framesvg.h

/*
    SPDX-FileCopyrightText: 2008 Aaron Seigo <aseigo@kde.org>
    SPDX-FileCopyrightText: 2008 Marco Martin <notmart@gmail.com>
 
    SPDX-License-Identifier: LGPL-2.0-or-later
*/
 
#ifndef KSVG_FRAMESVG_H
#define KSVG_FRAMESVG_H
 
#include <QObject>
#include <QPixmap>
 
#include <ksvg/ksvg_export.h>
 
#include <ksvg/svg.h>
 
class QPainter;
class QPoint;
class QPointF;
class QRect;
class QRectF;
class QSize;
class QSizeF;
class QMatrix;
 
namespace KSvg
{
class FrameSvgPrivate;
 
/**
 * @class FrameSvg ksvg/framesvg.h <KSvg/FrameSvg>
 *
 * @short Provides an SVG with borders.
 *
 * When using SVG images for a background of an object that may change
 * its aspect ratio, such as a dialog, simply scaling a single image
 * may not be enough.
 *
 * FrameSvg allows SVGs to provide several elements for borders as well
 * as a central element, each of which are scaled individually. These elements
 * should be named:
 * * @c center  - the central element, which will be scaled in both directions
 * * @c top     - the top border; the height is fixed, but it will be scaled
 * horizontally to the same width as @c center
 * * @c bottom  - the bottom border; scaled in the same way as @c top
 * * @c left    - the left border; the width is fixed, but it will be scaled
 * vertically to the same height as @c center
 * * @c right   - the right border; scaled in the same way as @c left
 * * @c topleft - fixed size; must be the same height as @c top and the same
 * width as @c left
 * * @c bottomleft, @c topright, @c bottomright - similar to @c topleft
 *
 * @c center must exist, but all the others are optional.  @c topleft and
 * @c topright will be ignored if @c top does not exist, and similarly for
 * @c bottomleft and @c bottomright.
 *
 * @see KSvg::Svg
 **/
class KSVG_EXPORT FrameSvg : public Svg
{
    Q_OBJECT
 
    Q_PROPERTY(EnabledBorders enabledBorders READ enabledBorders WRITE setEnabledBorders)
 
public:
    /**
     * @brief This flag enum specifies which borders should be drawn.
     */
    enum EnabledBorder {
        NoBorder = 0,
        TopBorder = 1,
        BottomBorder = 2,
        LeftBorder = 4,
        RightBorder = 8,
        AllBorders = TopBorder | BottomBorder | LeftBorder | RightBorder,
    };
    Q_DECLARE_FLAGS(EnabledBorders, EnabledBorder)
    Q_FLAG(EnabledBorders)
 
    // TODO: merge those two?
    enum LocationPrefix {
        Floating = 0, /**< Free floating.*/
        TopEdge, /**< Along the top of the screen*/
        BottomEdge, /**< Along the bottom of the screen*/
        LeftEdge, /**< Along the left side of the screen */
        RightEdge, /**< Along the right side of the screen */
    };
    Q_ENUM(LocationPrefix)
 
    enum MarginEdge {
        TopMargin = 0, /**< The top margin **/
        BottomMargin, /**< The bottom margin **/
        LeftMargin, /**< The left margin **/
        RightMargin, /**< The right margin **/
    };
    Q_ENUM(MarginEdge)
 
    /**
     * Constructs a new FrameSvg that paints the proper named subelements
     * as borders. It may also be used as a regular KSvg::Svg object
     * for direct access to elements in the Svg.
     *
     * @param parent options QObject to parent this to
     *
     * @related KSvg::Theme
     */
    explicit FrameSvg(QObject *parent = nullptr);
    ~FrameSvg() override;
 
    /**
     * Loads a new Svg
     * @param imagePath the new file
     */
    Q_INVOKABLE void setImagePath(const QString &path) override;
 
    /**
     * @brief This method sets which borders should be painted.
     * @param flags borders we want to paint
     *
     * @see ::EnabledBorder
     * @param borders
     */
    void setEnabledBorders(const EnabledBorders borders);
 
    /**
     * @brief This is a convenience method to get the enabled borders.
     * @return what borders are painted
     */
    EnabledBorders enabledBorders() const;
 
    /**
     * @brief This method resizes the frame, maintaining the same border size.
     * @param size the new size of the frame
     */
    Q_INVOKABLE void resizeFrame(const QSizeF &size);
 
    /**
     * @returns the size of the frame
     */
    Q_INVOKABLE QSizeF frameSize() const;
 
    /**
     *
     * @brief This method returns the margin size for the given edge.
     *
     * Note that @c 0 will be returned if the given margin is disabled.
     *
     * If you don't care about the margin being on or off, use
     * ::fixedMarginSize() instead.
     *
     * @param edge the margin edge we want, top, bottom, left or right
     * @return the margin size
     */
    Q_INVOKABLE qreal marginSize(const FrameSvg::MarginEdge edge) const;
 
    /**
     * @brief This is a convenience method that extracts the size of the four
     * margins and saves their size into the passed variables.
     *
     * If you don't care about the margins being on or off, use
     * ::getFixedMargins() instead.
     *
     * @param left left margin size
     * @param top top margin size
     * @param right right margin size
     * @param bottom bottom margin size
     */
    Q_INVOKABLE void getMargins(qreal &left, qreal &top, qreal &right, qreal &bottom) const;
 
    /**
     * @brief This method returns the margin size for the specified edge.
     *
     * Compared to ::marginSize(), this does not depend on whether the margin is
     * enabled or not.
     *
     * @param edge the margin edge we want, top, bottom, left or right
     * @return the margin size
     */
    Q_INVOKABLE qreal fixedMarginSize(const FrameSvg::MarginEdge edge) const;
 
    /**
     * @brief This is a convenience method that extracts the size of the four
     * margins and saves their size into the passed variables.
     *
     * Compared to ::getMargins(), this doesn't depend on whether the margins are
     * enabled or not.
     *
     * @param left left margin size
     * @param top top margin size
     * @param right right margin size
     * @param bottom bottom margin size
     */
    Q_INVOKABLE void getFixedMargins(qreal &left, qreal &top, qreal &right, qreal &bottom) const;
 
    /**
     * @brief This method returns the insets margin size for the specified edge.
     * @param edge the margin edge we want, top, bottom, left or right
     * @return the margin size
     * @since 5.77
     */
    Q_INVOKABLE qreal insetSize(const FrameSvg::MarginEdge edge) const;
 
    /**
     * @brief This is a convenience method that extracts the size of the four
     * inset margins and saves their size into the passed variables.
     *
     * @param left left margin size
     * @param top top margin size
     * @param right right margin size
     * @param bottom bottom margin size
     * @since 5.77
     */
    Q_INVOKABLE void getInset(qreal &left, qreal &top, qreal &right, qreal &bottom) const;
 
    /**
     * @brief This method returns the rectangle of the center element, taking
     * the margins into account.
     */
    Q_INVOKABLE QRectF contentsRect() const;
 
    /**
     * @brief This method sets the prefix (@see setElementPrefix) to 'north',
     * 'south', 'west' and 'east' when the location is TopEdge, BottomEdge,
     * LeftEdge and RightEdge, respectively. Clears the prefix in other cases.
     *
     * The prefix must exist in the SVG document, which means that this can only
     * be called successfully after setImagePath is called.
     *
     * @param location location in the UI this frame will be drawn
     */
    Q_INVOKABLE void setElementPrefix(KSvg::FrameSvg::LocationPrefix location);
 
    /**
     * @brief This method sets the prefix for the SVG elements to be used for
     * painting.
     *
     * For example, if prefix is 'active', then instead of using the 'top'
     * element of the SVG file to paint the top border, the 'active-top' element
     * will be used. The same goes for other SVG elements.
     *
     * If the elements with prefixes are not present, the default ones are used.
     * (for the sake of speed, the test is present only for the 'center' element)
     *
     * Setting the prefix manually resets the location to Floating.
     *
     * The prefix must exist in the SVG document, which means that this can only be
     * called successfully after setImagePath is called.
     *
     * @param prefix prefix for the SVG elements that make up the frame
     */
    Q_INVOKABLE void setElementPrefix(const QString &prefix);
 
    /**
     * @brief This method returns whether the SVG has the necessary elements
     * with the given prefix to draw a frame.
     *
     * @param prefix the given prefix we want to check if drawable (can have trailing '-' since 5.59)
     */
    Q_INVOKABLE bool hasElementPrefix(const QString &prefix) const;
 
    /**
     * @brief This is an overloaded method provided for convenience that is
     * equivalent to hasElementPrefix("north"), hasElementPrefix("south")
     * hasElementPrefix("west") and hasElementPrefix("east").
     *
     * @return true if the svg has the necessary elements with the given prefix
     * to draw a frame.
     *
     * @param location the given prefix we want to check if drawable
     */
    Q_INVOKABLE bool hasElementPrefix(KSvg::FrameSvg::LocationPrefix location) const;
 
    /**
     * @brief This method returns the prefix for SVG elements of the FrameSvg
     * (including a '-' at the end if not empty).
     *
     * @return the prefix
     * @see actualPrefix()
     */
    Q_INVOKABLE QString prefix();
 
    /**
     * @brief This method returns a mask that tightly contains the fully opaque
     * areas of the SVG.
     *
     * @return a region of opaque areas
     */
    Q_INVOKABLE QRegion mask() const;
 
    /**
     * @brief This method returns a pixmap whose alpha channel is the opacity of
     * the frame. It may be the frame itself or a special frame with the
     * "mask-" prefix.
     */
    QPixmap alphaMask() const;
 
    /**
     * @brief This method sets whether saving all the rendered prefixes in a
     * cache or not.
     *
     * @param cache whether to use the cache.
     */
    Q_INVOKABLE void setCacheAllRenderedFrames(bool cache);
 
    /**
     * @brief This method returns whether all the different prefixes should be
     * kept in a cache when rendered.
     */
    Q_INVOKABLE bool cacheAllRenderedFrames() const;
 
    /**
     * @brief This method deletes the internal cache.
     *
     * Calling this method frees memeory. Use this if you want to switch the
     * rendered element and you don't plan to switch back to the previous one
     * for a long time.
     *
     * This only works if setUsingRenderingCache(@c true) has been called.
     *
     * @see KSvg::Svg::setUsingRenderingCache()
     */
    Q_INVOKABLE void clearCache();
 
    /**
     * @brief This method returns a pixmap of the SVG represented by this
     * object.
     *
     * @param elementId the ID string of the element to render, or an empty
     * string for the whole SVG (the default).
     *
     * @return a QPixmap of the rendered SVG
     */
    Q_INVOKABLE QPixmap framePixmap();
 
    /**
     * @brief This method paints the loaded SVG with the elements that
     * represents the border.
     *
     * @param painter the QPainter to use
     * @param target the target rectangle on the paint device
     * @param source the portion rectangle of the source image
     */
    Q_INVOKABLE void paintFrame(QPainter *painter, const QRectF &target, const QRectF &source = QRectF());
 
    /**
     * @brief This method paints the loaded SVG with the elements that
     * represents the border.
     *
     * This is an overloaded member provided for convenience
     *
     * @param painter the QPainter to use
     * @param pos where to paint the svg
     */
    Q_INVOKABLE void paintFrame(QPainter *painter, const QPointF &pos = QPointF(0, 0));
 
    /**
     * @brief This method returns the prefix that is actually being used
     * (including a '-' at the end if not empty).
     *
     * @see ::prefix()
     */
    QString actualPrefix() const;
 
    /**
     * @brief This method returns whether we are in a transaction of many
     * changes at once.
     *
     * This is used to restrict rebuilding generated graphics for each change
     * made.
     *
     * @since 5.31
     */
    bool isRepaintBlocked() const;
 
    /**
     * @brief This method sets whether we should block rebuilding generated
     * graphics for each change made.
     *
     * Setting this to @c true will block rebuilding the generated graphics for
     * each change made and will do these changes in blocks instead.
     *
     * How to use this method:
     * When making several changes at once to the frame properties--such as
     * prefix, enabled borders, and size--set this property to true to avoid
     * regenerating the graphics for each change. Set it to false again after
     * applying all required changes.
     *
     * Note that any change will not be visible in the painted frame while this
     * property is set to true.
     * @since 5.31
     */
    void setRepaintBlocked(bool blocked);
 
    /**
     * @brief This method returns the minimum height required to correctly draw
     * this SVG.
     *
     * @since 5.101
     */
    Q_INVOKABLE int minimumDrawingHeight();
 
    /**
     * @brief This method returns the minimum width required to correctly draw
     * this SVG.
     *
     * @since 5.101
     */
    Q_INVOKABLE int minimumDrawingWidth();
 
private:
    FrameSvgPrivate *const d;
    friend class FrameData;
};
 
Q_DECLARE_OPERATORS_FOR_FLAGS(FrameSvg::EnabledBorders)
 
} // KSvg namespace
 
#endif // multiple inclusion guard