[FancyZones] Keep the same layouts on the new virtual desktops. (#23927)

src/modules/fancyzones/FancyZonesLib/FancyZones.cpp

@@ -716,13 +716,6 @@ void FancyZones::AddWorkArea(HMONITOR monitor, const FancyZonesDataTypes::WorkAr
         Logger::debug(L"Add new work area on virtual desktop {}", virtualDesktopIdStr.get());
     }
 
-    FancyZonesDataTypes::WorkAreaId parentId{};
-    auto parentArea = m_workAreaHandler.GetWorkArea(monitor);
-    if (parentArea)
-    {
-        parentId = parentArea->UniqueId();
-    }
-
     FancyZonesUtils::Rect rect{};
     if (monitor)
     {
@@ -733,7 +726,7 @@ void FancyZones::AddWorkArea(HMONITOR monitor, const FancyZonesDataTypes::WorkAr
         rect = FancyZonesUtils::GetAllMonitorsCombinedRect<&MONITORINFO::rcWork>();
     }
         
-    auto workArea = WorkArea::Create(m_hinstance, id, parentId, rect);
+    auto workArea = WorkArea::Create(m_hinstance, id, m_workAreaHandler.GetParent(monitor), rect);
     if (workArea)
     {
         if (updateWindowsPositions)
@@ -761,6 +754,7 @@ LRESULT CALLBACK FancyZones::s_WndProc(HWND window, UINT message, WPARAM wparam,
 
 void FancyZones::UpdateWorkAreas(bool updateWindowPositions) noexcept
 {
+    m_workAreaHandler.SaveParentIds();
     m_workAreaHandler.Clear();
 
     if (FancyZonesSettings::settings().spanZonesAcrossMonitors)

src/modules/fancyzones/FancyZonesLib/MonitorWorkAreaMap.cpp

@@ -61,6 +61,28 @@ void MonitorWorkAreaMap::AddWorkArea(HMONITOR monitor, std::unique_ptr<WorkArea>
     m_workAreaMap.insert({ monitor, std::move(workArea) });
 }
 
+FancyZonesDataTypes::WorkAreaId MonitorWorkAreaMap::GetParent(HMONITOR monitor) const
+{
+    if (m_workAreaParents.contains(monitor))
+    {
+        return m_workAreaParents.at(monitor);
+    }
+    
+    return FancyZonesDataTypes::WorkAreaId{};
+}
+
+void MonitorWorkAreaMap::SaveParentIds()
+{
+    m_workAreaParents.clear();
+    for (const auto& [monitor, workArea] : m_workAreaMap)
+    {
+        if (workArea)
+        {
+            m_workAreaParents.insert({ monitor, workArea->UniqueId() });
+        }
+    }
+}
+
 void MonitorWorkAreaMap::Clear() noexcept
 {
     m_workAreaMap.clear();

src/modules/fancyzones/FancyZonesLib/MonitorWorkAreaMap.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "GuidUtils.h"
+#include <FancyZonesLib/FancyZonesDataTypes.h>
 
 class WorkArea;
 
@@ -48,6 +49,13 @@ public:
      */
     void AddWorkArea(HMONITOR monitor, std::unique_ptr<WorkArea> workArea);
 
+    FancyZonesDataTypes::WorkAreaId GetParent(HMONITOR monitor) const;
+
+    /**
+    * Saving current work area IDs as parents for later use.
+    */
+    void SaveParentIds();
+
     /**
      * Clear all persisted work area related data.
      */
@@ -55,4 +63,5 @@ public:
     
 private:
     std::unordered_map<HMONITOR, std::unique_ptr<WorkArea>> m_workAreaMap;
+    std::unordered_map<HMONITOR, FancyZonesDataTypes::WorkAreaId> m_workAreaParents{};
 };