Add helper to get FloatingWindow by its WId

src/private/DockRegistry.cpp

@@ -504,6 +504,16 @@ FloatingWindow *DockRegistry::floatingWindowForHandle(QWindow *windowHandle) con
     return nullptr;
 }
 
+FloatingWindow *DockRegistry::floatingWindowForHandle(WId hwnd) const
+{
+    for (FloatingWindow *fw : m_floatingWindows) {
+        if (fw->windowHandle() && fw->windowHandle()->winId() == hwnd)
+            return fw;
+    }
+
+    return nullptr;
+}
+
 MainWindowBase *DockRegistry::mainWindowForHandle(QWindow *windowHandle) const
 {
     for (MainWindowBase *mw : m_mainWindows) {

src/private/DockRegistry_p.h

@@ -95,6 +95,9 @@ public:
     ///@brief returns the FloatingWindow with handle @p windowHandle
     FloatingWindow *floatingWindowForHandle(QWindow *windowHandle) const;
 
+    ///@brief returns the FloatingWindow with handle @p hwnd
+    FloatingWindow *floatingWindowForHandle(WId hwnd) const;
+
     ///@brief returns the MainWindow with handle @p windowHandle
     MainWindowBase *mainWindowForHandle(QWindow *windowHandle) const;