Docking: Amend 24dfebf. Fixed incorrect focus highlight on docking no…

…de with nested hierarchies.

imgui.cpp

@@ -6325,7 +6325,7 @@ void ImGui::UpdateWindowParentAndRootLinks(ImGuiWindow* window, ImGuiWindowFlags
     }
     if (parent_window && (flags & ImGuiWindowFlags_Popup))
         window->RootWindowPopupTree = parent_window->RootWindowPopupTree;
-    if (parent_window && !(flags & ImGuiWindowFlags_Modal) && (flags & (ImGuiWindowFlags_ChildWindow | ImGuiWindowFlags_Popup)))
+    if (parent_window && !(flags & ImGuiWindowFlags_Modal) && (flags & (ImGuiWindowFlags_ChildWindow | ImGuiWindowFlags_Popup))) // FIXME: simply use _NoTitleBar ?
         window->RootWindowForTitleBarHighlight = parent_window->RootWindowForTitleBarHighlight;
     while (window->RootWindowForNav->Flags & ImGuiWindowFlags_NavFlattened)
     {
@@ -15293,6 +15293,21 @@ void ImGui::DockNodeEndAmendTabBar()
     End();
 }
 
+static bool IsDockNodeTitleBarHighlighted(ImGuiDockNode* node, ImGuiDockNode* root_node, ImGuiWindow* host_window)
+{
+    // CTRL+Tab highlight (only highlighting leaf node, not whole hierarchy)
+    ImGuiContext& g = *GImGui;
+    if (g.NavWindowingTarget)
+        return (g.NavWindowingTarget->DockNode == node);
+
+    // FIXME-DOCKING: May want alternative to treat central node void differently? e.g. if (g.NavWindow == host_window)
+    if (g.NavWindow && g.NavWindow->RootWindowForTitleBarHighlight == host_window->RootWindowDockTree && root_node->LastFocusedNodeId == node->ID)
+        for (ImGuiDockNode* parent_node = g.NavWindow->RootWindow->DockNode; parent_node != NULL; parent_node = parent_node->HostWindow ? parent_node->HostWindow->RootWindow->DockNode : NULL)
+            if ((parent_node = ImGui::DockNodeGetRootNode(parent_node)) == root_node)
+                return true;
+    return false;
+}
+
 // Submit the tab bar corresponding to a dock node and various housekeeping details.
 static void ImGui::DockNodeUpdateTabBar(ImGuiDockNode* node, ImGuiWindow* host_window)
 {
@@ -15308,14 +15323,8 @@ static void ImGui::DockNodeUpdateTabBar(ImGuiDockNode* node, ImGuiWindow* host_w
     // Decide if we should use a focused title bar color
     bool is_focused = false;
     ImGuiDockNode* root_node = DockNodeGetRootNode(node);
-    if (g.NavWindowingTarget)
-        is_focused = (g.NavWindowingTarget->DockNode == node);
-    else if (g.NavWindow && g.NavWindow->RootWindowForTitleBarHighlight == host_window->RootWindowDockTree && root_node->LastFocusedNodeId == node->ID)
-    {
-        // FIXME-DOCKING: May want alternative to treat central node void differently? e.g. if (g.NavWindow == host_window)
-        if (g.NavWindow->DockNode && DockNodeIsInHierarchyOf(g.NavWindow->DockNode, root_node)) // Omit child windows injected in window hierarchy
-            is_focused = true;
-    }
+    if (IsDockNodeTitleBarHighlighted(node, root_node, host_window))
+        is_focused = true;
 
     // Hidden tab bar will show a triangle on the upper-left (in Begin)
     if (node->IsHiddenTabBar() || node->IsNoTabBar())