Nav: When focusing a parent window while closing a popup, hide its highlight for one frame to avoid potential double highlight and flicker with the common pattern of menu items leading to the opening other windows. (#787)

imgui.cpp

@@ -4247,6 +4247,8 @@ void ImGui::RenderNavHighlight(const ImRect& bb, ImGuiID id, ImGuiNavHighlightFl
     if (g.NavDisableHighlight && !(flags & ImGuiNavHighlightFlags_AlwaysDraw))
         return;    
     ImGuiWindow* window = ImGui::GetCurrentWindow();
+    if (window->DC.NavHideHighlightOneFrame)
+        return;
 
     float rounding = (flags & ImGuiNavHighlightFlags_NoRounding) ? 0.0f : g.Style.FrameRounding;
     ImRect display_rect = bb;
@@ -4767,6 +4769,7 @@ static void ClosePopupToLevel(int remaining)
     if (g.NavLayer == 0)
         focus_window = NavRestoreLastChildNavWindow(focus_window);
     ImGui::FocusWindow(focus_window);
+    focus_window->DC.NavHideHighlightOneFrame = true;
     g.OpenPopupStack.resize(remaining);
 }
 
@@ -5901,9 +5904,10 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         window->DC.CursorMaxPos = window->DC.CursorStartPos;
         window->DC.CurrentLineHeight = window->DC.PrevLineHeight = 0.0f;
         window->DC.CurrentLineTextBaseOffset = window->DC.PrevLineTextBaseOffset = 0.0f;
+        window->DC.NavHideHighlightOneFrame = false;
+        window->DC.NavHasScroll = (GetScrollMaxY() > 0.0f);
         window->DC.NavLayerActiveMask = window->DC.NavLayerActiveMaskNext;
         window->DC.NavLayerActiveMaskNext = 0x00;
-        window->DC.NavHasScroll = (GetScrollMaxY() > 0.0f);
         window->DC.MenuBarAppending = false;
         window->DC.MenuBarOffsetX = ImMax(window->WindowPadding.x, style.ItemSpacing.x);
         window->DC.LogLinePosY = window->DC.CursorPos.y - 9999.0f;

imgui_internal.h

@@ -820,6 +820,7 @@ struct IMGUI_API ImGuiDrawContext
     ImGuiID                 LastItemId;
     ImRect                  LastItemRect;
     bool                    LastItemRectHoveredRect;
+    bool                    NavHideHighlightOneFrame;
     bool                    NavHasScroll;           // Set when scrolling can be used (ScrollMax > 0.0f)
     int                     NavLayerCurrent;        // Current layer, 0..31 (we currently only use 0..1)
     int                     NavLayerCurrentMask;    // = (1 << NavLayerCurrent) used by ItemAdd prior to clipping.
@@ -857,6 +858,7 @@ struct IMGUI_API ImGuiDrawContext
         LastItemId = 0;
         LastItemRect = ImRect();
         LastItemRectHoveredRect = false;
+        NavHideHighlightOneFrame = false;
         NavHasScroll = false;
         NavLayerActiveMask = NavLayerActiveMaskNext = 0x00;
         NavLayerCurrent = 0;