qmarkdowntextedit.h

/*
 * MIT License
 *
 * Copyright (c) 2014-2026 Patrizio Bekerle -- <patrizio@bekerle.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#pragma once

#include <QEvent>
#include <QPlainTextEdit>
#include <QPoint>
#include <QPointF>
#include <QTextBlock>
#include <QVector>

#include "markdownhighlighter.h"
#include "qplaintexteditsearchwidget.h"

class LineNumArea;
class QKeyEvent;
class QMouseEvent;
class QTimer;

class QMarkdownTextEdit : public QPlainTextEdit {
    Q_OBJECT
    Q_PROPERTY(
        bool highlighting READ highlightingEnabled WRITE setHighlightingEnabled)

    friend class LineNumArea;

   public:
    enum AutoTextOption {
        None = 0x0000,

        // inserts closing characters for brackets and Markdown characters
        BracketClosing = 0x0001,

        // removes matching brackets and Markdown characters
        BracketRemoval = 0x0002
    };

    Q_DECLARE_FLAGS(AutoTextOptions, AutoTextOption)

    explicit QMarkdownTextEdit(QWidget *parent = nullptr,
                               bool initHighlighter = true);
    MarkdownHighlighter *highlighter();
    QPlainTextEditSearchWidget *searchWidget();
    void setIgnoredClickUrlSchemata(QStringList ignoredUrlSchemata);
    void setIgnoredClickUrlRegexps(
        QList<QRegularExpression> ignoredClickUrlRegexps);
    virtual void openUrl(const QString &urlString, bool openInNewTab = false);
    QString getMarkdownUrlAtPosition(const QString &text, int position);
    void initSearchFrame(QWidget *searchFrame, bool darkMode = false);
    void setAutoTextOptions(AutoTextOptions options);
    static bool isValidUrl(const QString &urlString);
    void resetMouseCursor() const;
    void setReadOnly(bool ro);
    void doSearch(QString &searchText,
                  QPlainTextEditSearchWidget::SearchMode searchMode =
                      QPlainTextEditSearchWidget::SearchMode::PlainTextMode);
    void hideSearchWidget(bool reset);
    void updateSettings();
    void setLineNumbersCurrentLineColor(QColor color);
    void setLineNumbersOtherLineColor(QColor color);
    void setSearchWidgetDebounceDelay(uint debounceDelay);
    void setBookmarkLines(const QHash<int, int> &bookmarkLines);

    void setHighlightingEnabled(bool enabled);
    [[nodiscard]] bool highlightingEnabled() const;

    void setHighlightCurrentLine(bool set);
    bool highlightCurrentLine();

    void setHangingIndentEnabled(bool enabled);
    [[nodiscard]] bool hangingIndentEnabled() const;

    void setCurrentLineHighlightColor(const QColor &c);
    QColor currentLineHighlightColor();

   public Q_SLOTS:
    void duplicateText();
    void setText(const QString &text);
    void setPlainText(const QString &text);
    void adjustRightMargin();
    void hide();
    bool openLinkAtCursorPosition();
    bool handleBackspaceEntered();
    void centerTheCursor();
    void undo();
    void moveTextUpDown(bool up);
    void setLineNumberEnabled(bool enabled);

   protected:
    QTextCursor _textCursor;
    MarkdownHighlighter *_highlighter = nullptr;
    bool _highlightingEnabled;
    QStringList _ignoredClickUrlSchemata;
    QList<QRegularExpression> _ignoredClickUrlRegexps;
    QPlainTextEditSearchWidget *_searchWidget;
    QWidget *_searchFrame;
    AutoTextOptions _autoTextOptions;
    bool _mouseButtonDown = false;
    bool _centerCursor = false;
    bool _highlightCurrentLine = false;
    bool _openLinkInNewTab = false;
    bool _hangingIndentEnabled = true;
    QColor _currentLineHighlightColor = QColor();
    uint _debounceDelay = 0;

    // Block (rectangular) selection state
    bool _blockSelectionActive = false;
    bool _blockSelectionDragging = false;
    QPoint
        _blockSelectionAnchor;    // Viewport position where Alt+click started
    QPoint _blockSelectionEnd;    // Current viewport position during drag
    int _blockSelStartBlock = -1;    // First block (line) in selection
    int _blockSelEndBlock = -1;      // Last block (line) in selection
    int _blockSelLeftCol = 0;        // Left column of rectangle
    int _blockSelRightCol = 0;       // Right column of rectangle
    void updateBlockSelection();
    void clearBlockSelection();
    void paintBlockSelection(QPainter &painter);
    int columnForBlockAtX(const QTextBlock &block, int x) const;
    qreal xForColumnInBlock(const QTextBlock &block, int column) const;
    QString blockSelectionText() const;
    void removeBlockSelectionText();
    void replaceBlockSelectionText(const QString &text);

    bool eventFilter(QObject *obj, QEvent *event) override;
    QMargins viewportMargins();
    bool increaseSelectedTextIndention(
        bool reverse,
        const QString &indentCharacters = QChar::fromLatin1('\t'));
    bool handleTabEntered(bool reverse, const QString &indentCharacters =
                                            QChar::fromLatin1('\t'));
    QMap<QString, QString> parseMarkdownUrlsFromText(const QString &text);
    bool handleReturnEntered();
    bool handleBracketClosing(const QChar openingCharacter,
                              QChar closingCharacter = QChar());
    bool bracketClosingCheck(const QChar openingCharacter,
                             QChar closingCharacter);
    bool quotationMarkCheck(const QChar quotationCharacter);
    void focusInEvent(QFocusEvent *event) override;
    void focusOutEvent(QFocusEvent *event) override;
    void paintEvent(QPaintEvent *e) override;
    static int listContentIndentLength(const QString &text);
    bool handleCharRemoval(MarkdownHighlighter::RangeType type, int block,
                           int position);
    void resizeEvent(QResizeEvent *event) override;
    void keyPressEvent(QKeyEvent *event) override;
    void mousePressEvent(QMouseEvent *event) override;
    void mouseMoveEvent(QMouseEvent *event) override;
    void mouseReleaseEvent(QMouseEvent *event) override;
    void mouseDoubleClickEvent(QMouseEvent *event) override;
    virtual int sidebarAdditionalWidth() const;
    virtual void paintSidebar(QPainter *painter, const QRect &eventRect);
    virtual bool sidebarMousePressEvent(QMouseEvent *event);
    void setLineNumberLeftMarginOffset(int offset);
    int _lineNumberLeftMarginOffset = 0;
    LineNumArea *lineNumberArea() { return _lineNumArea; }
    void updateLineNumAreaGeometry();
    void updateLineNumberArea(const QRect rect, int dy);
    Q_SLOT void updateLineNumberAreaWidth(int);
    bool hasMarkdownUrlAtViewportPosition(const QPoint &position);
    void updateLinkCursor(const QPoint &position,
                          Qt::KeyboardModifiers modifiers);
    bool _handleBracketClosingUsed;
    LineNumArea *_lineNumArea;

   private:
    struct LineBackup {
        QPointF position;
        qreal width;
    };
    struct BlockLayoutBackup {
        QTextBlock block;
        QVector<LineBackup> lines;
    };
    QRect hangingCursorBlockRepaintRect() const;
    void updateHangingCursorRepaintState();
    QVector<BlockLayoutBackup> applyHangingIndentLayout();
    void restoreHangingIndentLayout(const QVector<BlockLayoutBackup> &backups);
    QTimer *_hangingCursorRepaintTimer = nullptr;

   Q_SIGNALS:
    void urlClicked(QString url);
    void zoomIn();
    void zoomOut();
};