/*
    This file is part of the KDE libraries
    SPDX-FileCopyrightText: 1997 Martin Jones <mjones@kde.org>

    SPDX-License-Identifier: LGPL-2.0-or-later
*/

#ifndef KXYSELECTOR_H
#define KXYSELECTOR_H

#include <kwidgetsaddons_export.h>

#include <QWidget>
#include <memory>

/*!
 * \class KXYSelector
 * \inmodule KWidgetsAddons
 *
 * \brief Base class for other widgets which
 * provides the ability to choose from a two-dimensional
 * range of values.
 *
 * The currently chosen value is indicated
 * by a cross. An example is the KHSSelector which
 * allows to choose from a range of colors, and which is
 * used in KColorDialog.
 *
 * A custom drawing routine for the widget surface has
 * to be provided by the subclass.
 */
class KWIDGETSADDONS_EXPORT KXYSelector : public QWidget
{
    Q_OBJECT

    /*!
     * \property KXYSelector::xValue
     */
    Q_PROPERTY(int xValue READ xValue WRITE setXValue)

    /*!
     * \property KXYSelector::yValue
     */
    Q_PROPERTY(int yValue READ yValue WRITE setYValue)

public:
    /*!
     * Constructs a two-dimensional selector widget which
     * has a value range of [0..100] in both directions.
     */
    explicit KXYSelector(QWidget *parent = nullptr);

    ~KXYSelector() override;

    /*!
     * Sets the current values in horizontal and
     * vertical direction.
     *
     * \a xPos the horizontal value
     *
     * \a yPos the vertical value
     */
    void setValues(int xPos, int yPos);

    /*!
     * Sets the current horizontal value
     *
     * \a xPos the horizontal value
     */
    void setXValue(int xPos);

    /*!
     * Sets the current vertical value
     *
     * \a yPos the vertical value
     */
    void setYValue(int yPos);

    /*!
     * Sets the range of possible values.
     */
    void setRange(int minX, int minY, int maxX, int maxY);

    /*!
     * Sets the color used to draw the marker
     *
     * \a col the color
     */
    void setMarkerColor(const QColor &col);

    /*!
     * Returns the current value in horizontal direction.
     */
    int xValue() const;
    /*!
     * Returns the current value in vertical direction.
     */
    int yValue() const;

    /*!
     * Returns the rectangle on which subclasses should draw.
     */
    QRect contentsRect() const;

    QSize minimumSizeHint() const override;

Q_SIGNALS:
    /*!
     * This signal is emitted whenever the user chooses a value,
     * e.g. by clicking with the mouse on the widget.
     */
    void valueChanged(int x, int y);

protected:
    /*!
     * Override this function to draw the contents of the widget.
     * The default implementation does nothing.
     *
     * Draw within contentsRect() only.
     */
    virtual void drawContents(QPainter *);

    /*!
     * Override this function to draw the marker which
     * indicates the currently selected value pair.
     */
    virtual void drawMarker(QPainter *p, int xp, int yp);

    void paintEvent(QPaintEvent *e) override;
    void mousePressEvent(QMouseEvent *e) override;
    void mouseMoveEvent(QMouseEvent *e) override;
    void wheelEvent(QWheelEvent *) override;

    /*!
     * Converts a pixel position to its corresponding values.
     */
    void valuesFromPosition(int x, int y, int &xVal, int &yVal) const;

private:
    KWIDGETSADDONS_NO_EXPORT void setPosition(int xp, int yp);

private:
    friend class KXYSelectorPrivate;
    std::unique_ptr<class KXYSelectorPrivate> const d;

    Q_DISABLE_COPY(KXYSelector)
};

#endif /* KXYSELECTOR_H */