Nav: window that are filling the entire display/viewport gets their windowing highlight clamped within. (#787)

imgui.cpp

@@ -5760,13 +5760,13 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         if ((flags & ImGuiWindowFlags_Modal) != 0 && window == GetFrontMostModalRootWindow())
             window->DrawList->AddRectFilled(fullscreen_rect.Min, fullscreen_rect.Max, GetColorU32(ImGuiCol_ModalWindowDarkening, g.ModalWindowDarkeningRatio));
 
-        // Draw navigation windowing rectangle (via ImGuiKey_NavWindowing key), shows whole window selected
+        // Draw navigation selection/windowing rectangle background
         if (g.NavWindowingTarget == window)
         {
             ImRect bb = window->Rect();
             bb.Expand(g.FontSize);
-            window->DrawList->AddRectFilled(bb.Min, bb.Max, GetColorU32(ImGuiCol_NavWindowingHighlight, g.NavWindowingHighlightAlpha * 0.25f), g.Style.WindowRounding);
-            window->DrawList->AddRect(bb.Min, bb.Max, GetColorU32(ImGuiCol_NavWindowingHighlight, g.NavWindowingHighlightAlpha), g.Style.WindowRounding, ~0, 3.0f);
+            if (!bb.Contains(viewport_rect)) // Avoid drawing if the window covers all the viewport anyway
+                window->DrawList->AddRectFilled(bb.Min, bb.Max, GetColorU32(ImGuiCol_NavWindowingHighlight, g.NavWindowingHighlightAlpha * 0.25f), g.Style.WindowRounding);
         }
 
         // Draw window + handle manual resize
@@ -5839,6 +5839,16 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
                 window->DrawList->AddLine(title_bar_rect.GetBL() + ImVec2(style.WindowBorderSize, -1), title_bar_rect.GetBR() + ImVec2(-style.WindowBorderSize,-1), GetColorU32(ImGuiCol_Border), style.FrameBorderSize);
         }
 
+        // Draw navigation selection/windowing rectangle border
+        if (g.NavWindowingTarget == window)
+        {
+            ImRect bb = window->Rect();
+            bb.Expand(g.FontSize);
+            if (bb.Contains(viewport_rect))
+                bb.Expand(-g.FontSize - 2.0f);
+            window->DrawList->AddRect(bb.Min, bb.Max, GetColorU32(ImGuiCol_NavWindowingHighlight, g.NavWindowingHighlightAlpha), g.Style.WindowRounding, ~0, 3.0f);
+        }
+
         // Store a backup of SizeFull which we will use next frame to decide if we need scrollbars. 
         window->SizeFullAtLastBegin = window->SizeFull;