xdgshell: Tell the compositor the screen we're expecting to fill

The xdgshell protocol allows us to tell the output to fill. This makes
it possible to use fullscreen confidently on systems with multiple
screens knowing that our windows won't be overlapping one another by
calling setScreen accordingly before QWindow::showFullScreen.

Change-Id: I757854c3698639472f3a25ef298ddcca031e1ed5
Reviewed-by: David Edmundson <davidedmundson@kde.org>
(cherry picked from commit f915e53eaa596654ee1b9726a4767a1cba11336f)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/src/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp b/src/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp
index b7253de2b..af8bd9264 100644
--- a/src/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp
+++ b/src/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp
@@ -178,9 +178,12 @@ void QWaylandXdgSurface::Toplevel::requestWindowStates(Qt::WindowStates states)
     }
 
     if (changedStates & Qt::WindowFullScreen) {
-        if (states & Qt::WindowFullScreen)
-            set_fullscreen(nullptr);
-        else
+        if (states & Qt::WindowFullScreen) {
+            auto screen = m_xdgSurface->window()->waylandScreen();
+            if (screen) {
+                set_fullscreen(screen->output());
+            }
+        } else
             unset_fullscreen();
     }