[Bundle] ImGuiContextHookType_Begin/EndWindow: handle m_BeginWindowDepth

Author: pthom

imgui_canvas.cpp

@@ -160,6 +160,11 @@ bool ImGuiEx::Canvas::Begin(ImGuiID id, const ImVec2& size)
             //ImGui::SetNextWindowViewport( ImGui::GetCurrentWindow()->Viewport->ID );
 
             auto canvas = reinterpret_cast< Canvas * >( hook->UserData );
+
+            canvas->m_BeginWindowDepth += 1;
+            if (canvas->m_BeginWindowDepth > 1)
+                return;
+
             if ( canvas->m_SuspendCounter == 0 )
             {
                 if ( ( context->NextWindowData.Flags & ImGuiNextWindowDataFlags_HasPos ) != 0 )
@@ -195,6 +200,11 @@ bool ImGuiEx::Canvas::Begin(ImGuiID id, const ImVec2& size)
         endWindowHook.Callback = []( ImGuiContext * ctx, ImGuiContextHook * hook )
         {
             auto canvas = reinterpret_cast< Canvas * >( hook->UserData );
+
+            canvas->m_BeginWindowDepth -= 1;
+            if (canvas->m_BeginWindowDepth > 0)
+                return;
+
             canvas->Resume();
             ImGui::SetCursorScreenPos( canvas->m_BeginWindowCursorBackup );
             ImGui::GetCurrentWindow()->DC.IsSetPos = false;

imgui_canvas.h

@@ -265,6 +265,7 @@ struct Canvas
     // [ADAPT_IMGUI_BUNDLE]: added ImGuiContextHookType_BeginWindow, ImGuiContextHookType_EndWindow, cf https://github.com/thedmd/imgui-node-editor/issues/242#issuecomment-1681806764
     ImGuiID m_beginWindowHook, m_endWindowHook;
     ImVec2 m_BeginWindowCursorBackup;
+    int m_BeginWindowDepth = 0;
     // [/ADAPT_IMGUI_BUNDLE]
     };