From d0f80336786b6906b1d6d786d74d8ae9dc13a4b0 Mon Sep 17 00:00:00 2001
From: mpv <mpv@opencascade.com>
Date: Thu, 1 Jun 2017 13:19:31 +0300
Subject: [PATCH] Workaround for the problem that the local selection may be
 initialized without opening local context since OCCT 7.0.

---
 src/OCCViewer/OCCViewer_ViewModel.cxx  | 26 ++++++++++++++++++++++++--
 src/OCCViewer/OCCViewer_ViewModel.h    |  5 ++++-
 src/OCCViewer/OCCViewer_ViewWindow.cxx |  2 +-
 3 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/src/OCCViewer/OCCViewer_ViewModel.cxx b/src/OCCViewer/OCCViewer_ViewModel.cxx
index 3285f015e..0b0ce6a97 100644
--- a/src/OCCViewer/OCCViewer_ViewModel.cxx
+++ b/src/OCCViewer/OCCViewer_ViewModel.cxx
@@ -120,7 +120,8 @@ OCCViewer_Viewer::OCCViewer_Viewer( bool DisplayTrihedron)
   myIsRelative(true),
   myTopLayerId( 0 ),
   myTrihedronSize(100),
-  myClippingDlg (NULL)
+  myClippingDlg (NULL),
+  myIsUseLocalSelection(false)
 {
   // init CasCade viewers
   myV3dViewer = OCCViewer_VService::CreateViewer( TCollection_ExtendedString("Viewer3d").ToExtString() );
@@ -454,7 +455,7 @@ void OCCViewer_Viewer::onKeyPress(SUIT_ViewWindow* theWindow, QKeyEvent* theEven
     break;
   case  Qt::Key_N:
     if ( isPreselectionEnabled() ) {
-      if ( getAISContext()->HasOpenedContext() )
+      if ( useLocalSelection() )
 	getAISContext()->HilightNextDetected( aView->getViewPort()->getView() );
     }
     break;
@@ -1355,6 +1356,27 @@ OCCViewer_ViewWindow* OCCViewer_Viewer::createSubWindow()
   return new OCCViewer_ViewWindow(0,  this);
 }
 
+/*!
+  Sets using local selection state
+  \param theIsUseLocalSelection - state
+*/
+void OCCViewer_Viewer::setUseLocalSelection(bool theIsUseLocalSelection)
+{
+  myIsUseLocalSelection = theIsUseLocalSelection;
+}
+
+/* 
+ * Returns true if local context is opened or view model local state is set
+ */
+bool OCCViewer_Viewer::useLocalSelection() const
+{
+  if (myIsUseLocalSelection)
+    return true;
+
+  Handle(AIS_InteractiveContext) ic = getAISContext();
+  return !ic.IsNull() && ic->HasOpenedContext();
+}
+
 // obsolete  
 QColor OCCViewer_Viewer::backgroundColor( int theViewId ) const
 {
diff --git a/src/OCCViewer/OCCViewer_ViewModel.h b/src/OCCViewer/OCCViewer_ViewModel.h
index 63db7700b..329bb05bd 100755
--- a/src/OCCViewer/OCCViewer_ViewModel.h
+++ b/src/OCCViewer/OCCViewer_ViewModel.h
@@ -132,6 +132,9 @@ public:
 
   virtual OCCViewer_ViewWindow*   createSubWindow();
 
+  void                            setUseLocalSelection(bool theIsUseLocalSelection);
+  bool                            useLocalSelection() const;
+
 public:
   Handle(V3d_Viewer)              getViewer3d()    const { return myV3dViewer;}
   Handle(AIS_InteractiveContext)  getAISContext()  const { return myAISContext; }
@@ -279,7 +282,7 @@ protected:
   QString                         myClippingTexture;
   bool                            myTextureModulated;
   double                          myClippingTextureScale;
-
+  bool                            myIsUseLocalSelection;
 };
 
 #ifdef WIN32
diff --git a/src/OCCViewer/OCCViewer_ViewWindow.cxx b/src/OCCViewer/OCCViewer_ViewWindow.cxx
index a4bce4220..b7d38eab4 100644
--- a/src/OCCViewer/OCCViewer_ViewWindow.cxx
+++ b/src/OCCViewer/OCCViewer_ViewWindow.cxx
@@ -393,7 +393,7 @@ bool OCCViewer_ViewWindow::eventFilter( QObject* watched, QEvent* e )
 
         if ( aEvent->modifiers().testFlag(Qt::ControlModifier) ) {
           Handle(AIS_InteractiveContext) ic = myModel->getAISContext();
-          if ( isPreselectionEnabled() && ic->HasOpenedContext() ) {
+          if ( isPreselectionEnabled() && myModel->useLocalSelection() ) {
             if ( aEvent->delta() > 0 ) {
               ic->HilightNextDetected( myViewPort->getView() );
             } else {
-- 
2.39.2