plasma-framework/src/declarativeimports/core/windowthumbnail.h

/*
 *   Copyright 2013 by Martin Gräßlin <mgraesslin@kde.org>

 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Library General Public License as
 *   published by the Free Software Foundation; either version 2, 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 Library General Public
 *   License along with this program; if not, write to the
 *   Free Software Foundation, Inc.,
 *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
#ifndef PLASMA_WINDOWTHUMBNAIL_H
#define PLASMA_WINDOWTHUMBNAIL_H
#include <config-plasma.h>
#include <config-x11.h>

#include <cstdint>

// Qt
#include <QAbstractNativeEventFilter>
#include <QSGSimpleTextureNode>
#include <QQuickItem>
// xcb
#if HAVE_XCB_COMPOSITE
#include <xcb/damage.h>

#if HAVE_EGL
#include <EGL/egl.h>
#include <EGL/eglext.h>
#include <fixx11h.h> // egl.h could include XLib.h

#endif // HAVE_EGL

#endif // HAVE_XCB_COMPOSITE
class KWindowInfo;

namespace Plasma
{

class WindowTextureNode;

/**
 * @brief Renders a thumbnail for the window specified by the @c winId property.
 *
 * This declarative item is able to render a live updating thumbnail for the
 * window specified by the given @c winId property. If it is not possible to get
 * the thumbnail, the window's icon is rendered instead or in case that the window
 * Id is invalid a generic fallback icon is used.
 *
 * The thumbnail does not necessarily fill out the complete geometry as the
 * thumbnail gets scaled keeping the aspect ratio. This means the thumbnail gets
 * rendered into the center of the item's geometry.
 *
 * Note: live updating thumbnails are only implemented on the X11 platform. On X11
 * a running compositor is not required as this item takes care of redirecting the
 * window. For technical reasons the window's frame is not included on X11.
 *
 * If the window closes, the thumbnail does not get destroyed, which allows to have
 * a window close animation.
 *
 * Example usage:
 * @code
 * WindowThumbnail {
 *     winId: 102760466
 * }
 * @endcode
 *
 */
class WindowThumbnail : public QQuickItem, public QAbstractNativeEventFilter
{
    Q_OBJECT
    Q_PROPERTY(uint winId READ winId WRITE setWinId NOTIFY winIdChanged)
    Q_PROPERTY(qreal paintedWidth READ paintedWidth NOTIFY paintedSizeChanged)
    Q_PROPERTY(qreal paintedHeight READ paintedHeight NOTIFY paintedSizeChanged)
    Q_PROPERTY(bool thumbnailAvailable READ thumbnailAvailable NOTIFY thumbnailAvailableChanged)

public:
    explicit WindowThumbnail(QQuickItem *parent = nullptr);
    ~WindowThumbnail() override;
    bool nativeEventFilter(const QByteArray &eventType, void *message, long int *result) override;
    QSGNode *updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *updatePaintNodeData) override;

    uint32_t winId() const;
    void setWinId(uint32_t winId);

    qreal paintedWidth() const;
    qreal paintedHeight() const;
    bool thumbnailAvailable() const;

Q_SIGNALS:
    void winIdChanged();
    void paintedSizeChanged();
    void thumbnailAvailableChanged();

protected:
    void releaseResources() override;

private:
    void iconToTexture(WindowTextureNode *textureNode);
    void windowToTexture(WindowTextureNode *textureNode);
    void startRedirecting();
    void stopRedirecting();
    void resetDamaged();
    void setThumbnailAvailable(bool thumbnailAvailable);

    bool m_xcb;
    bool m_composite;
    uint32_t m_winId;
    QSizeF m_paintedSize;
    bool m_thumbnailAvailable;
    bool m_damaged;
    int m_depth;
#if HAVE_XCB_COMPOSITE
    xcb_pixmap_t pixmapForWindow();
    bool m_openGLFunctionsResolved;
    uint8_t m_damageEventBase;
    xcb_damage_damage_t m_damage;
    xcb_pixmap_t m_pixmap;

/*The following must *only* be used from the render thread*/
    uint m_texture;
#if HAVE_GLX
    bool windowToTextureGLX(WindowTextureNode *textureNode);
    void resolveGLXFunctions();
    bool loadGLXTexture();
    void bindGLXTexture();
    xcb_pixmap_t m_glxPixmap;
    xcb_visualid_t m_visualid;
    QFunctionPointer m_bindTexImage;
    QFunctionPointer m_releaseTexImage;
#endif // HAVE_GLX
#if HAVE_EGL
    bool xcbWindowToTextureEGL(WindowTextureNode *textureNode);
    void resolveEGLFunctions();
    void bindEGLTexture();
    bool m_eglFunctionsResolved;
    EGLImageKHR m_image;
    QFunctionPointer m_eglCreateImageKHR;
    QFunctionPointer m_eglDestroyImageKHR;
    QFunctionPointer m_glEGLImageTargetTexture2DOES;
#endif // HAVE_EGL
#endif
};

/**
 * @brief SimpleTextureNode which cleans up the texture
 *
 */
class WindowTextureNode : public QSGSimpleTextureNode
{
public:
    WindowTextureNode();
    virtual ~WindowTextureNode();
    void reset(QSGTexture *texture);
private:
    QScopedPointer<QSGTexture> m_texture;
};

}

#endif //  PLASMA_WINDOWTHUMBNAIL_H