output.h

/*
    SPDX-FileCopyrightText: 2013 Martin Gräßlin <[email protected]>

    SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
*/
#ifndef WAYLAND_OUTPUT_H
#define WAYLAND_OUTPUT_H

#include <QObject>
#include <QPointer>
#include <QSize>

#include <KWayland/Client/kwaylandclient_export.h>

struct wl_output;
class QPoint;
class QRect;

namespace KWayland
{
namespace Client
{

class EventQueue;

/**
 * @short Wrapper for the wl_output interface.
 *
 * This class provides a convenient wrapper for the wl_output interface.
 * Its main purpose is to hold the information about one Output.
 *
 * To use this class one needs to interact with the Registry. There are two
 * possible ways to create an Output interface:
 * @code
 * Output *c = registry->createOutput(name, version);
 * @endcode
 *
 * This creates the Output and sets it up directly. As an alternative this
 * can also be done in a more low level way:
 * @code
 * Output *c = new Output;
 * c->setup(registry->bindOutput(name, version));
 * @endcode
 *
 * The Output can be used as a drop-in replacement for any wl_output
 * pointer as it provides matching cast operators.
 *
 * Please note that all properties of Output are not valid until the
 * changed signal has been emitted. The wayland server is pushing the
 * information in an async way to the Output instance. By emitting changed
 * the Output indicates that all relevant information is available.
 *
 * @see Registry
 **/
class KWAYLANDCLIENT_EXPORT Output : public QObject
{
    Q_OBJECT
public:
    enum class SubPixel {
        Unknown,
        None,
        HorizontalRGB,
        HorizontalBGR,
        VerticalRGB,
        VerticalBGR
    };
    enum class Transform {
        Normal,
        Rotated90,
        Rotated180,
        Rotated270,
        Flipped,
        Flipped90,
        Flipped180,
        Flipped270
    };
    struct Mode {
        enum class Flag {
            None = 0,
            Current = 1 << 0,
            Preferred = 1 << 1
        };
        Q_DECLARE_FLAGS(Flags, Flag)
        /**
         * The size of this Mode in pixel space.
         **/
        QSize size;
        /**
         * The refresh rate in mHz of this Mode.
         **/
        int refreshRate = 0;
        /**
         * The flags of this Mode, that is whether it's the
         * Current and/or Preferred Mode of the Output.
         **/
        Flags flags = Flag::None;
        /**
         * The Output to which this Mode belongs.
         **/
        QPointer<Output> output;

        bool operator==(const Mode &m) const;
    };
    explicit Output(QObject *parent = nullptr);
    virtual ~Output();

    /**
     * Setup this Compositor to manage the @p output.
     * When using Registry::createOutput there is no need to call this
     * method.
     **/
    void setup(wl_output *output);

    /**
     * @returns @c true if managing a wl_output.
     **/
    bool isValid() const;
    operator wl_output*();
    operator wl_output*() const;
    wl_output *output();
    /**
     * Size in millimeters.
     **/
    QSize physicalSize() const;
    /**
     * Position within the global compositor space.
     **/
    QPoint globalPosition() const;
    /**
     * Textual description of the manufacturer.
     **/
    QString manufacturer() const;
    /**
     * Textual description of the model.
     **/
    QString model() const;
    /**
     * Size in the current mode.
     **/
    QSize pixelSize() const;
    /**
     * The geometry of this Output in pixels.
     * Convenient for QRect(globalPosition(), pixelSize()).
     * @see globalPosition
     * @see pixelSize
     **/
    QRect geometry() const;
    /**
     * Refresh rate in mHz of the current mode.
     **/
    int refreshRate() const;
    /**
     * Scaling factor of this output.
     *
     * A scale larger than 1 means that the compositor will automatically scale surface buffers
     * by this amount when rendering. This is used for very high resolution displays where
     * applications rendering at the native resolution would be too small to be legible.
     **/
    int scale() const;
    /**
     * Subpixel orientation of this Output.
     **/
    SubPixel subPixel() const;
    /**
     * Transform that maps framebuffer to Output.
     *
     * The purpose is mainly to allow clients render accordingly and tell the compositor,
     * so that for fullscreen surfaces, the compositor will still be able to scan out
     * directly from client surfaces.
     **/
    Transform transform() const;

    /**
     * @returns The Modes of this Output.
     **/
    QList<Mode> modes() const;

    /**
     * Sets the @p queue to use for bound proxies.
     **/
    void setEventQueue(EventQueue *queue);
    /**
     * @returns The event queue to use for bound proxies.
     **/
    EventQueue *eventQueue() const;

    /**
     * @returns The Output for the @p native wl_output. @c null if there is no Output for it.
     * @since 5.27
     **/
    static Output *get(wl_output *native);

    /**
    * Destroys the data hold by this Output.
    * This method is supposed to be used when the connection to the Wayland
    * server goes away. If the connection is not valid any more, it's not
    * possible to call release any more as that calls into the Wayland
    * connection and the call would fail.
    *
    * This method is automatically invoked when the Registry which created this
    * Output gets destroyed.
    *
    **/
    void destroy();

Q_SIGNALS:
    /**
     * Emitted whenever at least one of the data changed.
     **/
    void changed();
    /**
     * Emitted whenever a new Mode is added.
     * This normally only happens during the initial promoting of modes.
     * Afterwards only modeChanged should be emitted.
     * @param mode The newly added Mode.
     * @see modeChanged
     **/
    void modeAdded(const KWayland::Client::Output::Mode &mode);
    /**
     * Emitted whenever a Mode changes.
     * This normally means that the @c Mode::Flag::Current is added or removed.
     * @param mode The changed Mode
     **/
    void modeChanged(const KWayland::Client::Output::Mode &mode);

    /**
     * The corresponding global for this interface on the Registry got removed.
     *
     * This signal gets only emitted if the Compositor got created by
     * Registry::createOutput
     *
     * @since 5.5
     **/
    void removed();

private:
    class Private;
    QScopedPointer<Private> d;
};

Q_DECLARE_OPERATORS_FOR_FLAGS(Output::Mode::Flags)

}
}

Q_DECLARE_METATYPE(KWayland::Client::Output*)
Q_DECLARE_METATYPE(KWayland::Client::Output::SubPixel)
Q_DECLARE_METATYPE(KWayland::Client::Output::Transform)
Q_DECLARE_METATYPE(KWayland::Client::Output::Mode)

#endif