Compositor xdg-shell: Respect min and max size

[ChangeLog][Compositor] xdg-shell minimum and maximum sizes are now respected
when resizing.

Change-Id: Iaf6a2bd283117e948fda6693530e08f68f755a17
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

3 files changed, 17 insertions, 7 deletions

diff --git a/src/compositor/extensions/qwaylandxdgshell.cpp b/src/compositor/extensions/qwaylandxdgshell.cpp
index 205269a88..175caea62 100644
--- a/src/compositor/extensions/qwaylandxdgshell.cpp
+++ b/src/compositor/extensions/qwaylandxdgshell.cpp
@@ -935,9 +935,14 @@ QSize QWaylandXdgToplevel::sizeForResize(const QSizeF &size, const QPointF &delt
     else if (edges & Qt::BottomEdge)
         height += delta.y();
 
-    //TODO: use minSize given by the client here instead
-    QSizeF newSize(qMax(width, 1.0), qMax(height, 1.0));
-    return newSize.toSize();
+    QSize newSize = QSize(width, height)
+            .expandedTo(minSize())
+            .expandedTo({1, 1}); // We don't want to send a size of (0,0) as that means that the client decides
+
+    if (maxSize().isValid())
+        newSize = newSize.boundedTo(maxSize());
+
+    return newSize;
 }
 
 /*!
diff --git a/src/compositor/extensions/qwaylandxdgshell_p.h b/src/compositor/extensions/qwaylandxdgshell_p.h
index 70def5f7a..e87bb17f0 100644
--- a/src/compositor/extensions/qwaylandxdgshell_p.h
+++ b/src/compositor/extensions/qwaylandxdgshell_p.h
@@ -177,7 +177,7 @@ public:
     QString m_title;
     QString m_appId;
     QSize m_maxSize;
-    QSize m_minSize;
+    QSize m_minSize = {0, 0};
     QScopedPointer<QWaylandXdgToplevelDecorationV1> m_decoration;
 
     static QWaylandSurfaceRole s_role;
diff --git a/src/compositor/extensions/qwaylandxdgshellv6.cpp b/src/compositor/extensions/qwaylandxdgshellv6.cpp
index 0772846fd..d447ac3c8 100644
--- a/src/compositor/extensions/qwaylandxdgshellv6.cpp
+++ b/src/compositor/extensions/qwaylandxdgshellv6.cpp
@@ -934,9 +934,14 @@ QSize QWaylandXdgToplevelV6::sizeForResize(const QSizeF &size, const QPointF &de
     else if (edges & Qt::BottomEdge)
         height += delta.y();
 
-    //TODO: use minSize given by the client here instead
-    QSizeF newSize(qMax(width, 1.0), qMax(height, 1.0));
-    return newSize.toSize();
+    QSize newSize = QSize(width, height)
+            .expandedTo(minSize())
+            .expandedTo({1, 1}); // We don't want to send a size of (0,0) as that means that the client decides
+
+    if (maxSize().isValid())
+        newSize = newSize.boundedTo(maxSize());
+
+    return newSize;
 }
 
 /*!