src/XGUI/XGUI_Viewer.cpp

   1 #include "XGUI_Viewer.h"
   2 #include "XGUI_MainWindow.h"
   3 #include "XGUI_ViewWindow.h"
   4 #include "XGUI_ViewPort.h"
   5
   6 #include <QMdiArea>
   7 #include <QMdiSubWindow>
   8 #include <QApplication>
   9 #include <QMouseEvent>
  10 #include <QMenu>
  11
  12 #include <V3d_View.hxx>
  13
  14 #include <Aspect_DisplayConnection.hxx>
  15 #include <Graphic3d.hxx>
  16 #include <Graphic3d_GraphicDriver.hxx>
  17 #include <Geom_Axis2Placement.hxx>
  18 #include <AIS_Drawer.hxx>
  19 #include <Prs3d_DatumAspect.hxx>
  20 #include <Prs3d_LineAspect.hxx>
  21 #include <V3d_View.hxx>
  22 #include <Visual3d_View.hxx>
  23 #include <AIS_ListOfInteractive.hxx>
  24 #include <AIS_ListIteratorOfListOfInteractive.hxx>
  25 #include <AIS_Shape.hxx>
  26
  27
  28 #ifdef WIN32
  29 #include <WNT_Window.hxx>
  30 #else
  31 #include <Xw_Window.hxx>
  32 #endif
  33
  34 XGUI_Viewer::InteractionStyle2StatesMap XGUI_Viewer::myStateMap;
  35 XGUI_Viewer::InteractionStyle2ButtonsMap XGUI_Viewer::myButtonMap;
  36 static bool isInitialized = false;
  37
  38 /*!
  39  Creates viewer 3d [ static ]
  40  */
  41 Handle(V3d_Viewer) CreateViewer(const Standard_ExtString name, const Standard_CString displayName,
  42                                 const Standard_CString domain, const Standard_Real viewSize,
  43                                 const V3d_TypeOfOrientation viewProjection,
  44                                 const Standard_Boolean computedMode,
  45                                 const Standard_Boolean defaultComputedMode)
  46 {
  47   static Handle(Graphic3d_GraphicDriver) aGraphicDriver;
  48   if (aGraphicDriver.IsNull()) {
  49     Handle(Aspect_DisplayConnection) aDisplayConnection;
  50 #ifndef WIN32
  51     aDisplayConnection = new Aspect_DisplayConnection( displayName );
  52 #else
  53     aDisplayConnection = new Aspect_DisplayConnection();
  54 #endif
  55     aGraphicDriver = Graphic3d::InitGraphicDriver(aDisplayConnection);
  56   }
  57
  58   return new V3d_Viewer(aGraphicDriver, name, domain, viewSize, viewProjection, Quantity_NOC_GRAY30,
  59                         V3d_ZBUFFER, V3d_GOURAUD, V3d_WAIT, computedMode, defaultComputedMode,
  60                         V3d_TEX_NONE);
  61 }
  62
  63 // VSR: Uncomment below line to allow texture background support in OCC viewer
  64 #define OCC_ENABLE_TEXTURED_BACKGROUND
  65
  66 /*!
  67  Get data for supported background modes: gradient types, identifiers and supported image formats
  68  */
  69 QString XGUI_Viewer::backgroundData(QStringList& gradList, QIntList& idList, QIntList& txtList)
  70 {
  71   gradList << tr("Horizontal gradient") << tr("Vertical gradient")
  72       << tr("First diagonal gradient") << tr("Second diagonal gradient")
  73       << tr("First corner gradient") << tr("Second corner gradient")
  74       << tr("Third corner gradient") << tr("Fourth corner gradient");
  75   idList << XGUI::HorizontalGradient << XGUI::VerticalGradient << XGUI::Diagonal1Gradient
  76       << XGUI::Diagonal2Gradient << XGUI::Corner1Gradient << XGUI::Corner2Gradient
  77       << XGUI::Corner3Gradient << XGUI::Corner4Gradient;
  78 #ifdef OCC_ENABLE_TEXTURED_BACKGROUND
  79   txtList << XGUI::CenterTexture << XGUI::TileTexture << XGUI::StretchTexture;
  80 #endif
  81   return tr("Image files (*.bmp *.gif *.pix *.xwd *.rgb *.rs)");
  82 }
  83
  84 XGUI_Viewer::XGUI_Viewer(XGUI_MainWindow* theParent, bool DisplayTrihedron)
  85     : QObject(theParent),
  86     myMainWindow(theParent),
  87     myPreselectionEnabled(true),
  88     mySelectionEnabled(true),
  89     myMultiSelectionEnabled(true),
  90     myIsRelative(true),
  91     myInteractionStyle(XGUI::STANDARD),
  92     myTrihedronSize(100),
  93     myActiveView(0),
  94     myWndIdCount(0)
  95 {
  96   if (!isInitialized) {
  97     isInitialized = true;
  98
  99     // standard interaction style
 100     XGUI_Viewer::myStateMap[XGUI::STANDARD][XGUI::ZOOM] = Qt::ControlModifier;
 101     XGUI_Viewer::myButtonMap[XGUI::STANDARD][XGUI::ZOOM] = Qt::LeftButton;
 102
 103     XGUI_Viewer::myStateMap[XGUI::STANDARD][XGUI::PAN] = Qt::ControlModifier;
 104     XGUI_Viewer::myButtonMap[XGUI::STANDARD][XGUI::PAN] = Qt::MidButton;
 105
 106     XGUI_Viewer::myStateMap[XGUI::STANDARD][XGUI::ROTATE] = Qt::ControlModifier;
 107     XGUI_Viewer::myButtonMap[XGUI::STANDARD][XGUI::ROTATE] = Qt::RightButton;
 108
 109     XGUI_Viewer::myStateMap[XGUI::STANDARD][XGUI::FIT_AREA] = Qt::ControlModifier;
 110     XGUI_Viewer::myButtonMap[XGUI::STANDARD][XGUI::FIT_AREA] = Qt::RightButton;
 111
 112     // "key free" interaction style
 113     XGUI_Viewer::myStateMap[XGUI::KEY_FREE][XGUI::ZOOM] = Qt::NoModifier;
 114     XGUI_Viewer::myButtonMap[XGUI::KEY_FREE][XGUI::ZOOM] = Qt::RightButton;
 115
 116     XGUI_Viewer::myStateMap[XGUI::KEY_FREE][XGUI::PAN] = Qt::NoModifier;
 117     XGUI_Viewer::myButtonMap[XGUI::KEY_FREE][XGUI::PAN] = Qt::MidButton;
 118
 119     XGUI_Viewer::myStateMap[XGUI::KEY_FREE][XGUI::ROTATE] = Qt::NoModifier;
 120     XGUI_Viewer::myButtonMap[XGUI::KEY_FREE][XGUI::ROTATE] = Qt::LeftButton;
 121
 122     XGUI_Viewer::myStateMap[XGUI::KEY_FREE][XGUI::FIT_AREA] = Qt::NoModifier; // unused
 123     XGUI_Viewer::myButtonMap[XGUI::KEY_FREE][XGUI::FIT_AREA] = Qt::NoButton; // unused
 124   }
 125
 126   // init CasCade viewers
 127   myV3dViewer = CreateViewer(TCollection_ExtendedString("Viewer3d").ToExtString(), "", "", 1000.0,
 128                              V3d_XposYnegZpos, Standard_True, Standard_True);
 129   myV3dViewer->SetDefaultLights();
 130
 131   // init selector
 132   myAISContext = new AIS_InteractiveContext(myV3dViewer);
 133   myAISContext->SelectionColor(Quantity_NOC_WHITE);
 134
 135   // display isoline on planar faces (box for ex.)
 136   myAISContext->IsoOnPlane(true);
 137
 138   if (DisplayTrihedron) {
 139     Handle(Geom_Axis2Placement) anAxis = new Geom_Axis2Placement(gp::XOY());
 140     myTrihedron = new AIS_Trihedron(anAxis);
 141     myTrihedron->SetInfiniteState( Standard_True);
 142
 143     Quantity_Color Col(193 / 255., 205 / 255., 193 / 255., Quantity_TOC_RGB);
 144     myTrihedron->SetArrowColor(Col.Name());
 145     myTrihedron->SetSize(myTrihedronSize);
 146     Handle(AIS_Drawer) drawer = myTrihedron->Attributes();
 147     if (drawer->HasDatumAspect()) {
 148       Handle(Prs3d_DatumAspect) daspect = drawer->DatumAspect();
 149       daspect->FirstAxisAspect()->SetColor(Quantity_Color(1.0, 0.0, 0.0, Quantity_TOC_RGB));
 150       daspect->SecondAxisAspect()->SetColor(Quantity_Color(0.0, 1.0, 0.0, Quantity_TOC_RGB));
 151       daspect->ThirdAxisAspect()->SetColor(Quantity_Color(0.0, 0.0, 1.0, Quantity_TOC_RGB));
 152     }
 153   }
 154   // set zooming style to standard
 155   //myZoomingStyle = 0;
 156
 157   QMdiArea* aMDI = myMainWindow->mdiArea();
 158   connect(aMDI, SIGNAL(subWindowActivated(QMdiSubWindow*)), this, SLOT(onWindowActivated(QMdiSubWindow*)));
 159
 160 }
 161
 162 XGUI_Viewer::~XGUI_Viewer(void)
 163 {
 164   myAISContext.Nullify();
 165   myV3dViewer.Nullify();
 166 }
 167
 168 QMdiSubWindow* XGUI_Viewer::createView(V3d_TypeOfView theType)
 169 {
 170   // create view frame
 171   XGUI_ViewWindow* view = new XGUI_ViewWindow(this, theType);
 172   // get main view window (created by view frame)
 173   //OCCViewer_ViewWindow* vw = view->getView(OCCViewer_ViewFrame::MAIN_VIEW);
 174   // initialize main view window
 175   //initView( vw );
 176   // set default background for view window
 177   //vw->setBackground( background(0) ); // 0 means MAIN_VIEW (other views are not yet created here)
 178   // connect signal from viewport
 179   //connect(view->viewPort(), SIGNAL(vpClosed()), this, SLOT(onViewClosed()));
 180     //connect(view->viewPort(), SIGNAL(vpMapped()), this, SLOT(onViewMapped()));
 181   if (myViews.size() == 0)
 182     setTrihedronShown(true);
 183
 184   view->setBackground(XGUI_ViewBackground(XGUI::VerticalGradient, Qt::white, QColor(Qt::blue).lighter()));
 185   //view->setBackground(XGUI_ViewBackground(Qt::black));
 186   view->updateEnabledDrawMode();
 187
 188   QMdiArea* aMDI = myMainWindow->mdiArea();
 189   QMdiSubWindow* aWnd = aMDI->addSubWindow(view, Qt::FramelessWindowHint);
 190   addView(aWnd);
 191   aWnd->setGeometry(0, 0, aMDI->width() / 2, aMDI->height() / 2);
 192   aWnd->show();
 193   aWnd->setWindowTitle(QString("Viewer #%1").arg(++myWndIdCount));
 194   emit viewCreated(view);
 195   return aWnd;
 196 }
 197
 198 XGUI_ViewWindow* XGUI_Viewer::activeViewWindow() const
 199 {
 200   return dynamic_cast<XGUI_ViewWindow*>(myActiveView->widget());
 201 }
 202
 203 void XGUI_Viewer::getSelectedObjects(AIS_ListOfInteractive& theList)
 204 {
 205   theList.Clear();
 206   for (myAISContext->InitSelected(); myAISContext->MoreSelected(); myAISContext->NextSelected())
 207     theList.Append(myAISContext->SelectedInteractive());
 208 }
 209
 210 void XGUI_Viewer::getSelectedShapes(NCollection_List<TopoDS_Shape>& theList)
 211 {
 212   Handle(AIS_InteractiveContext) ic = AISContext();
 213
 214   for (ic->InitSelected(); ic->MoreSelected(); ic->NextSelected()) {
 215     TopoDS_Shape aShape = ic->SelectedShape();
 216     if (!aShape.IsNull())
 217       theList.Append(aShape);
 218   }
 219 }
 220
 221 void XGUI_Viewer::setObjectsSelected(const AIS_ListOfInteractive& theList)
 222 {
 223   AIS_ListIteratorOfListOfInteractive aIt;
 224   for (aIt.Initialize(theList); aIt.More(); aIt.Next())
 225     myAISContext->AddOrRemoveSelected(aIt.Value(), false);
 226   myAISContext->UpdateCurrentViewer();
 227 }
 228
 229 /*! Sets hot button
 230  *\param theOper - hot operation
 231  *\param theState - adding state to state map operations.
 232  *\param theButton - adding state to button map operations.
 233  */
 234 void XGUI_Viewer::setHotButton(XGUI::InteractionStyle theInteractionStyle,
 235                                XGUI::HotOperation theOper, Qt::KeyboardModifiers theState,
 236                                Qt::MouseButtons theButton)
 237 {
 238   myStateMap[theInteractionStyle][theOper] = theState;
 239   myButtonMap[theInteractionStyle][theOper] = theButton;
 240 }
 241
 242 /*! Gets hot button for operation \a theOper.
 243  *\param theOper - input hot operation
 244  *\param theState - output state from state map operations.
 245  *\param theButton - output state from button map operations.
 246  */
 247 void XGUI_Viewer::getHotButton(XGUI::InteractionStyle theInteractionStyle,
 248                                XGUI::HotOperation theOper, Qt::KeyboardModifiers& theState,
 249                                Qt::MouseButtons& theButton)
 250 {
 251   theState = myStateMap[theInteractionStyle][theOper];
 252   theButton = myButtonMap[theInteractionStyle][theOper];
 253 }
 254
 255 /*!
 256  Changes visibility of trihedron to opposite
 257  */
 258 void XGUI_Viewer::toggleTrihedron()
 259 {
 260   setTrihedronShown(!isTrihedronVisible());
 261 }
 262
 263 /*!
 264  \return true if trihedron is visible
 265  */
 266 bool XGUI_Viewer::isTrihedronVisible() const
 267 {
 268   return !myTrihedron.IsNull() && !myAISContext.IsNull() && myAISContext->IsDisplayed(myTrihedron);
 269 }
 270
 271 /*!
 272  Sets visibility state of trihedron
 273  \param on - new state
 274  */
 275
 276 void XGUI_Viewer::setTrihedronShown(bool on)
 277 {
 278   if (myTrihedron.IsNull())
 279     return;
 280
 281   if (on) {
 282     myAISContext->Display(myTrihedron);
 283     myAISContext->Deactivate(myTrihedron);
 284   } else {
 285     myAISContext->Erase(myTrihedron);
 286   }
 287 }
 288
 289 /*!
 290  \return trihedron size
 291  */
 292 double XGUI_Viewer::trihedronSize() const
 293 {
 294   double sz = 0;
 295   if (!myTrihedron.IsNull())
 296     sz = myTrihedron->Size();
 297   return sz;
 298 }
 299
 300 /*!
 301  Changes trihedron size
 302  \param sz - new size
 303  */
 304 void XGUI_Viewer::setTrihedronSize(const double sz, bool isRelative)
 305 {
 306   if (myTrihedronSize != sz || isRelative != myIsRelative) {
 307     myTrihedronSize = sz;
 308     myIsRelative = isRelative;
 309     updateTrihedron();
 310   }
 311 }
 312
 313 /*!
 314  * Update the size of the trihedron
 315  */
 316 void XGUI_Viewer::updateTrihedron()
 317 {
 318   if (myTrihedron.IsNull())
 319     return;
 320
 321   if (myIsRelative) {
 322     double newSz, oldSz;
 323
 324     if (computeTrihedronSize(newSz, oldSz))
 325       myTrihedron->SetSize(newSz);
 326
 327   } else if (myTrihedron->Size() != myTrihedronSize) {
 328     myTrihedron->SetSize(myTrihedronSize);
 329   }
 330 }
 331
 332 /*!
 333  Get new and current trihedron size corresponding to the current model size
 334  */
 335 bool XGUI_Viewer::computeTrihedronSize(double& theNewSize, double& theSize)
 336 {
 337   theNewSize = 100;
 338   theSize = 100;
 339
 340   //SRN: BUG IPAL8996, a usage of method ActiveView without an initialization
 341   Handle(V3d_Viewer) viewer = v3dViewer();
 342   viewer->InitActiveViews();
 343   if (!viewer->MoreActiveViews())
 344     return false;
 345
 346   Handle(V3d_View) view3d = viewer->ActiveView();
 347   //SRN: END of fix
 348
 349   if (view3d.IsNull())
 350     return false;
 351
 352   double Xmin = 0, Ymin = 0, Zmin = 0, Xmax = 0, Ymax = 0, Zmax = 0;
 353   double aMaxSide;
 354
 355   view3d->View()->MinMaxValues(Xmin, Ymin, Zmin, Xmax, Ymax, Zmax);
 356
 357   if (Xmin == RealFirst() || Ymin == RealFirst() || Zmin == RealFirst() || Xmax == RealLast()
 358       || Ymax == RealLast() || Zmax == RealLast())
 359     return false;
 360
 361   aMaxSide = Xmax - Xmin;
 362   if (aMaxSide < Ymax - Ymin)
 363     aMaxSide = Ymax - Ymin;
 364   if (aMaxSide < Zmax - Zmin)
 365     aMaxSide = Zmax - Zmin;
 366
 367   // IPAL21687
 368   // The boundary box of the view may be initialized but nullified
 369   // (case of infinite objects)
 370   if (aMaxSide < Precision::Confusion())
 371     return false;
 372
 373   static float EPS = (float)5.0E-3;
 374   theSize = trihedron()->Size();
 375   //theNewSize = aMaxSide*aSizeInPercents / 100.0;
 376
 377   return fabs(theNewSize - theSize) > theSize * EPS || fabs(theNewSize - theSize) > theNewSize * EPS;
 378 }
 379
 380 void XGUI_Viewer::onViewClosed(QMdiSubWindow* theView)
 381 {
 382   if ( !theView )
 383     return;
 384
 385   emit deleteView( static_cast<XGUI_ViewWindow*>(theView->widget()) );
 386   removeView( theView );
 387
 388   // if this is last view
 389   if (myViews.size() == 0) {
 390     Standard_Integer aViewsNb = 0;
 391     for ( myV3dViewer->InitActiveViews(); myV3dViewer->MoreActiveViews(); myV3dViewer->NextActiveViews())
 392       ++aViewsNb;
 393     if ( aViewsNb < 2 ) {
 394       //clean up presentations before last view is closed
 395       myAISContext->RemoveAll(Standard_False);
 396     }
 397   }
 398 }
 399
 400 /*!Remove view window \a theView from view manager.
 401  *And close the last view, if it has \a theView.
 402 */
 403 void XGUI_Viewer::removeView( QMdiSubWindow* theView )
 404 {
 405     XGUI_ViewWindow* aWindow = static_cast<XGUI_ViewWindow*>(theView->widget());
 406
 407     aWindow->disconnect( this );
 408     myViews.removeAt( myViews.indexOf( theView ) );
 409     if ( myActiveView == theView )
 410         myActiveView = 0;
 411     if ( myViews.size() == 0 )
 412         emit lastViewClosed();
 413 }
 414
 415
 416 /*void XGUI_Viewer::onViewMapped()
 417 {
 418   setTrihedronShown(true);
 419 }*/
 420
 421
 422 void XGUI_Viewer::addView(QMdiSubWindow* theView)
 423 {
 424     XGUI_ViewWindow* aWindow = dynamic_cast<XGUI_ViewWindow*>(theView->widget());
 425
 426     connect(aWindow, SIGNAL(closed(QMdiSubWindow*)),
 427             this,    SLOT(onViewClosed(QMdiSubWindow*)));
 428
 429     connect(aWindow, SIGNAL(tryClosing(XGUI_ViewWindow*)),
 430             this,    SIGNAL(tryCloseView(XGUI_ViewWindow*)));
 431
 432     connect(aWindow, SIGNAL(mousePressed(XGUI_ViewWindow*, QMouseEvent*)),
 433             this,    SLOT(onMousePressed(XGUI_ViewWindow*, QMouseEvent*)));
 434
 435     connect(aWindow, SIGNAL(mouseDoubleClicked(XGUI_ViewWindow*, QMouseEvent*)),
 436             this,    SIGNAL(mouseDoubleClick(XGUI_ViewWindow*, QMouseEvent*)));
 437
 438     connect(aWindow, SIGNAL(mouseMoving(XGUI_ViewWindow*, QMouseEvent*)),
 439             this,    SIGNAL(mouseMove(XGUI_ViewWindow*, QMouseEvent*)));
 440
 441     connect(aWindow, SIGNAL(keyPressed(XGUI_ViewWindow*, QKeyEvent*)),
 442             this,    SIGNAL(keyPress(XGUI_ViewWindow*, QKeyEvent*)));
 443
 444     connect(aWindow, SIGNAL(keyReleased(XGUI_ViewWindow*, QKeyEvent*)),
 445             this,    SIGNAL(keyRelease(XGUI_ViewWindow*, QKeyEvent*)));
 446
 447     connect(aWindow, SIGNAL(contextMenuRequested( QContextMenuEvent* )),
 448             this,    SLOT  (onContextMenuRequested( QContextMenuEvent* )));
 449     //connect(aWindow, SIGNAL( contextMenuRequested(QContextMenuEvent*) ),
 450     //        this, SIGNAL( contextMenuRequested(QContextMenuEvent*) ) );
 451
 452     connect(aWindow, SIGNAL(mouseMoving(XGUI_ViewWindow*, QMouseEvent*)),
 453             this, SLOT(onMouseMove(XGUI_ViewWindow*, QMouseEvent*)));
 454
 455     connect(aWindow, SIGNAL(mouseReleased(XGUI_ViewWindow*, QMouseEvent*)),
 456             this, SLOT(onMouseReleased(XGUI_ViewWindow*, QMouseEvent*)));
 457
 458     myViews.append(theView);
 459 }
 460
 461 /*!
 462     Emit activated for view \a view.
 463 */
 464 void XGUI_Viewer::onWindowActivated(QMdiSubWindow* view)
 465 {
 466   if (view && (view != myActiveView) && (!view->isMinimized())) {
 467     qDebug("onWindowActivated");
 468     myActiveView = view;
 469     ((XGUI_ViewWindow*)myActiveView->widget())->windowActivated();
 470     QList<QMdiSubWindow*>::iterator aIt;
 471     for (aIt = myViews.begin(); aIt != myViews.end(); ++aIt) {
 472       if ((*aIt) != myActiveView) {
 473         ((XGUI_ViewWindow*)(*aIt)->widget())->windowDeactivated();
 474       }
 475     }
 476   }
 477 }
 478
 479
 480 void XGUI_Viewer::onWindowMinimized(QMdiSubWindow* theWnd)
 481 {
 482   if (myActiveView == theWnd) {
 483     myActiveView = 0;
 484     QList<QMdiSubWindow*>::iterator aIt;
 485     for (aIt = myViews.begin(); aIt != myViews.end(); ++aIt) {
 486       if (!(*aIt)->widget()->isMinimized()) {
 487         (*aIt)->raise();
 488         onWindowActivated(*aIt);
 489         break;
 490       }
 491     }
 492   }
 493 }
 494
 495 /*!
 496   SLOT: called on mouse button press, stores current mouse position as start point for transformations
 497 */
 498 void XGUI_Viewer::onMousePressed(XGUI_ViewWindow* theWindow, QMouseEvent* theEvent)
 499 {
 500   myStartPnt.setX(theEvent->x()); myStartPnt.setY(theEvent->y());
 501   emit mousePress(theWindow, theEvent);
 502 }
 503
 504 /*!
 505   SLOT: called on mouse move, processes hilighting
 506 */
 507 void XGUI_Viewer::onMouseMove(XGUI_ViewWindow* theWindow, QMouseEvent* theEvent)
 508 {
 509   if (!mySelectionEnabled) return;
 510
 511   myCurPnt.setX(theEvent->x()); myCurPnt.setY(theEvent->y());
 512   Handle(V3d_View) aView3d = theWindow->viewPort()->getView();
 513   if ( !aView3d.IsNull() ) {
 514     myAISContext->MoveTo(theEvent->x(), theEvent->y(), aView3d);
 515   }
 516 }
 517
 518 /*!
 519   SLOT: called on mouse button release, finishes selection
 520 */
 521 void XGUI_Viewer::onMouseReleased(XGUI_ViewWindow* theWindow, QMouseEvent* theEvent)
 522 {
 523   if (!mySelectionEnabled || theEvent->button() != Qt::LeftButton) {
 524     emit mouseRelease(theWindow, theEvent);
 525     return;
 526   }
 527
 528   myEndPnt.setX(theEvent->x()); myEndPnt.setY(theEvent->y());
 529   bool aHasShift = (theEvent->modifiers() & Qt::ShiftModifier);
 530
 531   //if (!aHasShift)
 532   //  emit deselection();
 533
 534   if (myStartPnt == myEndPnt) {
 535     // the MoveTo is necessary for the second click in the same point. Otherwise the selection is lost.
 536     Handle(V3d_View) aView3d = theWindow->viewPort()->getView();
 537     if ( !aView3d.IsNull() ) {
 538       myAISContext->MoveTo(theEvent->x(), theEvent->y(), aView3d);
 539     }
 540     if (aHasShift && myMultiSelectionEnabled)
 541       myAISContext->ShiftSelect();
 542     else
 543       myAISContext->Select();
 544   } else {
 545     if (aHasShift && myMultiSelectionEnabled)
 546       myAISContext->ShiftSelect(myStartPnt.x(), myStartPnt.y(),
 547                                 myEndPnt.x(), myEndPnt.y(),
 548                                 theWindow->viewPort()->getView(), false );
 549     else
 550       myAISContext->Select(myStartPnt.x(), myStartPnt.y(),
 551                            myEndPnt.x(), myEndPnt.y(),
 552                            theWindow->viewPort()->getView(), false );
 553
 554     int Nb = myAISContext->NbSelected();
 555     if( Nb>1 && !myMultiSelectionEnabled ) {
 556       myAISContext->InitSelected();
 557       Handle( SelectMgr_EntityOwner ) anOwner = myAISContext->SelectedOwner();
 558       if( !anOwner.IsNull() ) {
 559         myAISContext->ClearSelected( Standard_False );
 560         myAISContext->AddOrRemoveSelected( anOwner, Standard_False );
 561       }
 562     }
 563
 564     myAISContext->UpdateCurrentViewer();
 565   }
 566   emit mouseRelease(theWindow, theEvent);
 567   emit selectionChanged();
 568 }
 569
 570 //******************************************************
 571 void XGUI_Viewer::setMultiSelectionEnabled(bool toEnable)
 572 {
 573   myMultiSelectionEnabled = toEnable;
 574   updateViewsDrawMode();
 575 }
 576
 577 //******************************************************
 578 void XGUI_Viewer::setSelectionEnabled(bool toEnable)
 579 {
 580   mySelectionEnabled = toEnable;
 581   updateViewsDrawMode();
 582 }
 583
 584 //******************************************************
 585 void XGUI_Viewer::updateViewsDrawMode() const
 586 {
 587   foreach(QMdiSubWindow* aWnd, myViews){
 588     XGUI_ViewWindow* aView = static_cast<XGUI_ViewWindow*>(aWnd->widget());
 589     aView->updateEnabledDrawMode();
 590   }
 591 }
 592
 593 //******************************************************
 594 void XGUI_Viewer::onContextMenuRequested(QContextMenuEvent* theEvent)
 595 {
 596   XGUI_ViewWindow* aWnd = dynamic_cast<XGUI_ViewWindow*>(sender());
 597   if (!aWnd) return;
 598
 599   QMenu aMenu;
 600
 601   // Include Viewer actions
 602   if (myActions.size() > 0) {
 603     aMenu.addActions(myActions);
 604     aMenu.addSeparator();
 605   }
 606   if (aWnd->actions().size() > 0) {
 607     aMenu.addActions(aWnd->actions());
 608     aMenu.addSeparator();
 609   }
 610
 611   QMdiArea* aMDI = myMainWindow->mdiArea();
 612   if (aMenu.actions().size() > 0) {
 613     QMenu* aSubMenu = aMenu.addMenu(tr("Windows"));
 614     aSubMenu->addActions(aMDI->actions());
 615   } else {
 616     aMenu.addActions(aMDI->actions());
 617   }
 618   aMenu.exec(theEvent->globalPos());
 619 }