compositor.cpp Example File

qwindow-compositor/compositor.cpp
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** Copyright (C) 2015 The Qt Company Ltd.
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** This file is part of the examples of the Qt Wayland module
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#include "compositor.h"

#include <QMouseEvent>
#include <QKeyEvent>
#include <QTouchEvent>

#include <QtWaylandCompositor/QWaylandXdgShell>
#include <QtWaylandCompositor/QWaylandWlShellSurface>
#include <QtWaylandCompositor/qwaylandinput.h>
#include <QtWaylandCompositor/qwaylanddrag.h>

#include <QDebug>
#include <QOpenGLContext>

#ifndef GL_TEXTURE_EXTERNAL_OES
#define GL_TEXTURE_EXTERNAL_OES 0x8D65
#endif

View::View()
    : m_textureTarget(GL_TEXTURE_2D)
    , m_texture(0)
    , m_wlShellSurface(nullptr)
    , m_xdgSurface(nullptr)
    , m_xdgPopup(nullptr)
    , m_parentView(nullptr)
{}

GLuint View::getTexture(GLenum *target)
{
    QWaylandBufferRef buf = currentBuffer();
    GLuint streamingTexture = buf.textureForPlane(0);
    if (streamingTexture)
        m_texture = streamingTexture;

    if (!buf.isShm() && buf.bufferFormatEgl() == QWaylandBufferRef::BufferFormatEgl_EXTERNAL_OES)
        m_textureTarget = GL_TEXTURE_EXTERNAL_OES;

    if (advance()) {
        buf = currentBuffer();
        if (!m_texture)
            glGenTextures(1, &m_texture);

        glBindTexture(m_textureTarget, m_texture);
        if (buf.isShm())
            glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        buf.bindToTexture();
    }

    buf.updateTexture();

    if (target)
        *target = m_textureTarget;

    return m_texture;
}

bool View::isCursor() const
{
    return surface()->isCursorSurface();
}

void View::onXdgSetMaximized()
{
    m_xdgSurface->requestMaximized(output()->geometry().size());

    // An improvement here, would have been to wait for the commit after the ack_configure for the
    // request above before moving the window. This would have prevented the window from being
    // moved until the contents of the window had actually updated. This improvement is left as an
    // exercise for the reader.
    setPosition(QPoint(0, 0));
}

void View::onXdgUnsetMaximized()
{
    m_xdgSurface->requestUnMaximized();
}

void View::onXdgSetFullscreen(QWaylandOutput* clientPreferredOutput)
{
    QWaylandOutput *outputToFullscreen = clientPreferredOutput
            ? clientPreferredOutput
            : output();

    m_xdgSurface->requestFullscreen(outputToFullscreen->geometry().size());

    // An improvement here, would have been to wait for the commit after the ack_configure for the
    // request above before moving the window. This would have prevented the window from being
    // moved until the contents of the window had actually updated. This improvement is left as an
    // exercise for the reader.
    setPosition(outputToFullscreen->position());
}

void View::onOffsetForNextFrame(const QPoint &offset)
{
    m_offset = offset;
    setPosition(position() + offset);
}

void View::onXdgUnsetFullscreen()
{
    onXdgUnsetMaximized();
}

Compositor::Compositor(QWindow *window)
    : QWaylandCompositor()
    , m_window(window)
    , m_wlShell(new QWaylandWlShell(this))
    , m_xdgShell(new QWaylandXdgShell(this))
{
    connect(m_wlShell, &QWaylandWlShell::shellSurfaceCreated, this, &Compositor::onWlShellSurfaceCreated);
    connect(m_xdgShell, &QWaylandXdgShell::xdgSurfaceCreated, this, &Compositor::onXdgSurfaceCreated);
    connect(m_xdgShell, &QWaylandXdgShell::createXdgPopup, this, &Compositor::onCreateXdgPopup);
}

Compositor::~Compositor()
{
}

void Compositor::create()
{
    new QWaylandOutput(this, m_window);
    QWaylandCompositor::create();

    connect(this, &QWaylandCompositor::surfaceCreated, this, &Compositor::onSurfaceCreated);
    connect(defaultInputDevice(), &QWaylandInputDevice::cursorSurfaceRequest, this, &Compositor::adjustCursorSurface);
    connect(defaultInputDevice()->drag(), &QWaylandDrag::dragStarted, this, &Compositor::startDrag);

    connect(this, &QWaylandCompositor::subsurfaceChanged, this, &Compositor::onSubsurfaceChanged);
}

void Compositor::onSurfaceCreated(QWaylandSurface *surface)
{
    connect(surface, &QWaylandSurface::surfaceDestroyed, this, &Compositor::surfaceDestroyed);
    connect(surface, &QWaylandSurface::mappedChanged, this, &Compositor::surfaceMappedChanged);
    connect(surface, &QWaylandSurface::redraw, this, &Compositor::triggerRender);

    connect(surface, &QWaylandSurface::subsurfacePositionChanged, this, &Compositor::onSubsurfacePositionChanged);

    View *view = new View;
    view->setSurface(surface);
    view->setOutput(outputFor(m_window));
    m_views << view;
    connect(view, &QWaylandView::surfaceDestroyed, this, &Compositor::viewSurfaceDestroyed);
    connect(surface, &QWaylandSurface::offsetForNextFrame, view, &View::onOffsetForNextFrame);
}

void Compositor::surfaceMappedChanged()
{
    QWaylandSurface *surface = qobject_cast<QWaylandSurface *>(sender());
    if (surface->isMapped()) {
        if (surface->role() == QWaylandWlShellSurface::role()
                || surface->role() == QWaylandXdgSurface::role()
                || surface->role() == QWaylandXdgPopup::role()) {
            defaultInputDevice()->setKeyboardFocus(surface);
        }
    } else if (popupActive()) {
        for (int i = 0; i < m_popupViews.count(); i++) {
            if (m_popupViews.at(i)->surface() == surface) {
                m_popupViews.removeAt(i);
                break;
            }
        }
    }
    triggerRender();
}

void Compositor::surfaceDestroyed()
{
    triggerRender();
}

void Compositor::viewSurfaceDestroyed()
{
    View *view = qobject_cast<View*>(sender());
    m_views.removeAll(view);
    delete view;
}

View * Compositor::findView(const QWaylandSurface *s) const
{
    Q_FOREACH (View* view, m_views) {
        if (view->surface() == s)
            return view;
    }
    return Q_NULLPTR;
}

void Compositor::onWlShellSurfaceCreated(QWaylandWlShellSurface *wlShellSurface)
{
    connect(wlShellSurface, &QWaylandWlShellSurface::startMove, this, &Compositor::onStartMove);
    connect(wlShellSurface, &QWaylandWlShellSurface::startResize, this, &Compositor::onWlStartResize);
    connect(wlShellSurface, &QWaylandWlShellSurface::setTransient, this, &Compositor::onSetTransient);
    connect(wlShellSurface, &QWaylandWlShellSurface::setPopup, this, &Compositor::onSetPopup);

    View *view = findView(wlShellSurface->surface());
    Q_ASSERT(view);
    view->m_wlShellSurface = wlShellSurface;
}

void Compositor::onXdgSurfaceCreated(QWaylandXdgSurface *xdgSurface)
{
    connect(xdgSurface, &QWaylandXdgSurface::startMove, this, &Compositor::onStartMove);
    connect(xdgSurface, &QWaylandXdgSurface::startResize, this, &Compositor::onXdgStartResize);

    View *view = findView(xdgSurface->surface());
    Q_ASSERT(view);
    view->m_xdgSurface = xdgSurface;

    connect(xdgSurface, &QWaylandXdgSurface::setMaximized, view, &View::onXdgSetMaximized);
    connect(xdgSurface, &QWaylandXdgSurface::setFullscreen, view, &View::onXdgSetFullscreen);
    connect(xdgSurface, &QWaylandXdgSurface::unsetMaximized, view, &View::onXdgUnsetMaximized);
    connect(xdgSurface, &QWaylandXdgSurface::unsetFullscreen, view, &View::onXdgUnsetFullscreen);
}

void Compositor::onCreateXdgPopup(QWaylandSurface *surface, QWaylandSurface *parent,
                                        QWaylandInputDevice *inputDevice, const QPoint &position,
                                        const QWaylandResource &resource)
{
    Q_UNUSED(inputDevice);

    QWaylandXdgPopup *xdgPopup = new QWaylandXdgPopup(m_xdgShell, surface, parent, resource);

    View *view = findView(surface);
    Q_ASSERT(view);

    View *parentView = findView(parent);
    Q_ASSERT(parentView);

    view->setPosition(parentView->position() + position);
    view->m_xdgPopup = xdgPopup;
}

void Compositor::onStartMove()
{
    closePopups();
    emit startMove();
}

void Compositor::onWlStartResize(QWaylandInputDevice *, QWaylandWlShellSurface::ResizeEdge edges)
{
    closePopups();
    emit startResize(int(edges), false);
}

void Compositor::onXdgStartResize(QWaylandInputDevice *inputDevice,
                                        QWaylandXdgSurface::ResizeEdge edges)
{
    Q_UNUSED(inputDevice);
    emit startResize(int(edges), true);
}

void Compositor::onSetTransient(QWaylandSurface *parent, const QPoint &relativeToParent, QWaylandWlShellSurface::FocusPolicy focusPolicy)
{
    Q_UNUSED(focusPolicy);
    QWaylandWlShellSurface *wlShellSurface = qobject_cast<QWaylandWlShellSurface*>(sender());
    View *view = findView(wlShellSurface->surface());

    if (view) {
        raise(view);
        View *parentView = findView(parent);
        if (parentView)
            view->setPosition(parentView->position() + relativeToParent);
    }
}

void Compositor::onSetPopup(QWaylandInputDevice *inputDevice, QWaylandSurface *parent, const QPoint &relativeToParent)
{
    Q_UNUSED(inputDevice);
    QWaylandWlShellSurface *surface = qobject_cast<QWaylandWlShellSurface*>(sender());
    View *view = findView(surface->surface());
    m_popupViews << view;
    if (view) {
        raise(view);
        View *parentView = findView(parent);
        if (parentView)
            view->setPosition(parentView->position() + relativeToParent);
    }
}

void Compositor::onSubsurfaceChanged(QWaylandSurface *child, QWaylandSurface *parent)
{
    View *view = findView(child);
    View *parentView = findView(parent);
    view->setParentView(parentView);
}

void Compositor::onSubsurfacePositionChanged(const QPoint &position)
{
    QWaylandSurface *surface = qobject_cast<QWaylandSurface*>(sender());
    if (!surface)
        return;
    View *view = findView(surface);
    view->setPosition(position);
    triggerRender();
}

void Compositor::triggerRender()
{
    m_window->requestUpdate();
}

void Compositor::startRender()
{
    QWaylandOutput *out = defaultOutput();
    if (out)
        out->frameStarted();
}

void Compositor::endRender()
{
    QWaylandOutput *out = defaultOutput();
    if (out)
        out->sendFrameCallbacks();
}

void Compositor::updateCursor()
{
    m_cursorView.advance();
    QImage image = m_cursorView.currentBuffer().image();
    if (!image.isNull())
        m_window->setCursor(QCursor(QPixmap::fromImage(image), m_cursorHotspotX, m_cursorHotspotY));
}

void Compositor::adjustCursorSurface(QWaylandSurface *surface, int hotspotX, int hotspotY)
{
    if ((m_cursorView.surface() != surface)) {
        if (m_cursorView.surface())
            disconnect(m_cursorView.surface(), &QWaylandSurface::redraw, this, &Compositor::updateCursor);
        if (surface)
            connect(surface, &QWaylandSurface::redraw, this, &Compositor::updateCursor);
    }

    m_cursorView.setSurface(surface);
    m_cursorHotspotX = hotspotX;
    m_cursorHotspotY = hotspotY;

    if (surface && surface->isMapped())
        updateCursor();
}

void Compositor::closePopups()
{
    Q_FOREACH (View *view, m_popupViews) {
        if (view->m_wlShellSurface)
            view->m_wlShellSurface->sendPopupDone();
    }
    m_popupViews.clear();

    m_xdgShell->closeAllPopups();
}

void Compositor::handleMouseEvent(QWaylandView *target, QMouseEvent *me)
{
    if (target && popupActive() && me->type() == QEvent::MouseButtonPress
        && target->surface()->client() != m_popupViews.first()->surface()->client()) {
        closePopups();
    }
    QWaylandInputDevice *input = defaultInputDevice();
    QWaylandSurface *surface = target ? target->surface() : nullptr;
    switch (me->type()) {
        case QEvent::MouseButtonPress:
            input->sendMousePressEvent(me->button());
            if (surface != input->keyboardFocus()) {
                if (surface == nullptr
                        || surface->role() == QWaylandWlShellSurface::role()
                        || surface->role() == QWaylandXdgSurface::role()
                        || surface->role() == QWaylandXdgPopup::role()) {
                    input->setKeyboardFocus(surface);
                }
            }
            break;
    case QEvent::MouseButtonRelease:
         input->sendMouseReleaseEvent(me->button());
         break;
    case QEvent::MouseMove:
        input->sendMouseMoveEvent(target, me->localPos(), me->globalPos());
    default:
        break;
    }
}

void Compositor::handleResize(View *target, const QSize &initialSize, const QPoint &delta, int edge)
{
    QWaylandWlShellSurface *wlShellSurface = target->m_wlShellSurface;
    if (wlShellSurface) {
        QWaylandWlShellSurface::ResizeEdge edges = QWaylandWlShellSurface::ResizeEdge(edge);
        QSize newSize = wlShellSurface->sizeForResize(initialSize, delta, edges);
        wlShellSurface->sendConfigure(newSize, edges);
    }

    QWaylandXdgSurface *xdgSurface = target->m_xdgSurface;
    if (xdgSurface) {
        QWaylandXdgSurface::ResizeEdge edges = static_cast<QWaylandXdgSurface::ResizeEdge>(edge);
        QSize newSize = xdgSurface->sizeForResize(initialSize, delta, edges);
        xdgSurface->requestResizing(newSize);
    }
}

void Compositor::startDrag()
{
    QWaylandDrag *currentDrag = defaultInputDevice()->drag();
    Q_ASSERT(currentDrag);
    View *iconView = findView(currentDrag->icon());
    iconView->setPosition(m_window->mapFromGlobal(QCursor::pos()));

    emit dragStarted(iconView);
}

void Compositor::handleDrag(View *target, QMouseEvent *me)
{
    QPointF pos = me->localPos();
    QWaylandSurface *surface = 0;
    if (target) {
        pos -= target->position();
        surface = target->surface();
    }
    QWaylandDrag *currentDrag = defaultInputDevice()->drag();
    currentDrag->dragMove(surface, pos);
    if (me->buttons() == Qt::NoButton) {
        m_views.removeOne(findView(currentDrag->icon()));
        currentDrag->drop();
    }
}

// We only have a flat list of views, plus pointers from child to parent,
// so maintaining a stacking order gets a bit complex. A better data
// structure is left as an exercise for the reader.

static int findEndOfChildTree(const QList<View*> &list, int index)
{
    int n = list.count();
    View *parent = list.at(index);
    while (index + 1 < n) {
        if (list.at(index+1)->parentView() != parent)
            break;
        index = findEndOfChildTree(list, index + 1);
    }
    return index;
}

void Compositor::raise(View *view)
{
    int startPos = m_views.indexOf(view);
    int endPos = findEndOfChildTree(m_views, startPos);

    int n = m_views.count();
    int tail =  n - endPos - 1;

    //bubble sort: move the child tree to the end of the list
    for (int i = 0; i < tail; i++) {
        int source = endPos + 1 + i;
        int dest = startPos + i;
        for (int j = source; j > dest; j--)
            m_views.swap(j, j-1);
    }
}

© 2016 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.