Add support for running compositors with custom device pixel ratio

And add a manual test for showing that it works with different scale factors as
well.

Task-number: QTBUG-55303
Change-Id: Ib842ea51cfb62a2d46713e95d56b8a9da445d14d
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>
Reviewed-by: Pier Luigi Fiorini <pierluigi.fiorini@hawaiios.org>

2 files changed, 13 insertions, 5 deletions

diff --git a/src/compositor/extensions/qwaylandwlshellintegration.cpp b/src/compositor/extensions/qwaylandwlshellintegration.cpp
index abf5b627c..b32416764 100644
--- a/src/compositor/extensions/qwaylandwlshellintegration.cpp
+++ b/src/compositor/extensions/qwaylandwlshellintegration.cpp
@@ -125,7 +125,8 @@ void WlShellIntegration::handleSetMaximized(QWaylandOutput *output)
     nextState = State::Maximized;
     finalPosition = designatedOutput->position() + designatedOutput->availableGeometry().topLeft();
 
-    m_shellSurface->sendConfigure(designatedOutput->availableGeometry().size(), QWaylandWlShellSurface::NoneEdge);
+    auto scaleFactor = m_item->view()->output()->scaleFactor();
+    m_shellSurface->sendConfigure(designatedOutput->availableGeometry().size() / scaleFactor, QWaylandWlShellSurface::NoneEdge);
 }
 
 void WlShellIntegration::handleSetFullScreen(QWaylandWlShellSurface::FullScreenMethod method, uint framerate, QWaylandOutput *output)
@@ -176,8 +177,9 @@ void WlShellIntegration::handleSetPopup(QWaylandSeat *seat, QWaylandSurface *par
         t.clear(&t);
         m_item->setRotation(0);
         m_item->setScale(1.0);
-        m_item->setX(relativeToParent.x());
-        m_item->setY(relativeToParent.y());
+        auto scaleFactor = m_item->output()->scaleFactor() / devicePixelRatio();
+        m_item->setX(relativeToParent.x() * scaleFactor);
+        m_item->setY(relativeToParent.y() * scaleFactor);
         m_item->setParentItem(parentItem);
     }
 
@@ -206,6 +208,11 @@ void WlShellIntegration::handlePopupRemoved()
     isPopup = false;
 }
 
+qreal WlShellIntegration::devicePixelRatio() const
+{
+    return m_item->window() ? m_item->window()->devicePixelRatio() : 1;
+}
+
 void WlShellIntegration::handleShellSurfaceDestroyed()
 {
     if (isPopup)
@@ -237,7 +244,7 @@ void WlShellIntegration::adjustOffsetForNextFrame(const QPointF &offset)
 
     float scaleFactor = m_item->view()->output()->scaleFactor();
     QQuickItem *moveItem = m_item->moveItem();
-    moveItem->setPosition(moveItem->position() + offset * scaleFactor);
+    moveItem->setPosition(moveItem->position() + offset * scaleFactor / devicePixelRatio());
 }
 
 bool WlShellIntegration::mouseMoveEvent(QMouseEvent *event)
@@ -250,7 +257,7 @@ bool WlShellIntegration::mouseMoveEvent(QMouseEvent *event)
             return true;
         }
         float scaleFactor = m_item->view()->output()->scaleFactor();
-        QPointF delta = (event->windowPos() - resizeState.initialMousePos) / scaleFactor;
+        QPointF delta = (event->windowPos() - resizeState.initialMousePos) / scaleFactor * devicePixelRatio();
         QSize newSize = m_shellSurface->sizeForResize(resizeState.initialSize, delta, resizeState.resizeEdges);
         m_shellSurface->sendConfigure(newSize, resizeState.resizeEdges);
     } else if (grabberState == GrabberState::Move) {
diff --git a/src/compositor/extensions/qwaylandwlshellintegration_p.h b/src/compositor/extensions/qwaylandwlshellintegration_p.h
index c0bbcfd10..d5ecffac1 100644
--- a/src/compositor/extensions/qwaylandwlshellintegration_p.h
+++ b/src/compositor/extensions/qwaylandwlshellintegration_p.h
@@ -86,6 +86,7 @@ private:
 
     void handlePopupClosed();
     void handlePopupRemoved();
+    qreal devicePixelRatio() const;
 
     QWaylandQuickShellSurfaceItem *m_item;
     QPointer<QWaylandWlShellSurface> m_shellSurface;