From e2408989a4fdcc068e030c5967c910679adfca24 Mon Sep 17 00:00:00 2001
From: Jon Evans <jon@craftyjon.com>
Date: Mon, 26 Feb 2018 20:49:42 -0500
Subject: [PATCH] GerbView: redraw negative items when visibility changes

---
 gerbview/gerbview_frame.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/gerbview/gerbview_frame.cpp b/gerbview/gerbview_frame.cpp
index 99bc247879..f73e2afd2f 100644
--- a/gerbview/gerbview_frame.cpp
+++ b/gerbview/gerbview_frame.cpp
@@ -498,8 +498,20 @@ void GERBVIEW_FRAME::SetElementVisibility( GERBVIEW_LAYER_ID aItemIdVisible,
         break;
 
     case LAYER_NEGATIVE_OBJECTS:
+    {
         m_DisplayOptions.m_DisplayNegativeObjects = aNewState;
+
+        auto view = GetGalCanvas()->GetView();
+
+        view->UpdateAllItemsConditionally( KIGFX::REPAINT,
+                                           []( KIGFX::VIEW_ITEM* aItem ) {
+            auto item = static_cast<GERBER_DRAW_ITEM*>( aItem );
+
+            // GetLayerPolarity() returns true for negative items
+            return item->GetLayerPolarity();
+        } );
         break;
+    }
 
     case LAYER_GERBVIEW_GRID:
         SetGridVisibility( aNewState );