textautogeneratelistviewdelegate.h

/*
  SPDX-FileCopyrightText: 2025 Laurent Montel <montel@kde.org>
 
  SPDX-License-Identifier: GPL-2.0-or-later
*/
#pragma once
 
#include "lrucache.h"
#include <QItemDelegate>
#include <QTextDocument>
#include <memory>
class QListView;
namespace TextAutogenerateText
{
class TextAutogenerateListViewTextSelection;
class TextAutogenerateListViewDelegate : public QItemDelegate
{
    Q_OBJECT
public:
    explicit TextAutogenerateListViewDelegate(QListView *view);
    ~TextAutogenerateListViewDelegate() override;
 
    void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const override;
    [[nodiscard]] QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const override;
 
    void clearSizeHintCache();
 
    void removeMessageCache(const QByteArray &uuid);
 
    void clearCache();
 
    void selectAll(const QStyleOptionViewItem &option, const QModelIndex &index);
 
    [[nodiscard]] bool mouseEvent(QEvent *event, const QStyleOptionViewItem &option, const QModelIndex &index);
    [[nodiscard]] bool helpEvent(QHelpEvent *event, QAbstractItemView *view, const QStyleOptionViewItem &option, const QModelIndex &index) override;
    [[nodiscard]] bool maybeStartDrag(QMouseEvent *event, const QStyleOptionViewItem &option, const QModelIndex &index);
 
    [[nodiscard]] QString selectedText() const;
    [[nodiscard]] bool hasSelection() const;
    [[nodiscard]] QTextDocument *documentForIndex(const QModelIndex &index, int width) const;
 
Q_SIGNALS:
    void updateView(const QModelIndex &index);
 
private:
    struct MessageLayout {
        // Text message
        QRect textRect;
        qreal baseLine; // used to draw sender/timestamp
    };
 
    [[nodiscard]] QSize sizeHint(const QModelIndex &index, int maxWidth, const QStyleOptionViewItem &option, qreal *pBaseLine) const;
    [[nodiscard]] QSize textSizeHint(QTextDocument *doc, qreal *pBaseLine) const;
    [[nodiscard]] TextAutogenerateListViewDelegate::MessageLayout doLayout(const QStyleOptionViewItem &option, const QModelIndex &index) const;
    [[nodiscard]] std::unique_ptr<QTextDocument> createTextDocument(const QString &text, int width) const;
    void draw(QPainter *painter, QRect rect, const QModelIndex &index, const QStyleOptionViewItem &option) const;
    [[nodiscard]] bool handleMouseEvent(QMouseEvent *mouseEvent, QRect messageRect, const QStyleOptionViewItem &option, const QModelIndex &index);
    [[nodiscard]] bool maybeStartDrag(QMouseEvent *mouseEvent, QRect messageRect, const QStyleOptionViewItem &option, const QModelIndex &index);
    // Cache SizeHint value
    // We need to clear it when we resize widget.
    mutable LRUCache<QByteArray, QSize> mSizeHintCache;
 
    mutable LRUCache<QByteArray, std::unique_ptr<QTextDocument>> mDocumentCache;
    QAbstractItemView *const mListView;
    TextAutogenerateListViewTextSelection *const mTextSelection;
};
}