shadowedrectangle.h

/*
 *  SPDX-FileCopyrightText: 2020 Arjen Hiemstra <ahiemstra@heimr.nl>
 *
 *  SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
#pragma once
 
#include <QQuickItem>
#include <memory>
 
#include <QQmlEngine>
 
class PaintedRectangleItem;
 
/**
 * @brief Grouped property for rectangle border.
 */
class BorderGroup : public QObject
{
    Q_OBJECT
    QML_ELEMENT
    QML_UNCREATABLE("")
    /**
     * @brief This property holds the border's width in pixels.
     *
     * default: ``0``px
     */
    Q_PROPERTY(qreal width READ width WRITE setWidth NOTIFY changed FINAL)
    /**
     * @brief This property holds the border's color.
     *
     * Full RGBA colors are supported.
     *
     * default: ``Qt::black``
     */
    Q_PROPERTY(QColor color READ color WRITE setColor NOTIFY changed FINAL)
 
public:
    explicit BorderGroup(QObject *parent = nullptr);
 
    qreal width() const;
    void setWidth(qreal newWidth);
 
    QColor color() const;
    void setColor(const QColor &newColor);
 
    Q_SIGNAL void changed();
 
    inline bool isEnabled() const
    {
        return !qFuzzyIsNull(m_width);
    }
 
private:
    qreal m_width = 0.0;
    QColor m_color = Qt::black;
};
 
/**
 * @brief Grouped property for the rectangle's shadow.
 */
class ShadowGroup : public QObject
{
    Q_OBJECT
    QML_ELEMENT
    QML_UNCREATABLE("")
    /**
     * @brief This property holds the shadow's approximate size in pixels.
     * @note The actual shadow size can be less than this value due to falloff.
     *
     * default: ``0``px
     */
    Q_PROPERTY(qreal size READ size WRITE setSize NOTIFY changed FINAL)
    /**
     * @brief This property holds the shadow's offset in pixels on the X axis.
     *
     * default: ``0``px
     */
    Q_PROPERTY(qreal xOffset READ xOffset WRITE setXOffset NOTIFY changed FINAL)
    /**
     * @brief This property holds the shadow's offset in pixels on the Y axis.
     *
     * default: ``0``px
     */
    Q_PROPERTY(qreal yOffset READ yOffset WRITE setYOffset NOTIFY changed FINAL)
    /**
     * @brief This property holds the shadow's color.
     *
     * Full RGBA colors are supported.
     *
     * default: ``Qt::black``
     */
    Q_PROPERTY(QColor color READ color WRITE setColor NOTIFY changed FINAL)
 
public:
    explicit ShadowGroup(QObject *parent = nullptr);
 
    qreal size() const;
    void setSize(qreal newSize);
 
    qreal xOffset() const;
    void setXOffset(qreal newXOffset);
 
    qreal yOffset() const;
    void setYOffset(qreal newYOffset);
 
    QColor color() const;
    void setColor(const QColor &newShadowColor);
 
    Q_SIGNAL void changed();
 
private:
    qreal m_size = 0.0;
    qreal m_xOffset = 0.0;
    qreal m_yOffset = 0.0;
    QColor m_color = Qt::black;
};
 
/**
 * @brief Grouped property for corner radius.
 */
class CornersGroup : public QObject
{
    Q_OBJECT
    QML_ELEMENT
    QML_UNCREATABLE("")
    /**
     * @brief This property holds the top-left corner's radius in pixels.
     *
     * Setting this to ``-1`` indicates that the value should be ignored.
     *
     * default: ``-1``px
     */
    Q_PROPERTY(qreal topLeftRadius READ topLeft WRITE setTopLeft NOTIFY changed FINAL)
 
    /**
     * @brief This property holds the top-right corner's radius in pixels.
     *
     * Setting this to ``-1`` indicates that the value should be ignored.
     *
     * default: ``-1``px
     */
    Q_PROPERTY(qreal topRightRadius READ topRight WRITE setTopRight NOTIFY changed FINAL)
 
    /**
     * @brief This property holds the bottom-left corner's radius in pixels.
     *
     * Setting this to ``-1`` indicates that the value should be ignored.
     *
     * default: ``-1``px
     */
    Q_PROPERTY(qreal bottomLeftRadius READ bottomLeft WRITE setBottomLeft NOTIFY changed FINAL)
 
    /**
     * @brief This property holds the bottom-right corner's radius in pixels.
     *
     * Setting this to ``-1`` indicates that the value should be ignored.
     *
     * default: ``-1``px
     */
    Q_PROPERTY(qreal bottomRightRadius READ bottomRight WRITE setBottomRight NOTIFY changed FINAL)
 
public:
    explicit CornersGroup(QObject *parent = nullptr);
 
    qreal topLeft() const;
    void setTopLeft(qreal newTopLeft);
 
    qreal topRight() const;
    void setTopRight(qreal newTopRight);
 
    qreal bottomLeft() const;
    void setBottomLeft(qreal newBottomLeft);
 
    qreal bottomRight() const;
    void setBottomRight(qreal newBottomRight);
 
    Q_SIGNAL void changed();
 
    QVector4D toVector4D(float all) const;
 
private:
    float m_topLeft = -1.0;
    float m_topRight = -1.0;
    float m_bottomLeft = -1.0;
    float m_bottomRight = -1.0;
};
 
/**
 * @brief A rectangle with a shadow behind it.
 *
 * This item will render a rectangle, with a shadow below it. The rendering is done
 * using distance fields, which provide greatly improved performance. The shadow is
 * rendered outside of the item's bounds, so the item's width and height are the
 * rectangle's width and height.
 *
 * @since 5.69
 * @since 2.12
 */
class ShadowedRectangle : public QQuickItem
{
    Q_OBJECT
    QML_ELEMENT
    /**
     * @brief This property holds the radii of the rectangle's corners.
     *
     * This is the amount of rounding to apply to all of the rectangle's
     * corners, in pixels. Each corner can have a different radius.
     *
     * default: ``0``
     *
     * @see corners
     */
    Q_PROPERTY(qreal radius READ radius WRITE setRadius NOTIFY radiusChanged FINAL)
 
    /**
     * @brief This property holds the rectangle's color.
     *
     * Full RGBA colors are supported.
     *
     * default: ``Qt::white``
     */
    Q_PROPERTY(QColor color READ color WRITE setColor NOTIFY colorChanged FINAL)
 
    /**
     * @brief This property holds the border's grouped property.
     *
     * Example usage:
     * @code
     * Kirigami.ShadowedRectangle {
     *     border.width: 2
     *     border.color: Kirigami.Theme.textColor
     * }
     * @endcode
     * @see BorderGroup
     */
    Q_PROPERTY(BorderGroup *border READ border CONSTANT FINAL)
 
    /**
     * @brief This property holds the shadow's grouped property.
     *
     * Example usage:
     * @code
     * Kirigami.ShadowedRectangle {
     *     shadow.size: 20
     *     shadow.xOffset: 5
     *     shadow.yOffset: 5
     * }
     * @endcode
     *
     * @see ShadowGroup
     */
    Q_PROPERTY(ShadowGroup *shadow READ shadow CONSTANT FINAL)
 
    /**
     * @brief This property holds the corners grouped property
     *
     * Note that the values from this group override \property radius for the
     * corner they affect.
     *
     * Example usage:
     * @code
     * Kirigami.ShadowedRectangle {
     *     corners.topLeftRadius: 4
     *     corners.topRightRadius: 5
     *     corners.bottomLeftRadius: 2
     *     corners.bottomRightRadius: 10
     * @endcode
     *
     * @see CornersGroup
     */
    Q_PROPERTY(CornersGroup *corners READ corners CONSTANT FINAL)
 
    /**
     * @brief This property holds the rectangle's render mode.
     *
     * default: ``RenderType::Auto``
     *
     * @see RenderType
     */
    Q_PROPERTY(RenderType renderType READ renderType WRITE setRenderType NOTIFY renderTypeChanged FINAL)
 
    /**
     * @brief This property tells whether software rendering is being used.
     *
     * default: ``false``
     */
    Q_PROPERTY(bool softwareRendering READ isSoftwareRendering NOTIFY softwareRenderingChanged FINAL)
 
public:
    ShadowedRectangle(QQuickItem *parent = nullptr);
    ~ShadowedRectangle() override;
 
    /**
     * @brief Available rendering types for ShadowedRectangle.
     */
    enum RenderType {
 
        /**
         * @brief Automatically determine the optimal rendering type.
         *
         * This will use the highest rendering quality possible, falling back to
         * lower quality if the hardware doesn't support it. It will use software
         * rendering if the QtQuick scene graph is set to use software rendering.
         */
        Auto,
 
        /**
         * @brief Use the highest rendering quality possible, even if the hardware might
         * not be able to handle it normally.
         */
        HighQuality,
 
        /**
         * @brief Use the lowest rendering quality, even if the hardware could handle
         * higher quality rendering.
         *
         * This might result in certain effects being omitted, like shadows.
         */
        LowQuality,
 
        /**
         * @brief Always use software rendering for this rectangle.
         *
         * Software rendering is intended as a fallback when the QtQuick scene
         * graph is configured to use software rendering. It will result in
         * a number of missing features, like shadows and multiple corner radii.
         */
        Software
    };
    Q_ENUM(RenderType)
 
    BorderGroup *border() const;
    ShadowGroup *shadow() const;
    CornersGroup *corners() const;
 
    qreal radius() const;
    void setRadius(qreal newRadius);
    Q_SIGNAL void radiusChanged();
 
    QColor color() const;
    void setColor(const QColor &newColor);
    Q_SIGNAL void colorChanged();
 
    RenderType renderType() const;
    void setRenderType(RenderType renderType);
    Q_SIGNAL void renderTypeChanged();
 
    void componentComplete() override;
 
    bool isSoftwareRendering() const;
 
Q_SIGNALS:
    void softwareRenderingChanged();
 
protected:
    PaintedRectangleItem *softwareItem() const;
    void itemChange(QQuickItem::ItemChange change, const QQuickItem::ItemChangeData &value) override;
    QSGNode *updatePaintNode(QSGNode *node, QQuickItem::UpdatePaintNodeData *data) override;
 
private:
    void checkSoftwareItem();
    const std::unique_ptr<BorderGroup> m_border;
    const std::unique_ptr<ShadowGroup> m_shadow;
    const std::unique_ptr<CornersGroup> m_corners;
    qreal m_radius = 0.0;
    QColor m_color = Qt::white;
    RenderType m_renderType = RenderType::Auto;
    PaintedRectangleItem *m_softwareItem = nullptr;
};