Implement QWindowContainer::minimumSizeHint()

It will return the minimumSize of the underlying QWindow.
The container can then be put inside QLayouts without risking to be
shrunk to a smaller size than the QWindow::minimumSize.
Whenever the QWindow::minimumWidth or QWindow::minimumHeight changes, we call QWindowContainer::updateGeometry(), which will make the layout re-query QWindowContainer::minimumSizeHint() again.

Task-number: QTBUG-121798
Change-Id: Ib7ece7d9d75f2e4964ca9042d8d8b95ce3b17739
Reviewed-by: Doris Verria <[email protected]>
Reviewed-by: Axel Spoerl <[email protected]>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/widgets/kernel/qwindowcontainer.cpp b/src/widgets/kernel/qwindowcontainer.cpp
index cfd785a82c2..c15ec54f350 100644
--- a/src/widgets/kernel/qwindowcontainer.cpp
+++ b/src/widgets/kernel/qwindowcontainer.cpp
@@ -221,6 +221,9 @@ QWindowContainer::QWindowContainer(QWindow *embeddedWindow, QWidget *parent, Qt:
 
     connect(qGuiApp, &QGuiApplication::focusWindowChanged,
             this, &QWindowContainer::focusWindowChanged);
+
+    connect(containedWindow(), &QWindow::minimumHeightChanged, this, &QWindowContainer::updateGeometry);
+    connect(containedWindow(), &QWindow::minimumWidthChanged, this, &QWindowContainer::updateGeometry);
 }
 
 QWindow *QWindowContainer::containedWindow() const
@@ -373,6 +376,11 @@ bool QWindowContainer::event(QEvent *e)
     return QWidget::event(e);
 }
 
+QSize QWindowContainer::minimumSizeHint() const
+{
+    return containedWindow() ? containedWindow()->minimumSize() : QSize(0, 0);
+}
+
 typedef void (*qwindowcontainer_traverse_callback)(QWidget *parent);
 static void qwindowcontainer_traverse(QWidget *parent, qwindowcontainer_traverse_callback callback)
 {