Introduce TVirtualX::GetDrawModeW method

Used in TGLPadPainter to handle Crosshair cursor drawing.

Author: linev

core/base/inc/TVirtualX.h

@@ -109,6 +109,7 @@ class TVirtualX : public TNamed, public TAttLine, public TAttFill, public TAttTe
    virtual void      SetAttMarker(WinContext_t wctxt, const TAttMarker &att);
    virtual void      SetAttText(WinContext_t wctxt, const TAttText &att);
    virtual void      SetDrawModeW(WinContext_t wctxt, EDrawMode mode);
+   virtual EDrawMode GetDrawModeW(WinContext_t wctxt);
    virtual void      ClearWindowW(WinContext_t wctxt);
    virtual void      UpdateWindowW(WinContext_t wctxt, Int_t mode);
 

core/base/src/TVirtualX.cxx

@@ -436,6 +436,14 @@ void TVirtualX::SetDrawModeW(WinContext_t /* wctxt */, EDrawMode mode)
    SetDrawMode(mode);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// Returns window draw mode
+
+TVirtualX::EDrawMode TVirtualX::GetDrawModeW(WinContext_t /* wctxt */)
+{
+   return GetDrawMode();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// Clear specified window
 

graf2d/x11/inc/TGX11.h

@@ -231,6 +231,7 @@ class TGX11 : public TVirtualX {
    void      SetAttMarker(WinContext_t wctxt, const TAttMarker &att) override;
    void      SetAttText(WinContext_t wctxt, const TAttText &att) override;
    void      SetDrawModeW(WinContext_t wctxt, EDrawMode mode) override;
+   EDrawMode GetDrawModeW(WinContext_t wctxt) override;
    void      ClearWindowW(WinContext_t wctxt) override;
    void      UpdateWindowW(WinContext_t wctxt, Int_t mode) override;
 

graf2d/x11/src/TGX11.cxx

@@ -4677,6 +4677,8 @@ void TGX11::SetAttText(WinContext_t wctxt, const TAttText &att)
    ctxt->fAttText = att;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// Set window draw mode
 
 void TGX11::SetDrawModeW(WinContext_t wctxt, EDrawMode mode)
 {
@@ -4694,3 +4696,12 @@ void TGX11::SetDrawModeW(WinContext_t wctxt, EDrawMode mode)
 
    ctxt->fDrawMode = mode;
 }
+
+////////////////////////////////////////////////////////////////////////////////
+/// Returns window draw mode
+
+TVirtualX::EDrawMode TGX11::GetDrawModeW(WinContext_t wctxt)
+{
+   auto ctxt = (XWindow_t *) wctxt;
+   return ctxt ? ctxt->fDrawMode : kCopy;
+}

graf3d/gl/src/TGLPadPainter.cxx

@@ -524,7 +524,7 @@ void TGLPadPainter::DrawLine(Double_t x1, Double_t y1, Double_t x2, Double_t y2)
       //from TView3D::ExecuteRotateView. This means in fact,
       //that TView3D wants to draw itself in a XOR mode, via
       //gVirtualX.
-      if (fWinContext) {
+      if (fWinContext && (gVirtualX->GetDrawModeW(fWinContext) == TVirtualX::kInvert)) {
          gVirtualX->DrawLineW(fWinContext,
                              gPad->XtoAbsPixel(x1), gPad->YtoAbsPixel(y1),
                              gPad->XtoAbsPixel(x2), gPad->YtoAbsPixel(y2));
@@ -564,7 +564,8 @@ void TGLPadPainter::DrawLine(Double_t x1, Double_t y1, Double_t x2, Double_t y2)
 void TGLPadPainter::DrawLineNDC(Double_t u1, Double_t v1, Double_t u2, Double_t v2)
 {
    if (fLocked) {
-      if (fWinContext) {
+      // this code used when crosshair cursor is drawn
+      if (fWinContext && (gVirtualX->GetDrawModeW(fWinContext) == TVirtualX::kInvert)) {
          const Int_t px1 = gPad->UtoPixel(u1);
          const Int_t py1 = gPad->VtoPixel(v1);
          const Int_t px2 = gPad->UtoPixel(u2);