/*
 * SPDX-FileCopyrightText: 2001-2015 Klaralvdalens Datakonsult AB. All rights reserved.
 *
 * This file is part of the KGantt library.
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#ifndef KGANTTABSTRACTROWCONTROLLER_H
#define KGANTTABSTRACTROWCONTROLLER_H

#include "kganttglobal.h"
#include <QPair>

QT_BEGIN_NAMESPACE
class QModelIndex;
QT_END_NAMESPACE

namespace KGantt
{

/*!\class KGantt::AbstractRowController kganttabstractrowcontroller.h KGanttAbstractRowController
 * \ingroup KGantt
 * \brief Abstract baseclass for row controllers. A row controller is used
 * by the GraphicsView to navigate the model and to determine the
 * row geometries
 */
class KGANTT_EXPORT AbstractRowController
{
public:
    /*! Constructor. Does nothing */
    AbstractRowController();

    /*! Destructor. Does nothing */
    virtual ~AbstractRowController();

    /*!\fn virtual int AbstractRowController::headerHeight() const = 0
     * \returns The height of the header part of the view.
     *
     * Implement this to control how much space is reserved at
     * the top of the view for a header
     */
    virtual int headerHeight() const = 0;
    virtual int maximumItemHeight() const = 0;

    /*!\fn virtual int AbstractRowController::totalHeight() const = 0
     * \returns the total height of the rows. For uniformly sized rows that would be
     * number_of_rows*row_height.
     */
    virtual int totalHeight() const = 0;

    /*!\fn virtual bool AbstractRowController::isRowVisible( const QModelIndex& idx ) const
     * \returns true if the row containing index \a idx is visible
     * in the view.
     *
     * Implement this to allow KGantt to optimize how items on
     * screen are created. It is not harmful to always return true here,
     * but the View will not perform optimally.
     */
    virtual bool isRowVisible(const QModelIndex &idx) const = 0;
    virtual bool isRowExpanded(const QModelIndex &idx) const = 0;

    /*!\fn virtual Span AbstractRowController::rowGeometry( const QModelIndex& idx ) const
     * \returns A Span consisting of the row offset and height for the row
     * containing \a idx. A simple implementation might look like
     *
     * \code
     * Span MyRowCtrlr::rowGeometry(const QModelIndex& idx)
     * {
     *      return Span(idx.row()*10,10);
     * }
     * \endcode
     */
    virtual Span rowGeometry(const QModelIndex &idx) const = 0;

    virtual QModelIndex indexAt(int height) const = 0;

    /*!\fn virtual QModelIndex AbstractRowController::indexAbove( const QModelIndex& idx ) const
     *\returns The modelindex for the previous row before \a idx.
     *
     *\see QTreeView::indexAbove
     */
    virtual QModelIndex indexAbove(const QModelIndex &idx) const = 0;

    /*!\fn virtual QModelIndex AbstractRowController::indexBelow( const QModelIndex& idx ) const
     *\returns The modelindex for the next row after \a idx.
     *
     *\see QTreeView::indexBelow
     */
    virtual QModelIndex indexBelow(const QModelIndex &idx) const = 0;
};
}

#endif /* KGANTTABSTRACTROWCONTROLLER_H */
