feat: VoiletMark 0.1.0 —— Qt5/C++ Markdown 编辑器

- 自动跟随系统的浅色/深色主题（Windows 注册表、macOS defaults、 Linux gsettings / KDE / XFCE），每 2 秒检测，可在菜单中手动锁定 - Markdown 语法高亮（标题、强调、行内代码、围栏代码块、链接、引用、列表、任务列表、分隔线） - 编辑器：行号栏、当前行高亮、Tab 缩进、拖放打开、Ctrl+滚轮缩放 - 文件：新建/打开/保存/另存为/最近打开，保留 BOM 与 CRLF，QSaveFile 原子写入 - 状态栏、未保存提示、窗口与编辑设置持久化 - CMake 构建脚本与 README
2026-10-22 17:06:27 +08:00
commit a1016ac7d7
15 changed files with 2006 additions and 0 deletions
@@ -0,0 +1,314 @@
+#include "MarkdownEditor.h"
+
+#include "MarkdownHighlighter.h"
+#include "ThemeManager.h"
+
+#include <QAbstractTextDocumentLayout>
+#include <QDragEnterEvent>
+#include <QDropEvent>
+#include <QFileInfo>
+#include <QFontDatabase>
+#include <QFontMetricsF>
+#include <QKeyEvent>
+#include <QMimeData>
+#include <QPainter>
+#include <QTextBlock>
+#include <QTextOption>
+#include <QUrl>
+#include <QWheelEvent>
+
+namespace {
+
+constexpr int kLineNumberRightPadding = 14;
+
+class LineNumberArea : public QWidget
+{
+public:
+    explicit LineNumberArea(MarkdownEditor *editor)
+        : QWidget(editor)
+        , m_editor(editor)
+    {
+        setAttribute(Qt::WA_OpaquePaintEvent, true);
+    }
+
+    QSize sizeHint() const override
+    {
+        return QSize(m_editor->lineNumberAreaWidth(), 0);
+    }
+
+protected:
+    void paintEvent(QPaintEvent *event) override
+    {
+        m_editor->lineNumberAreaPaintEvent(event);
+    }
+
+private:
+    MarkdownEditor *m_editor;
+};
+
+} // namespace
+
+MarkdownEditor::MarkdownEditor(QWidget *parent)
+    : QPlainTextEdit(parent)
+{
+    setObjectName(QStringLiteral("markdownEditor"));
+    setFrameShape(QFrame::NoFrame);
+    setWordWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
+    setLineWrapMode(QPlainTextEdit::WidgetWidth);
+    setCursorWidth(2);
+    setAcceptDrops(true);
+    document()->setDocumentMargin(18);
+
+    m_lineNumberArea = new LineNumberArea(this);
+    m_highlighter = new MarkdownHighlighter(document());
+
+    connect(this, &QPlainTextEdit::blockCountChanged,
+            this, &MarkdownEditor::updateLineNumberAreaWidth);
+    connect(this, &QPlainTextEdit::updateRequest,
+            this, &MarkdownEditor::updateLineNumberArea);
+    connect(this, &QPlainTextEdit::cursorPositionChanged,
+            this, &MarkdownEditor::updateCurrentLineHighlight);
+    connect(ThemeManager::instance(), &ThemeManager::schemeChanged,
+            this, &MarkdownEditor::applyTheme);
+
+    applyEditorFont();
+    updateLineNumberAreaWidth(0);
+    updateCurrentLineHighlight();
+}
+
+int MarkdownEditor::lineNumberAreaWidth() const
+{
+    int digits = 1;
+    int blocks = qMax(1, blockCount());
+    while (blocks >= 10) {
+        blocks /= 10;
+        ++digits;
+    }
+    return 18 + fontMetrics().horizontalAdvance(QLatin1Char('9')) * digits;
+}
+
+void MarkdownEditor::lineNumberAreaPaintEvent(QPaintEvent *event)
+{
+    QPainter painter(m_lineNumberArea);
+    const ThemeColors &colors = ThemeManager::instance()->colors();
+    painter.fillRect(event->rect(), colors.gutterBackground);
+
+    QTextBlock block = firstVisibleBlock();
+    int blockNumber = block.blockNumber();
+    int top = qRound(blockBoundingGeometry(block).translated(contentOffset()).top());
+    int bottom = top + qRound(blockBoundingRect(block).height());
+    const int currentLine = textCursor().blockNumber();
+
+    QFont numberFont = font();
+    if (numberFont.pointSizeF() > 8.5)
+        numberFont.setPointSizeF(numberFont.pointSizeF() - 1.5);
+    painter.setFont(numberFont);
+    const QFontMetrics metrics(numberFont);
+
+    while (block.isValid() && top <= event->rect().bottom()) {
+        if (block.isVisible() && bottom >= event->rect().top()) {
+            painter.setPen(blockNumber == currentLine ? colors.gutterActiveText : colors.gutterText);
+            painter.drawText(0, top, m_lineNumberArea->width() - kLineNumberRightPadding,
+                             metrics.height(), Qt::AlignRight | Qt::AlignVCenter,
+                             QString::number(blockNumber + 1));
+        }
+        block = block.next();
+        top = bottom;
+        bottom = top + qRound(blockBoundingRect(block).height());
+        ++blockNumber;
+    }
+}
+
+void MarkdownEditor::setEditorFontPointSize(int points)
+{
+    const int clamped = qBound(8, points, 48);
+    if (clamped == m_fontPointSize)
+        return;
+    m_fontPointSize = clamped;
+    applyEditorFont();
+}
+
+void MarkdownEditor::applyEditorFont()
+{
+    QFont font = QFontDatabase::systemFont(QFontDatabase::FixedFont);
+    font.setFamilies({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")});
+    font.setPointSize(m_fontPointSize);
+    font.setStyleHint(QFont::Monospace);
+    font.setFixedPitch(true);
+
+    setFont(font);
+    document()->setDefaultFont(font);
+    setTabStopDistance(QFontMetricsF(font).horizontalAdvance(QLatin1Char(' ')) * 4.0);
+    updateLineNumberAreaWidth(0);
+}
+
+void MarkdownEditor::updateLineNumberAreaWidth(int)
+{
+    setViewportMargins(lineNumberAreaWidth(), 0, 0, 0);
+}
+
+void MarkdownEditor::updateLineNumberArea(const QRect &rect, int dy)
+{
+    if (dy != 0)
+        m_lineNumberArea->scroll(0, dy);
+    else
+        m_lineNumberArea->update(0, rect.y(), m_lineNumberArea->width(), rect.height());
+
+    if (rect.contains(viewport()->rect()))
+        updateLineNumberAreaWidth(0);
+}
+
+void MarkdownEditor::updateCurrentLineHighlight()
+{
+    QTextEdit::ExtraSelection selection;
+    selection.format.setBackground(ThemeManager::instance()->colors().currentLine);
+    selection.format.setProperty(QTextFormat::FullWidthSelection, true);
+    selection.cursor = textCursor();
+    selection.cursor.clearSelection();
+    setExtraSelections({selection});
+}
+
+void MarkdownEditor::applyTheme()
+{
+    updateCurrentLineHighlight();
+    m_lineNumberArea->update();
+    viewport()->update();
+}
+
+void MarkdownEditor::resizeEvent(QResizeEvent *event)
+{
+    QPlainTextEdit::resizeEvent(event);
+    const QRect rect = contentsRect();
+    m_lineNumberArea->setGeometry(QRect(rect.left(), rect.top(),
+                                        lineNumberAreaWidth(), rect.height()));
+}
+
+void MarkdownEditor::keyPressEvent(QKeyEvent *event)
+{
+    if (event->key() == Qt::Key_Tab) {
+        if (textCursor().hasSelection())
+            indentSelection(false);
+        else
+            insertPlainText(QStringLiteral("    "));
+        return;
+    }
+    if (event->key() == Qt::Key_Backtab) {
+        indentSelection(true);
+        return;
+    }
+    QPlainTextEdit::keyPressEvent(event);
+}
+
+void MarkdownEditor::indentSelection(bool outdent)
+{
+    QTextCursor cursor = textCursor();
+    const int anchor = cursor.hasSelection() ? cursor.selectionStart() : cursor.position();
+    const int position = cursor.hasSelection() ? cursor.selectionEnd() : cursor.position();
+
+    QTextCursor startCursor(document());
+    startCursor.setPosition(anchor);
+    QTextCursor endCursor(document());
+    endCursor.setPosition(position);
+
+    const int firstBlock = startCursor.blockNumber();
+    const int lastBlock = endCursor.blockNumber();
+    const bool hadSelection = cursor.hasSelection();
+
+    cursor.beginEditBlock();
+    for (int index = firstBlock; index <= lastBlock; ++index) {
+        QTextBlock block = document()->findBlockByNumber(index);
+        QTextCursor blockCursor(block);
+        if (outdent) {
+            const QString text = block.text();
+            int removable = 0;
+            while (removable < 4 && removable < text.size()
+                   && text.at(removable) == QLatin1Char(' ')) {
+                ++removable;
+            }
+            if (removable > 0) {
+                blockCursor.setPosition(block.position());
+                blockCursor.setPosition(block.position() + removable, QTextCursor::KeepAnchor);
+                blockCursor.removeSelectedText();
+            }
+        } else {
+            blockCursor.setPosition(block.position());
+            blockCursor.insertText(QStringLiteral("    "));
+        }
+    }
+    cursor.endEditBlock();
+
+    // 还原选区（行宽变化后按块首尾重新计算）。
+    if (hadSelection) {
+        QTextCursor from(document());
+        from.setPosition(document()->findBlockByNumber(firstBlock).position());
+        QTextCursor to(document());
+        const QTextBlock last = document()->findBlockByNumber(lastBlock);
+        to.setPosition(last.position() + last.length() - 1);
+        from.setPosition(to.position(), QTextCursor::KeepAnchor);
+        setTextCursor(from);
+    }
+}
+
+void MarkdownEditor::wheelEvent(QWheelEvent *event)
+{
+    if (event->modifiers().testFlag(Qt::ControlModifier)) {
+        const int delta = event->angleDelta().y();
+        if (delta != 0) {
+            emit zoomStepRequested(delta > 0 ? 1 : -1);
+            event->accept();
+            return;
+        }
+    }
+    QPlainTextEdit::wheelEvent(event);
+}
+
+bool MarkdownEditor::acceptsLocalFiles(const QMimeData *mime) const
+{
+    if (!mime->hasUrls())
+        return false;
+    const QList<QUrl> urls = mime->urls();
+    for (const QUrl &url : urls) {
+        if (url.isLocalFile() && QFileInfo(url.toLocalFile()).isFile())
+            return true;
+    }
+    return false;
+}
+
+void MarkdownEditor::dragEnterEvent(QDragEnterEvent *event)
+{
+    if (acceptsLocalFiles(event->mimeData())) {
+        event->acceptProposedAction();
+        return;
+    }
+    QPlainTextEdit::dragEnterEvent(event);
+}
+
+void MarkdownEditor::dragMoveEvent(QDragMoveEvent *event)
+{
+    if (acceptsLocalFiles(event->mimeData())) {
+        event->acceptProposedAction();
+        return;
+    }
+    QPlainTextEdit::dragMoveEvent(event);
+}
+
+void MarkdownEditor::dropEvent(QDropEvent *event)
+{
+    if (event->mimeData()->hasUrls()) {
+        const QList<QUrl> urls = event->mimeData()->urls();
+        for (const QUrl &url : urls) {
+            if (url.isLocalFile() && QFileInfo(url.toLocalFile()).isFile()) {
+                event->acceptProposedAction();
+                emit fileDropped(url.toLocalFile());
+                return;
+            }
+        }
+    }
+    QPlainTextEdit::dropEvent(event);
+}