From 8265a72ffc4629fde76928773cffbca1db07e2dd Mon Sep 17 00:00:00 2001
From: vsv <vitaly.smetannikov@opencascade.com>
Date: Fri, 25 Sep 2015 11:57:12 +0300
Subject: [PATCH] Improve viewer performance

---
 src/XGUI/XGUI_Displayer.cpp        | 9 +++++++--
 src/XGUI/XGUI_Displayer.h          | 7 ++++++-
 src/XGUI/XGUI_WorkshopListener.cpp | 1 -
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/XGUI/XGUI_Displayer.cpp b/src/XGUI/XGUI_Displayer.cpp
index b41682090..4ddd90572 100644
--- a/src/XGUI/XGUI_Displayer.cpp
+++ b/src/XGUI/XGUI_Displayer.cpp
@@ -96,7 +96,7 @@ QString qIntListInfo(const QIntList& theValues, const QString& theSeparator = QS
 }
 
 XGUI_Displayer::XGUI_Displayer(XGUI_Workshop* theWorkshop)
-  : myWorkshop(theWorkshop), myEnableUpdateViewer(true)
+  : myWorkshop(theWorkshop), myEnableUpdateViewer(true), myNeedUpdate(false)
 {
   enableUpdateViewer(true);
   myCustomPrs = std::shared_ptr<GeomAPI_ICustomPrs>(new XGUI_CustomPrs());
@@ -689,7 +689,10 @@ bool XGUI_Displayer::enableUpdateViewer(const bool isEnabled)
   bool aWasEnabled = myEnableUpdateViewer;
 
   myEnableUpdateViewer = isEnabled;
-
+  if (myNeedUpdate && myEnableUpdateViewer) {
+    updateViewer();
+    myNeedUpdate = false;
+  }
   return aWasEnabled;
 }
 
@@ -700,6 +703,8 @@ void XGUI_Displayer::updateViewer() const
   if (!aContext.IsNull() && myEnableUpdateViewer) {
     myWorkshop->viewer()->Zfitall();
     aContext->UpdateCurrentViewer();
+  } else {
+    myNeedUpdate = true;
   }
 }
 
diff --git a/src/XGUI/XGUI_Displayer.h b/src/XGUI/XGUI_Displayer.h
index b189189f6..3cd6f9c73 100644
--- a/src/XGUI/XGUI_Displayer.h
+++ b/src/XGUI/XGUI_Displayer.h
@@ -141,6 +141,8 @@ class XGUI_EXPORT XGUI_Displayer: public QObject
   /// \param isEnabled a boolean value
   bool enableUpdateViewer(const bool isEnabled);
 
+  bool isUpdateEnabled() const { return myEnableUpdateViewer; }
+
   /// Updates the viewer
   void updateViewer() const;
 
@@ -307,7 +309,10 @@ private:
   QIntList myActiveSelectionModes;
 
   /// the enable update viewer flag
-  bool myEnableUpdateViewer;  
+  bool myEnableUpdateViewer; 
+
+  /// A flag that update was requested but not done
+  mutable bool myNeedUpdate;
 };
 
 #endif
diff --git a/src/XGUI/XGUI_WorkshopListener.cpp b/src/XGUI/XGUI_WorkshopListener.cpp
index 434b6cdd8..e5c95c78b 100755
--- a/src/XGUI/XGUI_WorkshopListener.cpp
+++ b/src/XGUI/XGUI_WorkshopListener.cpp
@@ -191,7 +191,6 @@ void XGUI_WorkshopListener::processEvent(const std::shared_ptr<Events_Message>&
     // the viewer's update context is unblocked, the viewer's update works
     XGUI_Displayer* aDisplayer = workshop()->displayer();
     aDisplayer->enableUpdateViewer(true);
-    aDisplayer->updateViewer();
   } else if (theMessage->eventID() == Events_Loop::eventByName(EVENT_OBJECT_ERROR_CHANGED)) {
     std::shared_ptr<ModelAPI_ObjectUpdatedMessage> aUpdMsg =
         std::dynamic_pointer_cast<ModelAPI_ObjectUpdatedMessage>(theMessage);
-- 
2.39.2