KChartAbstractGrid.h

/*
 * Copyright (C) 2001-2015 Klaralvdalens Datakonsult AB.  All rights reserved.
 *
 * This file is part of the KD Chart library.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#ifndef KCHARTABSTRACTGRID_H
#define KCHARTABSTRACTGRID_H

#include <QPair>

#include "KChartAbstractCoordinatePlane.h"
#include "KChartGridAttributes.h"
#include "KChartAbstractDiagram.h"
#include "KChartCartesianAxis.h"

namespace KChart {

    class PaintContext;


    /**
     * \internal
     *
     * \brief Abstract base class for grid classes: cartesian, polar, ...
     *
     * The AbstractGrid interface is the base class used by
     * AbstractCoordinatePlane, for calculating and for drawing
     * the grid lines of the plane.
     */
    class AbstractGrid
    {
    public:
        virtual ~AbstractGrid();
    protected:
        AbstractGrid ();


    public:
        /** \brief Returns the cached result of data calculation.
          *
          * For this, all derived classes need to implement the
          * pure-virtual calculateGrid() method.
          */
        DataDimensionsList updateData( AbstractCoordinatePlane* plane );

        /**
          * Doing the actual drawing.
          *
          * Every derived class must implement this.
          *
          * \note When implementing drawGrid():  Before you start drawing,
          * make sure to call updateData(), to get the data boundaries
          * recalculated.
          * For an example, see the implementation of CartesianGrid:drawGrid().
          */
        virtual void drawGrid( PaintContext* context ) = 0;

        /**
         * Causes grid to be recalculated upon the next call
         * of updateData().
         *
         * \see calculateGrid
         */
        void setNeedRecalculate();

        /**
         * Checks whether both coordinates of r are valid according
         * to isValueValid
         *
         * \see isValueValid
         */
        static bool isBoundariesValid(const QRectF& r );

        /**
         * Checks whether both coordinates of both points are valid
         * according to isValueValid
         *
         * \see isValueValid
         */
        static bool isBoundariesValid(const QPair<QPointF,QPointF>& b );

        /**
         * Checks whether all start and end properties of every
         * DataDimension in the list l are valid according to
         * isValueValid().
         *
         * \see isValueValid
         */
        static bool isBoundariesValid(const DataDimensionsList& l );

        /**
         * Checks if r is neither NaN nor infinity.
         */
        static bool isValueValid(const qreal& r );

        /**
         * Adjusts \a start and/or \a end so that they are a multiple of
         * \a stepWidth
         */
        static void adjustLowerUpperRange(
                qreal& start, qreal& end,
                qreal stepWidth,
                bool adjustLower, bool adjustUpper );

        /**
         * Adjusts \a dim so that \c dim.start and/or \c dim.end are a multiple
         * of \c dim.stepWidth.
         *
         * \see adjustLowerUpperRange
         */
        static const DataDimension adjustedLowerUpperRange(
                const DataDimension& dim,
                bool adjustLower, bool adjustUpper );

        GridAttributes gridAttributes;

    protected:
        DataDimensionsList mDataDimensions;
        AbstractCoordinatePlane* mPlane;

    private:
        /**
          * \brief Calculates the grid start/end/step width values.
          *
          * Gets the raw data dimensions - e.g. the data model's boundaries,
          * together with their isCalculated flags.
          *
          * Returns the calculated start/end values for the grid, and their
          * respective step widths.
          * If at least one of the step widths is Zero, all dimensions of
          * the returned list are considered invalid!
          *
          * \note This function needs to be implemented by all derived classes,
          * like CartesianGrid, PolarGrid, ...
          */
        virtual DataDimensionsList calculateGrid( const DataDimensionsList& rawDataDimensions ) const = 0;
        DataDimensionsList mCachedRawDataDimensions;
    };

}

#endif