
+/// 每 2 秒轮询一次，变化后立即重绘整个界面。
 class ThemeManager : public QObject
 {
     Q_OBJECT
 
 public:
-    enum class Mode { System, Light, Dark };
+    enum class Mode { System, Light, Dark, Schedule };
     enum class Scheme { Light, Dark };
 
     static ThemeManager *instance();
@@ -95,6 +98,9 @@ private:
     QString styleSheet() const;
 
     Scheme detectSystemScheme() const;
+    /// 6:00–18:00 浅色，其余时间深色。
+    Scheme scheduleScheme() const;
+    Scheme schemeForMode(Mode mode) const;
 
     Mode m_mode = Mode::System;
     Scheme m_scheme = Scheme::Light;