TGScrollBar.cxx

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// @(#)root/gui:$Id$
// Author: Fons Rademakers   10/01/98
 
/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/
/**************************************************************************
 
    This source is based on Xclass95, a Win95-looking GUI toolkit.
    Copyright (C) 1996, 1997 David Barth, Ricky Ralston, Hector Peraza.
 
    Xclass95 is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.
 
**************************************************************************/
 
 
/** \class  TGScrollBar
    \ingroup guiwidgets
 
The classes in this file implement scrollbars. Scrollbars can be
either placed horizontal or vertical. A scrollbar contains three
 
\class TGScrollBarElements
\ingroup guiwidgets
The "head", "tail" and "slider". The head and
tail are fixed at either end and have the typical arrows in them.
 
\class TGHScrollBar
\ingroup guiwidgets
The TGHScrollBar will generate the following event messages:
kC_HSCROLL, kSB_SLIDERPOS, position, 0
kC_HSCROLL, kSB_SLIDERTRACK, position, 0
 
\class TGVScrollBar
\ingroup guiwidgets
The TGVScrollBar will generate the following event messages:
kC_VSCROLL, kSB_SLIDERPOS, position, 0
kC_VSCROLL, kSB_SLIDERTRACK, position, 0
 
*/
 
 
#include "TGScrollBar.h"
#include "TGResourcePool.h"
#include "TGPicture.h"
#include "TImage.h"
#include "TSystem.h"
#include "TTimer.h"
#include "TEnv.h"
#include "TVirtualX.h"
 
#include <iostream>
 
 
Pixmap_t TGScrollBar::fgBckgndPixmap = 0;
Int_t    TGScrollBar::fgScrollBarWidth = kDefaultScrollBarWidth;
 
ClassImp(TGScrollBarElement);
ClassImp(TGScrollBar);
ClassImp(TGHScrollBar);
ClassImp(TGVScrollBar);
 
 
////////////////////////////////////////////////////////////////////////////////
 
class TSBRepeatTimer : public TTimer {
private:
   TGScrollBar   *fScrollBar;   // scroll bar
   Int_t          fSmallInc;    // step
public:
   TSBRepeatTimer(TGScrollBar *s, Long_t ms, Int_t inc) : TTimer(ms, kTRUE)
      { fScrollBar = s;  fSmallInc = inc; }
 
   Bool_t Notify() override;
   Int_t  GetSmallInc() const { return fSmallInc; }
};
 
////////////////////////////////////////////////////////////////////////////////
/// Notify when timer times out and reset the timer.
 
Bool_t TSBRepeatTimer::Notify()
{
   fScrollBar->HandleTimer(this);
   Reset();
   return kFALSE;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Constructor.
 
TGScrollBarElement::TGScrollBarElement(const TGWindow *p, const TGPicture *pic,
                                       UInt_t w, UInt_t h, UInt_t options, Pixel_t back) :
                                       TGFrame(p, w, h, options | kOwnBackground, back)
{
   fPic = fPicN = pic;
   fState = kButtonUp;
   fPicD = 0;
   fStyle = 0;
   if ((gClient->GetStyle() > 1) || (p && p->InheritsFrom("TGScrollBar")))
      fStyle = gClient->GetStyle();
 
   fBgndColor = fBackground;
   fHighColor = gClient->GetResourcePool()->GetHighLightColor();
   AddInput(kEnterWindowMask | kLeaveWindowMask);
}
 
////////////////////////////////////////////////////////////////////////////////
/// destructor
 
TGScrollBarElement::~TGScrollBarElement()
{
   if (fPicD) {
      fClient->FreePicture(fPicD);
   }
}
 
////////////////////////////////////////////////////////////////////////////////
/// Change state of scrollbar element (either up or down).
 
void TGScrollBarElement::SetState(Int_t state)
{
   if (state != fState) {
      switch (state) {
         case kButtonDown:
            fOptions &= ~kRaisedFrame;
            fOptions |= kSunkenFrame;
            break;
         case kButtonUp:
         case kButtonDisabled:
            fOptions &= ~kSunkenFrame;
            fOptions |= kRaisedFrame;
            break;
      }
      fState = state;
      fClient->NeedRedraw(this);
   }
}
 
////////////////////////////////////////////////////////////////////////////////
/// Enable/Disable scroll bar button chaging the state.
 
void TGScrollBarElement::SetEnabled(Bool_t on)
{
   if (on) {
      if (fState == kButtonUp) {
         return;
      }
      SetState(kButtonUp);
      fPic = fPicN;
   } else {
      if (fState == kButtonDisabled) {
         return;
      }
      SetState(kButtonDisabled);
 
      if (!fPicD) {
         TImage *img = TImage::Create();
         if (!img) return;
         TImage *img2 = TImage::Create();
         if (!img2) {
            if (img) delete img;
            return;
         }
         TString back = gEnv->GetValue("Gui.BackgroundColor", "#c0c0c0");
         img2->FillRectangle(back.Data(), 0, 0, fPic->GetWidth(), fPic->GetHeight());
         img->SetImage(fPicN->GetPicture(), fPicN->GetMask());
         Pixmap_t mask = img->GetMask();
         img2->Merge(img, "overlay");
 
         TString name = "disbl_";
         name += fPic->GetName();
         fPicD = fClient->GetPicturePool()->GetPicture(name.Data(), img2->GetPixmap(),
                                                       mask);
         delete img;
         delete img2;
      }
      fPic = fPicD;
   }
   fClient->NeedRedraw(this);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Draw border around scollbar element.
 
void TGScrollBarElement::DrawBorder()
{
   switch (fOptions & (kSunkenFrame | kRaisedFrame)) {
      case kSunkenFrame: // pressed
         gVirtualX->DrawLine(fId, GetBlackGC()(), 0, 0, fWidth-2, 0);
         gVirtualX->DrawLine(fId, GetBlackGC()(), 0, 0, 0, fHeight-2);
         gVirtualX->DrawLine(fId, GetShadowGC()(),  1, 1, fWidth-3, 1);
         gVirtualX->DrawLine(fId, GetShadowGC()(),  1, 1, 1, fHeight-3);
 
         gVirtualX->DrawLine(fId, GetWhiteGC()(),  0, fHeight-1, fWidth-1, fHeight-1);
         gVirtualX->DrawLine(fId, GetWhiteGC()(),  fWidth-1, fHeight-1, fWidth-1, 1);
         gVirtualX->DrawLine(fId, GetBckgndGC()(),  1, fHeight-2, fWidth-2, fHeight-2);
         gVirtualX->DrawLine(fId, GetBckgndGC()(),  fWidth-2, fHeight-2, fWidth-2, 2);
 
         if (fPic) {
            int x = (fWidth - fPic->GetWidth()) >> 1;
            int y = (fHeight - fPic->GetHeight()) >> 1;
            fPic->Draw(fId, GetBckgndGC()(), x+1, y+1); // 3, 3
         }
         break;
 
      case kRaisedFrame: // normal
      case kButtonDisabled:
         if (fStyle > 0) {
            // new modern (flat) version
            if (fBackground == fHighColor) {
               gVirtualX->DrawRectangle(fId, GetShadowGC()(), 0, 0, fWidth-1, fHeight-1);
            }
            else {
               if (fPic == 0)
                  gVirtualX->DrawRectangle(fId, GetShadowGC()(), 0, 0, fWidth-1, fHeight-1);
               else
                  gVirtualX->DrawRectangle(fId, GetBckgndGC()(), 0, 0, fWidth-1, fHeight-1);
            }
            if (fParent && fParent->InheritsFrom("TGHScrollBar")) {
               if (fWidth > 20) {
                  gVirtualX->DrawLine(fId, GetShadowGC()(), (fWidth/2)-3, 4, (fWidth/2)-3, fHeight-5);
                  gVirtualX->DrawLine(fId, GetShadowGC()(), (fWidth/2),   4, (fWidth/2),   fHeight-5);
                  gVirtualX->DrawLine(fId, GetShadowGC()(), (fWidth/2)+3, 4, (fWidth/2)+3, fHeight-5);
               }
            }
            else if (fParent && fParent->InheritsFrom("TGVScrollBar")) {
               if (fHeight > 20) {
                  gVirtualX->DrawLine(fId, GetShadowGC()(), 4, (fHeight/2)-3, fWidth-5, (fHeight/2)-3);
                  gVirtualX->DrawLine(fId, GetShadowGC()(), 4, (fHeight/2)  , fWidth-5, (fHeight/2));
                  gVirtualX->DrawLine(fId, GetShadowGC()(), 4, (fHeight/2)+3, fWidth-5, (fHeight/2)+3);
               }
            }
            else { // not used in a scroll bar (e.g. in a combo box)
               gVirtualX->DrawRectangle(fId, GetShadowGC()(), 0, 0, fWidth-1, fHeight-1);
            }
         }
         else {
            gVirtualX->DrawLine(fId, GetBckgndGC()(), 0, 0, fWidth-2, 0);
            gVirtualX->DrawLine(fId, GetBckgndGC()(), 0, 0, 0, fHeight-2);
            gVirtualX->DrawLine(fId, GetHilightGC()(), 1, 1, fWidth-3, 1);
            gVirtualX->DrawLine(fId, GetHilightGC()(), 1, 1, 1, fHeight-3);
 
            gVirtualX->DrawLine(fId, GetShadowGC()(),  1, fHeight-2, fWidth-2, fHeight-2);
            gVirtualX->DrawLine(fId, GetShadowGC()(),  fWidth-2, fHeight-2, fWidth-2, 1);
            gVirtualX->DrawLine(fId, GetBlackGC()(), 0, fHeight-1, fWidth-1, fHeight-1);
            gVirtualX->DrawLine(fId, GetBlackGC()(), fWidth-1, fHeight-1, fWidth-1, 0);
         }
         if (fPic) {
            int x = (fWidth - fPic->GetWidth()) >> 1;
            int y = (fHeight - fPic->GetHeight()) >> 1;
            fPic->Draw(fId, GetBckgndGC()(), x, y); // 2, 2
         }
         break;
 
      default:
         break;
   }
}
 
////////////////////////////////////////////////////////////////////////////////
/// Handle mouse crossing event.
 
Bool_t TGScrollBarElement::HandleCrossing(Event_t *event)
{
   if (fStyle > 0) {
      TGScrollBarElement *el = 0;
      TGScrollBar *bar = 0;
      if ((event->fType == kEnterNotify) && (fState != kButtonDisabled)) {
         fBgndColor = fHighColor;
      } else {
         fBgndColor = fBackground;
      }
      if (event->fType == kLeaveNotify) {
         fBgndColor = fBackground;
      }
      gVirtualX->SetWindowBackground(fId, fBgndColor);
      TGFrame::DoRedraw();
      DrawBorder();
      if (fParent && fParent->InheritsFrom("TGScrollBar")) {
         bar = (TGScrollBar *)fParent;
         if ((el = bar->GetHead()) != this) {
            el->ChangeBackground(fBgndColor);
            el->DrawBorder();
         }
         if ((el = bar->GetTail()) != this) {
            el->ChangeBackground(fBgndColor);
            el->DrawBorder();
         }
         if ((el = bar->GetSlider()) != this) {
            el->ChangeBackground(fBgndColor);
            el->DrawBorder();
         }
      }
   }
   return kTRUE;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Constructor.
/// \param p The parent window
/// \param w The scrollbar width
/// \param h The scrollbar height
/// \param options A bitmask of options (see EFrameType)
/// \param back The background color
/// \param headPicName Filename of the "head" picture (e.g. left arrow for a horizontal scrollbar)
/// \param tailPicName Filename of the "tail" picture (e.g. right arrow for a horizontal scrollbar)
TGScrollBar::TGScrollBar(const TGWindow *p, UInt_t w, UInt_t h,
                         UInt_t options, Pixel_t back, const char *headPicName, const char *tailPicName) :
   TGFrame(p, w, h, options | kOwnBackground, back),
   fX0(0), fY0(0), fXp(0), fYp(0), fDragging(kFALSE), fGrabPointer(kTRUE),
   fRange(0), fPsize(0), fPos(0), fSliderSize(0), fSliderRange(0),
   fSmallInc(1), fHead(0), fTail(0), fSlider(0), fHeadPic(0),
   fTailPic(0), fRepeat(0), fSubw()
{
   fAccelerated = kFALSE;
 
   fBgndColor = fBackground;
   fHighColor = gClient->GetResourcePool()->GetHighLightColor();
 
   fMsgWindow = p;
   if (gClient->GetStyle() == 0)
      SetBackgroundPixmap(GetBckgndPixmap());
   SetWindowName();
   AddInput(kEnterWindowMask | kLeaveWindowMask);
 
   fHeadPic = fClient->GetPictureOrEmpty(headPicName);
   fTailPic = fClient->GetPictureOrEmpty(tailPicName);
 
   fHead   = new TGScrollBarElement(this, fHeadPic, fgScrollBarWidth, fgScrollBarWidth,
                                    kRaisedFrame);
   fTail   = new TGScrollBarElement(this, fTailPic, fgScrollBarWidth, fgScrollBarWidth,
                                    kRaisedFrame);
   fSlider = new TGScrollBarElement(this, 0, fgScrollBarWidth, 50,
                                    kRaisedFrame);
 
   gVirtualX->GrabButton(fId, kAnyButton, kAnyModifier, kButtonPressMask |
                         kButtonReleaseMask | kPointerMotionMask, kNone, kNone);
 
   fDragging = kFALSE;
   fX0 = fY0 = (fgScrollBarWidth = std::max(fgScrollBarWidth, 5));
   fPos = 0;
 
   fSliderSize  = 50;
   fSliderRange = 1;
 
   fHead->SetEditDisabled(kEditDisable | kEditDisableGrab);
   fTail->SetEditDisabled(kEditDisable | kEditDisableGrab);
   fSlider->SetEditDisabled(kEditDisable | kEditDisableGrab);
   fEditDisabled = kEditDisableLayout | kEditDisableBtnEnable;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Delete a scrollbar (either horizontal or vertical).
 
TGScrollBar::~TGScrollBar()
{
   delete fHead;
   delete fTail;
   delete fSlider;
   if (fHeadPic) fClient->FreePicture(fHeadPic);
   if (fTailPic) fClient->FreePicture(fTailPic);
   if (fRepeat) { delete fRepeat; fRepeat = 0; }
}
 
////////////////////////////////////////////////////////////////////////////////
/// Handle mouse crossing event.
 
Bool_t TGScrollBar::HandleCrossing(Event_t *event)
{
   if (gClient->GetStyle() > 0) {
      if (event->fType == kEnterNotify) {
         fBgndColor = fHighColor;
      } else {
         fBgndColor = fBackground;
      }
      if (event->fType == kLeaveNotify) {
         fBgndColor = fBackground;
      }
      fHead->ChangeBackground(fBgndColor);
      fTail->ChangeBackground(fBgndColor);
      fSlider->ChangeBackground(fBgndColor);
      fHead->DrawBorder();
      fTail->DrawBorder();
      fSlider->DrawBorder();
   }
   return kTRUE;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Handle repeat timer for horizontal or vertical scrollbar. Every time
/// timer times out we move slider.
 
Bool_t TGScrollBar::HandleTimer(TTimer *t)
{
   // shorten time out time to 50 milli seconds
   t->SetTime(50);
 
   Window_t  dum1, dum2;
   Event_t   ev;
 
   ev.fCode    = kButton1;
   ev.fType    = kButtonPress;
   ev.fUser[0] = fSubw;
 
   if (IsAccelerated()) {
      ++fSmallInc;
      if (fSmallInc > 100) fSmallInc = 100;
   }
 
   gVirtualX->QueryPointer(fId, dum1, dum2, ev.fXRoot, ev.fYRoot, ev.fX, ev.fY,
                      ev.fState);
 
   HandleButton(&ev);
 
   return kTRUE;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Static method returning scrollbar background pixmap.
 
Pixmap_t TGScrollBar::GetBckgndPixmap()
{
   static Bool_t init = kFALSE;
   if (!init) {
      fgBckgndPixmap = gClient->GetResourcePool()->GetCheckeredPixmap();
      init = kTRUE;
   }
   return fgBckgndPixmap;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Static method returning the scrollbar width.
 
Int_t TGScrollBar::GetScrollBarWidth()
{
   return fgScrollBarWidth;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Change background color
 
void TGScrollBar::ChangeBackground(Pixel_t back)
{
   TGFrame::ChangeBackground(back);
   fHead->ChangeBackground(back);
   fTail->ChangeBackground(back);
   fSlider->ChangeBackground(back);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Create a horizontal scrollbar widget.
 
TGHScrollBar::TGHScrollBar(const TGWindow *p, UInt_t w, UInt_t h,
                           UInt_t options, ULong_t back) :
    TGScrollBar(p, w, h, options, back, "arrow_left.xpm", "arrow_right.xpm")
{
   fRange = std::max((Int_t) w - (fgScrollBarWidth << 1), 1);
   fPsize = fRange >> 1;
   fEditDisabled |= kEditDisableHeight;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Layout and move horizontal scrollbar components.
 
void TGHScrollBar::Layout()
{
   // Should also recalculate the slider size and range, etc.
   fHead->Move(0, 0);
   fHead->Resize(fgScrollBarWidth, fgScrollBarWidth);
   fTail->Move(fWidth-fgScrollBarWidth, 0);
   fTail->Resize(fgScrollBarWidth, fgScrollBarWidth);
 
   if (fSlider->GetX() != fX0) {
      fSlider->Move(fX0, 0);
      fSlider->Resize(50, fgScrollBarWidth);
      fClient->NeedRedraw(fSlider);
   }
}
 
////////////////////////////////////////////////////////////////////////////////
/// Handle a mouse button event in a horizontal scrolbar.
 
Bool_t TGHScrollBar::HandleButton(Event_t *event)
{
   Int_t newpos;
 
   if (event->fCode == kButton4) {
      if (!fHead->IsEnabled()) {
         return kFALSE;
      }
      //scroll left
      newpos = fPos - fPsize;
      if (newpos<0) newpos = 0;
      SetPosition(newpos);
      return kTRUE;
   }
   if (event->fCode == kButton5) {
      if (!fTail->IsEnabled()) {
         return kFALSE;
      }
      // scroll right
      newpos = fPos + fPsize;
      SetPosition(newpos);
      return kTRUE;
   }
 
   if (event->fType == kButtonPress) {
      if (event->fCode == kButton3) {
         fX0 = event->fX - fSliderSize/2;
         fX0 = std::max(fX0, fgScrollBarWidth);
         fX0 = std::min(fX0, fgScrollBarWidth + fSliderRange);
         ULong_t pos = (ULong_t)(fX0 - fgScrollBarWidth) * (ULong_t)(fRange-fPsize) / (ULong_t)fSliderRange;
         fPos = (Int_t)pos;
 
         fPos = std::max(fPos, 0);
         fPos = std::min(fPos, fRange-fPsize);
         fSlider->Move(fX0, 0);
 
         SendMessage(fMsgWindow, MK_MSG(kC_HSCROLL, kSB_SLIDERTRACK), fPos, 0);
         PositionChanged(fPos);
         return kTRUE;
      }
 
      // fUser[0] contains the subwindow (child) in which the event occured
      // (see GX11Gui.cxx)
      Window_t subw = (Window_t)event->fUser[0];
 
      if (subw == fSlider->GetId()) {
         fXp = event->fX - fX0;
         fYp = event->fY - fY0;
         fDragging = kTRUE;
 
      } else {
 
         if (!fRepeat)
            fRepeat = new TSBRepeatTimer(this, 400, fSmallInc); // 500
         fRepeat->Reset();
         gSystem->AddTimer(fRepeat);
         fSubw = subw;
 
         if (subw == fHead->GetId()) {
            //if (!fHead->IsEnabled()) {
             //  return kFALSE;
            //}
            fHead->SetState(kButtonDown);
            fPos -= fSmallInc;
         } else if (subw == fTail->GetId()) {
            //if (!fTail->IsEnabled()) {
           //    return kFALSE;
           // }
            fTail->SetState(kButtonDown);
            fPos += fSmallInc;
         } else if (event->fX > fgScrollBarWidth && event->fX < fX0)
            fPos -= fPsize;
         else if (event->fX > fX0+fSliderSize && event->fX < (Int_t)fWidth-fgScrollBarWidth)
            fPos += fPsize;
 
         fPos = std::max(fPos, 0);
         fPos = std::min(fPos, fRange-fPsize);
 
         fX0 = fgScrollBarWidth + fPos * fSliderRange / std::max(fRange-fPsize, 1);
 
         fX0 = std::max(fX0, fgScrollBarWidth);
         fX0 = std::min(fX0, fgScrollBarWidth + fSliderRange);
 
         fSlider->Move(fX0, 0);
 
         SendMessage(fMsgWindow, MK_MSG(kC_HSCROLL, kSB_SLIDERTRACK), fPos, 0);
         PositionChanged(fPos);
      }
 
      // last argument kFALSE forces all specified events to this window
      if (fGrabPointer && !fClient->IsEditable())
         gVirtualX->GrabPointer(fId, kButtonPressMask | kButtonReleaseMask |
                                kPointerMotionMask, kNone, kNone,
                                kTRUE, kFALSE);
   } else {
      fHead->SetState(kButtonUp);
      fTail->SetState(kButtonUp);
 
      if (fRepeat) {
         fRepeat->Remove();
         fRepeat->SetTime(400);  // might have been shortened in HandleTimer()
         fSmallInc = ((TSBRepeatTimer*)fRepeat)->GetSmallInc();
      }
 
      fDragging = kFALSE;
 
      fPos = std::max(fPos, 0);
      fPos = std::min(fPos, fRange-fPsize);
 
      SendMessage(fMsgWindow, MK_MSG(kC_HSCROLL, kSB_SLIDERPOS), fPos, 0);
      PositionChanged(fPos);
 
      if (fGrabPointer)
         gVirtualX->GrabPointer(0, 0, 0, 0, kFALSE);  // ungrab pointer
   }
   return kTRUE;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Handle mouse motion event in a horizontal scrollbar.
 
Bool_t TGHScrollBar::HandleMotion(Event_t *event)
{
   if (fDragging) {
      fX0 = event->fX - fXp;
      fY0 = event->fY - fYp;
 
      fX0 = std::max(fX0, fgScrollBarWidth);
      fX0 = std::min(fX0, fgScrollBarWidth + fSliderRange);
      fSlider->Move(fX0, 0);
      ULong_t pos = (ULong_t)(fX0 - fgScrollBarWidth) * (ULong_t)(fRange-fPsize) / (ULong_t)fSliderRange;
      fPos = (Int_t)pos;
 
      fPos = std::max(fPos, 0);
      fPos = std::min(fPos, fRange-fPsize);
 
      SendMessage(fMsgWindow, MK_MSG(kC_HSCROLL, kSB_SLIDERTRACK), fPos, 0);
      PositionChanged(fPos);
   }
   return kTRUE;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Set range of horizontal scrollbar.
 
void TGHScrollBar::SetRange(Int_t range, Int_t page_size)
{
   fRange = std::max(range, 1);
   fPsize = std::max(page_size, 0);
   fPos = std::max(fPos, 0);
   fPos = std::min(fPos, fRange-fPsize);
 
   fSliderSize = std::max(fPsize * (fWidth - (fgScrollBarWidth << 1)) /
                            fRange, (UInt_t) 6);
   fSliderSize = std::min((UInt_t)fSliderSize, fWidth - (fgScrollBarWidth << 1));
 
   fSliderRange = std::max(fWidth - (fgScrollBarWidth << 1) - fSliderSize,
                             (UInt_t) 1);
 
   fX0 = fgScrollBarWidth + fPos * fSliderRange / std::max(fRange-fPsize, 1);
   fX0 = std::max(fX0, fgScrollBarWidth);
   fX0 = std::min(fX0, fgScrollBarWidth + fSliderRange);
 
   fSlider->Move(fX0, 0);
   fSlider->Resize(fSliderSize, fgScrollBarWidth);
   fClient->NeedRedraw(fSlider);
 
   //  fPos = (fX0 - fgScrollBarWidth) * (fRange-fPsize) / fSliderRange;
 
   SendMessage(fMsgWindow, MK_MSG(kC_HSCROLL, kSB_SLIDERPOS), fPos, 0);
   PositionChanged(fPos);
   RangeChanged(fRange);
   PageSizeChanged(fPsize);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Set logical slider position of horizontal scrollbar.
 
void TGHScrollBar::SetPosition(Int_t pos)
{
   fPos = std::max(pos, 0);
   fPos = std::min(pos, fRange-fPsize);
 
   fX0 = fgScrollBarWidth + fPos * fSliderRange / std::max(fRange-fPsize, 1);
   fX0 = std::max(fX0, fgScrollBarWidth);
   fX0 = std::min(fX0, fgScrollBarWidth + fSliderRange);
 
   fSlider->Move(fX0, 0);
   fSlider->Resize(fSliderSize, fgScrollBarWidth);
   fClient->NeedRedraw(fSlider);
 
   SendMessage(fMsgWindow, MK_MSG(kC_HSCROLL, kSB_SLIDERPOS), fPos, 0);
   PositionChanged(fPos);
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Create a vertical scrollbar.
 
TGVScrollBar::TGVScrollBar(const TGWindow *p, UInt_t w, UInt_t h,
                           UInt_t options, ULong_t back) :
    TGScrollBar(p, w, h, options, back, "arrow_up.xpm", "arrow_down.xpm")
{
   fRange = std::max((Int_t) h - (fgScrollBarWidth << 1), 1);
   fPsize = fRange >> 1;
   fEditDisabled |= kEditDisableWidth;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Layout and move vertical scrollbar components.
 
void TGVScrollBar::Layout()
{
   // Should recalculate fSliderSize, fSliderRange, fX0, fY0, etc. too...
   fHead->Move(0, 0);
   fHead->Resize(fgScrollBarWidth, fgScrollBarWidth);
   fTail->Move(0, fHeight-fgScrollBarWidth);
   fTail->Resize(fgScrollBarWidth, fgScrollBarWidth);
 
   if (fSlider->GetY() != fY0) {
      fSlider->Move(0, fY0);
      fSlider->Resize(fgScrollBarWidth, 50);
      fClient->NeedRedraw(fSlider);
   }
}
 
////////////////////////////////////////////////////////////////////////////////
/// Handle mouse button event in vertical scrollbar.
 
Bool_t TGVScrollBar::HandleButton(Event_t *event)
{
   Int_t newpos;
 
   if (event->fCode == kButton4) {
      if (!fHead->IsEnabled()) {
         return kFALSE;
      }
      //scroll up
      newpos = fPos - fPsize;
      if (newpos<0) newpos = 0;
      SetPosition(newpos);
      return kTRUE;
   }
   if (event->fCode == kButton5) {
      if (!fTail->IsEnabled()) {
         return kFALSE;
      }
 
      // scroll down
      newpos = fPos + fPsize;
      SetPosition(newpos);
      return kTRUE;
   }
 
   if (event->fType == kButtonPress) {
      if (event->fCode == kButton3) {
         fY0 = event->fY - fSliderSize/2;
         fY0 = std::max(fY0, fgScrollBarWidth);
         fY0 = std::min(fY0, fgScrollBarWidth + fSliderRange);
         ULong_t pos = (ULong_t)(fY0 - fgScrollBarWidth) * (ULong_t)(fRange-fPsize) / (ULong_t)fSliderRange;
         fPos = (Int_t)pos;
 
         fPos = std::max(fPos, 0);
         fPos = std::min(fPos, fRange-fPsize);
         fSlider->Move(0, fY0);
 
         SendMessage(fMsgWindow, MK_MSG(kC_VSCROLL, kSB_SLIDERTRACK), fPos, 0);
         PositionChanged(fPos);
         return kTRUE;
      }
 
      // fUser[0] contains the subwindow (child) in which the event occured
      // (see GX11Gui.cxx)
      Window_t subw = (Window_t)event->fUser[0];
 
      if (subw == fSlider->GetId()) {
         fXp = event->fX - fX0;
         fYp = event->fY - fY0;
         fDragging = kTRUE;
 
      } else {
 
         if (!fRepeat)
            fRepeat = new TSBRepeatTimer(this, 400, fSmallInc); // 500
         fRepeat->Reset();
         gSystem->AddTimer(fRepeat);
         fSubw = subw;
 
         if (subw == fHead->GetId()) {
            //if (!fHead->IsEnabled()) {
            //   return kFALSE;
           // }
            fHead->SetState(kButtonDown);
            fPos -= fSmallInc;
         } else if (subw == fTail->GetId()) {
            //if (!fTail->IsEnabled()) {
            //   return kFALSE;
            //}
            fTail->SetState(kButtonDown);
            fPos += fSmallInc;
         } else if (event->fY > fgScrollBarWidth && event->fY < fY0)
            fPos -= fPsize;
         else if (event->fY > fY0+fSliderSize && event->fY < (Int_t)fHeight-fgScrollBarWidth)
            fPos += fPsize;
 
         fPos = std::max(fPos, 0);
         fPos = std::min(fPos, fRange-fPsize);
 
         ULong_t y0 = (ULong_t)fgScrollBarWidth + (ULong_t)fPos * (ULong_t)fSliderRange / (ULong_t)std::max(fRange-fPsize, 1);
         fY0 = (Int_t)y0;
 
         fY0 = std::max(fY0, fgScrollBarWidth);
         fY0 = std::min(fY0, fgScrollBarWidth + fSliderRange);
 
         fSlider->Move(0, fY0);
 
         SendMessage(fMsgWindow, MK_MSG(kC_VSCROLL, kSB_SLIDERTRACK), fPos, 0);
         PositionChanged(fPos);
      }
 
      // last argument kFALSE forces all specified events to this window
      if (fGrabPointer && !fClient->IsEditable())
         gVirtualX->GrabPointer(fId, kButtonPressMask | kButtonReleaseMask |
                                kPointerMotionMask, kNone, kNone,
                                kTRUE, kFALSE);
   } else {
      fHead->SetState(kButtonUp);
      fTail->SetState(kButtonUp);
 
      if (fRepeat) {
         fRepeat->Remove();
         fRepeat->SetTime(400);  // might have been shortened in HandleTimer()
         fSmallInc = ((TSBRepeatTimer*)fRepeat)->GetSmallInc();
      }
 
      fDragging = kFALSE;
 
      fPos = std::max(fPos, 0);
      fPos = std::min(fPos, fRange-fPsize);
 
      SendMessage(fMsgWindow, MK_MSG(kC_VSCROLL, kSB_SLIDERPOS), fPos, 0);
      PositionChanged(fPos);
 
      if (fGrabPointer) {
         gVirtualX->GrabPointer(0, 0, 0, 0, kFALSE);  // ungrab pointer
      }
   }
   return kTRUE;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Handle mouse motion in a vertical scrollbar.
 
Bool_t TGVScrollBar::HandleMotion(Event_t *event)
{
   if (fDragging) {
      fX0 = event->fX - fXp;
      fY0 = event->fY - fYp;
 
      fY0 = std::max(fY0, fgScrollBarWidth);
      fY0 = std::min(fY0, fgScrollBarWidth + fSliderRange);
      fSlider->Move(0, fY0);
      ULong_t pos = (ULong_t)(fY0 - fgScrollBarWidth) * (ULong_t)(fRange-fPsize) / fSliderRange;
      fPos = (Int_t)pos;
 
      fPos = std::max(fPos, 0);
      fPos = std::min(fPos, fRange-fPsize);
 
      SendMessage(fMsgWindow, MK_MSG(kC_VSCROLL, kSB_SLIDERTRACK), fPos, 0);
      PositionChanged(fPos);
   }
   return kTRUE;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Set range of vertical scrollbar.
 
void TGVScrollBar::SetRange(Int_t range, Int_t page_size)
{
   fRange = std::max(range, 1);
   fPsize = std::max(page_size, 0);
   fPos = std::max(fPos, 0);
   fPos = std::min(fPos, fRange-fPsize);
 
   fSliderSize = std::max(fPsize * (fHeight - (fgScrollBarWidth << 1)) /
                            fRange, (UInt_t) 6);
   fSliderSize = std::min((UInt_t)fSliderSize, fHeight - (fgScrollBarWidth << 1));
 
   fSliderRange = std::max(fHeight - (fgScrollBarWidth << 1) - fSliderSize,
                             (UInt_t)1);
 
   ULong_t y0 = (ULong_t)fgScrollBarWidth + (ULong_t)fPos * (ULong_t)fSliderRange / (ULong_t)std::max(fRange-fPsize, 1);
   fY0 = (Int_t)y0;
   fY0 = std::max(fY0, fgScrollBarWidth);
   fY0 = std::min(fY0, fgScrollBarWidth + fSliderRange);
 
   fSlider->Move(0, fY0);
   fSlider->Resize(fgScrollBarWidth, fSliderSize);
   fClient->NeedRedraw(fSlider);
 
   //  fPos = (fY0 - fgScrollBarWidth) * (fRange-fPsize) / fSliderRange;
 
 
   SendMessage(fMsgWindow, MK_MSG(kC_VSCROLL, kSB_SLIDERPOS), fPos, 0);
   PositionChanged(fPos);
   RangeChanged(fRange);
   PageSizeChanged(fPsize);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Set logical slider position of vertical scrollbar.
 
void TGVScrollBar::SetPosition(Int_t pos)
{
   fPos = std::max(pos, 0);
   fPos = std::min(pos, fRange-fPsize);
 
   ULong_t y0 = (ULong_t)fgScrollBarWidth + (ULong_t)fPos * (ULong_t)fSliderRange / (ULong_t)std::max(fRange-fPsize, 1);
   fY0 = (Int_t)y0;
   fY0 = std::max(fY0, fgScrollBarWidth);
   fY0 = std::min(fY0, fgScrollBarWidth + fSliderRange);
 
   fSlider->Move(0, fY0);
   fSlider->Resize(fgScrollBarWidth, fSliderSize);
   fClient->NeedRedraw(fSlider);
 
   SendMessage(fMsgWindow, MK_MSG(kC_VSCROLL, kSB_SLIDERPOS), fPos, 0);
   PositionChanged(fPos);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Save an horizontal scrollbar as a C++ statement(s) on output stream out.
 
void TGHScrollBar::SavePrimitive(std::ostream &out, Option_t *option /*= ""*/)
{
   // save options and custom color if not default
   auto extra_args = SaveCtorArgs(out);
 
   out << "   TGHScrollBar *" << GetName() << " = new TGHScrollBar(" << fParent->GetName() << "," << GetWidth() << ","
       << GetHeight() << extra_args << ");\n";
 
   if (option && strstr(option, "keep_names"))
      out << "   " << GetName() << "->SetName(\"" << GetName() << "\");\n";
 
   out << "   " << GetName() << "->SetRange(" << GetRange() << "," << GetPageSize() << ");\n";
   out << "   " << GetName() << "->SetPosition(" << GetPosition() << ");\n";
}
 
////////////////////////////////////////////////////////////////////////////////
/// Save an vertical scrollbar as a C++ statement(s) on output stream out.
 
void TGVScrollBar::SavePrimitive(std::ostream &out, Option_t *option /*= ""*/)
{
   // save options and custom color if not default
   auto extra_args = SaveCtorArgs(out);
 
   out << "   TGVScrollBar *" << GetName() << " = new TGVScrollBar(" << fParent->GetName() << "," << GetWidth() << ","
       << GetHeight() << extra_args << ");\n";
 
   if (option && strstr(option, "keep_names"))
      out << "   " << GetName() << "->SetName(\"" << GetName() << "\");\n";
 
   out << "   " << GetName() << "->SetRange(" << GetRange() << "," << GetPageSize() << ");\n";
   out << "   " << GetName() << "->SetPosition(" << GetPosition() << ");\n";
}