ImGuiWindow: Storing ParentWindow (#615, #646)

imgui.cpp

@@ -1641,6 +1641,7 @@ ImGuiWindow::ImGuiWindow(const char* name)
     DrawList->_OwnerName = Name;
     RootWindow = NULL;
     RootNonPopupWindow = NULL;
+    ParentWindow = NULL;
 
     FocusIdxAllCounter = FocusIdxTabCounter = -1;
     FocusIdxAllRequestCurrent = FocusIdxTabRequestCurrent = IM_INT_MAX;
@@ -3759,6 +3760,7 @@ bool ImGui::Begin(const char* name, bool* p_open, const ImVec2& size_on_first_us
     for (root_non_popup_idx = root_idx; root_non_popup_idx > 0; root_non_popup_idx--)
         if (!(g.CurrentWindowStack[root_non_popup_idx]->Flags & (ImGuiWindowFlags_ChildWindow | ImGuiWindowFlags_Popup)))
             break;
+    window->ParentWindow = parent_window;
     window->RootWindow = g.CurrentWindowStack[root_idx];
     window->RootNonPopupWindow = g.CurrentWindowStack[root_non_popup_idx];      // This is merely for displaying the TitleBgActive color.
 

imgui_internal.h

@@ -636,7 +636,8 @@ struct IMGUI_API ImGuiWindow
     float                   FontWindowScale;                    // Scale multiplier per-window
     ImDrawList*             DrawList;
     ImGuiWindow*            RootWindow;                         // If we are a child window, this is pointing to the first non-child parent window. Else point to ourself.
-    ImGuiWindow*            RootNonPopupWindow;                 // If we are a child widnow, this is pointing to the first non-child non-popup parent window. Else point to ourself.
+    ImGuiWindow*            RootNonPopupWindow;                 // If we are a child window, this is pointing to the first non-child non-popup parent window. Else point to ourself.
+    ImGuiWindow*            ParentWindow;                       // If we are a child window, this is pointing to our parent window. Else point to NULL.
 
     // Focus
     int                     FocusIdxAllCounter;                 // Start at -1 and increase as assigned via FocusItemRegister()