From a4b95ed992cacad075d1ce6e1cffdeadf932cd4c Mon Sep 17 00:00:00 2001
From: vsv <vsv@opencascade.com>
Date: Mon, 30 Sep 2019 19:09:08 +0300
Subject: [PATCH] Optimize updates of viewer

---
 src/XGUI/XGUI_ViewerProxy.cpp | 9 ++++++---
 src/XGUI/XGUI_ViewerProxy.h   | 2 +-
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/XGUI/XGUI_ViewerProxy.cpp b/src/XGUI/XGUI_ViewerProxy.cpp
index 84e45201e..4cc8abee1 100644
--- a/src/XGUI/XGUI_ViewerProxy.cpp
+++ b/src/XGUI/XGUI_ViewerProxy.cpp
@@ -486,16 +486,18 @@ void XGUI_ViewerProxy::displayHighlight(FeaturePtr theFeature, const TopoDS_Shap
   }
 }
 
-void XGUI_ViewerProxy::eraseHighlight()
+bool XGUI_ViewerProxy::eraseHighlight()
 {
   Handle(AIS_InteractiveContext) aContext = AISContext();
   Handle(AIS_InteractiveObject) anAISIO;
   AIS_ListIteratorOfListOfInteractive aLIt;
+  bool isErased = myHighlights.Extent() > 0;
   for (aLIt.Initialize(myHighlights); aLIt.More(); aLIt.Next()) {
     anAISIO = aLIt.Value();
     aContext->Remove(anAISIO, false);
   }
   myHighlights.Clear();
+  return isErased;
 }
 
 void XGUI_ViewerProxy::updateHighlight()
@@ -531,8 +533,9 @@ void XGUI_ViewerProxy::updateHighlight()
       }
     }
     if (!isDisplayed) {
-      eraseHighlight();
-      aContext->UpdateCurrentViewer();
+      if (eraseHighlight()) {
+        aContext->UpdateCurrentViewer();
+      }
       myResult = ResultPtr();
     }
   }
diff --git a/src/XGUI/XGUI_ViewerProxy.h b/src/XGUI/XGUI_ViewerProxy.h
index 723aae644..19e23ac3b 100644
--- a/src/XGUI/XGUI_ViewerProxy.h
+++ b/src/XGUI/XGUI_ViewerProxy.h
@@ -216,7 +216,7 @@ private slots:
 
  private:
    void displayHighlight(FeaturePtr theFeature, const TopoDS_Shape& theIgnoreShape);
-   void eraseHighlight();
+   bool eraseHighlight();
 
 
   XGUI_Workshop* myWorkshop;
-- 
2.39.2