File indexing completed on 2024-12-01 09:54:11

 /*
     This file is part of the KDE libraries
     SPDX-FileCopyrightText: 2006, 2007 Andreas Hartmetz <ahartmetz@gmail.com>
     SPDX-FileCopyrightText: 2008 Urs Wolfer <uwolfer@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #ifndef KEXTENDABLEITEMDELEGATE_H
 #define KEXTENDABLEITEMDELEGATE_H
 
 #include <QStyledItemDelegate>
 #include <memory>
 
 #include <kitemviews_export.h>
 
 class QAbstractItemView;
 
 /**
  * @class KExtendableItemDelegate kextendableitemdelegate.h KExtendableItemDelegate
  *
  * This delegate makes it possible to display an arbitrary QWidget ("extender") that spans all columns below a line of items.
  * The extender will logically belong to a column in the row above it.
  *
  * It is your responsibility to devise a way to trigger extension and contraction of items, by calling
  * extendItem() and contractItem(). You can e.g. reimplement itemActivated() and similar functions.
  *
  * @warning extendItem() reparents the provided widget @a extender to the
  * viewport of the itemview it belongs to. The @a extender is destroyed when
  * you call contractItem() for the associated index. If you fail to do that
  * and the associated item gets deleted you're in trouble. It remains as a
  * visible artefact in your treeview. Additionally when closing your
  * application you get an assertion failure from KExtendableItemDelegate. Make
  * sure that you always call contractItem for indices before you delete them.
  *
  * @author Andreas Hartmetz <ahartmetz@gmail.com>
  *
  * @since 4.1
  */
 class KITEMVIEWS_EXPORT KExtendableItemDelegate : public QStyledItemDelegate
 {
     Q_OBJECT
 
 public:
     enum auxDataRoles {
         ShowExtensionIndicatorRole = Qt::UserRole + 200,
     };
 
     /**
      * Create a new KExtendableItemDelegate that belongs to @p parent. In contrast to generic
      * QAbstractItemDelegates, an instance of this class can only ever be the delegate for one
      * instance of af QAbstractItemView subclass.
      */
     KExtendableItemDelegate(QAbstractItemView *parent);
     ~KExtendableItemDelegate() override;
 
     /**
      * Re-implemented for internal reasons. API not affected.
      */
     QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const override;
 
     /**
      * Re-implemented for internal reasons. API not affected.
      */
     void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const override;
 
     /**
      * Insert the @p extender for item at @p index into the view.
      * If you need a parent for the extender at construction time, use the itemview's viewport().
      * The delegate takes ownership of the extender; the extender will also be reparented and
      * resized to the viewport.
      */
     void extendItem(QWidget *extender, const QModelIndex &index);
 
     /**
      * Remove the extender of item at @p index from the view. The extender widget
      * will be deleted.
      */
     void contractItem(const QModelIndex &index);
 
     /**
      * Close all extenders and delete all extender widgets.
      */
     void contractAll();
 
     /**
      * Return whether there is an extender that belongs to @p index.
      */
     bool isExtended(const QModelIndex &index) const;
 
     /**
      * Reimplement this function to adjust the internal geometry of the extender.
      * The external geometry of the extender will be set by the delegate.
      */
     virtual void updateExtenderGeometry(QWidget *extender, const QStyleOptionViewItem &option, const QModelIndex &index) const;
 
 Q_SIGNALS:
     /**
      * This signal indicates that the item at @p index was extended with @p extender.
      */
     void extenderCreated(QWidget *extender, const QModelIndex &index);
 
     /**
      * This signal indicates that the @p extender belonging to @p index has emitted the destroyed() signal.
      */
     void extenderDestroyed(QWidget *extender, const QModelIndex &index);
 
 protected:
     /**
      * Reimplement this function to fine-tune the position of the extender. @p option.rect will be a rectangle
      * that is as wide as the viewport and as high as the usual item height plus the extender size hint's height.
      * Its upper left corner will be at the upper left corner of the usual item.
      * You can place the returned rectangle of this function anywhere inside that area.
      */
     QRect extenderRect(QWidget *extender, const QStyleOptionViewItem &option, const QModelIndex &index) const;
 
     /**
      * The pixmap that is displayed to extend an item. @p pixmap must have the same size as the pixmap in setContractPixmap.
      */
     void setExtendPixmap(const QPixmap &pixmap);
 
     /**
      * The pixmap that is displayed to contract an item. @p pixmap must have the same size as the pixmap in setExtendPixmap.
      */
     void setContractPixmap(const QPixmap &pixmap);
 
     /**
      * Return the pixmap that is displayed to extend an item.
      */
     QPixmap extendPixmap();
 
     /**
      * Return the pixmap that is displayed to contract an item.
      */
     QPixmap contractPixmap();
 
 private:
     friend class KExtendableItemDelegatePrivate;
     std::unique_ptr<class KExtendableItemDelegatePrivate> const d;
 
     Q_PRIVATE_SLOT(d, void _k_extenderDestructionHandler(QObject *destroyed))
     Q_PRIVATE_SLOT(d, void _k_verticalScroll())
 };
 #endif // KEXTENDABLEITEMDELEGATE_H