Title bar uses TitleBgActive color even when window has popups/menus over (#253)

imgui.cpp

@@ -623,7 +623,7 @@ ImGuiStyle::ImGuiStyle()
     Colors[ImGuiCol_FrameBg]                = ImVec4(0.80f, 0.80f, 0.80f, 0.30f);   // Background of checkbox, radio button, plot, slider, text input
     Colors[ImGuiCol_FrameBgHovered]         = ImVec4(0.90f, 0.80f, 0.80f, 0.40f);
     Colors[ImGuiCol_FrameBgActive]          = ImVec4(0.90f, 0.65f, 0.65f, 0.45f);
-    Colors[ImGuiCol_TitleBg]                = ImVec4(0.50f, 0.50f, 1.00f, 0.40f);
+    Colors[ImGuiCol_TitleBg]                = ImVec4(0.50f, 0.50f, 1.00f, 0.45f);
     Colors[ImGuiCol_TitleBgCollapsed]       = ImVec4(0.40f, 0.40f, 0.80f, 0.20f);
     Colors[ImGuiCol_TitleBgActive]          = ImVec4(0.50f, 0.50f, 1.00f, 0.55f);
     Colors[ImGuiCol_MenuBarBg]              = ImVec4(0.40f, 0.40f, 0.55f, 0.60f);
@@ -1441,6 +1441,7 @@ struct ImGuiWindow
     float                   FontWindowScale;                    // Scale multiplier per-window
     ImDrawList*             DrawList;
     ImGuiWindow*            RootWindow;
+    ImGuiWindow*            RootNonPopupWindow;
 
     // Focus
     int                     FocusIdxAllCounter;                 // Start at -1 and increase as assigned via FocusItemRegister()
@@ -1799,6 +1800,7 @@ ImGuiWindow::ImGuiWindow(const char* name)
     DrawList = (ImDrawList*)ImGui::MemAlloc(sizeof(ImDrawList));
     new(DrawList) ImDrawList();
     RootWindow = NULL;
+    RootNonPopupWindow = NULL;
 
     FocusIdxAllCounter = FocusIdxTabCounter = -1;
     FocusIdxAllRequestCurrent = FocusIdxTabRequestCurrent = IM_INT_MAX;
@@ -3606,14 +3608,15 @@ bool ImGui::Begin(const char* name, bool* p_opened, const ImVec2& size_on_first_
     }
 
     // Update known root window (if we are a child window, otherwise window == window->RootWindow)
-    size_t root_idx = g.CurrentWindowStack.size() - 1;
-    while (root_idx > 0)
-    {
-        if ((g.CurrentWindowStack[root_idx]->Flags & ImGuiWindowFlags_ChildWindow) == 0)
+    size_t root_idx, root_non_popup_idx;
+    for (root_idx = g.CurrentWindowStack.size() - 1; root_idx > 0; root_idx--)
+        if (!(g.CurrentWindowStack[root_idx]->Flags & ImGuiWindowFlags_ChildWindow))
+            break;
+    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;
-        root_idx--;
-    }
     window->RootWindow = g.CurrentWindowStack[root_idx];
+    window->RootNonPopupWindow = g.CurrentWindowStack[root_non_popup_idx];      // This is merely for displaying the TitleBgActive color.
 
     // Default alpha
     if (bg_alpha < 0.0f)
@@ -3916,7 +3919,7 @@ bool ImGui::Begin(const char* name, bool* p_opened, const ImVec2& size_on_first_
 
             // Title bar
             if (!(flags & ImGuiWindowFlags_NoTitleBar))
-                window->DrawList->AddRectFilled(title_bar_rect.GetTL(), title_bar_rect.GetBR(), window->Color((g.FocusedWindow && window->RootWindow == g.FocusedWindow->RootWindow) ? ImGuiCol_TitleBgActive : ImGuiCol_TitleBg), window_rounding, 1|2);
+                window->DrawList->AddRectFilled(title_bar_rect.GetTL(), title_bar_rect.GetBR(), window->Color((g.FocusedWindow && window->RootNonPopupWindow == g.FocusedWindow->RootNonPopupWindow) ? ImGuiCol_TitleBgActive : ImGuiCol_TitleBg), window_rounding, 1|2);
 
             // Menu bar
             if (flags & ImGuiWindowFlags_MenuBar)