Keep toplevel windows in the top left corner of the screen

We can't know the actual position of a window on the screen. This causes
an issue when Widgets try to position a popup/menu absolutely and keep
it on the screen when the screen geometry doesn't include (0,0).
Instead report their positions always as the top left corner of
the screen that they are on.
This new behavior can be disabled for qt-shell or via an environment
variable by users that rely on the old behavior.

Fixes: QTBUG-85297
Change-Id: Iacb91cb03a0df87af950115760d2f41124ac06a3
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: David Edmundson <davidedmundson@kde.org>
Reviewed-by: Aleix Pol Gonzalez <aleixpol@kde.org>

1 files changed, 13 insertions, 1 deletions

diff --git a/src/client/qwaylandwindow.cpp b/src/client/qwaylandwindow.cpp
index 888c4639..85266422 100644
--- a/src/client/qwaylandwindow.cpp
+++ b/src/client/qwaylandwindow.cpp
@@ -328,8 +328,13 @@ void QWaylandWindow::setGeometry_helper(const QRect &rect)
     }
 }
 
-void QWaylandWindow::setGeometry(const QRect &rect)
+void QWaylandWindow::setGeometry(const QRect &r)
 {
+    auto rect = r;
+    if (fixedToplevelPositions && !QPlatformWindow::parent() && window()->type() != Qt::Popup
+        && window()->type() != Qt::ToolTip) {
+        rect.moveTo(screen()->geometry().topLeft());
+    }
     setGeometry_helper(rect);
 
     if (window()->isVisible() && rect.isValid()) {
@@ -1210,6 +1215,13 @@ void QWaylandWindow::handleScreensChanged()
 
     QWindowSystemInterface::handleWindowScreenChanged(window(), newScreen->QPlatformScreen::screen());
     mLastReportedScreen = newScreen;
+    if (fixedToplevelPositions && !QPlatformWindow::parent() && window()->type() != Qt::Popup
+        && window()->type() != Qt::ToolTip
+        && geometry().topLeft() != newScreen->geometry().topLeft()) {
+        auto geometry = this->geometry();
+        geometry.moveTo(newScreen->geometry().topLeft());
+        setGeometry(geometry);
+    }
 
     int scale = newScreen->isPlaceholder() ? 1 : static_cast<QWaylandScreen *>(newScreen)->scale();
     if (scale != mScale) {