Compositor: Fix coordinate system inconsistencies

Several properties were using pixel coordinates and surface coordinates without
converting.

[ChangeLog][Compositor] QWaylandSurface::destinationSize has been added which
returns the size of the surface that will be displayed on the screen in surface
coordinates.

[ChangeLog][Compositor] Fixed a bug where QWaylandSurface::inputRegionContains
would return true for some points outside surfaces with buffer scale > 1.

[ChangeLog][Compositor] Fixed a bug which caused ShellSurfaceItems for surfaces
with buffer scale > 1 to move too much when resizing interactively.

It also gets rid of all calls to QWaylandSurface::size, which confusingly
returns the size of the surface's buffer in pixel coordinates. Most properties
now use destionationSize's surface coordinates consistently. Hopefully,
QWaylandSurface::size can be renamed or removed in Qt 6.

Change-Id: I007256a8df7759cf74fbfd51624fa1f90c083336
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/compositor/extensions/qwaylandxdgshell.cpp b/src/compositor/extensions/qwaylandxdgshell.cpp
index bd332287e..d0df8f066 100644
--- a/src/compositor/extensions/qwaylandxdgshell.cpp
+++ b/src/compositor/extensions/qwaylandxdgshell.cpp
@@ -311,7 +311,7 @@ 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());
+    return QRect(QPoint(), m_surface->destinationSize());
 }
 
 void QWaylandXdgSurfacePrivate::updateFallbackWindowGeometry()
@@ -510,7 +510,7 @@ void QWaylandXdgSurface::initialize(QWaylandXdgShell *xdgShell, QWaylandSurface
     d->init(resource.resource());
     setExtensionContainer(surface);
     d->m_windowGeometry = d->calculateFallbackWindowGeometry();
-    connect(surface, &QWaylandSurface::sizeChanged, this, &QWaylandXdgSurface::handleSurfaceSizeChanged);
+    connect(surface, &QWaylandSurface::destinationSizeChanged, this, &QWaylandXdgSurface::handleSurfaceSizeChanged);
     connect(surface, &QWaylandSurface::bufferScaleChanged, this, &QWaylandXdgSurface::handleBufferScaleChanged);
     emit shellChanged();
     emit surfaceChanged();