0032433: Visualization, TKService - introduce Wasm_Window implementing Aspect_Window interface using Emscripten SDK

Introduced Wasm_Window implementing Aspect_Window interface. Aspect_WindowInputListener has been extended by touch input callbacks (moved from AIS_ViewController), which now implements redirection of single taps to UpdateMouseClick(). AIS_ViewController::FetchNavigationKeys() now requests more frames even if Delta is zero, but navigation keys are pressed - indicated by a new flag AIS_WalkDelta::IsDefined(). Fixed missing implementation of Xw_Window::DisplayConnection() getter. The property has been moved to the base class Aspect_Window. Removed unused Aspect_Convert.hxx. DRAWEXE targeting Wasm: - added exposing of FS interface so that it is possible uploading/downloading files to/from emulated file system on JavaScript level; - added printer redirecting messages to Module.printMessage callback accepting message gravity; - Run_Appli() now skips std::cin when Module.noExitRuntime is set.
2025-04-03 17:56:21 +03:00 · 2021-04-25 17:51:49 +03:00 · 2021-04-25 17:51:49 +03:00 · f9ab9f7f1c
commit f9ab9f7f1c
parent 7b3a032f1e
28 changed files with 1743 additions and 775 deletions
--- a/adm/UDLIST
+++ b/adm/UDLIST
@ -216,6 +216,7 @@ n SelectMgr
 n StdPrs
 n StdSelect
 n V3d
 n Wasm
 n WNT
 n Xw
 n Cocoa
--- a/samples/webgl/CMakeLists.txt
+++ b/samples/webgl/CMakeLists.txt
@ -28,7 +28,6 @@ if (NOT "${SOURCE_MAP_BASE}" STREQUAL "")
 endif()
 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -s MODULARIZE=1")
 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -s EXPORT_NAME='createOccViewerModule'")
 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -s EXTRA_EXPORTED_RUNTIME_METHODS=['ccall','cwrap']")
 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --extern-post-js ${CMAKE_CURRENT_SOURCE_DIR}/occt-webgl-viewer.js")
 INCLUDE_DIRECTORIES(${PROJECT_SOURCE_DIR})
--- a/samples/webgl/WasmOcctView.cpp
+++ b/samples/webgl/WasmOcctView.cpp
@ -21,14 +21,12 @@
 #include "WasmOcctView.h"
 #include "WasmVKeys.h"
 #include "WasmOcctPixMap.h"
 #include <AIS_Shape.hxx>
 #include <AIS_ViewCube.hxx>
 #include <Aspect_Handle.hxx>
 #include <Aspect_DisplayConnection.hxx>
 #include <Aspect_NeutralWindow.hxx>
 #include <Message.hxx>
 #include <Message_Messenger.hxx>
 #include <Graphic3d_CubeMapPacked.hxx>
@ -36,6 +34,7 @@
 #include <Prs3d_DatumAspect.hxx>
 #include <Prs3d_ToolCylinder.hxx>
 #include <Prs3d_ToolDisk.hxx>
 #include <Wasm_Window.hxx>
 #include <BRep_Builder.hxx>
 #include <BRepBndLib.hxx>
@ -50,25 +49,6 @@
 namespace
 {
  EM_JS(int, jsCanvasGetWidth, (), {
    return Module.canvas.width;
  });
  EM_JS(int, jsCanvasGetHeight, (), {
    return Module.canvas.height;
  });
  EM_JS(float, jsDevicePixelRatio, (), {
    var aDevicePixelRatio = window.devicePixelRatio || 1;
    return aDevicePixelRatio;
  });
  //! Return cavas size in pixels.
  static Graphic3d_Vec2i jsCanvasSize()
  {
    return Graphic3d_Vec2i (jsCanvasGetWidth(), jsCanvasGetHeight());
  }
  //! Auxiliary wrapper for loading model.
  struct ModelAsyncLoader
  {
@ -199,7 +179,7 @@ void WasmOcctView::run()
 // ================================================================
 void WasmOcctView::initWindow()
 {
-  myDevicePixelRatio = jsDevicePixelRatio();
+  myDevicePixelRatio = emscripten_get_device_pixel_ratio();
  myCanvasId = THE_CANVAS_ID;
  const char* aTargetId = !myCanvasId.IsEmpty() ? myCanvasId.ToCString() : EMSCRIPTEN_EVENT_TARGET_WINDOW;
  const EM_BOOL toUseCapture = EM_TRUE;
@ -340,13 +320,8 @@ bool WasmOcctView::initViewer()
    }
  }
-  Handle(Aspect_NeutralWindow) aWindow = new Aspect_NeutralWindow();
+  Handle(Wasm_Window) aWindow = new Wasm_Window (THE_CANVAS_ID);
-  Graphic3d_Vec2i aWinSize = jsCanvasSize();
+  aWindow->Size (myWinSizeOld.x(), myWinSizeOld.y());
  if (aWinSize.x() < 10 || aWinSize.y() < 10)
  {
    Message::DefaultMessenger()->Send (TCollection_AsciiString ("Warning: invalid canvas size"), Message_Warning);
  }
  aWindow->SetSize (aWinSize.x(), aWinSize.y());
  myTextStyle = new Prs3d_TextAspect();
  myTextStyle->SetFont (Font_NOF_ASCII_MONO);
@ -403,6 +378,24 @@ void WasmOcctView::initDemoScene()
  // Build with "--preload-file MySampleFile.brep" option to load some shapes here.
 }
 // ================================================================
 // Function : ProcessInput
 // Purpose  :
 // ================================================================
 void WasmOcctView::ProcessInput()
 {
  if (!myView.IsNull())
  {
    // Queue onRedrawView()/redrawView callback to redraw canvas after all user input is flushed by browser.
    // Redrawing viewer on every single message would be a pointless waste of resources,
    // as user will see only the last drawn frame due to WebGL implementation details.
    if (++myUpdateRequests == 1)
    {
      emscripten_async_call (onRedrawView, this, 0);
    }
  }
 }
 // ================================================================
 // Function : UpdateView
 // Purpose  :
@ -412,22 +405,8 @@ void WasmOcctView::UpdateView()
  if (!myView.IsNull())
  {
    myView->Invalidate();
-    updateView();
+    // queue next onRedrawView()/redrawView()
-  }
+    ProcessInput();
 }
 // ================================================================
 // Function : updateView
 // Purpose  :
 // ================================================================
 void WasmOcctView::updateView()
 {
  if (!myView.IsNull())
  {
    if (++myUpdateRequests == 1)
    {
      emscripten_async_call (onRedrawView, this, 0);
    }
  }
 }
@ -452,14 +431,6 @@ void WasmOcctView::handleViewRedraw (const Handle(AIS_InteractiveContext)& theCt
 {
  myUpdateRequests = 0;
  AIS_ViewController::handleViewRedraw (theCtx, theView);
  for (NCollection_DataMap<unsigned int, Aspect_VKey>::Iterator aNavKeyIter (myNavKeyMap);
       !myToAskNextFrame && aNavKeyIter.More(); aNavKeyIter.Next())
  {
    const Aspect_VKey aVKey = aNavKeyIter.Key() & ~Aspect_VKeyFlags_ALL;
    myToAskNextFrame = myKeys.IsKeyDown (aVKey);
  }
  if (myToAskNextFrame)
  {
    // ask more frames
@ -481,23 +452,21 @@ EM_BOOL WasmOcctView::onResizeEvent (int theEventType, const EmscriptenUiEvent*
    return EM_FALSE;
  }
-  Handle(Aspect_NeutralWindow) aWindow = Handle(Aspect_NeutralWindow)::DownCast (myView->Window());
+  Handle(Wasm_Window) aWindow = Handle(Wasm_Window)::DownCast (myView->Window());
-  Graphic3d_Vec2i aWinSizeOld, aWinSizeNew (jsCanvasSize());
+  Graphic3d_Vec2i aWinSizeNew;
-  if (aWinSizeNew.x() < 10 || aWinSizeNew.y() < 10)
+  aWindow->DoResize();
-  {
+  aWindow->Size (aWinSizeNew.x(), aWinSizeNew.y());
-    Message::DefaultMessenger()->Send (TCollection_AsciiString ("Warning: invalid canvas size"), Message_Warning);
+  const float aPixelRatio = emscripten_get_device_pixel_ratio();
-  }
+  if (aWinSizeNew != myWinSizeOld
  aWindow->Size (aWinSizeOld.x(), aWinSizeOld.y());
  const float aPixelRatio = jsDevicePixelRatio();
  if (aWinSizeNew != aWinSizeOld
   || aPixelRatio != myDevicePixelRatio)
  {
    myWinSizeOld = aWinSizeNew;
    if (myDevicePixelRatio != aPixelRatio)
    {
      myDevicePixelRatio = aPixelRatio;
      initPixelScaleRatio();
    }
-    aWindow->SetSize (aWinSizeNew.x(), aWinSizeNew.y());
+
    myView->MustBeResized();
    myView->Invalidate();
    myView->Redraw();
@ -517,73 +486,8 @@ EM_BOOL WasmOcctView::onMouseEvent (int theEventType, const EmscriptenMouseEvent
    return EM_FALSE;
  }
-  Graphic3d_Vec2i aWinSize;
+  Handle(Wasm_Window) aWindow = Handle(Wasm_Window)::DownCast (myView->Window());
-  myView->Window()->Size (aWinSize.x(), aWinSize.y());
+  return aWindow->ProcessMouseEvent (*this, theEventType, theEvent) ? EM_TRUE : EM_FALSE;
  const Graphic3d_Vec2i aNewPos = convertPointToBacking (Graphic3d_Vec2i (theEvent->targetX, theEvent->targetY));
  Aspect_VKeyFlags aFlags = 0;
  if (theEvent->ctrlKey  == EM_TRUE) { aFlags |= Aspect_VKeyFlags_CTRL;  }
  if (theEvent->shiftKey == EM_TRUE) { aFlags |= Aspect_VKeyFlags_SHIFT; }
  if (theEvent->altKey   == EM_TRUE) { aFlags |= Aspect_VKeyFlags_ALT;   }
  if (theEvent->metaKey  == EM_TRUE) { aFlags |= Aspect_VKeyFlags_META;  }
  const bool isEmulated = false;
  const Aspect_VKeyMouse aButtons = WasmVKeys_MouseButtonsFromNative (theEvent->buttons);
  switch (theEventType)
  {
    case EMSCRIPTEN_EVENT_MOUSEMOVE:
    {
      if ((aNewPos.x() < 0 || aNewPos.x() > aWinSize.x()
        || aNewPos.y() < 0 || aNewPos.y() > aWinSize.y())
        && PressedMouseButtons() == Aspect_VKeyMouse_NONE)
      {
        return EM_FALSE;
      }
      if (UpdateMousePosition (aNewPos, aButtons, aFlags, isEmulated))
      {
        updateView();
      }
      break;
    }
    case EMSCRIPTEN_EVENT_MOUSEDOWN:
    case EMSCRIPTEN_EVENT_MOUSEUP:
    {
      if (aNewPos.x() < 0 || aNewPos.x() > aWinSize.x()
       || aNewPos.y() < 0 || aNewPos.y() > aWinSize.y())
      {
        return EM_FALSE;
      }
      if (UpdateMouseButtons (aNewPos, aButtons, aFlags, isEmulated))
      {
        updateView();
      }
      break;
    }
    case EMSCRIPTEN_EVENT_CLICK:
    case EMSCRIPTEN_EVENT_DBLCLICK:
    {
      if (aNewPos.x() < 0 || aNewPos.x() > aWinSize.x()
       || aNewPos.y() < 0 || aNewPos.y() > aWinSize.y())
      {
        return EM_FALSE;
      }
      break;
    }
    case EMSCRIPTEN_EVENT_MOUSEENTER:
    {
      break;
    }
    case EMSCRIPTEN_EVENT_MOUSELEAVE:
    {
      // there is no SetCapture() support, so that mouse unclick events outside canvas will not arrive,
      // so we have to forget current state...
      if (UpdateMouseButtons (aNewPos, Aspect_VKeyMouse_NONE, aFlags, isEmulated))
      {
        updateView();
      }
      break;
    }
  }
  return EM_TRUE;
 }
 // ================================================================
@ -598,40 +502,8 @@ EM_BOOL WasmOcctView::onWheelEvent (int theEventType, const EmscriptenWheelEvent
    return EM_FALSE;
  }
-  Graphic3d_Vec2i aWinSize;
+  Handle(Wasm_Window) aWindow = Handle(Wasm_Window)::DownCast (myView->Window());
-  myView->Window()->Size (aWinSize.x(), aWinSize.y());
+  return aWindow->ProcessWheelEvent (*this, theEventType, theEvent) ? EM_TRUE : EM_FALSE;
  const Graphic3d_Vec2i aNewPos = convertPointToBacking (Graphic3d_Vec2i (theEvent->mouse.targetX, theEvent->mouse.targetY));
  if (aNewPos.x() < 0 || aNewPos.x() > aWinSize.x()
   || aNewPos.y() < 0 || aNewPos.y() > aWinSize.y())
  {
    return EM_FALSE;
  }
  double aDelta = 0.0;
  switch (theEvent->deltaMode)
  {
    case DOM_DELTA_PIXEL:
    {
      aDelta = theEvent->deltaY / (5.0 * myDevicePixelRatio);
      break;
    }
    case DOM_DELTA_LINE:
    {
      aDelta = theEvent->deltaY * 8.0;
      break;
    }
    case DOM_DELTA_PAGE:
    {
      aDelta = theEvent->deltaY >= 0.0 ? 24.0 : -24.0;
      break;
    }
  }
  if (UpdateZoom (Aspect_ScrollDelta (aNewPos, -aDelta)))
  {
    updateView();
  }
  return EM_TRUE;
 }
 // ================================================================
@ -640,90 +512,13 @@ EM_BOOL WasmOcctView::onWheelEvent (int theEventType, const EmscriptenWheelEvent
 // ================================================================
 EM_BOOL WasmOcctView::onTouchEvent (int theEventType, const EmscriptenTouchEvent* theEvent)
 {
  const double aClickTolerance = 5.0;
  if (myView.IsNull())
  {
    return EM_FALSE;
  }
-  Graphic3d_Vec2i aWinSize;
+  Handle(Wasm_Window) aWindow = Handle(Wasm_Window)::DownCast (myView->Window());
-  myView->Window()->Size (aWinSize.x(), aWinSize.y());
+  return aWindow->ProcessTouchEvent (*this, theEventType, theEvent) ? EM_TRUE : EM_FALSE;
  bool hasUpdates = false;
  for (int aTouchIter = 0; aTouchIter < theEvent->numTouches; ++aTouchIter)
  {
    const EmscriptenTouchPoint& aTouch = theEvent->touches[aTouchIter];
    if (!aTouch.isChanged)
    {
      continue;
    }
    const Standard_Size aTouchId = (Standard_Size )aTouch.identifier;
    const Graphic3d_Vec2i aNewPos = convertPointToBacking (Graphic3d_Vec2i (aTouch.targetX, aTouch.targetY));
    switch (theEventType)
    {
      case EMSCRIPTEN_EVENT_TOUCHSTART:
      {
        if (aNewPos.x() >= 0 && aNewPos.x() < aWinSize.x()
         && aNewPos.y() >= 0 && aNewPos.y() < aWinSize.y())
        {
          hasUpdates = true;
          AddTouchPoint (aTouchId, Graphic3d_Vec2d (aNewPos));
          myClickTouch.From.SetValues (-1.0, -1.0);
          if (myTouchPoints.Extent() == 1)
          {
            myClickTouch.From = Graphic3d_Vec2d (aNewPos);
          }
        }
        break;
      }
      case EMSCRIPTEN_EVENT_TOUCHMOVE:
      {
        const int anOldIndex = myTouchPoints.FindIndex (aTouchId);
        if (anOldIndex != 0)
        {
          hasUpdates = true;
          UpdateTouchPoint (aTouchId, Graphic3d_Vec2d (aNewPos));
          if (myTouchPoints.Extent() == 1
           && (myClickTouch.From - Graphic3d_Vec2d (aNewPos)).cwiseAbs().maxComp() > aClickTolerance)
          {
            myClickTouch.From.SetValues (-1.0, -1.0);
          }
        }
        break;
      }
      case EMSCRIPTEN_EVENT_TOUCHEND:
      case EMSCRIPTEN_EVENT_TOUCHCANCEL:
      {
        if (RemoveTouchPoint (aTouchId))
        {
          if (myTouchPoints.IsEmpty()
           && myClickTouch.From.minComp() >= 0.0)
          {
            if (myDoubleTapTimer.IsStarted()
             && myDoubleTapTimer.ElapsedTime() <= myMouseDoubleClickInt)
            {
              myView->FitAll (0.01, false);
              myView->Invalidate();
            }
            else
            {
              myDoubleTapTimer.Stop();
              myDoubleTapTimer.Reset();
              myDoubleTapTimer.Start();
              SelectInViewer (Graphic3d_Vec2i (myClickTouch.From), AIS_SelectionScheme_Replace);
            }
          }
          hasUpdates = true;
        }
        break;
      }
    }
  }
  if (hasUpdates)
  {
    updateView();
  }
  return hasUpdates || !myTouchPoints.IsEmpty() ? EM_TRUE : EM_FALSE;
 }
 // ================================================================
@ -775,35 +570,34 @@ EM_BOOL WasmOcctView::onKeyDownEvent (int theEventType, const EmscriptenKeyboard
    return EM_FALSE;
  }
-  const double aTimeStamp = EventTime();
+  Handle(Wasm_Window) aWindow = Handle(Wasm_Window)::DownCast (myView->Window());
-  const Aspect_VKey aVKey = WasmVKeys_VirtualKeyFromNative (theEvent->keyCode);
+  return aWindow->ProcessKeyEvent (*this, theEventType, theEvent) ? EM_TRUE : EM_FALSE;
-  if (aVKey == Aspect_VKey_UNKNOWN)
+}
  {
    return EM_FALSE;
  }
  if (theEvent->repeat == EM_TRUE)
  {
    return EM_FALSE;
  }
 //=======================================================================
 //function : KeyDown
 //purpose  :
 //=======================================================================
 void WasmOcctView::KeyDown (Aspect_VKey theKey,
                            double theTime,
                            double thePressure)
 {
  const unsigned int aModifOld = myKeys.Modifiers();
-  AIS_ViewController::KeyDown (aVKey, aTimeStamp);
+  AIS_ViewController::KeyDown (theKey, theTime, thePressure);
  const unsigned int aModifNew = myKeys.Modifiers();
  if (aModifNew != aModifOld
-   && navigationKeyModifierSwitch (aModifOld, aModifNew, aTimeStamp))
+   && navigationKeyModifierSwitch (aModifOld, aModifNew, theTime))
  {
    // modifier key just pressed
  }
  Aspect_VKey anAction = Aspect_VKey_UNKNOWN;
-  if (myNavKeyMap.Find (aVKey | myKeys.Modifiers(), anAction)
+  if (myNavKeyMap.Find (theKey | myKeys.Modifiers(), anAction)
  &&  anAction != Aspect_VKey_UNKNOWN)
  {
-    AIS_ViewController::KeyDown (anAction, aTimeStamp);
+    AIS_ViewController::KeyDown (anAction, theTime, thePressure);
    UpdateView();
  }
  return EM_FALSE;
 }
 // ================================================================
@ -818,32 +612,36 @@ EM_BOOL WasmOcctView::onKeyUpEvent (int theEventType, const EmscriptenKeyboardEv
    return EM_FALSE;
  }
-  const double aTimeStamp = EventTime();
+  Handle(Wasm_Window) aWindow = Handle(Wasm_Window)::DownCast (myView->Window());
-  const Aspect_VKey aVKey = WasmVKeys_VirtualKeyFromNative (theEvent->keyCode);
+  return aWindow->ProcessKeyEvent (*this, theEventType, theEvent) ? EM_TRUE : EM_FALSE;
-  if (aVKey == Aspect_VKey_UNKNOWN)
+}
  {
    return EM_FALSE;
  }
 //=======================================================================
 //function : KeyUp
 //purpose  :
 //=======================================================================
 void WasmOcctView::KeyUp (Aspect_VKey theKey,
                          double theTime)
 {
  const unsigned int aModifOld = myKeys.Modifiers();
-  AIS_ViewController::KeyUp (aVKey, aTimeStamp);
+  AIS_ViewController::KeyUp (theKey, theTime);
  Aspect_VKey anAction = Aspect_VKey_UNKNOWN;
-  if (myNavKeyMap.Find (aVKey | myKeys.Modifiers(), anAction)
+  if (myNavKeyMap.Find (theKey | myKeys.Modifiers(), anAction)
  &&  anAction != Aspect_VKey_UNKNOWN)
  {
-    AIS_ViewController::KeyUp (anAction, aTimeStamp);
+    AIS_ViewController::KeyUp (anAction, theTime);
-    UpdateView();
+    processKeyPress (anAction);
  }
  const unsigned int aModifNew = myKeys.Modifiers();
  if (aModifNew != aModifOld
-   && navigationKeyModifierSwitch (aModifOld, aModifNew, aTimeStamp))
+   && navigationKeyModifierSwitch (aModifOld, aModifNew, theTime))
  {
    // modifier key released
  }
-  return processKeyPress (aVKey | aModifNew) ? EM_TRUE : EM_FALSE;
+  processKeyPress (theKey | aModifNew);
 }
 //==============================================================================
--- a/samples/webgl/WasmOcctView.h
+++ b/samples/webgl/WasmOcctView.h
@ -136,9 +136,6 @@ private:
  //! Application event loop.
  void mainloop();
  //! Request view redrawing.
  void updateView();
  //! Flush events and redraw view.
  void redrawView();
@ -146,25 +143,24 @@ private:
  virtual void handleViewRedraw (const Handle(AIS_InteractiveContext)& theCtx,
                                 const Handle(V3d_View)& theView) override;
  //! Schedule processing of window input events with the next repaint event.
  virtual void ProcessInput() override;
  //! Handle key down event.
  virtual void KeyDown (Aspect_VKey theKey,
                        double theTime,
                        double thePressure) override;
  //! Handle key up event.
  virtual void KeyUp (Aspect_VKey theKey,
                      double theTime) override;
  //! Dump WebGL context information.
  void dumpGlInfo (bool theIsBasic);
  //! Initialize pixel scale ratio.
  void initPixelScaleRatio();
  //! Return point from logical units to backing store.
  Graphic3d_Vec2d convertPointToBacking (const Graphic3d_Vec2d& thePnt) const
  {
    return thePnt * myDevicePixelRatio;
  }
  //! Return point from logical units to backing store.
  Graphic3d_Vec2i convertPointToBacking (const Graphic3d_Vec2i& thePnt) const
  {
    Graphic3d_Vec2d aPnt = Graphic3d_Vec2d (thePnt) * myDevicePixelRatio + Graphic3d_Vec2d (0.5);
    return Graphic3d_Vec2i (aPnt);
  }
 //! @name Emscripten callbacks
 private:
  //! Window resize event.
@ -245,8 +241,7 @@ private:
  Handle(Prs3d_TextAspect)       myTextStyle;        //!< text style for OSD elements
  Handle(AIS_ViewCube)           myViewCube;         //!< view cube object
  TCollection_AsciiString        myCanvasId;         //!< canvas element id on HTML page
-  Aspect_Touch                   myClickTouch;       //!< single touch position for handling clicks
+  Graphic3d_Vec2i                myWinSizeOld;
  OSD_Timer                      myDoubleTapTimer;   //!< timer for handling double tap
  float                          myDevicePixelRatio; //!< device pixel ratio for handling high DPI displays
  unsigned int                   myUpdateRequests;   //!< counter for unhandled update requests
--- a/samples/webgl/WasmVKeys.h
+++ b/samples/webgl/WasmVKeys.h
@ -1,264 +0,0 @@
 // Copyright (c) 2019 OPEN CASCADE SAS
 //
 // This file is part of the examples of the Open CASCADE Technology software library.
 //
 // Permission is hereby granted, free of charge, to any person obtaining a copy
 // of this software and associated documentation files (the "Software"), to deal
 // in the Software without restriction, including without limitation the rights
 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 // copies of the Software, and to permit persons to whom the Software is
 // furnished to do so, subject to the following conditions:
 //
 // The above copyright notice and this permission notice shall be included in all
 // copies or substantial portions of the Software.
 //
 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE
 #ifndef _WasmVKeys_HeaderFile
 #define _WasmVKeys_HeaderFile
 #include <Aspect_VKey.hxx>
 #include <emscripten/key_codes.h>
 //! Convert Emscripten mouse buttons into Aspect_VKeyMouse.
 inline Aspect_VKeyMouse WasmVKeys_MouseButtonsFromNative (unsigned short theButtons)
 {
  Aspect_VKeyMouse aButtons = Aspect_VKeyMouse_NONE;
  if ((theButtons & 0x1) != 0)
  {
    aButtons |= Aspect_VKeyMouse_LeftButton;
  }
  if ((theButtons & 0x2) != 0)
  {
    aButtons |= Aspect_VKeyMouse_RightButton;
  }
  if ((theButtons & 0x4) != 0)
  {
    aButtons |= Aspect_VKeyMouse_MiddleButton;
  }
  return aButtons;
 }
 //! Convert DOM virtual key into Aspect_VKey.
 inline Aspect_VKey WasmVKeys_VirtualKeyFromNative (Standard_Integer theKey)
 {
  if (theKey >= DOM_VK_0
   && theKey <= DOM_VK_9)
  {
    // numpad keys
    return Aspect_VKey((theKey - DOM_VK_0) + Aspect_VKey_0);
  }
  if (theKey >= DOM_VK_A
   && theKey <= DOM_VK_Z)
  {
    // main latin alphabet keys
    return Aspect_VKey((theKey - DOM_VK_A) + Aspect_VKey_A);
  }
  if (theKey >= DOM_VK_F1
   && theKey <= DOM_VK_F24)
  {
    // special keys
    if (theKey <= DOM_VK_F12)
    {
      return Aspect_VKey((theKey - DOM_VK_F1) + Aspect_VKey_F1);
    }
    return Aspect_VKey_UNKNOWN;
  }
  if (theKey >= DOM_VK_NUMPAD0
   && theKey <= DOM_VK_NUMPAD9)
  {
    // numpad keys
    return Aspect_VKey((theKey - DOM_VK_NUMPAD0) + Aspect_VKey_Numpad0);
  }
  switch (theKey)
  {
    case DOM_VK_CANCEL:
    case DOM_VK_HELP:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_BACK_SPACE:
      return Aspect_VKey_Backspace;
    case DOM_VK_TAB:
      return Aspect_VKey_Tab;
    case DOM_VK_CLEAR:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_RETURN:
    case DOM_VK_ENTER:
      return Aspect_VKey_Enter;
    case DOM_VK_SHIFT:
      return Aspect_VKey_Shift;
    case DOM_VK_CONTROL:
      return Aspect_VKey_Control;
    case DOM_VK_ALT:
      return Aspect_VKey_Alt;
    case DOM_VK_PAUSE:
    case DOM_VK_CAPS_LOCK:
    case DOM_VK_KANA:
    //case DOM_VK_HANGUL:
    case DOM_VK_EISU:
    case DOM_VK_JUNJA:
    case DOM_VK_FINAL:
    case DOM_VK_HANJA:
    //case DOM_VK_KANJI:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_ESCAPE:
      return Aspect_VKey_Escape;
    case DOM_VK_CONVERT:
    case DOM_VK_NONCONVERT:
    case DOM_VK_ACCEPT:
    case DOM_VK_MODECHANGE:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_SPACE:
      return Aspect_VKey_Space;
    case DOM_VK_PAGE_UP:
      return Aspect_VKey_PageUp;
    case DOM_VK_PAGE_DOWN:
      return Aspect_VKey_PageDown;
    case DOM_VK_END:
      return Aspect_VKey_End;
    case DOM_VK_HOME:
      return Aspect_VKey_Home;
    case DOM_VK_LEFT:
      return Aspect_VKey_Left;
    case DOM_VK_UP:
      return Aspect_VKey_Up;
    case DOM_VK_RIGHT:
      return Aspect_VKey_Right;
    case DOM_VK_DOWN:
      return Aspect_VKey_Down;
    case DOM_VK_SELECT:
    case DOM_VK_PRINT:
    case DOM_VK_EXECUTE:
    case DOM_VK_PRINTSCREEN:
    case DOM_VK_INSERT:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_DELETE:
      return Aspect_VKey_Delete;
    case DOM_VK_COLON:
      return Aspect_VKey_Comma;
    case DOM_VK_SEMICOLON:
      return Aspect_VKey_Semicolon;
    case DOM_VK_LESS_THAN:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_EQUALS:
      return Aspect_VKey_Equal;
    case DOM_VK_GREATER_THAN:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_QUESTION_MARK:
      return Aspect_VKey_Slash;
    case DOM_VK_AT: // @ key
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_WIN:
      return Aspect_VKey_Meta;
    case DOM_VK_CONTEXT_MENU:
    case DOM_VK_SLEEP:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_MULTIPLY:
      return Aspect_VKey_NumpadMultiply;
    case DOM_VK_ADD:
      return Aspect_VKey_NumpadAdd;
    case DOM_VK_SEPARATOR:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_SUBTRACT:
      return Aspect_VKey_NumpadSubtract;
    case DOM_VK_DECIMAL:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_DIVIDE:
      return Aspect_VKey_NumpadDivide;
    case DOM_VK_NUM_LOCK:
      return Aspect_VKey_Numlock;
    case DOM_VK_SCROLL_LOCK:
      return Aspect_VKey_Scroll;
    case DOM_VK_WIN_OEM_FJ_JISHO:
    case DOM_VK_WIN_OEM_FJ_MASSHOU:
    case DOM_VK_WIN_OEM_FJ_TOUROKU:
    case DOM_VK_WIN_OEM_FJ_LOYA:
    case DOM_VK_WIN_OEM_FJ_ROYA:
    case DOM_VK_CIRCUMFLEX:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_EXCLAMATION:
    case DOM_VK_DOUBLE_QUOTE:
    //case DOM_VK_HASH:
    case DOM_VK_DOLLAR:
    case DOM_VK_PERCENT:
    case DOM_VK_AMPERSAND:
    case DOM_VK_UNDERSCORE:
    case DOM_VK_OPEN_PAREN:
    case DOM_VK_CLOSE_PAREN:
    case DOM_VK_ASTERISK:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_PLUS:
      return Aspect_VKey_Plus;
    case DOM_VK_PIPE:
    case DOM_VK_HYPHEN_MINUS:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_OPEN_CURLY_BRACKET:
      return Aspect_VKey_BracketLeft;
    case DOM_VK_CLOSE_CURLY_BRACKET:
      return Aspect_VKey_BracketRight;
    case DOM_VK_TILDE:
      return Aspect_VKey_Tilde;
    case DOM_VK_VOLUME_MUTE:
      return Aspect_VKey_VolumeMute;
    case DOM_VK_VOLUME_DOWN:
      return Aspect_VKey_VolumeDown;
    case DOM_VK_VOLUME_UP:
      return Aspect_VKey_VolumeUp;
    case DOM_VK_COMMA:
      return Aspect_VKey_Comma;
    case DOM_VK_PERIOD:
      return Aspect_VKey_Period;
    case DOM_VK_SLASH:
      return Aspect_VKey_Slash;
    case DOM_VK_BACK_QUOTE:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_OPEN_BRACKET:
      return Aspect_VKey_BracketLeft;
    case DOM_VK_BACK_SLASH:
      return Aspect_VKey_Backslash;
    case DOM_VK_CLOSE_BRACKET:
      return Aspect_VKey_BracketRight;
    case DOM_VK_QUOTE:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_META:
      return Aspect_VKey_Meta;
    case DOM_VK_ALTGR:
      return Aspect_VKey_Alt;
    case DOM_VK_WIN_ICO_HELP:
    case DOM_VK_WIN_ICO_00:
    case DOM_VK_WIN_ICO_CLEAR:
    case DOM_VK_WIN_OEM_RESET:
    case DOM_VK_WIN_OEM_JUMP:
    case DOM_VK_WIN_OEM_PA1:
    case DOM_VK_WIN_OEM_PA2:
    case DOM_VK_WIN_OEM_PA3:
    case DOM_VK_WIN_OEM_WSCTRL:
    case DOM_VK_WIN_OEM_CUSEL:
    case DOM_VK_WIN_OEM_ATTN:
    case DOM_VK_WIN_OEM_FINISH:
    case DOM_VK_WIN_OEM_COPY:
    case DOM_VK_WIN_OEM_AUTO:
    case DOM_VK_WIN_OEM_ENLW:
    case DOM_VK_WIN_OEM_BACKTAB:
    case DOM_VK_ATTN:
    case DOM_VK_CRSEL:
    case DOM_VK_EXSEL:
    case DOM_VK_EREOF:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_PLAY:
      return Aspect_VKey_MediaPlayPause;
    case DOM_VK_ZOOM:
    case DOM_VK_PA1:
    case DOM_VK_WIN_OEM_CLEAR:
      return Aspect_VKey_UNKNOWN;
  }
  return Aspect_VKey_UNKNOWN;
 }
 #endif // _WasmVKeys_HeaderFile
--- a/src/AIS/AIS_ViewController.cxx
+++ b/src/AIS/AIS_ViewController.cxx
@ -86,6 +86,7 @@ AIS_ViewController::AIS_ViewController()
  myMouseStopDragOnUnclick (false),
  //
  myTouchToleranceScale      (1.0f),
  myTouchClickThresholdPx    (3.0f),
  myTouchRotationThresholdPx (6.0f),
  myTouchZRotationThreshold  (float(2.0 * M_PI / 180.0)),
  myTouchPanThresholdPx      (4.0f),
@ -1010,14 +1011,12 @@ void AIS_ViewController::AddTouchPoint (Standard_Size theId,
                                        Standard_Boolean theClearBefore)
 {
  myUI.MoveTo.ToHilight = false;
-  if (theClearBefore)
+  Aspect_WindowInputListener::AddTouchPoint (theId, thePnt, theClearBefore);
  {
    RemoveTouchPoint ((Standard_Size )-1);
  }
-  myTouchPoints.Add (theId, Aspect_Touch (thePnt, false));
+  myTouchClick.From = Graphic3d_Vec2d (-1.0);
  if (myTouchPoints.Extent() == 1)
  {
    myTouchClick.From = thePnt;
    myUpdateStartPointRot = true;
    myStartRotCoord = thePnt;
    if (myToAllowDragging)
@ -1043,18 +1042,9 @@ void AIS_ViewController::AddTouchPoint (Standard_Size theId,
 bool AIS_ViewController::RemoveTouchPoint (Standard_Size theId,
                                           Standard_Boolean theClearSelectPnts)
 {
-  if (theId == (Standard_Size )-1)
+  if (!Aspect_WindowInputListener::RemoveTouchPoint (theId, theClearSelectPnts))
  {
-    myTouchPoints.Clear (false);
+    return false;
  }
  else
  {
    const Standard_Integer anOldExtent = myTouchPoints.Extent();
    myTouchPoints.RemoveKey (theId);
    if (myTouchPoints.Extent() == anOldExtent)
    {
      return false;
    }
  }
  if (myTouchPoints.Extent() == 1)
@ -1079,6 +1069,30 @@ bool AIS_ViewController::RemoveTouchPoint (Standard_Size theId,
    }
    myUI.Dragging.ToStop = true;
    if (theId == (Standard_Size )-1)
    {
      // abort clicking
      myTouchClick.From = Graphic3d_Vec2d (-1);
    }
    else if (myTouchClick.From.minComp() >= 0.0)
    {
      bool isDoubleClick = false;
      if (myTouchDoubleTapTimer.IsStarted()
       && myTouchDoubleTapTimer.ElapsedTime() <= myMouseDoubleClickInt)
      {
        isDoubleClick = true;
      }
      else
      {
        myTouchDoubleTapTimer.Stop();
        myTouchDoubleTapTimer.Reset();
        myTouchDoubleTapTimer.Start();
      }
      // emulate mouse click
      UpdateMouseClick (Graphic3d_Vec2i (myTouchClick.From), Aspect_VKeyMouse_LeftButton, Aspect_VKeyFlags_NONE, isDoubleClick);
    }
  }
  myUI.IsNewGesture = true;
  return true;
@ -1091,13 +1105,13 @@ bool AIS_ViewController::RemoveTouchPoint (Standard_Size theId,
 void AIS_ViewController::UpdateTouchPoint (Standard_Size theId,
                                           const Graphic3d_Vec2d& thePnt)
 {
-  if (Aspect_Touch* aTouch = myTouchPoints.ChangeSeek (theId))
+  Aspect_WindowInputListener::UpdateTouchPoint (theId, thePnt);
  const double aTouchTol = double(myTouchToleranceScale) * double(myTouchClickThresholdPx);
  if (myTouchPoints.Extent() == 1
   && (myTouchClick.From - thePnt).cwiseAbs().maxComp() > aTouchTol)
  {
-    aTouch->To = thePnt;
+    myTouchClick.From.SetValues (-1.0, -1.0);
  }
  else
  {
    AddTouchPoint (theId, thePnt);
  }
 }
@ -1195,12 +1209,14 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  if (myKeys.HoldDuration (Aspect_VKey_NavJump, aNewEventTime, aDuration))
  {
    myKeys.KeyUp (Aspect_VKey_NavJump, aNewEventTime);
    aWalk.SetDefined (true);
    aWalk.SetJumping (true);
  }
  if (!aWalk.IsJumping()
   && theCrouchRatio < 1.0
   && myKeys.HoldDuration (Aspect_VKey_NavCrouch, aNewEventTime, aDuration))
  {
    aWalk.SetDefined (true);
    aWalk.SetRunning (false);
    aWalk.SetCrouching (true);
  }
@ -1215,6 +1231,7 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  {
    double aProgress = Abs (Min (aMaxDuration, aDuration));
    aProgress *= aRunRatio;
    aWalk.SetDefined (true);
    aWalk[AIS_WalkTranslation_Forward].Value += aProgress;
    aWalk[AIS_WalkTranslation_Forward].Pressure = aPressure;
    aWalk[AIS_WalkTranslation_Forward].Duration = aDuration;
@ -1223,6 +1240,7 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  {
    double aProgress = Abs (Min (aMaxDuration, aDuration));
    aProgress *= aRunRatio;
    aWalk.SetDefined (true);
    aWalk[AIS_WalkTranslation_Forward].Value += -aProgress;
    aWalk[AIS_WalkTranslation_Forward].Pressure = aPressure;
    aWalk[AIS_WalkTranslation_Forward].Duration = aDuration;
@ -1231,6 +1249,7 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  {
    double aProgress = Abs (Min (aMaxDuration, aDuration));
    aProgress *= aRunRatio;
    aWalk.SetDefined (true);
    aWalk[AIS_WalkTranslation_Side].Value = -aProgress;
    aWalk[AIS_WalkTranslation_Side].Pressure = aPressure;
    aWalk[AIS_WalkTranslation_Side].Duration = aDuration;
@ -1239,6 +1258,7 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  {
    double aProgress = Abs (Min (aMaxDuration, aDuration));
    aProgress *= aRunRatio;
    aWalk.SetDefined (true);
    aWalk[AIS_WalkTranslation_Side].Value = aProgress;
    aWalk[AIS_WalkTranslation_Side].Pressure = aPressure;
    aWalk[AIS_WalkTranslation_Side].Duration = aDuration;
@ -1246,6 +1266,7 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  if (myKeys.HoldDuration (Aspect_VKey_NavLookLeft, aNewEventTime, aDuration, aPressure))
  {
    double aProgress = Abs (Min (aMaxDuration, aDuration)) * aPressure;
    aWalk.SetDefined (true);
    aWalk[AIS_WalkRotation_Yaw].Value = aProgress;
    aWalk[AIS_WalkRotation_Yaw].Pressure = aPressure;
    aWalk[AIS_WalkRotation_Yaw].Duration = aDuration;
@ -1253,6 +1274,7 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  if (myKeys.HoldDuration (Aspect_VKey_NavLookRight, aNewEventTime, aDuration, aPressure))
  {
    double aProgress = Abs (Min (aMaxDuration, aDuration)) * aPressure;
    aWalk.SetDefined (true);
    aWalk[AIS_WalkRotation_Yaw].Value = -aProgress;
    aWalk[AIS_WalkRotation_Yaw].Pressure = aPressure;
    aWalk[AIS_WalkRotation_Yaw].Duration = aDuration;
@ -1260,6 +1282,7 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  if (myKeys.HoldDuration (Aspect_VKey_NavLookUp, aNewEventTime, aDuration, aPressure))
  {
    double aProgress = Abs (Min (aMaxDuration, aDuration)) * aPressure;
    aWalk.SetDefined (true);
    aWalk[AIS_WalkRotation_Pitch].Value = !myToInvertPitch ? -aProgress : aProgress;
    aWalk[AIS_WalkRotation_Pitch].Pressure = aPressure;
    aWalk[AIS_WalkRotation_Pitch].Duration = aDuration;
@ -1267,6 +1290,7 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  if (myKeys.HoldDuration (Aspect_VKey_NavLookDown, aNewEventTime, aDuration, aPressure))
  {
    double aProgress = Abs (Min (aMaxDuration, aDuration)) * aPressure;
    aWalk.SetDefined (true);
    aWalk[AIS_WalkRotation_Pitch].Value = !myToInvertPitch ? aProgress : -aProgress;
    aWalk[AIS_WalkRotation_Pitch].Pressure = aPressure;
    aWalk[AIS_WalkRotation_Pitch].Duration = aDuration;
@ -1274,6 +1298,7 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  if (myKeys.HoldDuration (Aspect_VKey_NavRollCCW, aNewEventTime, aDuration, aPressure))
  {
    double aProgress = Abs (Min (aMaxDuration, aDuration)) * aPressure;
    aWalk.SetDefined (true);
    aWalk[AIS_WalkRotation_Roll].Value = -aProgress;
    aWalk[AIS_WalkRotation_Roll].Pressure = aPressure;
    aWalk[AIS_WalkRotation_Roll].Duration = aDuration;
@ -1281,6 +1306,7 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  if (myKeys.HoldDuration (Aspect_VKey_NavRollCW, aNewEventTime, aDuration, aPressure))
  {
    double aProgress = Abs (Min (aMaxDuration, aDuration)) * aPressure;
    aWalk.SetDefined (true);
    aWalk[AIS_WalkRotation_Roll].Value = aProgress;
    aWalk[AIS_WalkRotation_Roll].Pressure = aPressure;
    aWalk[AIS_WalkRotation_Roll].Duration = aDuration;
@ -1288,6 +1314,7 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  if (myKeys.HoldDuration (Aspect_VKey_NavSlideUp, aNewEventTime, aDuration, aPressure))
  {
    double aProgress = Abs (Min (aMaxDuration, aDuration));
    aWalk.SetDefined (true);
    aWalk[AIS_WalkTranslation_Up].Value = aProgress;
    aWalk[AIS_WalkTranslation_Up].Pressure = aPressure;
    aWalk[AIS_WalkTranslation_Up].Duration = aDuration;
@ -1295,6 +1322,7 @@ AIS_WalkDelta AIS_ViewController::FetchNavigationKeys (Standard_Real theCrouchRa
  if (myKeys.HoldDuration (Aspect_VKey_NavSlideDown, aNewEventTime, aDuration, aPressure))
  {
    double aProgress = Abs (Min (aMaxDuration, aDuration));
    aWalk.SetDefined (true);
    aWalk[AIS_WalkTranslation_Up].Value = -aProgress;
    aWalk[AIS_WalkTranslation_Up].Pressure = aPressure;
    aWalk[AIS_WalkTranslation_Up].Duration = aDuration;
@ -1956,6 +1984,10 @@ AIS_WalkDelta AIS_ViewController::handleNavigationKeys (const Handle(AIS_Interac
  }
  if (aWalk.IsEmpty())
  {
    if (aWalk.IsDefined())
    {
      setAskNextFrame();
    }
    return aWalk;
  }
  else if (myGL.OrbitRotation.ToRotate
--- a/src/AIS/AIS_ViewController.hxx
+++ b/src/AIS/AIS_ViewController.hxx
@ -372,9 +372,6 @@ public: //! @name multi-touch input
  //! Set scale factor for adjusting tolerances for starting multi-touch gestures.
  void SetTouchToleranceScale (float theTolerance) { myTouchToleranceScale = theTolerance; }
  //! Return TRUE if touches map is not empty.
  bool HasTouchPoints() const { return !myTouchPoints.IsEmpty(); }
  //! Add touch point with the given ID.
  //! This method is expected to be called from UI thread.
  //! @param theId touch unique identifier
@ -382,7 +379,7 @@ public: //! @name multi-touch input
  //! @param theClearBefore if TRUE previously registered touches will be removed
  Standard_EXPORT virtual void AddTouchPoint (Standard_Size theId,
                                              const Graphic3d_Vec2d& thePnt,
-                                              Standard_Boolean theClearBefore = false);
+                                              Standard_Boolean theClearBefore = false) Standard_OVERRIDE;
  //! Remove touch point with the given ID.
  //! This method is expected to be called from UI thread.
@ -390,7 +387,7 @@ public: //! @name multi-touch input
  //! @param theClearSelectPnts if TRUE will initiate clearing of selection points
  //! @return TRUE if point has been removed
  Standard_EXPORT virtual bool RemoveTouchPoint (Standard_Size theId,
-                                                 Standard_Boolean theClearSelectPnts = false);
+                                                 Standard_Boolean theClearSelectPnts = false) Standard_OVERRIDE;
  //! Update touch point with the given ID.
  //! If point with specified ID was not registered before, it will be added.
@ -398,7 +395,9 @@ public: //! @name multi-touch input
  //! @param theId touch unique identifier
  //! @param thePnt touch coordinates
  Standard_EXPORT virtual void UpdateTouchPoint (Standard_Size theId,
-                                                 const Graphic3d_Vec2d& thePnt);
+                                                 const Graphic3d_Vec2d& thePnt) Standard_OVERRIDE;
  using Aspect_WindowInputListener::HasTouchPoints;
 public: //! @name 3d mouse input
@ -749,13 +748,16 @@ protected: //! @name mouse input variables
 protected: //! @name multi-touch input variables
  Standard_ShortReal  myTouchToleranceScale;      //!< tolerance scale factor; 1.0 by default
  Standard_ShortReal  myTouchClickThresholdPx;    //!< touch click threshold in pixels; 3 by default
  Standard_ShortReal  myTouchRotationThresholdPx; //!< threshold for starting one-touch rotation     gesture in pixels;  6 by default
  Standard_ShortReal  myTouchZRotationThreshold;  //!< threshold for starting two-touch Z-rotation   gesture in radians; 2 degrees by default
  Standard_ShortReal  myTouchPanThresholdPx;      //!< threshold for starting two-touch panning      gesture in pixels;  4 by default
  Standard_ShortReal  myTouchZoomThresholdPx;     //!< threshold for starting two-touch zoom (pitch) gesture in pixels;  6 by default
  Standard_ShortReal  myTouchZoomRatio;           //!< distance ratio for mapping two-touch zoom (pitch) gesture from pixels to zoom; 0.13 by default
-  Aspect_TouchMap     myTouchPoints;              //!< map of active touches
+  Aspect_Touch        myTouchClick;               //!< single touch position for handling clicks
  OSD_Timer           myTouchDoubleTapTimer;      //!< timer for handling double tap
  Graphic3d_Vec2d     myStartPanCoord;            //!< touch coordinates at the moment of starting panning  gesture
  Graphic3d_Vec2d     myStartRotCoord;            //!< touch coordinates at the moment of starting rotating gesture
  Standard_Integer    myNbTouchesLast;            //!< number of touches within previous gesture flush to track gesture changes
--- a/src/AIS/AIS_WalkDelta.hxx
+++ b/src/AIS/AIS_WalkDelta.hxx
@ -51,7 +51,7 @@ struct AIS_WalkDelta
 {
  //! Empty constructor.
  AIS_WalkDelta()
-  : myIsJumping (false), myIsCrouching (false), myIsRunning (false) {}
+  : myIsDefined (false), myIsJumping (false), myIsCrouching (false), myIsRunning (false) {}
  //! Return translation component.
  const AIS_WalkPart& operator[] (AIS_WalkTranslation thePart) const { return myTranslation[thePart]; }
@ -83,6 +83,12 @@ struct AIS_WalkDelta
  //! Set running state.
  void SetRunning (bool theIsRunning) { myIsRunning = theIsRunning; }
  //! Return TRUE if navigation keys are pressed even if delta from the previous frame is empty.
  bool IsDefined() const { return myIsDefined || !IsEmpty(); }
  //! Set if any navigation key is pressed.
  void SetDefined (bool theIsDefined) { myIsDefined = theIsDefined; }
  //! Return TRUE when both Rotation and Translation deltas are empty.
  bool IsEmpty() const { return !ToMove() && !ToRotate(); }
@ -106,6 +112,7 @@ private:
  AIS_WalkPart myTranslation[3];
  AIS_WalkPart myRotation[3];
  bool myIsDefined;
  bool myIsJumping;
  bool myIsCrouching;
  bool myIsRunning;
--- a/src/Aspect/Aspect_Convert.hxx
+++ b/src/Aspect/Aspect_Convert.hxx
@ -1,86 +0,0 @@
 // Copyright (c) 1999-2014 OPEN CASCADE SAS
 //
 // This file is part of Open CASCADE Technology software library.
 //
 // This library is free software; you can redistribute it and/or modify it under
 // the terms of the GNU Lesser General Public License version 2.1 as published
 // by the Free Software Foundation, with special exception defined in the file
 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
 // distribution for complete text of the license and disclaimer of any warranty.
 //
 // Alternatively, this file may be used under the terms of Open CASCADE
 // commercial license or contractual agreement.
 #ifndef _Aspect_Convert_HeaderFile
 #define _Aspect_Convert_HeaderFile
 #include <Standard.hxx>
 #include <Standard_Real.hxx>
 //! Auxiliary functions for DCU <-> Pixels conversions.
 namespace Aspect_Convert
 {
  inline Standard_Integer Round (Standard_Real theValue)
  {
    return Standard_Integer(theValue + (theValue >= 0 ? 0.5 : -0.5 ));
  }
  inline void ConvertCoordinates (const Standard_Integer theParentPxSizeX, const Standard_Integer theParentPxSizeY,
                                  const Standard_Real theQCenterX, const Standard_Real theQCenterY,
                                  const Standard_Real theQSizeX,   const Standard_Real theQSizeY,
                                  Standard_Integer& thePxLeft,  Standard_Integer& thePxTop,
                                  Standard_Integer& thePxSizeX, Standard_Integer& thePxSizeY)
  {
    Standard_Real theParentSizeMin = Min (theParentPxSizeX, theParentPxSizeY);
    thePxSizeX = Round (theQSizeX * theParentSizeMin);
    thePxSizeY = Round (theQSizeY * theParentSizeMin);
    Standard_Integer thePxCenterX = Round(theQCenterX * Standard_Real (theParentPxSizeX));
    Standard_Integer thePxCenterY = Round((1.0 - theQCenterY) * Standard_Real (theParentPxSizeY));
    thePxLeft = thePxCenterX - thePxSizeX / 2;
    thePxTop  = thePxCenterY - thePxSizeY / 2;
  }
  inline void ConvertCoordinates (const Standard_Integer theParentPxSizeX, const Standard_Integer theParentPxSizeY,
                                  const Standard_Integer thePxLeft,  const Standard_Integer thePxTop,
                                  const Standard_Integer thePxSizeX, const Standard_Integer thePxSizeY,
                                  Standard_Real& theQCenterX, Standard_Real& theQCenterY,
                                  Standard_Real& theQSizeX,   Standard_Real& theQSizeY)
  {
    Standard_Real theParentSizeMin = Min (theParentPxSizeX, theParentPxSizeY);
    theQSizeX = Standard_Real(thePxSizeX) / theParentSizeMin;
    theQSizeY = Standard_Real(thePxSizeY) / theParentSizeMin;
    Standard_Integer thePxCenterX = thePxLeft + thePxSizeX / 2;
    Standard_Integer thePxCenterY = thePxTop  + thePxSizeY / 2;
    theQCenterX =       Standard_Real (thePxCenterX) / Standard_Real (theParentPxSizeX);
    theQCenterY = 1.0 - Standard_Real (thePxCenterY) / Standard_Real (theParentPxSizeY);
  }
  inline void FitIn (const Standard_Integer theParentPxSizeX, const Standard_Integer theParentPxSizeY,
                     Standard_Integer& thePxLeft,  Standard_Integer& thePxTop,
                     Standard_Integer& thePxSizeX, Standard_Integer& thePxSizeY)
  {
    if (thePxLeft < 0)
    {
      //thePxSizeX -= 2 * thePxLeft;
      thePxLeft = 0;
    }
    if ((thePxLeft + thePxSizeX) > theParentPxSizeX)
    {
      thePxSizeX = theParentPxSizeX - thePxLeft;
    }
    if (thePxTop < 0)
    {
      //thePxSizeY -= 2 * thePxTop;
      thePxTop = 0;
    }
    if ((thePxTop + thePxSizeY) > theParentPxSizeY)
    {
      thePxSizeY = theParentPxSizeY - thePxTop;
    }
  }
 } // namespace Aspect_Convert
 #endif /* _Aspect_Convert_HeaderFile */
--- a/src/Aspect/Aspect_Window.hxx
+++ b/src/Aspect/Aspect_Window.hxx
@ -24,6 +24,7 @@
 #include <Aspect_GradientFillMethod.hxx>
 #include <Aspect_TypeOfResize.hxx>
 #include <Aspect_Drawable.hxx>
 #include <Graphic3d_Vec2.hxx>
 #include <Standard.hxx>
 #include <Standard_Transient.hxx>
 #include <Standard_Type.hxx>
@ -36,7 +37,7 @@ DEFINE_STANDARD_HANDLE(Aspect_Window, Standard_Transient)
 //! Defines a window.
 class Aspect_Window : public Standard_Transient
 {
-
+  DEFINE_STANDARD_RTTIEXT(Aspect_Window, Standard_Transient)
 public:
  //! Modifies the window background.
@ -102,6 +103,9 @@ public:
  //! Returns native Window FB config (GLXFBConfig on Xlib)
  Standard_EXPORT virtual Aspect_FBConfig NativeFBConfig() const = 0;
  //! Returns connection to Display or NULL.
  const Handle(Aspect_DisplayConnection)& DisplayConnection() const { return myDisplay; }
  //! Sets window title.
  virtual void SetTitle (const TCollection_AsciiString& theTitle) { (void )theTitle; }
@ -114,12 +118,29 @@ public:
  //! on platforms implementing thread-unsafe connections to display.
  //! NULL can be passed instead otherwise.
  virtual void InvalidateContent (const Handle(Aspect_DisplayConnection)& theDisp) { (void )theDisp; }
-  
+
 public:
  //! Return device pixel ratio (logical to backing store scale factor).
  virtual Standard_Real DevicePixelRatio() const { return 1.0; }
  //! Convert point from logical units into backing store units.
  virtual Graphic3d_Vec2d ConvertPointToBacking (const Graphic3d_Vec2d& thePnt) const
  {
    return thePnt * DevicePixelRatio();
  }
  //! Convert point from backing store units to logical units.
  virtual Graphic3d_Vec2d ConvertPointFromBacking (const Graphic3d_Vec2d& thePnt) const
  {
    return thePnt / DevicePixelRatio();
  }
 public:
  //! Dumps the content of me into the stream
  Standard_EXPORT void DumpJson (Standard_OStream& theOStream, Standard_Integer theDepth = -1) const;
  DEFINE_STANDARD_RTTIEXT(Aspect_Window,Standard_Transient)
 protected:
  //! Initializes the data of a Window.
@ -127,6 +148,7 @@ protected:
 protected:
  Handle(Aspect_DisplayConnection) myDisplay; //!< Display connection
  Aspect_Background MyBackground;
  Aspect_GradientBackground MyGradientBackground;
  Aspect_FillMethod MyBackgroundFillMethod;
--- a/src/Aspect/Aspect_WindowInputListener.cxx
+++ b/src/Aspect/Aspect_WindowInputListener.cxx
@ -75,6 +75,70 @@ void Aspect_WindowInputListener::KeyFromAxis (Aspect_VKey theNegative,
  myKeys.KeyFromAxis (theNegative, thePositive, theTime, thePressure);
 }
 // =======================================================================
 // function : AddTouchPoint
 // purpose  :
 // =======================================================================
 void Aspect_WindowInputListener::AddTouchPoint (Standard_Size theId,
                                                const Graphic3d_Vec2d& thePnt,
                                                Standard_Boolean theClearBefore)
 {
  if (theClearBefore)
  {
    RemoveTouchPoint ((Standard_Size )-1);
  }
  myTouchPoints.Add (theId, Aspect_Touch (thePnt, false));
 }
 // =======================================================================
 // function : RemoveTouchPoint
 // purpose  :
 // =======================================================================
 bool Aspect_WindowInputListener::RemoveTouchPoint (Standard_Size theId,
                                                   Standard_Boolean theClearSelectPnts)
 {
  (void )theClearSelectPnts;
  if (theId == (Standard_Size )-1)
  {
    myTouchPoints.Clear (false);
  }
  else
  {
    const Standard_Integer anOldExtent = myTouchPoints.Extent();
    myTouchPoints.RemoveKey (theId);
    if (myTouchPoints.Extent() == anOldExtent)
    {
      return false;
    }
  }
  if (myTouchPoints.Extent() == 1)
  {
    // avoid incorrect transition from pinch to one finger
    Aspect_Touch& aFirstTouch = myTouchPoints.ChangeFromIndex (1);
    aFirstTouch.To = aFirstTouch.From;
  }
  return true;
 }
 // =======================================================================
 // function : UpdateTouchPoint
 // purpose  :
 // =======================================================================
 void Aspect_WindowInputListener::UpdateTouchPoint (Standard_Size theId,
                                                   const Graphic3d_Vec2d& thePnt)
 {
  if (Aspect_Touch* aTouch = myTouchPoints.ChangeSeek (theId))
  {
    aTouch->To = thePnt;
  }
  else
  {
    AddTouchPoint (theId, thePnt);
  }
 }
 // =======================================================================
 // function : update3dMouseTranslation
 // purpose  :
--- a/src/Aspect/Aspect_WindowInputListener.hxx
+++ b/src/Aspect/Aspect_WindowInputListener.hxx
@ -15,6 +15,7 @@
 #define _Aspect_WindowInputListener_HeaderFile
 #include <Aspect_VKeySet.hxx>
 #include <Aspect_TouchMap.hxx>
 #include <Graphic3d_Vec.hxx>
 #include <Standard.hxx>
 #include <Standard_DefineAlloc.hxx>
@ -159,6 +160,39 @@ public: //! @name mouse input
  //! Return last mouse position.
  const Graphic3d_Vec2i& LastMousePosition() const { return myMousePositionLast; }
 public: //! @name multi-touch input
  //! Return TRUE if touches map is not empty.
  bool HasTouchPoints() const { return !myTouchPoints.IsEmpty(); }
  //! Return map of active touches.
  const Aspect_TouchMap& TouchPoints() const { return myTouchPoints; }
  //! Add touch point with the given ID.
  //! This method is expected to be called from UI thread.
  //! @param theId touch unique identifier
  //! @param thePnt touch coordinates
  //! @param theClearBefore if TRUE previously registered touches will be removed
  Standard_EXPORT virtual void AddTouchPoint (Standard_Size theId,
                                              const Graphic3d_Vec2d& thePnt,
                                              Standard_Boolean theClearBefore = false);
  //! Remove touch point with the given ID.
  //! This method is expected to be called from UI thread.
  //! @param theId touch unique identifier
  //! @param theClearSelectPnts if TRUE will initiate clearing of selection points
  //! @return TRUE if point has been removed
  Standard_EXPORT virtual bool RemoveTouchPoint (Standard_Size theId,
                                                 Standard_Boolean theClearSelectPnts = false);
  //! Update touch point with the given ID.
  //! If point with specified ID was not registered before, it will be added.
  //! This method is expected to be called from UI thread.
  //! @param theId touch unique identifier
  //! @param thePnt touch coordinates
  Standard_EXPORT virtual void UpdateTouchPoint (Standard_Size theId,
                                                 const Graphic3d_Vec2d& thePnt);
 public: //! @name 3d mouse input
  //! Return acceleration ratio for translation event; 2.0 by default.
@ -222,6 +256,10 @@ protected: //! @name mouse input variables
  Aspect_VKeyMouse myMousePressed;      //!< active mouse buttons
  Aspect_VKeyFlags myMouseModifiers;    //!< active key modifiers passed with last mouse event
 protected:
  Aspect_TouchMap  myTouchPoints;       //!< map of active touches
 protected: //! @name 3d mouse input variables
  bool                   my3dMouseButtonState[32];//!< cached button state
--- a/src/Aspect/FILES
+++ b/src/Aspect/FILES
@ -6,7 +6,6 @@ Aspect_Background.hxx
 Aspect_CircularGrid.cxx
 Aspect_CircularGrid.hxx
 Aspect_ColorSpace.hxx
 Aspect_Convert.hxx
 Aspect_Display.hxx
 Aspect_DisplayConnection.cxx
 Aspect_DisplayConnection.hxx
--- a/src/Cocoa/Cocoa_Window.mm
+++ b/src/Cocoa/Cocoa_Window.mm
@ -26,7 +26,6 @@
 #include <Cocoa_LocalPool.hxx>
 #include <Image_AlienPixMap.hxx>
 #include <Aspect_Convert.hxx>
 #include <Aspect_WindowDefinitionError.hxx>
 IMPLEMENT_STANDARD_RTTIEXT(Cocoa_Window,Aspect_Window)
--- a/src/DRAWEXE/CMakeLists.txt
+++ b/src/DRAWEXE/CMakeLists.txt
@ -49,6 +49,7 @@ if (EMSCRIPTEN)
  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -s MODULARIZE=1")
  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -s EXPORT_NAME='createDRAWEXE'")
  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -s \"EXTRA_EXPORTED_RUNTIME_METHODS=['FS']\"")
  # Embed Draw Harness .tcl scripts at recognizable location.
  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --preload-file ${CMAKE_CURRENT_SOURCE_DIR}/../DrawResources@/DrawResources")
--- a/src/DRAWEXE/DRAWEXE.cxx
+++ b/src/DRAWEXE/DRAWEXE.cxx
@ -17,6 +17,7 @@
 #include <DBRep.hxx>
 #include <DrawTrSurf.hxx>
 #include <Message.hxx>
 #include <Message_PrinterOStream.hxx>
 #include <Message_PrinterSystemLog.hxx>
 #include <NCollection_IndexedMap.hxx>
 #include <Standard_ErrorHandler.hxx>
@ -33,6 +34,85 @@
  #include <XDEDRAW.hxx>
 #endif
 Standard_IMPORT Standard_Boolean Draw_Interprete (const char* theCommand);
 #if defined(__EMSCRIPTEN__)
 #include <emscripten/bind.h>
 #include <emscripten/emscripten.h>
 //! Draw Harness interface for JavaScript.
 class DRAWEXE
 {
 public:
  //! Evaluate Tcl command.
  static int eval (const std::string& theCommand)
  {
    int aRes = 0;
    try
    {
      OCC_CATCH_SIGNALS
      //aRes = Draw::GetInterpretor().Eval (theCommand.c_str());
      aRes = Draw_Interprete (theCommand.c_str()) ? 1 : 0;
    }
    catch (Standard_Failure& anExcept)
    {
      std::cout << "Failed to evaluate command: " << anExcept.GetMessageString() << std::endl;
    }
    return aRes;
  }
  //! Check if Tcl command is complete.
  static bool isComplete (const std::string& theCommand)
  {
    return Draw::GetInterpretor().Complete (theCommand.c_str());
  }
 };
 //! Print message to Module.printMessage callback.
 EM_JS(void, occJSPrintMessage, (const char* theStr, int theGravity), {
  if (Module.printMessage != undefined && Module.printMessage != null) {
    Module.printMessage (UTF8ToString(theStr), theGravity);
  } else if (Module.print != undefined && Module.print != null) {
    Module.print (UTF8ToString(theStr));
  } else {
    //console.info (UTF8ToString(theStr));
  }
 });
 //! Auxiliary printer to a Module.printMessage callback accepting text and gravity.
 class DRAWEXE_WasmModulePrinter : public Message_Printer
 {
  DEFINE_STANDARD_RTTI_INLINE(DRAWEXE_WasmModulePrinter, Message_Printer)
 public:
  //! Main constructor.
  DRAWEXE_WasmModulePrinter (const Message_Gravity theTraceLevel = Message_Info)
  {
    SetTraceLevel (theTraceLevel);
  }
  //! Destructor.
  virtual ~DRAWEXE_WasmModulePrinter() {}
 protected:
  //! Puts a message.
  virtual void send (const TCollection_AsciiString& theString,
                     const Message_Gravity theGravity) const Standard_OVERRIDE
  {
    if (theGravity >= myTraceLevel)
    {
      occJSPrintMessage (theString.ToCString(), (int )theGravity);
    }
  }
 };
 EMSCRIPTEN_BINDINGS(DRAWEXE) {
  emscripten::function("eval",       &DRAWEXE::eval);
  emscripten::function("isComplete", &DRAWEXE::isComplete);
 }
 #endif
 #ifdef OCCT_NO_PLUGINS
 //! Mimic pload command by loading pre-defined set of statically linked plugins.
 static Standard_Integer Pload (Draw_Interpretor& theDI,
@ -154,8 +234,13 @@ void Draw_InitAppli (Draw_Interpretor& theDI)
 {
 #if defined(__EMSCRIPTEN__)
  // open JavaScript console within the Browser to see this output
-  Handle(Message_PrinterSystemLog) aJSConsolePrinter = new Message_PrinterSystemLog ("DRAWEXE");
+  Message_Gravity aGravity = Message_Info;
  Handle(Message_PrinterSystemLog) aJSConsolePrinter = new Message_PrinterSystemLog ("DRAWEXE", aGravity);
  Message::DefaultMessenger()->AddPrinter (aJSConsolePrinter);
  // replace printer into std::cout by a printer into a custom callback Module.printMessage accepting message gravity
  Message::DefaultMessenger()->RemovePrinters (STANDARD_TYPE(Message_PrinterOStream));
  Handle(DRAWEXE_WasmModulePrinter) aJSModulePrinter = new DRAWEXE_WasmModulePrinter (aGravity);
  Message::DefaultMessenger()->AddPrinter (aJSModulePrinter);
 #endif
  Draw::Commands (theDI);
--- a/src/DRAWEXE/DRAWEXE.html
+++ b/src/DRAWEXE/DRAWEXE.html
@ -11,10 +11,81 @@
 <div>
  <canvas id=occViewerCanvas oncontextmenu=event.preventDefault() tabindex=-1 style="border:0 none;background-color:#000" width="409" height="409"></canvas>
 </div>
-<h4>Output (open JavaScript console):</h4>
+<h4>For output - open JavaScript console in your Browser.</h4>
 <p id="output"></p>
 <script type="text/javascript" src="DRAWEXE.js" charset="utf-8"></script>
 <script>
 /**
 * Class defining an interface to DRAWEXE and WebAssembly Module.
 */
 class DrawTerm
 {
  /**
   * Class constructor.
   */
  constructor()
  {
    // define WebGL canvas for WebAssembly viewer
    this.canvas = document.getElementById ('occViewerCanvas'); // canvas element for OpenGL context
    this.canvas.tabIndex = -1;
    this.canvas.onclick = (theEvent) =>
    {
      this.canvas.focus()
    };
  }
  /**
   * C++ std::cout callback redirecting to console.
   */
  print (theText)
  {
    //var anElement = document.getElementById('output');
    //anElement.innerHTML += theText + "<br>";
    console.warn (theText);
  }
  /**
   * C++ std::cerr callback redirecting to console.
   */
  printErr (theText)
  {
    //var anElement = document.getElementById('output');
    //anElement.innerHTML += theText + "<br>";
    console.warn (theText);
  }
  /**
   * C++ Message::Send() callback redirecting to Terminal.
   */
  printMessage (theText, theGravity)
  {
    switch (theGravity)
    {
      case 0: // trace
        console.debug (theText);
        return;
      case 1: // info
        console.info (theText);
        return;
      case 2: // warning
        console.warn (theText);
        return;
      case 3: // alarm
      case 4: // fail
        console.error (theText);
        return;
    }
    console.info (theText);
  }
  onRuntimeInitialized()
  {
    //
  }
 };
 // Define a global DRAWEXE instance (will be initialized asynchronously).
 var DRAWEXE = new DrawTerm();
 //! Check browser support.
 function isWasmSupported()
 {
@ -30,38 +101,22 @@ function isWasmSupported()
  } catch (e) {}
  return false;
 }
 if (!isWasmSupported())
 {
  var anElement = document.getElementById('output');
  anElement.innerHTML += "Browser is too old - WebAssembly support is missing!<br>Please check updates or install a modern browser.<br>";
 }
-
+else
 var DRAWEXE =
 {
-  print: (function() {
+  // load DRAWEXE.wasm (asynchronously) and wait initialization completion
-    var anElement = document.getElementById('output');
+  createDRAWEXE(DRAWEXE).then (function(Module) {
-    //return function(theText) { anElement.innerHTML += theText + "<br>"; };
+    //DRAWEXE.printMessage ("Hint: use \"pload ALL\" command to load standard commands\r\n", 1);
-    return function(theText) { console.warn(theText); };
+    //DRAWEXE.eval ("dversion");
-  })(),
+  }).catch ((theError) => {
-  printErr: function(theText) {
+    DRAWEXE.printMessage ("WebAssebly initialization has failed:\r\n" + theError, 4);
-    //var anElement = document.getElementById('output');
+  });
-    //anElement.innerHTML += theText + "<br>";
+}
    console.warn(theText);
  },
  canvas: (function() {
    var aCanvas = document.getElementById('occViewerCanvas');
    return aCanvas;
  })(),
  onRuntimeInitialized: function() {
    //
  }
 };
 const DRAWEXEInitialized = createDRAWEXE(DRAWEXE);
 DRAWEXEInitialized.then(function(Module) {
  //DRAWEXE.eval("dversion");
 });
 </script>
 </body>
--- a/src/Draw/Draw_Window.cxx
+++ b/src/Draw/Draw_Window.cxx
@ -39,6 +39,15 @@
  #include <unistd.h>
 #endif
 #if defined(__EMSCRIPTEN__)
  #include <emscripten/emscripten.h>
  //! Returns Module.noExitRuntime flag.
  EM_JS(bool, occJSModuleNoExitRuntime, (), {
    return Module.noExitRuntime === true;
  });
 #endif
 #ifdef HAVE_TK
 #if defined(__APPLE__) && !defined(HAVE_XLIB)
  // use forward declaration for small subset of used Tk functions
@ -266,6 +275,9 @@ Draw_Window::Draw_Window (const char* theTitle,
  }
  getDrawWindowList().Append (this);
 #else
  (void )theParent;
  (void )theWin;
 #endif
  init (anXY, aSize);
@ -843,7 +855,9 @@ void Draw_Window::DrawString (Standard_Integer theX, Standard_Integer theY,
 #elif defined(HAVE_XLIB)
  XDrawString (Draw_WindowDisplay, GetDrawable(), myBase->gc, theX, theY, (char* )theText, strlen(theText));
 #else
-  //
+  (void )theX;
  (void )theY;
  (void )theText;
 #endif
 }
@ -1200,11 +1214,16 @@ void Run_Appli(Standard_Boolean (*interprete) (const char*))
 {
  Interprete = interprete;
  bool toWaitInput = true;
 #ifdef __EMSCRIPTEN__
  toWaitInput = !occJSModuleNoExitRuntime();
 #endif
  // Commands will come from standard input, so set up an event handler for standard input.
  // If the input device is aEvaluate the .rc file, if one has been specified,
  // set up an event handler for standard input, and print a prompt if the input device is a terminal.
  Tcl_Channel anInChannel = Tcl_GetStdChannel(TCL_STDIN);
-  if (anInChannel)
+  if (anInChannel && toWaitInput)
  {
    Tcl_CreateChannelHandler (anInChannel, TCL_READABLE, StdinProc, (ClientData )anInChannel);
  }
@ -1237,6 +1256,11 @@ void Run_Appli(Standard_Boolean (*interprete) (const char*))
  // When there are no windows left, Tk_MainLoop returns and we exit.
  Tk_MainLoop();
 #else
  if (!toWaitInput)
  {
    return;
  }
  for (;;)
  {
    Tcl_DoOneEvent (0); // practically the same as Tk_MainLoop()
--- a/src/TKService/PACKAGES
+++ b/src/TKService/PACKAGES
@ -3,6 +3,7 @@ Graphic3d
 Xw
 Image
 Media
 Wasm
 WNT
 Cocoa
 Font
--- a/src/ViewerTest/ViewerTest_EventManager.cxx
+++ b/src/ViewerTest/ViewerTest_EventManager.cxx
@ -17,12 +17,39 @@
 #include <ViewerTest_EventManager.hxx>
 #include <AIS_AnimationCamera.hxx>
 #include <Aspect_DisplayConnection.hxx>
 #include <AIS_InteractiveContext.hxx>
 #include <AIS_Shape.hxx>
 #include <Aspect_Grid.hxx>
 #include <Draw.hxx>
 #include <Message.hxx>
 #include <ViewerTest_ContinuousRedrawer.hxx>
 #include <ViewerTest_V3dView.hxx>
 #include <ViewerTest.hxx>
 #if defined(_WIN32)
  //
 #elif defined(HAVE_XLIB)
  #include <Xw_Window.hxx>
  #include <X11/Xlib.h>
  #include <X11/Xutil.h>
 #elif defined(__EMSCRIPTEN__)
  #include <Wasm_Window.hxx>
  #include <emscripten.h>
  #include <emscripten/html5.h>
  //! Callback flushing events and redrawing the WebGL canvas.
  static void onWasmRedrawView (void* )
  {
    Handle(ViewerTest_EventManager) aViewCtrl = ViewerTest::CurrentEventManager();
    const Handle(V3d_View)& aView = ViewerTest::CurrentView();
    const Handle(AIS_InteractiveContext)& aCtx = ViewerTest::GetAISContext();
    if (!aViewCtrl.IsNull() && !aView.IsNull() && !aCtx.IsNull())
    {
      aViewCtrl->ProcessExpose();
    }
  }
 #endif
 Standard_IMPORT Standard_Boolean Draw_Interprete (const char* theCommand);
@ -48,7 +75,8 @@ ViewerTest_EventManager::ViewerTest_EventManager (const Handle(V3d_View)&
 : myCtx  (theCtx),
  myView (theView),
  myToPickPnt (Standard_False),
-  myIsTmpContRedraw (Standard_False)
+  myIsTmpContRedraw (Standard_False),
  myUpdateRequests (0)
 {
  myViewAnimation = GlobalViewAnimation();
@ -73,6 +101,9 @@ ViewerTest_EventManager::ViewerTest_EventManager (const Handle(V3d_View)&
  addActionHotKeys (Aspect_VKey_NavSlideRight,     Aspect_VKey_Right | Aspect_VKeyFlags_SHIFT);
  addActionHotKeys (Aspect_VKey_NavSlideUp,        Aspect_VKey_Up    | Aspect_VKeyFlags_SHIFT);
  addActionHotKeys (Aspect_VKey_NavSlideDown,      Aspect_VKey_Down  | Aspect_VKeyFlags_SHIFT);
  // window could be actually not yet set to the View
  //SetupWindowCallbacks (theView->Window());
 }
 //=======================================================================
@ -89,6 +120,23 @@ ViewerTest_EventManager::~ViewerTest_EventManager()
  }
 }
 // =======================================================================
 // function : UpdateMouseClick
 // purpose  :
 // =======================================================================
 bool ViewerTest_EventManager::UpdateMouseClick (const Graphic3d_Vec2i& thePoint,
                                                Aspect_VKeyMouse theButton,
                                                Aspect_VKeyFlags theModifiers,
                                                bool theIsDoubleClick)
 {
  if (theIsDoubleClick && !myView.IsNull() && !myCtx.IsNull())
  {
    FitAllAuto (myCtx, myView);
    return true;
  }
  return AIS_ViewController::UpdateMouseClick (thePoint, theButton, theModifiers, theIsDoubleClick);
 }
 //=======================================================================
 //function : UpdateMouseButtons
 //purpose  :
@ -124,7 +172,6 @@ void ViewerTest_EventManager::ProcessExpose()
 {
  if (!myView.IsNull())
  {
    myView->Invalidate();
    FlushViewEvents (myCtx, myView, true);
  }
 }
@ -136,6 +183,7 @@ void ViewerTest_EventManager::ProcessExpose()
 void ViewerTest_EventManager::handleViewRedraw (const Handle(AIS_InteractiveContext)& theCtx,
                                                const Handle(V3d_View)& theView)
 {
  myUpdateRequests = 0;
  AIS_ViewController::handleViewRedraw (theCtx, theView);
  // On non-Windows platforms Aspect_Window::InvalidateContent() from rendering thread does not work as expected
@ -148,10 +196,16 @@ void ViewerTest_EventManager::handleViewRedraw (const Handle(AIS_InteractiveCont
     && (!aRedrawer.IsStarted() || aRedrawer.IsPaused()))
    {
      myIsTmpContRedraw = true;
-    #ifndef _WIN32
+    #if !defined(_WIN32) && !defined(__EMSCRIPTEN__)
      aRedrawer.Start (theView->Window(), 60.0);
    #endif
    }
    // ask more frames
    ++myUpdateRequests;
  #if defined(__EMSCRIPTEN__)
    emscripten_async_call (onWasmRedrawView, this, 0);
  #endif
  }
  else if (myIsTmpContRedraw)
  {
@ -180,7 +234,9 @@ void ViewerTest_EventManager::ProcessConfigure (bool theIsResized)
      return;
    }
    myView->Window()->DoResize();
    myView->MustBeResized();
    myView->Invalidate();
    FlushViewEvents (myCtx, myView, true);
  }
 }
@ -191,10 +247,25 @@ void ViewerTest_EventManager::ProcessConfigure (bool theIsResized)
 //==============================================================================
 void ViewerTest_EventManager::ProcessInput()
 {
-  if (!myView.IsNull())
+  if (myView.IsNull())
  {
-    FlushViewEvents (myCtx, myView, true);
+    return;
  }
 #if defined(__EMSCRIPTEN__)
  // Queue onWasmRedrawView() callback to redraw canvas after all user input is flushed by browser.
  // Redrawing viewer on every single message would be a pointless waste of resources,
  // as user will see only the last drawn frame due to WebGL implementation details.
  if (++myUpdateRequests == 1)
  {
  #if defined(__EMSCRIPTEN__)
    emscripten_async_call (onWasmRedrawView, this, 0);
  #endif
  }
 #else
  // handle synchronously
  ProcessExpose();
 #endif
 }
 // =======================================================================
@ -538,3 +609,145 @@ void ViewerTest_EventManager::ProcessKeyPress (Aspect_VKey theKey)
    Draw_Interprete (aCmd.ToCString());
  }
 }
 #if defined(__EMSCRIPTEN__)
 //! Handle browser window resize event.
 static EM_BOOL onResizeCallback (int theEventType, const EmscriptenUiEvent* theEvent, void* )
 {
  Handle(ViewerTest_EventManager) aViewCtrl = ViewerTest::CurrentEventManager();
  if (!aViewCtrl.IsNull()
   && !ViewerTest::CurrentView().IsNull())
  {
    Handle(Wasm_Window) aWindow = Handle(Wasm_Window)::DownCast (ViewerTest::CurrentView()->Window());
    return aWindow->ProcessUiEvent (*aViewCtrl, theEventType, theEvent) ? EM_TRUE : EM_FALSE;
  }
  return EM_FALSE;
 }
 //! Handle mouse input event.
 static EM_BOOL onWasmMouseCallback (int theEventType, const EmscriptenMouseEvent* theEvent, void* )
 {
  Handle(ViewerTest_EventManager) aViewCtrl = ViewerTest::CurrentEventManager();
  if (!aViewCtrl.IsNull()
   && !ViewerTest::CurrentView().IsNull())
  {
    Handle(Wasm_Window) aWindow = Handle(Wasm_Window)::DownCast (ViewerTest::CurrentView()->Window());
    return aWindow->ProcessMouseEvent (*aViewCtrl, theEventType, theEvent) ? EM_TRUE : EM_FALSE;
  }
  return EM_FALSE;
 }
 //! Handle mouse wheel event.
 static EM_BOOL onWasmWheelCallback (int theEventType, const EmscriptenWheelEvent* theEvent, void* )
 {
  Handle(ViewerTest_EventManager) aViewCtrl = ViewerTest::CurrentEventManager();
  if (!aViewCtrl.IsNull()
   && !ViewerTest::CurrentView().IsNull())
  {
    Handle(Wasm_Window) aWindow = Handle(Wasm_Window)::DownCast (ViewerTest::CurrentView()->Window());
    return aWindow->ProcessWheelEvent (*aViewCtrl, theEventType, theEvent) ? EM_TRUE : EM_FALSE;
  }
  return EM_FALSE;
 }
 //! Handle touch input event.
 static EM_BOOL onWasmTouchCallback (int theEventType, const EmscriptenTouchEvent* theEvent, void* )
 {
  Handle(ViewerTest_EventManager) aViewCtrl = ViewerTest::CurrentEventManager();
  if (!aViewCtrl.IsNull()
   && !ViewerTest::CurrentView().IsNull())
  {
    Handle(Wasm_Window) aWindow = Handle(Wasm_Window)::DownCast (ViewerTest::CurrentView()->Window());
    return aWindow->ProcessTouchEvent (*aViewCtrl, theEventType, theEvent) ? EM_TRUE : EM_FALSE;
  }
  return EM_FALSE;
 }
 //! Handle keyboard input event.
 static EM_BOOL onWasmKeyCallback (int theEventType, const EmscriptenKeyboardEvent* theEvent, void* )
 {
  Handle(ViewerTest_EventManager) aViewCtrl = ViewerTest::CurrentEventManager();
  if (!aViewCtrl.IsNull()
   && !ViewerTest::CurrentView().IsNull())
  {
    Handle(Wasm_Window) aWindow = Handle(Wasm_Window)::DownCast (ViewerTest::CurrentView()->Window());
    aWindow->ProcessKeyEvent (*aViewCtrl, theEventType, theEvent);
    return EM_TRUE;
  }
  return EM_FALSE;
 }
 #endif
 // ==============================================================================
 // function : SetupWindowCallbacks
 // purpose  :
 // ==============================================================================
 void ViewerTest_EventManager::SetupWindowCallbacks (const Handle(Aspect_Window)& theWin)
 {
 #ifdef _WIN32
  (void )theWin;
 #elif defined(HAVE_XLIB)
  // X11
  Window anXWin = (Window )theWin->NativeHandle();
  Display* anXDisplay = (Display* )theWin->DisplayConnection()->GetDisplayAspect();
  XSynchronize (anXDisplay, 1);
  // X11 : For keyboard on SUN
  XWMHints aWmHints;
  memset (&aWmHints, 0, sizeof(aWmHints));
  aWmHints.flags = InputHint;
  aWmHints.input = 1;
  XSetWMHints (anXDisplay, anXWin, &aWmHints);
  XSelectInput (anXDisplay, anXWin,
                ExposureMask | KeyPressMask | KeyReleaseMask
              | ButtonPressMask | ButtonReleaseMask
              | StructureNotifyMask
              | PointerMotionMask
              | Button1MotionMask | Button2MotionMask
              | Button3MotionMask | FocusChangeMask);
  Atom aDeleteWindowAtom = theWin->DisplayConnection()->GetAtom (Aspect_XA_DELETE_WINDOW);
  XSetWMProtocols (anXDisplay, anXWin, &aDeleteWindowAtom, 1);
  XSynchronize (anXDisplay, 0);
 #elif defined(__EMSCRIPTEN__)
  Handle(Wasm_Window) aWindow = Handle(Wasm_Window)::DownCast (theWin);
  if (aWindow->CanvasId().IsEmpty()
   || aWindow->CanvasId() == "#")
  {
    Message::SendFail ("Error: unable registering callbacks to Module.canvas");
    return;
  }
  const char* aTargetId = aWindow->CanvasId().ToCString();
  const EM_BOOL toUseCapture = EM_TRUE;
  void* anOpaque = NULL; //this; // unused
  // make sure to clear previously set listeners (e.g. created by another ViewerTest_EventManager instance)
  emscripten_html5_remove_all_event_listeners();
  // resize event implemented only for a window by browsers,
  // so that if web application changes canvas size by other means it should use another way to tell OCCT about resize
  emscripten_set_resize_callback     (EMSCRIPTEN_EVENT_TARGET_WINDOW, anOpaque, toUseCapture, onResizeCallback);
  emscripten_set_mousedown_callback  (aTargetId, anOpaque, toUseCapture, onWasmMouseCallback);
  emscripten_set_mouseup_callback    (aTargetId, anOpaque, toUseCapture, onWasmMouseCallback);
  emscripten_set_mousemove_callback  (aTargetId, anOpaque, toUseCapture, onWasmMouseCallback);
  emscripten_set_dblclick_callback   (aTargetId, anOpaque, toUseCapture, onWasmMouseCallback);
  emscripten_set_click_callback      (aTargetId, anOpaque, toUseCapture, onWasmMouseCallback);
  emscripten_set_mouseenter_callback (aTargetId, anOpaque, toUseCapture, onWasmMouseCallback);
  emscripten_set_mouseleave_callback (aTargetId, anOpaque, toUseCapture, onWasmMouseCallback);
  emscripten_set_wheel_callback      (aTargetId, anOpaque, toUseCapture, onWasmWheelCallback);
  emscripten_set_touchstart_callback (aTargetId, anOpaque, toUseCapture, onWasmTouchCallback);
  emscripten_set_touchend_callback   (aTargetId, anOpaque, toUseCapture, onWasmTouchCallback);
  emscripten_set_touchmove_callback  (aTargetId, anOpaque, toUseCapture, onWasmTouchCallback);
  emscripten_set_touchcancel_callback(aTargetId, anOpaque, toUseCapture, onWasmTouchCallback);
  // keyboard input requires a focusable element or EMSCRIPTEN_EVENT_TARGET_WINDOW
  emscripten_set_keydown_callback    (aTargetId, anOpaque, toUseCapture, onWasmKeyCallback);
  emscripten_set_keyup_callback      (aTargetId, anOpaque, toUseCapture, onWasmKeyCallback);
 #else
  (void )theWin;
 #endif
 }
--- a/src/ViewerTest/ViewerTest_EventManager.hxx
+++ b/src/ViewerTest/ViewerTest_EventManager.hxx
@ -22,6 +22,7 @@
 #include <TCollection_AsciiString.hxx>
 class AIS_InteractiveContext;
 class Aspect_Window;
 class V3d_View;
 DEFINE_STANDARD_HANDLE(ViewerTest_EventManager, Standard_Transient)
@ -58,6 +59,9 @@ public:
  //! Destructor.
  Standard_EXPORT virtual ~ViewerTest_EventManager();
  //! Setup or adjust window callbacks.
  Standard_EXPORT static void SetupWindowCallbacks (const Handle(Aspect_Window)& theWin);
  //! Return interactive context.
  const Handle(AIS_InteractiveContext)& Context() const { return myCtx; }
@ -75,6 +79,12 @@ public:
    myPickPntArgVec[2] = theArgZ;
  }
  //! Handle mouse button click event.
  Standard_EXPORT virtual bool UpdateMouseClick (const Graphic3d_Vec2i& thePoint,
                                                  Aspect_VKeyMouse theButton,
                                                  Aspect_VKeyFlags theModifiers,
                                                  bool theIsDoubleClick) Standard_OVERRIDE;
  //! Handle mouse button press/release event.
  Standard_EXPORT virtual bool UpdateMouseButtons (const Graphic3d_Vec2i& thePoint,
                                                   Aspect_VKeyMouse theButtons,
@ -138,6 +148,8 @@ private:
  Standard_Boolean myToPickPnt;
  Standard_Boolean myIsTmpContRedraw;
  unsigned int     myUpdateRequests; //!< counter for unhandled update requests
 };
 #endif // _ViewerTest_EventManager_HeaderFile
--- a/src/ViewerTest/ViewerTest_ViewerCommands.cxx
+++ b/src/ViewerTest/ViewerTest_ViewerCommands.cxx
@ -112,6 +112,9 @@
  #include <X11/Xutil.h>
 #elif defined(__APPLE__)
  #include <Cocoa_Window.hxx>
 #elif defined(__EMSCRIPTEN__)
  #include <Wasm_Window.hxx>
  #include <emscripten/emscripten.h>
 #else
  #include <Aspect_NeutralWindow.hxx>
 #endif
@ -135,10 +138,32 @@ static void VProcessEvents(ClientData,int);
 typedef Cocoa_Window ViewerTest_Window;
 extern void ViewerTest_SetCocoaEventManagerView (const Handle(Cocoa_Window)& theWindow);
 extern void GetCocoaScreenResolution (Standard_Integer& theWidth, Standard_Integer& theHeight);
 #elif defined(__EMSCRIPTEN__)
 typedef Wasm_Window ViewerTest_Window;
 #else
 typedef Aspect_NeutralWindow ViewerTest_Window;
 #endif
 #if defined(__EMSCRIPTEN__)
 //! Return DOM id of default WebGL canvas from Module.canvas.
 EM_JS(char*, occJSModuleCanvasId, (), {
  const aCanvasId = Module.canvas.id;
  const aNbBytes  = lengthBytesUTF8 (aCanvasId) + 1;
  const aStrPtr   = Module._malloc (aNbBytes);
  stringToUTF8 (aCanvasId, aStrPtr, aNbBytes);
  return aStrPtr;
 });
 //! Return DOM id of default WebGL canvas from Module.canvas.
 static TCollection_AsciiString getModuleCanvasId()
 {
  char* aRawId = occJSModuleCanvasId();
  TCollection_AsciiString anId (aRawId != NULL ? aRawId : "");
  free (aRawId);
  return anId;
 }
 #endif
 static Handle(ViewerTest_Window)& VT_GetWindow()
 {
  static Handle(ViewerTest_Window) aWindow;
@ -160,8 +185,6 @@ NCollection_DoubleMap <TCollection_AsciiString, Handle(V3d_View)> ViewerTest_myV
 static NCollection_DoubleMap <TCollection_AsciiString, Handle(AIS_InteractiveContext)>  ViewerTest_myContexts;
 static NCollection_DoubleMap <TCollection_AsciiString, Handle(Graphic3d_GraphicDriver)> ViewerTest_myDrivers;
 static void OSWindowSetup();
 static struct
 {
  Quantity_Color FlatColor;
@ -1663,15 +1686,18 @@ TCollection_AsciiString ViewerTest::ViewerInit (const Standard_Integer thePxLeft
  // window fit in the small screens (actual for remote desktops, see #23003).
  // The position corresponds to the window's client area, thus some
  // gap is added for window frame to be visible.
-  Standard_Integer aPxLeft   = 20;
+  Standard_Integer aPxLeft  = 20,  aPxTop    = 40;
-  Standard_Integer aPxTop    = 40;
+  Standard_Integer aPxWidth = 409, aPxHeight = 409;
-  Standard_Integer aPxWidth  = 409;
+  Standard_Boolean isDefViewSize = Standard_True;
  Standard_Integer aPxHeight = 409;
  Standard_Boolean toCreateViewer = Standard_False;
  const Standard_Boolean isVirtual = Draw_VirtualWindows || theIsVirtual;
  if (!theViewToClone.IsNull())
  {
    theViewToClone->Window()->Size (aPxWidth, aPxHeight);
    isDefViewSize = Standard_False;
  #if !defined(__EMSCRIPTEN__)
    (void )isDefViewSize;
  #endif
  }
  Handle(Graphic3d_GraphicDriverFactory) aFactory = Graphic3d_GraphicDriverFactory::DefaultDriverFactory();
@ -1692,17 +1718,29 @@ TCollection_AsciiString ViewerTest::ViewerInit (const Standard_Integer thePxLeft
  Handle(Graphic3d_GraphicDriver) aGraphicDriver;
  ViewerTest_Names aViewNames(theViewName);
-  if (ViewerTest_myViews.IsBound1 (aViewNames.GetViewName ()))
+  if (ViewerTest_myViews.IsBound1 (aViewNames.GetViewName()))
  {
    aViewNames.SetViewName (aViewNames.GetViewerName() + "/" + CreateName<Handle(V3d_View)>(ViewerTest_myViews, "View"));
  }
  if (thePxLeft != 0)
  {
    aPxLeft = thePxLeft;
  }
  if (thePxTop != 0)
  {
    aPxTop = thePxTop;
  }
  if (thePxWidth != 0)
  {
    isDefViewSize = Standard_False;
    aPxWidth = thePxWidth;
  }
  if (thePxHeight != 0)
  {
    isDefViewSize = Standard_False;
    aPxHeight = thePxHeight;
  }
  // Get graphic driver (create it or get from another view)
  const bool isNewDriver = !ViewerTest_myDrivers.IsBound1 (aViewNames.GetDriverName());
@ -1862,6 +1900,25 @@ TCollection_AsciiString ViewerTest::ViewerInit (const Standard_Integer thePxLeft
                                     aPxLeft, aPxTop,
                                     aPxWidth, aPxHeight);
  ViewerTest_SetCocoaEventManagerView (VT_GetWindow());
 #elif defined(__EMSCRIPTEN__)
  // current EGL implementation in Emscripten supports only one global WebGL canvas returned by Module.canvas property;
  // the code should be revised for handling multiple canvas elements (which is technically also possible)
  TCollection_AsciiString aCanvasId = getModuleCanvasId();
  if (!aCanvasId.IsEmpty())
  {
    aCanvasId = TCollection_AsciiString("#") + aCanvasId;
  }
  VT_GetWindow() = new Wasm_Window (aCanvasId);
  Graphic3d_Vec2i aRealSize;
  VT_GetWindow()->Size (aRealSize.x(), aRealSize.y());
  if (!isDefViewSize || (aRealSize.x() <= 0 && aRealSize.y() <= 0))
  {
    // Wasm_Window wraps an existing HTML element without creating a new one.
    // Keep size defined on a web page instead of defaulting to 409x409 (as in case of other platform),
    // but resize canvas if vinit has been called with explicitly specified dimensions.
    VT_GetWindow()->SetSizeLogical (Graphic3d_Vec2d (aPxWidth, aPxHeight));
  }
 #else
  // not implemented
  VT_GetWindow() = new Aspect_NeutralWindow();
@ -1887,7 +1944,8 @@ TCollection_AsciiString ViewerTest::ViewerInit (const Standard_Integer thePxLeft
  ViewerTest_myViews.Bind (aViewNames.GetViewName(), aView);
  // Setup for X11 or NT
-  OSWindowSetup();
+  SetDisplayConnection (ViewerTest::CurrentView()->Viewer()->Driver()->GetDisplayConnection());
  ViewerTest_EventManager::SetupWindowCallbacks (VT_GetWindow());
  // Set parameters for V3d_View and V3d_Viewer
  const Handle (V3d_View) aV3dView = ViewerTest::CurrentView();
@ -2540,15 +2598,7 @@ void ActivateView (const TCollection_AsciiString& theViewName,
    ViewerTest::CurrentView (aView);
    ViewerTest::SetAISContext (anAISContext);
    aView->Window()->SetTitle (TCollection_AsciiString("3D View - ") + theViewName + "(*)");
-#if defined(_WIN32)
+    VT_GetWindow() = Handle(ViewerTest_Window)::DownCast(ViewerTest::CurrentView()->Window());
    VT_GetWindow() = Handle(WNT_Window)::DownCast(ViewerTest::CurrentView()->Window());
 #elif defined(HAVE_XLIB)
    VT_GetWindow() = Handle(Xw_Window)::DownCast(ViewerTest::CurrentView()->Window());
 #elif defined(__APPLE__)
    VT_GetWindow() = Handle(Cocoa_Window)::DownCast(ViewerTest::CurrentView()->Window());
 #else
    VT_GetWindow() = Handle(Aspect_NeutralWindow)::DownCast(ViewerTest::CurrentView()->Window());
 #endif
    SetDisplayConnection(ViewerTest::CurrentView()->Viewer()->Driver()->GetDisplayConnection());
    if (theToUpdate)
    {
@ -3473,45 +3523,6 @@ int ViewerMainLoop (Standard_Integer , const char** )
 }
 #endif
 //==============================================================================
 //function : OSWindowSetup
 //purpose  : Setup for the X11 window to be able to catch the event
 //==============================================================================
 static void OSWindowSetup()
 {
 #ifdef _WIN32
  //
 #elif defined(HAVE_XLIB)
  // X11
  Window anXWin = VT_GetWindow()->XWindow();
  SetDisplayConnection (ViewerTest::CurrentView()->Viewer()->Driver()->GetDisplayConnection());
  Display* aDisplay = (Display* )GetDisplayConnection()->GetDisplayAspect();
  XSynchronize (aDisplay, 1);
  // X11 : For keyboard on SUN
  XWMHints aWmHints;
  memset (&aWmHints, 0, sizeof(aWmHints));
  aWmHints.flags = InputHint;
  aWmHints.input = 1;
  XSetWMHints (aDisplay, anXWin, &aWmHints);
  XSelectInput (aDisplay, anXWin,
                ExposureMask | KeyPressMask | KeyReleaseMask
              | ButtonPressMask | ButtonReleaseMask
              | StructureNotifyMask
              | PointerMotionMask
              | Button1MotionMask | Button2MotionMask
              | Button3MotionMask | FocusChangeMask);
  Atom aDeleteWindowAtom = GetDisplayConnection()->GetAtom (Aspect_XA_DELETE_WINDOW);
  XSetWMProtocols (aDisplay, anXWin, &aDeleteWindowAtom, 1);
  XSynchronize (aDisplay, 0);
 #else
  //
 #endif
 }
 //==============================================================================
 //function : VFit
 //purpose  :
--- a/src/WNT/WNT_Window.cxx
+++ b/src/WNT/WNT_Window.cxx
@ -21,7 +21,6 @@
 #if defined(_WIN32) && !defined(OCCT_UWP)
 #include <Aspect_Convert.hxx>
 #include <Aspect_ScrollDelta.hxx>
 #include <Aspect_WindowDefinitionError.hxx>
 #include <Aspect_WindowError.hxx>
--- a/src/Wasm/FILES
+++ b/src/Wasm/FILES
@ -0,0 +1,2 @@
 Wasm_Window.cxx
 Wasm_Window.hxx
--- a/src/Wasm/Wasm_Window.cxx
+++ b/src/Wasm/Wasm_Window.cxx
@ -0,0 +1,779 @@
 // Created by: Kirill Gavrilov
 // Copyright (c) 2021 OPEN CASCADE SAS
 //
 // This file is part of Open CASCADE Technology software library.
 //
 // This library is free software; you can redistribute it and/or modify it under
 // the terms of the GNU Lesser General Public License version 2.1 as published
 // by the Free Software Foundation, with special exception defined in the file
 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
 // distribution for complete text of the license and disclaimer of any warranty.
 //
 // Alternatively, this file may be used under the terms of Open CASCADE
 // commercial license or contractual agreement.
 #include <Wasm_Window.hxx>
 #include <Aspect_ScrollDelta.hxx>
 #include <Aspect_WindowInputListener.hxx>
 #if defined(__EMSCRIPTEN__)
  #include <emscripten.h>
  #include <emscripten/html5.h>
  #include <emscripten/key_codes.h>
 #endif
 IMPLEMENT_STANDARD_RTTIEXT(Wasm_Window, Aspect_Window)
 // =======================================================================
 // function : Wasm_Window
 // purpose  :
 // =======================================================================
 Wasm_Window::Wasm_Window (const TCollection_AsciiString& theCanvasId,
                          const bool theToScaleBacking)
 : myCanvasId (theCanvasId),
  mySize (0),
  myDevicePixelRatio (1.0),
  myToScaleBacking (theToScaleBacking),
  myIsMapped (true)
 {
 #if defined(__EMSCRIPTEN__)
  myDevicePixelRatio = emscripten_get_device_pixel_ratio();
  emscripten_get_canvas_element_size (myCanvasId.ToCString(), &mySize.x(), &mySize.y());
  if (myToScaleBacking)
  {
    myDevicePixelRatio = emscripten_get_device_pixel_ratio();
    Graphic3d_Vec2d aCssSize;
    emscripten_get_element_css_size (myCanvasId.ToCString(), &aCssSize.x(), &aCssSize.y());
    Graphic3d_Vec2i aCanvasSize = Graphic3d_Vec2i (aCssSize * myDevicePixelRatio);
    if (aCanvasSize != mySize)
    {
      mySize = aCanvasSize;
      emscripten_set_canvas_element_size (myCanvasId.ToCString(), aCanvasSize.x(), aCanvasSize.y());
      emscripten_set_element_css_size    (myCanvasId.ToCString(), aCssSize.x(),    aCssSize.y());
    }
  }
 #endif
 }
 // =======================================================================
 // function : ~Wasm_Window
 // purpose  :
 // =======================================================================
 Wasm_Window::~Wasm_Window()
 {
  //
 }
 // =======================================================================
 // function : DoResize
 // purpose  :
 // =======================================================================
 Aspect_TypeOfResize Wasm_Window::DoResize()
 {
  if (IsVirtual())
  {
    return Aspect_TOR_UNKNOWN;
  }
 #if defined(__EMSCRIPTEN__)
  emscripten_get_canvas_element_size (myCanvasId.ToCString(), &mySize.x(), &mySize.y());
  if (myToScaleBacking)
  {
    myDevicePixelRatio = emscripten_get_device_pixel_ratio();
    Graphic3d_Vec2d aCssSize;
    emscripten_get_element_css_size (myCanvasId.ToCString(), &aCssSize.x(), &aCssSize.y());
    Graphic3d_Vec2i aCanvasSize = Graphic3d_Vec2i (aCssSize * myDevicePixelRatio);
    if (aCanvasSize != mySize)
    {
      mySize = aCanvasSize;
      emscripten_set_canvas_element_size (myCanvasId.ToCString(), aCanvasSize.x(), aCanvasSize.y());
      emscripten_set_element_css_size    (myCanvasId.ToCString(), aCssSize.x(),    aCssSize.y());
    }
  }
 #endif
  return Aspect_TOR_UNKNOWN;
 }
 // =======================================================================
 // function : Ratio
 // purpose  :
 // =======================================================================
 Standard_Real Wasm_Window::Ratio() const
 {
  Graphic3d_Vec2i aCanvasSize = mySize;
  if (!IsVirtual())
  {
  #if defined(__EMSCRIPTEN__)
    emscripten_get_canvas_element_size (myCanvasId.ToCString(), &aCanvasSize.x(), &aCanvasSize.y());
  #endif
  }
  return (aCanvasSize.x() != 0 && aCanvasSize.y() != 0)
        ? Standard_Real(aCanvasSize.x()) / Standard_Real(aCanvasSize.y())
        : 1.0;
 }
 // =======================================================================
 // function : Position
 // purpose  :
 // =======================================================================
 void Wasm_Window::Position (Standard_Integer& theX1, Standard_Integer& theY1,
                            Standard_Integer& theX2, Standard_Integer& theY2) const
 {
  theX1 = 0;
  theY1 = 0;
  if (IsVirtual())
  {
    theX2 = mySize.x();
    theY2 = mySize.y();
    return;
  }
 #if defined(__EMSCRIPTEN__)
  emscripten_get_canvas_element_size (myCanvasId.ToCString(), &theX2, &theY2);
 #endif
 }
 // =======================================================================
 // function : Size
 // purpose  :
 // =======================================================================
 void Wasm_Window::Size (Standard_Integer& theWidth,
                        Standard_Integer& theHeight) const
 {
  if (IsVirtual())
  {
    theWidth  = mySize.x();
    theHeight = mySize.y();
    return;
  }
 #if defined(__EMSCRIPTEN__)
  emscripten_get_canvas_element_size (myCanvasId.ToCString(), &theWidth, &theHeight);
 #endif
 }
 // =======================================================================
 // function : SetSizeLogical
 // purpose  :
 // =======================================================================
 void Wasm_Window::SetSizeLogical (const Graphic3d_Vec2d& theSize)
 {
  mySize = Graphic3d_Vec2i (theSize * myDevicePixelRatio);
  if (IsVirtual())
  {
    return;
  }
 #if defined(__EMSCRIPTEN__)
  emscripten_set_canvas_element_size (myCanvasId.ToCString(), mySize.x(),  mySize.y());
  emscripten_set_element_css_size    (myCanvasId.ToCString(), theSize.x(), theSize.y());
 #endif
 }
 // =======================================================================
 // function : SetSizeBacking
 // purpose  :
 // =======================================================================
 void Wasm_Window::SetSizeBacking (const Graphic3d_Vec2i& theSize)
 {
  mySize = theSize;
  if (IsVirtual())
  {
    return;
  }
 #if defined(__EMSCRIPTEN__)
  Graphic3d_Vec2i aCanvasSize = mySize;
  Graphic3d_Vec2d aCssSize = Graphic3d_Vec2d (mySize) / myDevicePixelRatio;
  emscripten_set_canvas_element_size (myCanvasId.ToCString(), aCanvasSize.x(), aCanvasSize.y());
  emscripten_set_element_css_size    (myCanvasId.ToCString(), aCssSize.x(),    aCssSize.y());
 #endif
 }
 // =======================================================================
 // function : InvalidateContent
 // purpose  :
 // =======================================================================
 void Wasm_Window::InvalidateContent (const Handle(Aspect_DisplayConnection)& )
 {
  //
 }
 // =======================================================================
 // function : ProcessMessage
 // purpose  :
 // =======================================================================
 bool Wasm_Window::ProcessMessage (Aspect_WindowInputListener& theListener,
                                  int theEventType, const void* theEvent)
 {
 #if defined(__EMSCRIPTEN__)
  switch (theEventType)
  {
    case EMSCRIPTEN_EVENT_MOUSEMOVE:
    case EMSCRIPTEN_EVENT_MOUSEDOWN:
    case EMSCRIPTEN_EVENT_MOUSEUP:
    case EMSCRIPTEN_EVENT_CLICK:
    case EMSCRIPTEN_EVENT_DBLCLICK:
    case EMSCRIPTEN_EVENT_MOUSEENTER:
    case EMSCRIPTEN_EVENT_MOUSELEAVE:
    {
      return ProcessMouseEvent (theListener, theEventType, (const EmscriptenMouseEvent* )theEvent);
    }
    case EMSCRIPTEN_EVENT_TOUCHSTART:
    case EMSCRIPTEN_EVENT_TOUCHMOVE:
    case EMSCRIPTEN_EVENT_TOUCHEND:
    case EMSCRIPTEN_EVENT_TOUCHCANCEL:
    {
      return ProcessTouchEvent (theListener, theEventType, (const EmscriptenTouchEvent* )theEvent);
    }
    case EMSCRIPTEN_EVENT_WHEEL:
    {
      return ProcessWheelEvent (theListener, theEventType, (const EmscriptenWheelEvent* )theEvent);
    }
    case EMSCRIPTEN_EVENT_KEYDOWN:
    case EMSCRIPTEN_EVENT_KEYUP:
    case EMSCRIPTEN_EVENT_KEYPRESS:
    {
      return ProcessKeyEvent (theListener, theEventType, (const EmscriptenKeyboardEvent* )theEvent);
    }
    case EMSCRIPTEN_EVENT_RESIZE:
    case EMSCRIPTEN_EVENT_CANVASRESIZED:
    {
      return ProcessUiEvent (theListener, theEventType, (const EmscriptenUiEvent* )theEvent);
    }
  }
  return false;
 #else
  (void )theListener;
  (void )theEventType;
  (void )theEvent;
  return false;
 #endif
 }
 // =======================================================================
 // function : ProcessMouseEvent
 // purpose  :
 // =======================================================================
 bool Wasm_Window::ProcessMouseEvent (Aspect_WindowInputListener& theListener,
                                     int theEventType, const EmscriptenMouseEvent* theEvent)
 {
 #if defined(__EMSCRIPTEN__)
  const Graphic3d_Vec2d aNewPos2d = ConvertPointToBacking (Graphic3d_Vec2d (theEvent->targetX, theEvent->targetY));
  const Graphic3d_Vec2i aNewPos2i = Graphic3d_Vec2i (aNewPos2d + Graphic3d_Vec2d (0.5));
  Aspect_VKeyFlags aFlags = 0;
  if (theEvent->ctrlKey  == EM_TRUE) { aFlags |= Aspect_VKeyFlags_CTRL;  }
  if (theEvent->shiftKey == EM_TRUE) { aFlags |= Aspect_VKeyFlags_SHIFT; }
  if (theEvent->altKey   == EM_TRUE) { aFlags |= Aspect_VKeyFlags_ALT;   }
  if (theEvent->metaKey  == EM_TRUE) { aFlags |= Aspect_VKeyFlags_META;  }
  const bool isEmulated = false;
  const Aspect_VKeyMouse aButtons = Wasm_Window::MouseButtonsFromNative (theEvent->buttons);
  switch (theEventType)
  {
    case EMSCRIPTEN_EVENT_MOUSEMOVE:
    {
      if ((aNewPos2i.x() < 0 || aNewPos2i.x() > mySize.x()
        || aNewPos2i.y() < 0 || aNewPos2i.y() > mySize.y())
        && theListener.PressedMouseButtons() == Aspect_VKeyMouse_NONE)
      {
        return false;
      }
      if (theListener.UpdateMousePosition (aNewPos2i, aButtons, aFlags, isEmulated))
      {
        theListener.ProcessInput();
      }
      break;
    }
    case EMSCRIPTEN_EVENT_MOUSEDOWN:
    case EMSCRIPTEN_EVENT_MOUSEUP:
    {
      if (aNewPos2i.x() < 0 || aNewPos2i.x() > mySize.x()
       || aNewPos2i.y() < 0 || aNewPos2i.y() > mySize.y())
      {
        return false;
      }
      if (theListener.UpdateMouseButtons (aNewPos2i, aButtons, aFlags, isEmulated))
      {
        theListener.ProcessInput();
      }
      break;
    }
    case EMSCRIPTEN_EVENT_CLICK:
    case EMSCRIPTEN_EVENT_DBLCLICK:
    {
      if (aNewPos2i.x() < 0 || aNewPos2i.x() > mySize.x()
       || aNewPos2i.y() < 0 || aNewPos2i.y() > mySize.y())
      {
        return false;
      }
      break;
    }
    case EMSCRIPTEN_EVENT_MOUSEENTER:
    {
      break;
    }
    case EMSCRIPTEN_EVENT_MOUSELEAVE:
    {
      // there is no SetCapture() support, so that mouse unclick events outside canvas will not arrive,
      // so we have to forget current state...
      if (theListener.UpdateMouseButtons (aNewPos2i, Aspect_VKeyMouse_NONE, aFlags, isEmulated))
      {
        theListener.ProcessInput();
      }
      break;
    }
  }
  return true;
 #else
  (void )theListener;
  (void )theEventType;
  (void )theEvent;
  return false;
 #endif
 }
 // =======================================================================
 // function : ProcessWheelEvent
 // purpose  :
 // =======================================================================
 bool Wasm_Window::ProcessWheelEvent (Aspect_WindowInputListener& theListener,
                                     int theEventType, const EmscriptenWheelEvent* theEvent)
 {
 #if defined(__EMSCRIPTEN__)
  if (theEventType != EMSCRIPTEN_EVENT_WHEEL)
  {
    return false;
  }
  const Graphic3d_Vec2d aNewPos2d = ConvertPointToBacking (Graphic3d_Vec2d (theEvent->mouse.targetX, theEvent->mouse.targetY));
  const Graphic3d_Vec2i aNewPos2i = Graphic3d_Vec2i (aNewPos2d + Graphic3d_Vec2d (0.5));
  if (aNewPos2i.x() < 0 || aNewPos2i.x() > mySize.x()
   || aNewPos2i.y() < 0 || aNewPos2i.y() > mySize.y())
  {
    return false;
  }
  double aDelta = 0.0;
  switch (theEvent->deltaMode)
  {
    case DOM_DELTA_PIXEL:
    {
      aDelta = theEvent->deltaY / (5.0 * DevicePixelRatio());
      break;
    }
    case DOM_DELTA_LINE:
    {
      aDelta = theEvent->deltaY * 8.0;
      break;
    }
    case DOM_DELTA_PAGE:
    {
      aDelta = theEvent->deltaY >= 0.0 ? 24.0 : -24.0;
      break;
    }
  }
  aDelta /= 15.0;
  if (theListener.UpdateMouseScroll (Aspect_ScrollDelta (aNewPos2i, -aDelta)))
  {
    theListener.ProcessInput();
  }
  return true;
 #else
  (void )theListener;
  (void )theEventType;
  (void )theEvent;
  return false;
 #endif
 }
 // =======================================================================
 // function : ProcessTouchEvent
 // purpose  :
 // =======================================================================
 bool Wasm_Window::ProcessTouchEvent (Aspect_WindowInputListener& theListener,
                                     int theEventType, const EmscriptenTouchEvent* theEvent)
 {
  bool hasUpdates = false;
 #if defined(__EMSCRIPTEN__)
  if (theEventType != EMSCRIPTEN_EVENT_TOUCHSTART
   && theEventType != EMSCRIPTEN_EVENT_TOUCHMOVE
   && theEventType != EMSCRIPTEN_EVENT_TOUCHEND
   && theEventType != EMSCRIPTEN_EVENT_TOUCHCANCEL)
  {
    return false;
  }
  for (int aTouchIter = 0; aTouchIter < theEvent->numTouches; ++aTouchIter)
  {
    const EmscriptenTouchPoint& aTouch = theEvent->touches[aTouchIter];
    if (!aTouch.isChanged)
    {
      continue;
    }
    const Standard_Size aTouchId = (Standard_Size )aTouch.identifier;
    const Graphic3d_Vec2d aNewPos2d = ConvertPointToBacking (Graphic3d_Vec2d (aTouch.targetX, aTouch.targetY));
    const Graphic3d_Vec2i aNewPos2i = Graphic3d_Vec2i (aNewPos2d + Graphic3d_Vec2d (0.5));
    switch (theEventType)
    {
      case EMSCRIPTEN_EVENT_TOUCHSTART:
      {
        if (aNewPos2i.x() >= 0 && aNewPos2i.x() < mySize.x()
         && aNewPos2i.y() >= 0 && aNewPos2i.y() < mySize.y())
        {
          hasUpdates = true;
          theListener.AddTouchPoint (aTouchId, aNewPos2d);
        }
        break;
      }
      case EMSCRIPTEN_EVENT_TOUCHMOVE:
      {
        const int anOldIndex = theListener.TouchPoints().FindIndex (aTouchId);
        if (anOldIndex != 0)
        {
          hasUpdates = true;
          theListener.UpdateTouchPoint (aTouchId, aNewPos2d);
        }
        break;
      }
      case EMSCRIPTEN_EVENT_TOUCHEND:
      case EMSCRIPTEN_EVENT_TOUCHCANCEL:
      {
        if (theListener.RemoveTouchPoint (aTouchId))
        {
          hasUpdates = true;
        }
        break;
      }
    }
  }
  if (hasUpdates)
  {
    theListener.ProcessInput();
  }
 #else
  (void )theEventType;
  (void )theEvent;
 #endif
  return hasUpdates || theListener.HasTouchPoints();
 }
 // =======================================================================
 // function : ProcessKeyEvent
 // purpose  :
 // =======================================================================
 bool Wasm_Window::ProcessKeyEvent (Aspect_WindowInputListener& theListener,
                                   int theEventType, const EmscriptenKeyboardEvent* theEvent)
 {
 #if defined(__EMSCRIPTEN__)
  if (theEventType != EMSCRIPTEN_EVENT_KEYDOWN
   && theEventType != EMSCRIPTEN_EVENT_KEYUP
   && theEventType != EMSCRIPTEN_EVENT_KEYPRESS)
  {
    return false;
  }
  const double aTimeStamp = theListener.EventTime();
  const Aspect_VKey aVKey = Wasm_Window::VirtualKeyFromNative (theEvent->keyCode);
  if (aVKey == Aspect_VKey_UNKNOWN)
  {
    return false;
  }
  switch (theEventType)
  {
    case EMSCRIPTEN_EVENT_KEYDOWN:
    {
      if (theEvent->repeat == EM_TRUE)
      {
        return false;
      }
      theListener.KeyDown (aVKey, aTimeStamp);
      theListener.ProcessInput();
      return false;
    }
    case EMSCRIPTEN_EVENT_KEYUP:
    {
      theListener.KeyUp (aVKey, aTimeStamp);
      theListener.ProcessInput();
      return false;
    }
  }
 #else
  (void )theListener;
  (void )theEventType;
  (void )theEvent;
 #endif
  return false;
 }
 // =======================================================================
 // function : ProcessUiEvent
 // purpose  :
 // =======================================================================
 bool Wasm_Window::ProcessUiEvent (Aspect_WindowInputListener& theListener,
                                  int theEventType, const EmscriptenUiEvent* )
 {
 #if defined(__EMSCRIPTEN__)
  if (theEventType != EMSCRIPTEN_EVENT_RESIZE
   && theEventType != EMSCRIPTEN_EVENT_CANVASRESIZED)
  {
    return false;
  }
 #else
  (void )theEventType;
 #endif
  theListener.ProcessConfigure (true);
  return true;
 }
 // =======================================================================
 // function : MouseButtonsFromNative
 // purpose  :
 // =======================================================================
 Aspect_VKeyMouse Wasm_Window::MouseButtonsFromNative (unsigned short theButtons)
 {
  Aspect_VKeyMouse aButtons = Aspect_VKeyMouse_NONE;
  if ((theButtons & 0x1) != 0)
  {
    aButtons |= Aspect_VKeyMouse_LeftButton;
  }
  if ((theButtons & 0x2) != 0)
  {
    aButtons |= Aspect_VKeyMouse_RightButton;
  }
  if ((theButtons & 0x4) != 0)
  {
    aButtons |= Aspect_VKeyMouse_MiddleButton;
  }
  return aButtons;
 }
 // =======================================================================
 // function : VirtualKeyFromNative
 // purpose  :
 // =======================================================================
 Aspect_VKey Wasm_Window::VirtualKeyFromNative (Standard_Integer theKey)
 {
 #if defined(__EMSCRIPTEN__)
  if (theKey >= DOM_VK_0
   && theKey <= DOM_VK_9)
  {
    // numpad keys
    return Aspect_VKey((theKey - DOM_VK_0) + Aspect_VKey_0);
  }
  if (theKey >= DOM_VK_A
   && theKey <= DOM_VK_Z)
  {
    // main latin alphabet keys
    return Aspect_VKey((theKey - DOM_VK_A) + Aspect_VKey_A);
  }
  if (theKey >= DOM_VK_F1
   && theKey <= DOM_VK_F24)
  {
    // special keys
    if (theKey <= DOM_VK_F12)
    {
      return Aspect_VKey((theKey - DOM_VK_F1) + Aspect_VKey_F1);
    }
    return Aspect_VKey_UNKNOWN;
  }
  if (theKey >= DOM_VK_NUMPAD0
   && theKey <= DOM_VK_NUMPAD9)
  {
    // numpad keys
    return Aspect_VKey((theKey - DOM_VK_NUMPAD0) + Aspect_VKey_Numpad0);
  }
  switch (theKey)
  {
    case DOM_VK_CANCEL:
    case DOM_VK_HELP:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_BACK_SPACE:
      return Aspect_VKey_Backspace;
    case DOM_VK_TAB:
      return Aspect_VKey_Tab;
    case DOM_VK_CLEAR:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_RETURN:
    case DOM_VK_ENTER:
      return Aspect_VKey_Enter;
    case DOM_VK_SHIFT:
      return Aspect_VKey_Shift;
    case DOM_VK_CONTROL:
      return Aspect_VKey_Control;
    case DOM_VK_ALT:
      return Aspect_VKey_Alt;
    case DOM_VK_PAUSE:
    case DOM_VK_CAPS_LOCK:
    case DOM_VK_KANA:
    //case DOM_VK_HANGUL:
    case DOM_VK_EISU:
    case DOM_VK_JUNJA:
    case DOM_VK_FINAL:
    case DOM_VK_HANJA:
    //case DOM_VK_KANJI:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_ESCAPE:
      return Aspect_VKey_Escape;
    case DOM_VK_CONVERT:
    case DOM_VK_NONCONVERT:
    case DOM_VK_ACCEPT:
    case DOM_VK_MODECHANGE:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_SPACE:
      return Aspect_VKey_Space;
    case DOM_VK_PAGE_UP:
      return Aspect_VKey_PageUp;
    case DOM_VK_PAGE_DOWN:
      return Aspect_VKey_PageDown;
    case DOM_VK_END:
      return Aspect_VKey_End;
    case DOM_VK_HOME:
      return Aspect_VKey_Home;
    case DOM_VK_LEFT:
      return Aspect_VKey_Left;
    case DOM_VK_UP:
      return Aspect_VKey_Up;
    case DOM_VK_RIGHT:
      return Aspect_VKey_Right;
    case DOM_VK_DOWN:
      return Aspect_VKey_Down;
    case DOM_VK_SELECT:
    case DOM_VK_PRINT:
    case DOM_VK_EXECUTE:
    case DOM_VK_PRINTSCREEN:
    case DOM_VK_INSERT:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_DELETE:
      return Aspect_VKey_Delete;
    case DOM_VK_COLON:
      return Aspect_VKey_Comma;
    case DOM_VK_SEMICOLON:
      return Aspect_VKey_Semicolon;
    case DOM_VK_LESS_THAN:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_EQUALS:
      return Aspect_VKey_Equal;
    case DOM_VK_GREATER_THAN:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_QUESTION_MARK:
      return Aspect_VKey_Slash;
    case DOM_VK_AT: // @ key
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_WIN:
      return Aspect_VKey_Meta;
    case DOM_VK_CONTEXT_MENU:
    case DOM_VK_SLEEP:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_MULTIPLY:
      return Aspect_VKey_NumpadMultiply;
    case DOM_VK_ADD:
      return Aspect_VKey_NumpadAdd;
    case DOM_VK_SEPARATOR:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_SUBTRACT:
      return Aspect_VKey_NumpadSubtract;
    case DOM_VK_DECIMAL:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_DIVIDE:
      return Aspect_VKey_NumpadDivide;
    case DOM_VK_NUM_LOCK:
      return Aspect_VKey_Numlock;
    case DOM_VK_SCROLL_LOCK:
      return Aspect_VKey_Scroll;
    case DOM_VK_WIN_OEM_FJ_JISHO:
    case DOM_VK_WIN_OEM_FJ_MASSHOU:
    case DOM_VK_WIN_OEM_FJ_TOUROKU:
    case DOM_VK_WIN_OEM_FJ_LOYA:
    case DOM_VK_WIN_OEM_FJ_ROYA:
    case DOM_VK_CIRCUMFLEX:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_EXCLAMATION:
    case DOM_VK_DOUBLE_QUOTE:
    //case DOM_VK_HASH:
    case DOM_VK_DOLLAR:
    case DOM_VK_PERCENT:
    case DOM_VK_AMPERSAND:
    case DOM_VK_UNDERSCORE:
    case DOM_VK_OPEN_PAREN:
    case DOM_VK_CLOSE_PAREN:
    case DOM_VK_ASTERISK:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_PLUS:
      return Aspect_VKey_Plus;
    case DOM_VK_PIPE:
    case DOM_VK_HYPHEN_MINUS:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_OPEN_CURLY_BRACKET:
      return Aspect_VKey_BracketLeft;
    case DOM_VK_CLOSE_CURLY_BRACKET:
      return Aspect_VKey_BracketRight;
    case DOM_VK_TILDE:
      return Aspect_VKey_Tilde;
    case DOM_VK_VOLUME_MUTE:
      return Aspect_VKey_VolumeMute;
    case DOM_VK_VOLUME_DOWN:
      return Aspect_VKey_VolumeDown;
    case DOM_VK_VOLUME_UP:
      return Aspect_VKey_VolumeUp;
    case DOM_VK_COMMA:
      return Aspect_VKey_Comma;
    case DOM_VK_PERIOD:
      return Aspect_VKey_Period;
    case DOM_VK_SLASH:
      return Aspect_VKey_Slash;
    case DOM_VK_BACK_QUOTE:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_OPEN_BRACKET:
      return Aspect_VKey_BracketLeft;
    case DOM_VK_BACK_SLASH:
      return Aspect_VKey_Backslash;
    case DOM_VK_CLOSE_BRACKET:
      return Aspect_VKey_BracketRight;
    case DOM_VK_QUOTE:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_META:
      return Aspect_VKey_Meta;
    case DOM_VK_ALTGR:
      return Aspect_VKey_Alt;
    case DOM_VK_WIN_ICO_HELP:
    case DOM_VK_WIN_ICO_00:
    case DOM_VK_WIN_ICO_CLEAR:
    case DOM_VK_WIN_OEM_RESET:
    case DOM_VK_WIN_OEM_JUMP:
    case DOM_VK_WIN_OEM_PA1:
    case DOM_VK_WIN_OEM_PA2:
    case DOM_VK_WIN_OEM_PA3:
    case DOM_VK_WIN_OEM_WSCTRL:
    case DOM_VK_WIN_OEM_CUSEL:
    case DOM_VK_WIN_OEM_ATTN:
    case DOM_VK_WIN_OEM_FINISH:
    case DOM_VK_WIN_OEM_COPY:
    case DOM_VK_WIN_OEM_AUTO:
    case DOM_VK_WIN_OEM_ENLW:
    case DOM_VK_WIN_OEM_BACKTAB:
    case DOM_VK_ATTN:
    case DOM_VK_CRSEL:
    case DOM_VK_EXSEL:
    case DOM_VK_EREOF:
      return Aspect_VKey_UNKNOWN;
    case DOM_VK_PLAY:
      return Aspect_VKey_MediaPlayPause;
    case DOM_VK_ZOOM:
    case DOM_VK_PA1:
    case DOM_VK_WIN_OEM_CLEAR:
      return Aspect_VKey_UNKNOWN;
  }
 #else
  (void )theKey;
 #endif
  return Aspect_VKey_UNKNOWN;
 }
--- a/src/Wasm/Wasm_Window.hxx
+++ b/src/Wasm/Wasm_Window.hxx
@ -0,0 +1,185 @@
 // Created by: Kirill Gavrilov
 // Copyright (c) 2021 OPEN CASCADE SAS
 //
 // This file is part of Open CASCADE Technology software library.
 //
 // This library is free software; you can redistribute it and/or modify it under
 // the terms of the GNU Lesser General Public License version 2.1 as published
 // by the Free Software Foundation, with special exception defined in the file
 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
 // distribution for complete text of the license and disclaimer of any warranty.
 //
 // Alternatively, this file may be used under the terms of Open CASCADE
 // commercial license or contractual agreement.
 #ifndef _Wasm_Window_HeaderFile
 #define _Wasm_Window_HeaderFile
 #include <Aspect_Window.hxx>
 #include <Aspect_VKey.hxx>
 #include <Aspect_Handle.hxx>
 #include <Graphic3d_Vec2.hxx>
 class Aspect_WindowInputListener;
 struct EmscriptenMouseEvent;
 struct EmscriptenWheelEvent;
 struct EmscriptenTouchEvent;
 struct EmscriptenKeyboardEvent;
 struct EmscriptenUiEvent;
 //! This class defines WebAssembly window (HTML5 canvas) intended for creation of OpenGL (WebGL) context.
 //!
 //! Note that canvas may define an independent dimensions for backing store (WebGL buffer to render)
 //! and for CSS (logical units to present buffer onto screen).
 //! These dimensions differ when browser is dragged into a high pixel density screen (HiDPI),
 //! or when user scales page in the browser (in both cases window.devicePixelRatio JavaScript property becomes not equal to 1.0).
 //!
 //! By default, Wasm_Window::DoResize() will scale backing store of a canvas basing on DevicePixelRatio() scale factor
 //! to ensure canvas content being rendered with the native resolution and not stretched by browser.
 //! This, however, might have side effects:
 //! - a slow GPU might experience performance issues on drawing into larger buffer (e.g. HiDPI);
 //! - user interface displayed in 3D Viewer (e.g. AIS presentations) should be scaled proportionally to be accessible,
 //!   which might require extra processing at application level.
 //! Consider changing ToScaleBacking flag passed to Wasm_Window constructor in case of issues.
 class Wasm_Window : public Aspect_Window
 {
  DEFINE_STANDARD_RTTIEXT(Wasm_Window, Aspect_Window)
 public:
  //! Convert Emscripten mouse buttons into Aspect_VKeyMouse.
  Standard_EXPORT static Aspect_VKeyMouse MouseButtonsFromNative (unsigned short theButtons);
  //! Convert DOM virtual key into Aspect_VKey.
  Standard_EXPORT static Aspect_VKey VirtualKeyFromNative (Standard_Integer theKey);
 public:
  //! Wraps existing HTML5 canvas into window.
  //! @param[in] theCanvasId target HTML element id defined in a querySelector() syntax
  //! @param[in] theToScaleBacking when TRUE, window will automatically scale backing store of canvas
  //!                              basing on DevicePixelRatio() scale factor within DoResize()
  Standard_EXPORT Wasm_Window (const TCollection_AsciiString& theCanvasId,
                               const bool theToScaleBacking = true);
  //! Destroys the window.
  Standard_EXPORT virtual ~Wasm_Window();
  //! Return true if window is not hidden.
  virtual Standard_Boolean IsMapped() const Standard_OVERRIDE { return myIsMapped; }
  //! Change window mapped flag to TRUE.
  virtual void Map()   const Standard_OVERRIDE { myIsMapped = Standard_True; }
  //! Change window mapped flag to FALSE.
  virtual void Unmap() const Standard_OVERRIDE { myIsMapped = Standard_False; }
  //! Resize window.
  //! In case of ToScaleBacking flag, this method will resize the backing store of canvas
  //! basing on DevicePixelRatio() scale factor and CSS canvas size.
  Standard_EXPORT virtual Aspect_TypeOfResize DoResize() Standard_OVERRIDE;
  //! Apply the mapping change to the window.
  virtual Standard_Boolean DoMapping() const Standard_OVERRIDE { return Standard_True; }
  //! Returns window ratio equal to the physical width/height dimensions.
  Standard_EXPORT virtual Standard_Real Ratio() const Standard_OVERRIDE;
  //! Returns The Window POSITION in PIXEL
  Standard_EXPORT virtual void Position (Standard_Integer& theX1,
                                         Standard_Integer& theY1,
                                         Standard_Integer& theX2,
                                         Standard_Integer& theY2) const Standard_OVERRIDE;
  //! Return the window size in pixels.
  Standard_EXPORT virtual void Size (Standard_Integer& theWidth,
                                     Standard_Integer& theHeight) const Standard_OVERRIDE;
  //! Set new window size in logical (density-independent units).
  //! Backing store will be resized basing on DevicePixelRatio().
  Standard_EXPORT void SetSizeLogical (const Graphic3d_Vec2d& theSize);
  //! Set new window size in pixels.
  //! Logical size of the element will be resized basing on DevicePixelRatio().
  Standard_EXPORT void SetSizeBacking (const Graphic3d_Vec2i& theSize);
  //! Returns canvas id.
  const TCollection_AsciiString& CanvasId() const { return myCanvasId; }
  //! Current EGL implementation in Emscripten accepts only 0 for native window id.
  virtual Aspect_Drawable NativeHandle() const Standard_OVERRIDE { return 0; }
  //! Always returns 0 for this class.
  virtual Aspect_Drawable NativeParentHandle() const Standard_OVERRIDE { return 0; }
  //! Always returns 0 for this class.
  virtual Aspect_FBConfig NativeFBConfig() const Standard_OVERRIDE { return 0; }
  //! Return device pixel ratio (logical to backing store scale factor).
  virtual Standard_Real DevicePixelRatio() const Standard_OVERRIDE { return myDevicePixelRatio; }
  //! Invalidate entire window content through generation of Expose event.
  Standard_EXPORT virtual void InvalidateContent (const Handle(Aspect_DisplayConnection)& theDisp) Standard_OVERRIDE;
 public:
  //! Process a single window message.
  //! @param[in,out] theListener listener to redirect message
  //! @param[in] theEventType message type to process
  //! @param[in] theEvent message to process
  //! @return TRUE if message has been processed
  Standard_EXPORT virtual bool ProcessMessage (Aspect_WindowInputListener& theListener,
                                               int theEventType, const void* theEvent);
  //! Process a mouse input message.
  //! @param[in,out] theListener listener to redirect message
  //! @param[in] theEventType message type to process
  //! @param[in] theEvent message to process
  //! @return TRUE if message has been processed
  Standard_EXPORT virtual bool ProcessMouseEvent (Aspect_WindowInputListener& theListener,
                                                  int theEventType, const EmscriptenMouseEvent* theEvent);
  //! Process a (mouse) wheel input message.
  //! @param[in,out] theListener listener to redirect message
  //! @param[in] theEventType message type to process
  //! @param[in] theEvent message to process
  //! @return TRUE if message has been processed
  Standard_EXPORT virtual bool ProcessWheelEvent (Aspect_WindowInputListener& theListener,
                                                  int theEventType, const EmscriptenWheelEvent* theEvent);
  //! Process a mouse input message.
  //! @param[in,out] theListener listener to redirect message
  //! @param[in] theEventType message type to process
  //! @param[in] theEvent message to process
  //! @return TRUE if message has been processed
  Standard_EXPORT virtual bool ProcessTouchEvent (Aspect_WindowInputListener& theListener,
                                                  int theEventType, const EmscriptenTouchEvent* theEvent);
  //! Process a keyboard input message.
  //! @param[in,out] theListener listener to redirect message
  //! @param[in] theEventType message type to process
  //! @param[in] theEvent message to process
  //! @return TRUE if message has been processed
  Standard_EXPORT virtual bool ProcessKeyEvent (Aspect_WindowInputListener& theListener,
                                               int theEventType, const EmscriptenKeyboardEvent* theEvent);
  //! Process a UI input message (like window resize).
  //! @param[in,out] theListener listener to redirect message
  //! @param[in] theEventType message type to process
  //! @param[in] theEvent message to process
  //! @return TRUE if message has been processed
  Standard_EXPORT virtual bool ProcessUiEvent (Aspect_WindowInputListener& theListener,
                                               int theEventType, const EmscriptenUiEvent* theEvent);
 protected:
  TCollection_AsciiString  myCanvasId;
  Graphic3d_Vec2i          mySize;
  Standard_Real            myDevicePixelRatio;
  Standard_Boolean         myToScaleBacking;
  mutable Standard_Boolean myIsMapped;
 };
 #endif // _Wasm_Window_HeaderFile
--- a/src/Xw/Xw_Window.cxx
+++ b/src/Xw/Xw_Window.cxx
@ -15,7 +15,6 @@
 #include <Xw_Window.hxx>
 #include <Aspect_Convert.hxx>
 #include <Aspect_ScrollDelta.hxx>
 #include <Aspect_WindowDefinitionError.hxx>
 #include <Aspect_WindowInputListener.hxx>
@ -44,7 +43,6 @@ Xw_Window::Xw_Window (const Handle(Aspect_DisplayConnection)& theXDisplay,
                      const Standard_Integer thePxWidth,
                      const Standard_Integer thePxHeight)
 : Aspect_Window(),
  myDisplay  (theXDisplay),
  myXWindow  (0),
  myFBConfig (NULL),
  myXLeft    (thePxLeft),
@ -53,6 +51,7 @@ Xw_Window::Xw_Window (const Handle(Aspect_DisplayConnection)& theXDisplay,
  myYBottom  (thePxTop + thePxHeight),
  myIsOwnWin (Standard_True)
 {
  myDisplay = theXDisplay;
  if (thePxWidth <= 0 || thePxHeight <= 0)
  {
    throw Aspect_WindowDefinitionError("Xw_Window, Coordinate(s) out of range");
@ -129,7 +128,6 @@ Xw_Window::Xw_Window (const Handle(Aspect_DisplayConnection)& theXDisplay,
                      const Aspect_Drawable theXWin,
                      const Aspect_FBConfig theFBConfig)
 : Aspect_Window(),
  myDisplay  (theXDisplay),
  myXWindow  (theXWin),
  myFBConfig (theFBConfig),
  myXLeft    (0),
@ -138,6 +136,7 @@ Xw_Window::Xw_Window (const Handle(Aspect_DisplayConnection)& theXDisplay,
  myYBottom  (512),
  myIsOwnWin (Standard_False)
 {
  myDisplay = theXDisplay;
  if (theXWin == 0)
  {
    throw Aspect_WindowDefinitionError("Xw_Window, given invalid X window");
--- a/src/Xw/Xw_Window.hxx
+++ b/src/Xw/Xw_Window.hxx
@ -93,9 +93,6 @@ public:
  //! @return native Window handle
  Aspect_Drawable XWindow() const { return myXWindow; }
  //! @return connection to X Display
  Standard_EXPORT const Handle(Aspect_DisplayConnection)& DisplayConnection() const;
  //! @return native Window handle
  virtual Aspect_Drawable NativeHandle() const Standard_OVERRIDE
  {
@ -133,7 +130,6 @@ public:
 protected:
  Handle(Aspect_DisplayConnection) myDisplay; //!< X Display connection
  Aspect_Drawable  myXWindow;  //!< XLib window handle
  Aspect_FBConfig  myFBConfig; //!< GLXFBConfig
  Standard_Integer myXLeft;    //!< left   position in pixels