Take buffer scale into account when calculating unset window geometry

This fixes a resize issue where the window would scale to be bufferScale times
the size it should have been.

Change-Id: I4d3eee52d54a063c0a617a053cbe05b351f18f76
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>
Reviewed-by: Pier Luigi Fiorini <pierluigi.fiorini@hawaiios.org>

3 files changed, 33 insertions, 7 deletions

diff --git a/src/compositor/extensions/qwaylandxdgshell.cpp b/src/compositor/extensions/qwaylandxdgshell.cpp
index 0b45b21ac..8b07283e7 100644
--- a/src/compositor/extensions/qwaylandxdgshell.cpp
+++ b/src/compositor/extensions/qwaylandxdgshell.cpp
@@ -246,6 +246,27 @@ void QWaylandXdgSurfacePrivate::handleFocusReceived()
     q->sendConfigure(current.size, current.states);
 }
 
+QRect QWaylandXdgSurfacePrivate::calculateFallbackWindowGeometry() const
+{
+    // TODO: The unset window geometry should include subsurfaces as well, so this solution
+    // won't work too well on those kinds of clients.
+    return QRect(QPoint(0, 0), m_surface->size() / m_surface->bufferScale());
+}
+
+void QWaylandXdgSurfacePrivate::updateFallbackWindowGeometry()
+{
+    Q_Q(QWaylandXdgSurface);
+    if (!m_unsetWindowGeometry)
+        return;
+
+    const QRect unsetGeometry = calculateFallbackWindowGeometry();
+    if (unsetGeometry == m_windowGeometry)
+        return;
+
+    m_windowGeometry = unsetGeometry;
+    emit q->windowGeometryChanged();
+}
+
 void QWaylandXdgSurfacePrivate::xdg_surface_destroy_resource(Resource *resource)
 {
     Q_UNUSED(resource);
@@ -625,8 +646,9 @@ void QWaylandXdgSurface::initialize(QWaylandXdgShell *xdgShell, QWaylandSurface
     d->m_surface = surface;
     d->init(resource.resource());
     setExtensionContainer(surface);
-    d->m_windowGeometry = QRect(QPoint(0,0), surface->size());
+    d->m_windowGeometry = d->calculateFallbackWindowGeometry();
     connect(surface, &QWaylandSurface::sizeChanged, this, &QWaylandXdgSurface::handleSurfaceSizeChanged);
+    connect(surface, &QWaylandSurface::bufferScaleChanged, this, &QWaylandXdgSurface::handleBufferScaleChanged);
     emit surfaceChanged();
     emit windowGeometryChanged();
     QWaylandCompositorExtension::initialize();
@@ -652,12 +674,13 @@ QList<int> QWaylandXdgSurface::statesAsInts() const
 void QWaylandXdgSurface::handleSurfaceSizeChanged()
 {
     Q_D(QWaylandXdgSurface);
-    if (d->m_unsetWindowGeometry && d->m_windowGeometry.size() != surface()->size()) {
-        // TODO: The unset window geometry should include subsurfaces as well, so this solution
-        // won't work too well on those kinds of clients.
-        d->m_windowGeometry.setSize(surface()->size());
-        emit windowGeometryChanged();
-    }
+    d->updateFallbackWindowGeometry();
+}
+
+void QWaylandXdgSurface::handleBufferScaleChanged()
+{
+    Q_D(QWaylandXdgSurface);
+    d->updateFallbackWindowGeometry();
 }
 
 /*!
diff --git a/src/compositor/extensions/qwaylandxdgshell.h b/src/compositor/extensions/qwaylandxdgshell.h
index 2187086ac..2da7f3d3d 100644
--- a/src/compositor/extensions/qwaylandxdgshell.h
+++ b/src/compositor/extensions/qwaylandxdgshell.h
@@ -190,6 +190,7 @@ private:
 
 private Q_SLOTS:
     void handleSurfaceSizeChanged();
+    void handleBufferScaleChanged();
 };
 
 class Q_WAYLAND_COMPOSITOR_EXPORT QWaylandXdgPopup : public QWaylandShellSurfaceTemplate<QWaylandXdgPopup>
diff --git a/src/compositor/extensions/qwaylandxdgshell_p.h b/src/compositor/extensions/qwaylandxdgshell_p.h
index fa0e7037d..23c95bdeb 100644
--- a/src/compositor/extensions/qwaylandxdgshell_p.h
+++ b/src/compositor/extensions/qwaylandxdgshell_p.h
@@ -107,6 +107,8 @@ public:
 
     void handleFocusLost();
     void handleFocusReceived();
+    QRect calculateFallbackWindowGeometry() const;
+    void updateFallbackWindowGeometry();
 
 private:
     QWaylandXdgShell *m_xdgShell;