// @(#)root/gui:$Name:  $:$Id: TGListBox.cxx,v 1.46 2005/08/23 17:00:41 brun Exp $
// Author: Fons Rademakers   12/01/98

/*************************************************************************
 * 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.

**************************************************************************/

//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TGListBox, TGLBContainer, TGLBEntry and TGTextLBEntry                //
//                                                                      //
// A listbox is a box, possibly with scrollbar, containing entries.     //
// Currently entries are simple text strings (TGTextLBEntry).           //
// A TGListBox looks a lot like a TGCanvas. It has a TGViewPort         //
// containing a TGLBContainer which contains the entries and it also    //
// has a vertical scrollbar which becomes visible if there are more     //
// items than fit in the visible part of the container.                 //
//                                                                      //
// The TGListBox is user callable. The other classes are service        //
// classes of the listbox.                                              //
//                                                                      //
// Selecting an item in the listbox will generate the event:            //
// kC_COMMAND, kCM_LISTBOX, listbox id, item id.                        //
//                                                                      //
//////////////////////////////////////////////////////////////////////////

#include "TGListBox.h"
#include "TGScrollBar.h"
#include "TGResourcePool.h"
#include "TMath.h"
#include "TSystem.h"
#include "Riostream.h"


const TGFont *TGTextLBEntry::fgDefaultFont = 0;
TGGC         *TGTextLBEntry::fgDefaultGC = 0;

ClassImp(TGLBEntry)
ClassImp(TGTextLBEntry)
ClassImp(TGLineLBEntry)
ClassImp(TGLBContainer)
ClassImp(TGListBox)

//______________________________________________________________________________
TGLBEntry::TGLBEntry(const TGWindow *p, Int_t id, UInt_t options, Pixel_t back) :
             TGFrame(p, 10, 10, options | kOwnBackground, back)
{
   // ctor

   fActive = kFALSE;
   fEntryId = id;
   fBkcolor = back;

   SetWindowName();
}

//______________________________________________________________________________
void TGLBEntry::Activate(Bool_t a)
{
   // Toggle active state of listbox entry.

   if (fActive == a) return;
   fActive = a;
   fClient->NeedRedraw(this);
}

//______________________________________________________________________________
void TGLBEntry::Toggle()
{
   // Toggle active state of listbox entry.

   fActive = !fActive;
   fClient->NeedRedraw(this);
}


//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TGTextLBEntry                                                        //
//                                                                      //
// Text string listbox entries.                                         //
// A TGTextLBEntry is for TGListBox internal use.                       //
//                                                                      //
//////////////////////////////////////////////////////////////////////////

//______________________________________________________________________________
TGTextLBEntry::TGTextLBEntry(const TGWindow *p, TGString *s, Int_t id,
      GContext_t norm, FontStruct_t font, UInt_t options, ULong_t back) :
   TGLBEntry(p, id, options, back)
{
   // Create a text listbox entry. The TGString is adopted.

   fText        = s;
   fTextChanged = kTRUE;
   fFontStruct  = font;
   fNormGC      = norm;

   int max_ascent, max_descent;

   if (fText) fTWidth  = gVirtualX->TextWidth(fFontStruct, fText->GetString(), fText->GetLength());
   gVirtualX->GetFontProperties(fFontStruct, max_ascent, max_descent);
   fTHeight = max_ascent + max_descent;
   Resize(fTWidth, fTHeight + 1);
   SetWindowName();
}

//______________________________________________________________________________
TGTextLBEntry::~TGTextLBEntry()
{
   // Delete text listbox entry.

   if (fText) delete fText;
}

//______________________________________________________________________________
void TGTextLBEntry::DrawCopy(Handle_t id, Int_t x, Int_t y)
{
   // Draw text listbox entry on window/pixmap.

   int max_ascent, max_descent;

   y += (fHeight - fTHeight) >> 1;

   gVirtualX->GetFontProperties(fFontStruct, max_ascent, max_descent);

   if (fActive) {
      gVirtualX->SetForeground(fNormGC, fgDefaultSelectedBackground );
      gVirtualX->FillRectangle(id,fNormGC, x, y, fWidth, fHeight); 
      gVirtualX->SetForeground(fNormGC, fClient->GetResourcePool()->GetSelectedFgndColor());
      fText->Draw(id, fNormGC, x + 3, y + max_ascent);
   } else {
      gVirtualX->SetForeground(fNormGC, fBkcolor);
      gVirtualX->FillRectangle(id,fNormGC, x, y, fWidth, fHeight);
      gVirtualX->SetForeground(fNormGC, GetForeground());
      fText->Draw(id, fNormGC, x + 3, y + max_ascent);
   }
}

//______________________________________________________________________________
void TGTextLBEntry::DoRedraw()
{
   // Redraw text listbox entry.

   DrawCopy(fId, 0, 0);
}

//______________________________________________________________________________
void TGTextLBEntry::SetText(TGString *new_text)
{
   // Set or change text in text entry.

   if (fText) delete fText;
   fText = new_text;
   fTextChanged = kTRUE;

   int max_ascent, max_descent;
   fTWidth = gVirtualX->TextWidth(fFontStruct, fText->GetString(), fText->GetLength());
   gVirtualX->GetFontProperties(fFontStruct, max_ascent, max_descent);
   fTHeight = max_ascent + max_descent;

   Resize(fTWidth, fTHeight + 1);

   fClient->NeedRedraw(this);
}

//______________________________________________________________________________
FontStruct_t TGTextLBEntry::GetDefaultFontStruct()
{
   if (!fgDefaultFont)
      fgDefaultFont = gClient->GetResourcePool()->GetDefaultFont();
   return fgDefaultFont->GetFontStruct();
}

//______________________________________________________________________________
const TGGC &TGTextLBEntry::GetDefaultGC()
{
   if (!fgDefaultGC)
      fgDefaultGC = new TGGC(*gClient->GetResourcePool()->GetFrameGC());
   return *fgDefaultGC;
}

//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TGLineLBEntry                                                        //
//                                                                      //
// Line style and width listbox entries.                                //
//                                                                      //
//////////////////////////////////////////////////////////////////////////

//______________________________________________________________________________
 TGLineLBEntry::TGLineLBEntry(const TGWindow *p, Int_t id, const char *str,
                             UInt_t w, Style_t style, UInt_t options, ULong_t back) :
   TGTextLBEntry(p, new TGString(str), id, GetDefaultGC()(),
                 GetDefaultFontStruct(), options, back)
{
   // Create the line style listbox entry

   GCValues_t gcv;

   gcv.fMask =  kGCLineStyle | kGCLineWidth | kGCFillStyle | kGCDashList;
   fLineWidth = gcv.fLineWidth  = w;
   gcv.fFillStyle  = kFillSolid;
   gcv.fDashLen = 2;
   gcv.fDashOffset = 0;
   memcpy(gcv.fDashes, "\x5\x5", 3);
   gcv.fLineStyle = kLineOnOffDash;
   fLineGC = fClient->GetGC(&gcv, kTRUE);
   SetLineStyle(style);

   int max_ascent, max_descent;

   fTWidth  = gVirtualX->TextWidth(GetDefaultFontStruct(), "8", 1);
   fTWidth += 15;                     // for drawing
   gVirtualX->GetFontProperties(GetDefaultFontStruct(),
                                max_ascent, max_descent);
   fTHeight = max_ascent + max_descent;

   Resize(fTWidth, fTHeight + 1);
   SetWindowName();
}

//______________________________________________________________________________
 TGLineLBEntry::~TGLineLBEntry()
{
   // Delete line style listbox entry.

   fClient->FreeGC(fLineGC);
}

//______________________________________________________________________________
 void  TGLineLBEntry::Update(TGLBEntry *e)
{
   // Update line style listbox entry.

   TGTextLBEntry::Update(e);

   fClient->FreeGC(fLineGC);
   fLineGC = ((TGLineLBEntry *)e)->GetLineGC();
   fLineGC->AddReference();
}

//______________________________________________________________________________
 void TGLineLBEntry::SetLineStyle(Style_t linestyle)
{
   // The linstyle corresponds to TPad line style

   static const char* dashed = "\x3\x3";
   static const char* dotted= "\x1\x2";
   static const char* dasheddotted = "\x3\x4\x1\x4";
   static const char* ls05 = "\x5\x3\x1\x3";
   static const char* ls06 = "\x5\x3\x1\x3\x1\x3\x1\x3";
   static const char* ls07 = "\x5\x5";
   static const char* ls08 = "\x5\x3\x1\x3\x1\x3";
   static const char* ls09 = "\x20\x5";
   static const char* ls10 = "\x20\x10\x1\x10";


   if (linestyle <= 1)  {
      fLineGC->SetLineStyle(kLineSolid);
   } else {
      switch (linestyle) {
         case 2:
            fLineGC->SetDashList(dashed, 2);
            break;
         case 3:
            fLineGC->SetDashList(dotted, 2);
            break;
         case 4:
            fLineGC->SetDashList(dasheddotted, 4);
            break;
         case 5:
            fLineGC->SetDashList(ls05, 4);
            break;
         case 6:
            fLineGC->SetDashList(ls06, 8);
            break;
         case 7:
            fLineGC->SetDashList(ls07, 2);
            break;
         case 8:
            fLineGC->SetDashList(ls08, 6);
            break;
         case 9:
            fLineGC->SetDashList(ls09, 2);
            break;
         case 10:
            fLineGC->SetDashList(ls10, 4);
            break;
      }
   }
   fLineGC->SetCapStyle(0); // flat cap
   fLineStyle = linestyle;
}

//______________________________________________________________________________
 void TGLineLBEntry::SetLineWidth(Int_t width)
{
   // Set or change line witdh in an entry.

   fLineWidth = width;
   fLineGC->SetLineWidth(fLineWidth);
}

//______________________________________________________________________________
 void TGLineLBEntry::DrawCopy(Handle_t id, Int_t x, Int_t y)
{
   // draw copy on window/pixmap

   TGTextLBEntry::DrawCopy(id, x, y);

   if (fActive) {
      gVirtualX->SetForeground(fLineGC->GetGC(),
                               fClient->GetResourcePool()->GetSelectedFgndColor());
   } else {
      gVirtualX->SetForeground(fLineGC->GetGC(),
                               fClient->GetResourcePool()->GetBlackColor());
   }
   gVirtualX->DrawLine(id, fLineGC->GetGC(), x + fTWidth + 5, y + fHeight/2,
                       x + fWidth - 5, y + fHeight/2);
}

//______________________________________________________________________________
 void TGLineLBEntry::DoRedraw()
{
   // Redraw line style listbox entry.

   DrawCopy(fId, 0, 0);
}

//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TGLBContainer                                                        //
//                                                                      //
// A Composite frame that contains a list of TGLBEnties.                //
// A TGLBContainer is for TGListBox internal use.                       //
//                                                                      //
//////////////////////////////////////////////////////////////////////////

//______________________________________________________________________________
TGLBContainer::TGLBContainer(const TGWindow *p, UInt_t w, UInt_t h,
                             UInt_t options, ULong_t back) :
   TGContainer(p, w, h, options, back)
{
   // Create a listbox container.

   fLastActive = 0;
   fMsgWindow  = p;
   fMultiSelect = kFALSE;

   SetWindowName();
}

//______________________________________________________________________________
TGLBContainer::~TGLBContainer()
{
   // Delete the listbox container.

   Cleanup();
}

//______________________________________________________________________________
void TGLBContainer::AddEntry(TGLBEntry *lbe, TGLayoutHints *lhints)
{
   // Add listbox entry with hints to container. To show entry call
   // MapSubwindows() and Layout().

   lbe->SetBackgroundColor(fgWhitePixel);
   AddFrame(lbe, lhints);
   fClient->NeedRedraw(this);
}

//______________________________________________________________________________
void TGLBContainer::InsertEntry(TGLBEntry *lbe, TGLayoutHints *lhints, Int_t afterID)
{
   // Insert listbox entry after specified entry with id afterID. If afterID = -1
   // then add entry at head of list. To show entry call MapSubwindows() and
   // Layout().

   lbe->SetBackgroundColor(fgWhitePixel);

   TGLBEntry      *e;
   TGFrameElement *el, *nw;
   TIter next(fList);

   while ((el = (TGFrameElement *) next())) {
      e = (TGLBEntry *) el->fFrame;
      if (e->EntryId() == afterID) break;
   }

   if (!el && afterID != -1) {
      AddFrame(lbe, lhints);
   } else {
      nw = new TGFrameElement(lbe, lhints);
      nw->fFrame  = lbe;
      nw->fLayout = lhints;
      nw->fState  = 1;
      //lbe->SetFrameElement(nw);

      if (afterID == -1)
         fList->AddFirst(nw);
      else
         fList->AddAfter(el, nw);
   }
   fClient->NeedRedraw(this);
}

//______________________________________________________________________________
void TGLBContainer::AddEntrySort(TGLBEntry *lbe, TGLayoutHints *lhints)
{
   // Insert listbox entry before the list box entry with a higher id.
   // To show entry call MapSubwindows() and Layout().

   lbe->SetBackgroundColor(fgWhitePixel);

   TGLBEntry      *e;
   TGFrameElement *el, *nw;
   TIter next(fList);

   while ((el = (TGFrameElement *) next())) {
      e = (TGLBEntry *) el->fFrame;
      if (e->EntryId() > lbe->EntryId()) break;
   }

   if (!el) {
      AddFrame(lbe, lhints);
   } else {
      nw = new TGFrameElement(lbe, lhints);
      nw->fFrame  = lbe;
      nw->fLayout = lhints;
      nw->fState  = 1;
      //lbe->SetFrameElement(nw);

      fList->AddBefore(el, nw);
   }
   fClient->NeedRedraw(this);
}

//______________________________________________________________________________
void TGLBContainer::RemoveEntry(Int_t id)
{
   // Remove the entry with specified id from the listbox container.
   // To update the listbox call Layout().

   TGLBEntry      *e;
   TGFrameElement *el;
   TGLayoutHints  *l;

   TIter next(fList);

   while ((el = (TGFrameElement *) next())) {
      e = (TGLBEntry *) el->fFrame;
      l = el->fLayout;
      if (e->EntryId() == id) {
         if (fLastActive == e) fLastActive = 0;
         e->DestroyWindow();
         fList->Remove(el);  // avoid calling RemoveFrame(e)
         delete el;          // idem
         delete e;
         delete l;
         fClient->NeedRedraw(this);
         break;
      }
   }
}

//______________________________________________________________________________
void TGLBContainer::RemoveEntries(Int_t from_ID, Int_t to_ID)
{
   // Remove entries from from_ID to to_ID (including).
   // To update the listbox call Layout().

   TGLBEntry      *e;
   TGFrameElement *el;
   TGLayoutHints  *l;

   TIter next(fList);

   while ((el = (TGFrameElement *) next())) {
      e = (TGLBEntry *) el->fFrame;
      l = el->fLayout;
      if ((e->EntryId() >= from_ID) && (e->EntryId() <= to_ID)) {
         if (fLastActive == e) fLastActive = 0;
         e->DestroyWindow();
         fList->Remove(el);  // avoid calling RemoveFrame(e)
         delete el;          // idem
         delete e;
         delete l;
         fClient->NeedRedraw(this);
      }
   }
}

//______________________________________________________________________________
TGLBEntry *TGLBContainer::Select(Int_t id)
{
   // Select the entry with the specified id.
   // Returns the selected TGLBEntry.

   return Select(id, kTRUE);
}

//______________________________________________________________________________
TGLBEntry *TGLBContainer::Select(Int_t id, Bool_t sel)
{
   // Select / deselect the entry with the specified id.
   // Returns the selected TGLBEntry.

   TGLBEntry      *f;
   TGFrameElement *el;

   if (fLastActive) {
      fLastActive->Activate(kFALSE);
      fLastActive = 0;
   }

   TIter next(fList);
   while ((el = (TGFrameElement *) next())) {
      f = (TGLBEntry *) el->fFrame;
      if (f->EntryId() == id) {
         f->Activate(sel);
         if (fMultiSelect == kFALSE && sel == kTRUE) {
            fLastActive = f;
            fLastActiveEl = el;
         }
         fClient->NeedRedraw(this);
         return f;
      }
   }

   return 0;
}

//______________________________________________________________________________
Int_t TGLBContainer::GetSelected() const
{
   // Returns id of selected entry. In case of no selected entry or
   // if multi selection is switched on returns -1.

   if (fLastActive == 0) return -1;
   return fLastActive->EntryId();
}

//______________________________________________________________________________
Bool_t TGLBContainer::GetSelection(Int_t id)
{
   // Returns kTrue if entry id is selected.

   TGLBEntry     *f;
   TGFrameElement *el;

   TIter next(fList);
   while ((el = (TGFrameElement *) next())) {
      f = (TGLBEntry *) el->fFrame;
      if (f->EntryId() == id)
         return f->IsActive();
   }

   return kFALSE;
}

//______________________________________________________________________________
void TGLBContainer::GetSelectedEntries(TList *selected)
{
   // Adds all selected entries (TGLBEntry) of the list box into
   // the list selected.

   TGLBEntry      *f;
   TGFrameElement *el;

   TIter next(fList);
   while ((el = (TGFrameElement *) next())) {
      f = (TGLBEntry *) el->fFrame;
      if (f->IsActive()) {
         selected->Add(f);
      }
   }
}

//______________________________________________________________________________
void TGLBContainer::SetMultipleSelections(Bool_t multi)
{
   // enables and disables multible selections of entries

   TGFrameElement *el;

   fMultiSelect = multi;
   if (!fMultiSelect) {
      // deselect all entries
      TIter next(fList);
      while ((el = (TGFrameElement *) next())) {
         ((TGLBEntry *)(el->fFrame))->Activate(kFALSE);
      }
   }
   fLastActive = 0;
   fLastActiveEl = 0;
   fClient->NeedRedraw(this);
}

//______________________________________________________________________________
TGVScrollBar *TGLBContainer::GetVScrollbar() const
{
   // return a pointer to vertical scroll bar

   return fListBox ? fListBox->GetVScrollbar() : 0;
}

//______________________________________________________________________________
void TGLBContainer::SetVsbPosition(Int_t newPos)
{
   // set new hor. position

   TGVScrollBar *vb = GetVScrollbar();

   if (vb && vb->IsMapped()) {
      vb->SetPosition(newPos);
   }
}

//______________________________________________________________________________
Bool_t TGLBContainer::HandleButton(Event_t *event)
{
   // Handle mouse button event in the listbox container.

   int xf0, yf0, xff, yff;

   TGLBEntry *f;
   TGFrameElement *el;
   TGLBEntry *last = fLastActive;

   TGPosition pos = GetPagePosition();
   Int_t x = pos.fX + event->fX;
   Int_t y = pos.fY + event->fY;
   Bool_t activate = kFALSE;

   TGVScrollBar *vb = GetVScrollbar();

   if ((event->fCode == kButton4) && vb){
      // scroll 2 lines up (a button down is always followed by a button up)
      Int_t newpos = vb->GetPosition() - 1;
      if (newpos < 0) newpos = 0;
      vb->SetPosition(newpos);
      fClient->NeedRedraw(this);
      return kTRUE;
   }
   if ((event->fCode == kButton5) && vb) {
      // scroll 2 lines down (a button down is always followed by a button up)
      Int_t newpos = vb->GetPosition() + 1;
      vb->SetPosition(newpos);
      fClient->NeedRedraw(this);
      return kTRUE;
   }

   gVirtualX->SetInputFocus(fId);

   if (fMultiSelect) {
      if (event->fType == kButtonPress) {
         TIter next(fList);
         while ((el = (TGFrameElement *) next())) {
            f = (TGLBEntry *) el->fFrame;
            xf0 = f->GetX();
            yf0 = f->GetY();
            xff = xf0 + f->GetWidth();
            yff = yf0 + f->GetHeight();

            activate = fMapSubwindows ? (f->GetId() == (Window_t)event->fUser[0]) :
                        (x > xf0) && (x < xff) && (y > yf0) &&  (y < yff);

            if (activate)  {
               fLastActive = f;
               fLastActiveEl = el;
               f->Toggle();
               fChangeStatus = f->IsActive() ? 1 : 0;
               SendMessage(fMsgWindow, MK_MSG(kC_CONTAINER, kCT_ITEMCLICK),
                           f->EntryId(), 0);
               break;
            }
         }
      } else {
         fChangeStatus = -1;
      }
   } else {
      if (event->fType == kButtonPress) {
         if (fLastActive) {
            fLastActive->Activate(kFALSE);
            fLastActive = 0;
         }
         TIter next(fList);
         while ((el = (TGFrameElement *) next())) {
            f = (TGLBEntry *) el->fFrame;
            xf0 = f->GetX();
            yf0 = f->GetY();
            xff = xf0 + f->GetWidth();
            yff = yf0 + f->GetHeight();

            activate = fMapSubwindows ? (f->GetId() == (Window_t)event->fUser[0]) :
                        (x > xf0) && (x < xff) && (y > yf0) &&  (y < yff) && !f->IsActive();

            if (activate)  {
               f->Activate(kTRUE);
               fLastActive = f;
               fLastActiveEl = el;
            } else {
               f->Activate(kFALSE);
            }
         }
      } else {
         if (fLastActive) {
            f = fLastActive;
            SendMessage(fMsgWindow, MK_MSG(kC_CONTAINER, kCT_ITEMCLICK),
                        f->EntryId(), 0);
         }
      }
   }
   if (fChangeStatus || (last != fLastActive)) fClient->NeedRedraw(this);
   return kTRUE;
}

//______________________________________________________________________________
Bool_t TGLBContainer::HandleMotion(Event_t *event)
{
   // Handle mouse motion event in listbox container.

   int xf0, yf0, xff, yff;

   static Long_t was = gSystem->Now();
   Long_t now = (long)gSystem->Now();

   if ((now-was) < 50) return kFALSE;
   was = now;

   if (!fListBox->GetParent()->InheritsFrom("TGComboBoxPopup")) {
      return kFALSE;
   }

   TGLBEntry *f;
   TGFrameElement *el;
   TGPosition pos = GetPagePosition();
   Int_t x = pos.fX + event->fX;
   Int_t y = pos.fY + event->fY;
   Bool_t activate = kFALSE;
   TGLBEntry *last = fLastActive;

   if (fMultiSelect) {

      if (fChangeStatus >= 0) {
         TIter next(fList);
         while ((el = (TGFrameElement *) next())) {
            f = (TGLBEntry *) el->fFrame;
            xf0 = f->GetX();
            yf0 = f->GetY();
            xff = xf0 + f->GetWidth();
            yff = yf0 + f->GetHeight();
            activate = fMapSubwindows ? (f->GetId() == (Window_t)event->fUser[0]) :
                        (x > xf0) && (x < xff) && (y > yf0) &&  (y < yff);

            if (activate) {
               if (fChangeStatus != (f->IsActive() ? 1 : 0)) {
                  f->Toggle();
                  fClient->NeedRedraw(this);
                  SendMessage(fMsgWindow, MK_MSG(kC_CONTAINER, kCT_ITEMCLICK),
                              f->EntryId(), 0);
               }
               break;
            }
         }
      }
   } else {
      TIter next(fList);
      while ((el = (TGFrameElement *) next())) {
         f = (TGLBEntry *) el->fFrame;
         xf0 = f->GetX();
         yf0 = f->GetY();
         xff = xf0 + f->GetWidth();
         yff = yf0 + f->GetHeight();

         activate = fMapSubwindows ? (f->GetId() == (Window_t)event->fUser[0]) :
                        (x > xf0) && (x < xff) && (y > yf0) &&  (y < yff)  && !f->IsActive();;

         if (activate)  {
            f->Activate(kTRUE);
            fLastActive = f;
         } else {
            f->Activate(kFALSE);
         }
         if (last != fLastActive) fClient->NeedRedraw(this);
      }
   }

   return kTRUE;
}

//______________________________________________________________________________
Int_t TGLBContainer::GetPos(Int_t id)
{
   // Returns the position in the list box of the entry id.
   // The first position has position no 0. Returns -1 if entry id
   // is not in the list of entries.

   Int_t          pos = 0;
   TGLBEntry      *f;
   TGFrameElement *el;

   TIter next(fList);
   while ((el = (TGFrameElement *) next())) {
      f = (TGLBEntry *) el->fFrame;
      if (f->EntryId() == id)
         return pos;
      pos++;
   }

  return -1;
}


//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TGListBox                                                            //
//                                                                      //
// A listbox contains a container frame which is viewed through a       //
// viewport. If the container is larger than the viewport than a        //
// vertical scrollbar is added.                                         //
//                                                                      //
// Selecting an item in the listbox will generate the event:            //
// kC_COMMAND, kCM_LISTBOX, listbox id, item id.                        //
//                                                                      //
//////////////////////////////////////////////////////////////////////////

//______________________________________________________________________________
TGListBox::TGListBox(const TGWindow *p, Int_t id,
                     UInt_t options, ULong_t back) :
   TGCompositeFrame(p, 10, 10, options, back)
{
   // Create a listbox.

   fMsgWindow = p;
   fWidgetId  = id;

   fItemVsize = 1;
   fIntegralHeight = kTRUE;

   InitListBox();
}

//______________________________________________________________________________
TGListBox::~TGListBox()
{
   // Delete a listbox widget.

   if (!MustCleanup()) {
      delete fVScrollbar;
      delete fVport;
      delete fLbc;
   }
}

//______________________________________________________________________________
void TGListBox::InitListBox()
{
   // initiate the internal classes of a list box

   fVport = new TGViewPort(this, 6, 6, kChildFrame | kOwnBackground, fgWhitePixel);
   fVScrollbar = new TGVScrollBar(this, kDefaultScrollBarWidth, 6);
   fLbc = new TGLBContainer(fVport, 10, 10, kVerticalFrame, fgWhitePixel);
   fLbc->fViewPort = fVport;
   fLbc->Associate(this);
   fLbc->SetListBox(this);
   SetContainer(fLbc);


   AddFrame(fVport, 0);
   AddFrame(fVScrollbar, 0);

   fVScrollbar->Associate(this);

   fVScrollbar->AddInput(kButtonPressMask | kButtonReleaseMask |
                         kPointerMotionMask);
   fLbc->AddInput(kButtonPressMask | kButtonReleaseMask );
}

//______________________________________________________________________________
void TGListBox::DrawBorder()
{
   // Draw borders of the list box widget.

   switch (fOptions & (kSunkenFrame | kRaisedFrame | kDoubleBorder)) {
      case kSunkenFrame | kDoubleBorder:
         gVirtualX->DrawLine(fId, GetShadowGC()(), 0, 0, fWidth-2, 0);
         gVirtualX->DrawLine(fId, GetShadowGC()(), 0, 0, 0, fHeight-2);
         gVirtualX->DrawLine(fId, GetBlackGC()(), 1, 1, fWidth-3, 1);
         gVirtualX->DrawLine(fId, GetBlackGC()(), 1, 1, 1, fHeight-3);

         gVirtualX->DrawLine(fId, GetHilightGC()(), 0, fHeight-1, fWidth-1, fHeight-1);
         gVirtualX->DrawLine(fId, GetHilightGC()(), fWidth-1, fHeight-1, fWidth-1, 0);
         gVirtualX->DrawLine(fId, GetBckgndGC()(),  1, fHeight-2, fWidth-2, fHeight-2);
         gVirtualX->DrawLine(fId, GetBckgndGC()(),  fWidth-2, 1, fWidth-2, fHeight-2);
         break;

      default:
         TGCompositeFrame::DrawBorder();
         break;
   }
}

//______________________________________________________________________________
void TGListBox::AddEntry(TGString *s, Int_t id)
{
   // Add entry with specified string and id to listbox. The id will be
   // used in the event processing routine when the item is selected.
   // The string will be adopted by the listbox.

   TGTextLBEntry *lbe;
   TGLayoutHints *lhints;

   lbe = new TGTextLBEntry(fLbc, s, id);
   lhints = new TGLayoutHints(kLHintsExpandX | kLHintsTop);
   fItemVsize = TMath::Max(fItemVsize, lbe->GetDefaultHeight());
   fLbc->AddEntry(lbe, lhints);
}

//______________________________________________________________________________
void TGListBox::AddEntry(const char *s, Int_t id)
{
   // Add entry with specified string and id to listbox. The id will be
   // used in the event processing routine when the item is selected.

   AddEntry(new TGString(s), id);
}

//______________________________________________________________________________
void TGListBox::AddEntry(TGLBEntry *lbe, TGLayoutHints *lhints)
{
   // Add specified TGLBEntry and TGLayoutHints to listbox. The
   // entry and layout will be adopted and later deleted by the listbox.

   fItemVsize = TMath::Max(fItemVsize, lbe->GetDefaultHeight());
   fLbc->AddEntry(lbe, lhints);
}

//______________________________________________________________________________
void TGListBox::AddEntrySort(TGString *s, Int_t id)
{
   // Add entry with specified string and id to listbox sorted by increasing id.
   // This sorting works proberly only if EntrySort functions are used to add
   // entries without mixing them with other add or insert functions.  The id will be
   // used in the event processing routine when the item is selected.
   // The string will be adopted by the listbox.

   TGTextLBEntry *lbe;
   TGLayoutHints *lhints;

   lbe = new TGTextLBEntry(fLbc, s, id);
   lhints = new TGLayoutHints(kLHintsExpandX | kLHintsTop);
   fItemVsize = TMath::Max(fItemVsize, lbe->GetDefaultHeight());
   fLbc->AddEntrySort(lbe, lhints);
}

//______________________________________________________________________________
void TGListBox::AddEntrySort(const char *s, Int_t id)
{
   // Add entry with specified string and id to listbox sorted by increasing id.
   // This sorting works proberly only if EntrySort functions are used to add
   // entries without mixing them with other add or insert functions. The id will be
   // used in the event processing routine when the item is selected.

   AddEntrySort(new TGString(s), id);
}

//______________________________________________________________________________
void TGListBox::AddEntrySort(TGLBEntry *lbe, TGLayoutHints *lhints)
{
   // Add specified TGLBEntry and TGLayoutHints to listbox sorted by increasing id.
   // This sorting works proberly only if EntrySort functions are used to add
   // entries without mixing them with other add or insert functions. The
   // entry and layout will be adopted and later deleted by the listbox.

   fItemVsize = TMath::Max(fItemVsize, lbe->GetDefaultHeight());
   fLbc->AddEntrySort(lbe, lhints);
}

//______________________________________________________________________________
void TGListBox::InsertEntry(TGString *s, Int_t id, Int_t afterID)
{
   // Insert entry with specified string and id behind the entry with afterID.
   // The string will be adopted and later deleted by the listbox.

   TGTextLBEntry *lbe;
   TGLayoutHints *lhints;

   lbe = new TGTextLBEntry(fLbc, s, id);
   lhints = new TGLayoutHints(kLHintsExpandX | kLHintsTop);
   fItemVsize = TMath::Max(fItemVsize, lbe->GetDefaultHeight());
   fLbc->InsertEntry(lbe, lhints, afterID);
}

//______________________________________________________________________________
void TGListBox::InsertEntry(const char *s, Int_t id, Int_t afterID)
{
   // Insert entry with specified string and id behind the entry with afterID.

   InsertEntry(new TGString(s), id, afterID);
}

//______________________________________________________________________________
void TGListBox::InsertEntry(TGLBEntry *lbe, TGLayoutHints *lhints, int afterID)
{
   // Insert the specified TGLBEntry and layout hints behind afterID.
   // The entry and layout will be adopted and later deleted by the listbox.

   fItemVsize = TMath::Max(fItemVsize, lbe->GetDefaultHeight());
   fLbc->InsertEntry(lbe, lhints, afterID);
}

//______________________________________________________________________________
TGLBEntry *TGListBox::GetEntry(Int_t id) const
{
   // returns list box entry with specified id

   TIter next(fLbc->GetList());
   TGFrameElement *el;

   while ((el = (TGFrameElement *)next())) {
      TGLBEntry *lbe = (TGLBEntry *)el->fFrame;
      if (lbe->EntryId() == id) return lbe;
   }
   return 0;
}

//______________________________________________________________________________
void TGListBox::SetTopEntry(Int_t id)
{
   // Scroll the entry with id to the top of the listbox.

   Int_t idPos;

   idPos = fLbc->GetPos(id);

   // id not found in list of entries
   if (idPos < 0)
      return;

   // call layout to define the range of the scroll bars
   Layout();

   // SetPosition will send a message which will handled by
   // the function TGListBox::ProcessMessage. Now ProcessMessage will
   // set the viewport. SetPosition also will check that the idPos is
   // not out of range.
   fVScrollbar->SetPosition(idPos);
}

//______________________________________________________________________________
void TGListBox::Resize(UInt_t w, UInt_t h)
{
   // Resize the listbox widget. If fIntegralHeight is true make the height
   // an integral number of the maximum height of a single entry.

   if (fIntegralHeight)
      h = TMath::Max(fItemVsize, ((h - (fBorderWidth << 1)) / fItemVsize) * fItemVsize)
                     + (fBorderWidth << 1);
   TGCompositeFrame::Resize(w, h);
   fClient->NeedRedraw(fLbc);
}

//______________________________________________________________________________
void TGListBox::MoveResize(Int_t x, Int_t y, UInt_t w, UInt_t h)
{
   // Move and resize the listbox widget.

   if (fIntegralHeight)
      h = TMath::Max(fItemVsize, ((h - (fBorderWidth << 1)) / fItemVsize) * fItemVsize)
                     + (fBorderWidth << 1);
   TGCompositeFrame::MoveResize(x, y, w, h);
   fClient->NeedRedraw(fLbc);
}

//______________________________________________________________________________
TGDimension TGListBox::GetDefaultSize() const
{
   // Return default size of listbox widget.

   UInt_t h;

   if (fIntegralHeight)
      h = TMath::Max(fItemVsize, ((fHeight - (fBorderWidth << 1)) / fItemVsize) * fItemVsize)
                     + (fBorderWidth << 1);
   else
      h = fHeight;

   return TGDimension(fWidth, h);
}

//______________________________________________________________________________
void TGListBox::Layout()
{
   // Layout the listbox components.

   TGFrame *container;
   UInt_t   cw, ch, tch;
   Bool_t   need_vsb;

   need_vsb = kFALSE;

   container = fVport->GetContainer();

   // test whether we need vertical scrollbar or not

   cw = fWidth - (fBorderWidth << 1);
   ch = fHeight - (fBorderWidth << 1);

   container->SetWidth(cw);
   container->SetHeight(ch);

   if (container->GetDefaultHeight() > ch) {
      need_vsb = kTRUE;
      cw -= fVScrollbar->GetDefaultWidth();
      if ((Int_t) cw < 0) {
         Warning("Layout", "width would become too small, setting to 10");
         cw = 10;
      }
      container->SetWidth(cw);
   }

   fVport->MoveResize(fBorderWidth, fBorderWidth, cw, ch);
   container->Layout();
   tch = TMath::Max(container->GetDefaultHeight(), ch);
   container->SetHeight(0); // force a resize in TGFrame::Resize
   container->Resize(cw, tch);
   //fVport->SetPos(0, 0);

   if (need_vsb) {
      fVScrollbar->MoveResize(cw+fBorderWidth, fBorderWidth, fVScrollbar->GetDefaultWidth(), ch);
      fVScrollbar->MapWindow();
   } else {
      fVScrollbar->UnmapWindow();
      fVScrollbar->SetPosition(0);
   }

   fVScrollbar->SetRange(container->GetHeight()/fItemVsize, fVport->GetHeight()/fItemVsize);
   fClient->NeedRedraw(container);
}

//______________________________________________________________________________
Int_t TGListBox::GetSelected() const
{
   // Return id of selected listbox item.

   TGLBContainer *ct = (TGLBContainer *) fVport->GetContainer();
   return ct->GetSelected();
}

//______________________________________________________________________________
void TGListBox::GetSelectedEntries(TList *selected)
{
   // Adds all selected entries (TGLBEntry) of the list box into
   // the list selected.

   fLbc->GetSelectedEntries(selected);
}

//______________________________________________________________________________
Bool_t TGListBox::ProcessMessage(Long_t msg, Long_t parm1, Long_t)
{
   // Process messages generated by the listbox container and forward
   // messages to the listbox message handling window.

   switch (GET_MSG(msg)) {
      case kC_VSCROLL:
         switch (GET_SUBMSG(msg)) {
            case kSB_SLIDERTRACK:
            case kSB_SLIDERPOS:
               fVport->SetVPos(Int_t(-parm1 * fItemVsize));
               break;
         }
         break;

      case kC_CONTAINER:
         switch (GET_SUBMSG(msg)) {
            case kCT_ITEMCLICK:
               {
                  SendMessage(fMsgWindow, MK_MSG(kC_COMMAND, kCM_LISTBOX),
                              fWidgetId, parm1);
                  if (GetMultipleSelections()) SelectionChanged();
                  TGLBEntry *entry = GetSelectedEntry();
                  if (entry) {
                     if (entry->InheritsFrom(TGTextLBEntry::Class())) {
                        const char *text;
                        text = ((TGTextLBEntry*)entry)->GetText()->GetString();
                        Selected(text);
                     }
                     Selected(fWidgetId, (Int_t) parm1);
                     Selected((Int_t) parm1);
                  }
               }
            break;
         }
         break;

      default:
         break;

   }
   return kTRUE;
}

//______________________________________________________________________________
void TGListBox::Selected(Int_t widgetId, Int_t id)
{
   // Emit signal with list box id and entry id.

   Long_t args[2];

   args[0] = widgetId;
   args[1] = id;

   Emit("Selected(Int_t,Int_t)", args);
}

//______________________________________________________________________________
TGLBEntry *TGListBox::FindEntry(const char *name) const
{
   // find entry by name

   TGFrameElement *el = (TGFrameElement *)fLbc->FindItem(name);
   return (TGLBEntry *)(el ? el->fFrame : 0);
}

//______________________________________________________________________________
void TGListBox::SavePrimitive(ofstream &out, Option_t *option)
{
    // Save a list box widget as a C++ statement(s) on output stream out.

   if (fBackground != GetWhitePixel()) SaveUserColor(out, option);

   out << endl << "   // list box" << endl;

   out<<"   TGListBox *";
   out << GetName() << " = new TGListBox(" << fParent->GetName();

   if (fBackground == GetWhitePixel()) {
       if (GetOptions() == (kSunkenFrame | kDoubleBorder)) {
          if (fWidgetId == -1) {
               out <<");" << endl;
           } else {
             out << "," << fWidgetId << ");" << endl;
           }
       } else {
         out << "," << fWidgetId << "," << GetOptionString() <<");" << endl;
       }
   } else {
     out << "," << fWidgetId << "," << GetOptionString() << ",ucolor);" << endl;
   }

   if (!fLbc->GetList()) return;

   TGFrameElement *el;
   TIter next(fLbc->GetList());

   while ((el = (TGFrameElement *) next())) {
      out << "   " << GetName() << "->AddEntry(";
      el->fFrame->SavePrimitive(out, option);
      out << ");"<< endl;
   }
   out << "   " << GetName() << "->Resize(" << GetWidth() << "," << GetHeight()
       << ");" << endl;
}

//______________________________________________________________________________
void TGTextLBEntry::SavePrimitive(ofstream &out, Option_t *)
{
    // Save a list box entry widget as a C++ statement(s) on output stream out

    char quote = '"';
    out << quote << GetText()->GetString() << quote << "," << EntryId();
}