window.cpp Example File

qwindow-compositor/window.cpp
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 #include "window.h"

 #include <QMouseEvent>
 #include <QOpenGLWindow>
 #include <QOpenGLTexture>
 #include <QOpenGLFunctions>
 #include <QMatrix4x4>

 #include "compositor.h"
 #include <QtWaylandCompositor/qwaylandseat.h>

 Window::Window()
 {
 }

 void Window::setCompositor(Compositor *comp) {
     m_compositor = comp;
     connect(m_compositor, &Compositor::startMove, this, &Window::startMove);
     connect(m_compositor, &Compositor::startResize, this, &Window::startResize);
     connect(m_compositor, &Compositor::dragStarted, this, &Window::startDrag);
 }

 void Window::initializeGL()
 {
     QImage backgroundImage = QImage(QLatin1String(":/background.jpg")).rgbSwapped();
     backgroundImage.invertPixels();
     m_backgroundTexture = new QOpenGLTexture(backgroundImage, QOpenGLTexture::DontGenerateMipMaps);
     m_backgroundTexture->setMinificationFilter(QOpenGLTexture::Nearest);
     m_backgroundImageSize = backgroundImage.size();
     m_textureBlitter.create();
     m_compositor->create(); // the compositor's hardware integration may depend on GL
 }

 void Window::drawBackground()
 {
     for (int y = 0; y < height(); y += m_backgroundImageSize.height()) {
         for (int x = 0; x < width(); x += m_backgroundImageSize.width()) {
             QMatrix4x4 targetTransform = QOpenGLTextureBlitter::targetTransform(QRect(QPoint(x,y), m_backgroundImageSize), QRect(QPoint(0,0), size()));
             m_textureBlitter.blit(m_backgroundTexture->textureId(),
                               targetTransform,
                               QOpenGLTextureBlitter::OriginTopLeft);
         }
     }
 }

 QPointF Window::getAnchorPosition(const QPointF &position, int resizeEdge, const QSize &windowSize)
 {
     float y = position.y();
     if (resizeEdge & QWaylandXdgSurfaceV5::ResizeEdge::TopEdge)
         y += windowSize.height();

     float x = position.x();
     if (resizeEdge & QWaylandXdgSurfaceV5::ResizeEdge::LeftEdge)
         x += windowSize.width();

     return QPointF(x, y);
 }

 QPointF Window::getAnchoredPosition(const QPointF &anchorPosition, int resizeEdge, const QSize &windowSize)
 {
     return anchorPosition - getAnchorPosition(QPointF(), resizeEdge, windowSize);
 }

 void Window::paintGL()
 {
     m_compositor->startRender();
     QOpenGLFunctions *functions = context()->functions();
     functions->glClearColor(1.f, .6f, .0f, 0.5f);
     functions->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

     m_textureBlitter.bind();
     drawBackground();

     functions->glEnable(GL_BLEND);
     functions->glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

     GLenum currentTarget = GL_TEXTURE_2D;
     Q_FOREACH (View *view, m_compositor->views()) {
         if (view->isCursor())
             continue;
         auto texture = view->getTexture();
         if (!texture)
             continue;
         if (texture->target() != currentTarget) {
             currentTarget = texture->target();
             m_textureBlitter.bind(currentTarget);
         }
         QWaylandSurface *surface = view->surface();
         if ((surface && surface->hasContent()) || view->isBufferLocked()) {
             QSize s = view->size();
             if (!s.isEmpty()) {
                 if (m_mouseView == view && m_grabState == ResizeGrab && m_resizeAnchored)
                     view->setPosition(getAnchoredPosition(m_resizeAnchorPosition, m_resizeEdge, s));
                 QPointF pos = view->position() + view->parentPosition();
                 QRectF surfaceGeometry(pos, s);
                 auto surfaceOrigin = view->textureOrigin();
                 auto sf = view->animationFactor();
                 QRectF targetRect(surfaceGeometry.topLeft() * sf, surfaceGeometry.size() * sf);
                 QMatrix4x4 targetTransform = QOpenGLTextureBlitter::targetTransform(targetRect, QRect(QPoint(), size()));
                 m_textureBlitter.blit(texture->textureId(), targetTransform, surfaceOrigin);
             }
         }
     }
     functions->glDisable(GL_BLEND);

     m_textureBlitter.release();
     m_compositor->endRender();
 }

 View *Window::viewAt(const QPointF &point)
 {
     View *ret = nullptr;
     Q_FOREACH (View *view, m_compositor->views()) {
         if (view == m_dragIconView)
             continue;
         QRectF geom(view->position(), view->size());
         if (geom.contains(point))
             ret = view;
     }
     return ret;
 }

 void Window::startMove()
 {
     m_grabState = MoveGrab;
 }

 void Window::startResize(int edge, bool anchored)
 {
     m_initialSize = m_mouseView->windowSize();
     m_grabState = ResizeGrab;
     m_resizeEdge = edge;
     m_resizeAnchored = anchored;
     m_resizeAnchorPosition = getAnchorPosition(m_mouseView->position(), edge, m_mouseView->surface()->size());
 }

 void Window::startDrag(View *dragIcon)
 {
     m_grabState = DragGrab;
     m_dragIconView = dragIcon;
     m_compositor->raise(dragIcon);
 }

 void Window::mousePressEvent(QMouseEvent *e)
 {
     if (mouseGrab())
         return;
     if (m_mouseView.isNull()) {
         m_mouseView = viewAt(e->localPos());
         if (!m_mouseView) {
             m_compositor->closePopups();
             return;
         }
         if (e->modifiers() == Qt::AltModifier || e->modifiers() == Qt::MetaModifier)
             m_grabState = MoveGrab; //start move
         else
             m_compositor->raise(m_mouseView);
         m_initialMousePos = e->localPos();
         m_mouseOffset = e->localPos() - m_mouseView->position();

         QMouseEvent moveEvent(QEvent::MouseMove, e->localPos(), e->globalPos(), Qt::NoButton, Qt::NoButton, e->modifiers());
         sendMouseEvent(&moveEvent, m_mouseView);
     }
     sendMouseEvent(e, m_mouseView);
 }

 void Window::mouseReleaseEvent(QMouseEvent *e)
 {
     if (!mouseGrab())
         sendMouseEvent(e, m_mouseView);
     if (e->buttons() == Qt::NoButton) {
         if (m_grabState == DragGrab) {
             View *view = viewAt(e->localPos());
             m_compositor->handleDrag(view, e);
         }
         m_mouseView = nullptr;
         m_grabState = NoGrab;
     }
 }

 void Window::mouseMoveEvent(QMouseEvent *e)
 {
     switch (m_grabState) {
     case NoGrab: {
         View *view = m_mouseView ? m_mouseView.data() : viewAt(e->localPos());
         sendMouseEvent(e, view);
         if (!view)
             setCursor(Qt::ArrowCursor);
     }
         break;
     case MoveGrab: {
         m_mouseView->setPosition(e->localPos() - m_mouseOffset);
         update();
     }
         break;
     case ResizeGrab: {
         QPoint delta = (e->localPos() - m_initialMousePos).toPoint();
         m_compositor->handleResize(m_mouseView, m_initialSize, delta, m_resizeEdge);
     }
         break;
     case DragGrab: {
         View *view = viewAt(e->localPos());
         m_compositor->handleDrag(view, e);
         if (m_dragIconView) {
             m_dragIconView->setPosition(e->localPos() + m_dragIconView->offset());
             update();
         }
     }
         break;
     }
 }

 void Window::sendMouseEvent(QMouseEvent *e, View *target)
 {
     QPointF mappedPos = e->localPos();
     if (target)
         mappedPos -= target->position();
     QMouseEvent viewEvent(e->type(), mappedPos, e->localPos(), e->button(), e->buttons(), e->modifiers());
     m_compositor->handleMouseEvent(target, &viewEvent);
 }

 void Window::keyPressEvent(QKeyEvent *e)
 {
     m_compositor->defaultSeat()->sendKeyPressEvent(e->nativeScanCode());
 }

 void Window::keyReleaseEvent(QKeyEvent *e)
 {
     m_compositor->defaultSeat()->sendKeyReleaseEvent(e->nativeScanCode());
 }