    // @(#)root/gui:$Name:  $:$Id: TGTab.cxx,v 1.13 2003/12/15 18:04:27 brun Exp $
    // Author: Fons Rademakers   13/01/98

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

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

    //////////////////////////////////////////////////////////////////////////
    //                                                                      //
    // TGTab, TGTabElement, TGTabLayout                                     //
    //                                                                      //
    // A tab widget contains a set of composite frames each with a little   //
    // tab with a name (like a set of folders with tabs).                   //
    //                                                                      //
    // The TGTab is user callable. The TGTabElement and TGTabLayout are     //
    // service classes of the tab widget.                                   //
    //                                                                      //
    // Clicking on a tab will bring the associated composite frame to the   //
    // front and generate the following event:                              //
    // kC_COMMAND, kCM_TAB, tab id, 0.                                      //
    //                                                                      //
    //////////////////////////////////////////////////////////////////////////

    #include "TGTab.h"
    #include "TGResourcePool.h"
    #include "TList.h"
    #include "TMath.h"
    #include "Riostream.h"

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

    ClassImp(TGTabElement)
    ClassImp(TGTabLayout)
    ClassImpQ(TGTab)

    //______________________________________________________________________________
     TGTabElement::TGTabElement(const TGWindow *p, TGString *text, UInt_t w, UInt_t h,
                               GContext_t norm, FontStruct_t font,
                               UInt_t options, ULong_t back) :
       TGFrame(p, w, h, options, back)
    {
       // Create a tab element. Text is adopted by tab element.

       fText        = text;
       fBorderWidth = 0;
       fNormGC      = norm;
       fFontStruct  = font;

       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(TMath::Max(fTWidth+12, (UInt_t)45), fTHeight+6);
    }

    //______________________________________________________________________________
     TGTabElement::~TGTabElement()
    {
       // Delete tab element.

       if (fText) delete fText;
    }

    //______________________________________________________________________________
     void TGTabElement::DrawBorder()
    {
       // Draw little tab element.

       gVirtualX->DrawLine(fId, GetHilightGC()(), 0, fHeight-1, 0, 2);
       gVirtualX->DrawLine(fId, GetHilightGC()(), 0, 2, 2, 0);
       gVirtualX->DrawLine(fId, GetHilightGC()(), 2, 0, fWidth-3, 0);
       gVirtualX->DrawLine(fId, GetShadowGC()(),  fWidth-2, 1, fWidth-2, fHeight-1);
       gVirtualX->DrawLine(fId, GetBlackGC()(), fWidth-2, 1, fWidth-1, 2);
       gVirtualX->DrawLine(fId, GetBlackGC()(), fWidth-1, 2, fWidth-1, fHeight-2);
       gVirtualX->DrawLine(fId, GetHilightGC()(), fWidth-1, fHeight-1, fWidth-1, fHeight-1);

       if (fText) {
          int max_ascent, max_descent;
          gVirtualX->GetFontProperties(fFontStruct, max_ascent, max_descent);
          fText->Draw(fId, fNormGC, 6, max_ascent+3);
       }
    }

    //______________________________________________________________________________
     TGDimension TGTabElement::GetDefaultSize() const
    {
       // Return default size of tab element.

       return TGDimension(TMath::Max(fTWidth+12, (UInt_t)45), fTHeight+6);
    }

    //______________________________________________________________________________
     void TGTabElement::SetText(TGString *text)
    {
       // Set new tab text.

       if (fText) delete fText;
       fText = text;

       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;

       fClient->NeedRedraw(this);
    }

    //______________________________________________________________________________
    TGTabLayout::TGTabLayout(TGTab *main)
    {
       // Create a tab layout manager.

       fMain = main;
       fList = fMain->GetList();
    }

    //______________________________________________________________________________
    void TGTabLayout::Layout()
    {
       // Layout the tab widget.

       Int_t  i, xtab;
       UInt_t tw;
       UInt_t tabh = fMain->GetTabHeight(), bw = fMain->GetBorderWidth();
       UInt_t w = fMain->GetWidth();
       UInt_t h = fMain->GetHeight();

       xtab = 2;

       fMain->GetContainer()->MoveResize(0, tabh, w, h - tabh);

       // first frame is the container, so take next...
       TGFrameElement *el, *elnxt;
       TIter next(fList);
       i = 0;
       next();   // skip first
       while ((el = (TGFrameElement *) next())) {
          elnxt = (TGFrameElement *) next();
          tw = el->fFrame->GetDefaultWidth();
          if (i == fMain->GetCurrent()) {
             el->fFrame->MoveResize(xtab-2, 0, tw+3, tabh+1);
             elnxt->fFrame->RaiseWindow();
             el->fFrame->RaiseWindow();
          } else {
             el->fFrame->MoveResize(xtab, 2, tw, tabh-1);
             el->fFrame->LowerWindow();
          }
          elnxt->fFrame->MoveResize(bw, tabh + bw, w - (bw << 1), h - tabh - (bw << 1));
          elnxt->fFrame->Layout();
          xtab += (Int_t)tw;
          i++;
       }
    }

    //______________________________________________________________________________
    TGDimension TGTabLayout::GetDefaultSize() const
    {
       // Get default size of tab widget.

       TGDimension dsize, dsize_te;
       TGDimension size(0,0), size_te(0,0);

       TGFrameElement *el, *elnxt;
       TIter next(fList);
       next();   // skip first container
       while ((el = (TGFrameElement *)next())) {
          dsize_te = el->fFrame->GetDefaultSize();
          size_te.fWidth += dsize_te.fWidth;
          elnxt = (TGFrameElement *) next();
          dsize = elnxt->fFrame->GetDefaultSize();
          if (size.fWidth < dsize.fWidth) size.fWidth = dsize.fWidth;
          if (size.fHeight < dsize.fHeight) size.fHeight = dsize.fHeight;
       }

       // check if tab elements make a larger width than the containers
       if (size.fWidth < size_te.fWidth) size.fWidth = size_te.fWidth;

       size.fWidth += fMain->GetBorderWidth() << 1;
       size.fHeight += fMain->GetTabHeight() + (fMain->GetBorderWidth() << 1);

       return size;
    }

    //______________________________________________________________________________
    TGTab::TGTab(const TGWindow *p, UInt_t w, UInt_t h,
                 GContext_t norm, FontStruct_t font,
                 UInt_t options, ULong_t back) :
       TGCompositeFrame(p, w, h, options, back)
    {
       // Create tab widget.

       fMsgWindow  = p;

       fBorderWidth = 2;
       fCurrent     = 0;
       fRemoved     = new TList;

       fNormGC     = norm;
       fFontStruct = font;

       int max_ascent, max_descent;
       gVirtualX->GetFontProperties(fFontStruct, max_ascent, max_descent);
       fTabh = max_ascent + max_descent + 6;

       SetLayoutManager(new TGTabLayout(this));

       // we need this in order to avoid border blinking when switching tabs...
       fContainer = new TGCompositeFrame(this, fWidth, fHeight - fTabh,
                           kVerticalFrame | kRaisedFrame | kDoubleBorder);
       AddFrame(fContainer, 0);

       AddInput(kButtonPressMask);
    }

    //______________________________________________________________________________
    TGTab::~TGTab()
    {
       // Delete tab widget. This deletes the tab windows and the containers.
       // The tab string is deleted by the TGTabElement dtor.

       TGFrameElement *el;
       TIter next(fList);

       while ((el = (TGFrameElement *) next())) {
          delete el->fFrame;
          // delete el->fLayout; // el->fLayout is NULL!
       }

       fRemoved->Delete();
       delete fRemoved;
    }

    //______________________________________________________________________________
    TGCompositeFrame *TGTab::AddTab(TGString *text)
    {
       // Add a tab to the tab widget. Returns the new container, which
       // is owned by the tab widget. The text is adopted by the tab widget.

       TGCompositeFrame *cf;

       AddFrame(new TGTabElement(this, text, 50, 20, fNormGC, fFontStruct), 0);
       cf = new TGCompositeFrame(this, fWidth, fHeight-21);
       AddFrame(cf, 0);

       return cf;
    }

    //______________________________________________________________________________
    TGCompositeFrame *TGTab::AddTab(const char *text)
    {
       // Add a tab to the tab widget. Returns the new container. The container
       // is owned by the tab widget.

       return AddTab(new TGString(text));
    }

    //______________________________________________________________________________
    void TGTab::RemoveTab(Int_t tabIndex)
    {
       // Remove container and tab of tab with index tabIndex.
       // Does NOT remove the container contents!

       if (tabIndex < 0) return;

       TGFrameElement *elTab, *elCont ;
       Int_t  count = 0 ;

       TIter next(fList) ;
       next() ; // skip first container

       while ((elTab = (TGFrameElement *) next())) {
          elCont = (TGFrameElement *) next();

          if (count == tabIndex) {
             elCont->fFrame->UnmapWindow();   // will be destroyed later
             TGFrame *frame = elTab->fFrame;
             RemoveFrame(elTab->fFrame);
             frame->DestroyWindow();
             delete frame;
             fRemoved->Add(elCont->fFrame);   // delete only in dtor
             RemoveFrame(elCont->fFrame);
             if (tabIndex == fCurrent) {
               // select another tab only if the current is the one we delete
               SetTab(0);
             } else
                fCurrent--;
             break;
          }
          count++;
       }
    }

    //______________________________________________________________________________
    void TGTab::ChangeTab(Int_t tabIndex)
    {
       // Make tabIdx the current tab. Utility method called by SetTab and
       // HandleButton().

       if (tabIndex != fCurrent) {
          TGFrameElement *el, *elnxt;
          UInt_t tw;
          Int_t  xtab  = 2;
          Int_t  count = 0;

          TIter next(fList);
          next();           // skip first container

          fCurrent = tabIndex;
          while ((el = (TGFrameElement *) next())) {
             elnxt = (TGFrameElement *) next();
             tw = el->fFrame->GetDefaultWidth();
             if (count == fCurrent) {
                el->fFrame->MoveResize(xtab-2, 0, tw+3, fTabh+1);
                elnxt->fFrame->RaiseWindow();
                el->fFrame->RaiseWindow();
             } else {
                el->fFrame->MoveResize(xtab, 2, tw, fTabh-1);
                el->fFrame->LowerWindow();
             }
             xtab += tw;
             count++;
          }
          SendMessage(fMsgWindow, MK_MSG(kC_COMMAND, kCM_TAB), fCurrent, 0);
          fClient->ProcessLine(fCommand, MK_MSG(kC_COMMAND, kCM_TAB), fCurrent, 0);
          Selected(fCurrent);
       }
    }

    //______________________________________________________________________________
    Bool_t TGTab::SetTab(Int_t tabIndex)
    {
       // Brings the composite frame with the index tabIndex to the
       // front and generate the following event if the front tab has changed:
       // kC_COMMAND, kCM_TAB, tab id, 0.
       // Returns kFALSE if tabIndex is a not valid index

       // check if tabIndex is a valid index
       if (tabIndex < 0)
          return kFALSE;

       // count the tabs
       TIter next(fList);
       Int_t count = 0;
       while (next())
          count++;

       count = count / 2 - 1;
       if (tabIndex > count)
          return kFALSE;

       // change tab and generate event
       ChangeTab(tabIndex);

       return kTRUE;
    }

    //______________________________________________________________________________
    Bool_t TGTab::HandleButton(Event_t *event)
    {
       // Handle button event in the tab widget. Basically we only handle
       // button events in the small tabs.

       if (event->fType == kButtonPress) {
          TGFrameElement *el;
          TIter next(fList);

          next();   // skip first container

          Int_t i = 0;
          Int_t c = fCurrent;
          while ((el = (TGFrameElement *) next())) {
             if (el->fFrame->GetId() == (Window_t)event->fUser[0])  // fUser[0] is child window
                c = i;
             next(); i++;
          }

          // change tab and generate event
          ChangeTab(c);
       }
       return kTRUE;
    }

    //______________________________________________________________________________
    TGCompositeFrame *TGTab::GetTabContainer(Int_t tabIndex) const
    {
       // Return container of tab with index tabIndex.
       // Returns 0 in case tabIndex is out of range.

       if (tabIndex < 0) return 0;

       TGFrameElement *el;
       Int_t  count = 0;

       TIter next(fList);
       next();           // skip first container

       while (next()) {
          el = (TGFrameElement *) next();
          if (count == tabIndex)
             return (TGCompositeFrame *) el->fFrame;
          count++;
       }

       return 0;
    }

    //______________________________________________________________________________
    TGTabElement *TGTab::GetTabTab(Int_t tabIndex) const
    {
       // Return the tab element of tab with index tabIndex.
       // Returns 0 in case tabIndex is out of range.

       if (tabIndex < 0) return 0;

       TGFrameElement *el;
       Int_t  count = 0;

       TIter next(fList);
       next();           // skip first container

       while ((el = (TGFrameElement *) next())) {
          next();
          if (count == tabIndex)
             return (TGTabElement *) el->fFrame;
          count++;
       }

       return 0;
    }

    //______________________________________________________________________________
    Int_t TGTab::GetNumberOfTabs() const
    {
       // Return number of tabs.

       Int_t count = 0;

       TIter next(fList);
       next();           // skip first container

       while (next()) {
          next();
          count++;
       }

       return count;
    }

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

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

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

       char quote = '"';

       // font + GC
       option = GetName()+5;         // unique digit id of the name
       char ParGC[50], ParFont[50];
       sprintf(ParFont,"%s::GetDefaultFontStruct()",IsA()->GetName());
       sprintf(ParGC,"%s::GetDefaultGC()()",IsA()->GetName());

       if ((GetDefaultFontStruct() != fFontStruct) || (GetDefaultGC()() != fNormGC)) {
          TGFont *ufont = gClient->GetResourcePool()->GetFontPool()->FindFont(fFontStruct);
          if (ufont) {
             ufont->SavePrimitive(out, option);
             sprintf(ParFont,"ufont->GetFontStruct()");
          }

          TGGC *userGC = gClient->GetResourcePool()->GetGCPool()->FindGC(fNormGC);
          if (userGC) {
             userGC->SavePrimitive(out, option);
             sprintf(ParGC,"uGC->GetGC()");
          }
       }

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

       out << endl << "   // tab widget" << endl;

       out << "   TGTab *";
       out << GetName() << " = new TGTab(" << fParent->GetName()
           << "," << GetWidth() << "," << GetHeight();

       if (fBackground == GetDefaultFrameBackground()) {
           if (GetOptions() == kChildFrame) {
              if (fFontStruct == GetDefaultFontStruct()) {
                 if (fNormGC == GetDefaultGC()()) {
                    out <<");" << endl;
                   } else {
                     out << "," << ParGC <<");" << endl;
                   }
               } else {
                 out << "," << ParGC << "," << ParFont <<");" << endl;
               }
           } else {
             out << "," << ParGC << "," << ParFont << "," << GetOptionString() <<");" << endl;
           }
       } else {
         out << "," << ParGC << "," << ParFont << "," << GetOptionString()  << ",ucolor);" << endl;
       }

       TGCompositeFrame *cf;
       for (Int_t i=0; i<GetNumberOfTabs(); i++) {
          cf = GetTabContainer(i);
          out << endl << "   // container of " << quote
              << GetTabTab(i)->GetString() << quote << endl;
          out << "   TGCompositeFrame *" << cf->GetName() << ";" << endl;
          out << "   " << cf->GetName() << " = " << GetName()
                       << "->AddTab(" << quote << GetTabTab(i)->GetString()
                       << quote << ");" << endl;
          if (((TGCompositeFrame *)cf)->GetLayoutManager() != 0) {
             out << "   " << cf->GetName() <<"->SetLayoutManager(";
             ((TGCompositeFrame *)cf)->GetLayoutManager()->SavePrimitive(out, option);
             out << ");" << endl;
          }

          TGFrameElement *el;
          TIter next(cf->GetList());
          while ((el = (TGFrameElement *) next())) {
             el->fFrame->SavePrimitive(out, option);
    		       out << "   " << cf->GetName() << "->AddFrame(" << el->fFrame->GetName();
    					    el->fLayout->SavePrimitive(out, option);
    					    out << ");" << endl;
          }
          //cf->SavePrimitive(out, option);
          if (GetTabTab(i)->GetBackground() != GetTabTab(i)->GetDefaultFrameBackground()) {
             GetTabTab(i)->SaveUserColor(out, option);
             out << "   TGTabElement *tab" << i << " = "
                 << GetName() << "->GetTabTab(" << i << ");" << endl;
             out << "   tab" << i << "->ChangeBackground(ucolor);" << endl;
          }

       }
       out << endl << "   " << GetName() << "->SetTab(" << GetCurrent() << ");" << endl;
       out << endl << "   " << GetName() << "->Resize(" << GetName()
           << "->GetDefaultSize());" << endl;
    }

    // __________________________________________________________________________
    void TGTabLayout::SavePrimitive(ofstream &out, Option_t *)
    {

       // Save tab layout manager as a C++ statement(s) on out stream

       out << "new TGTabLayout(" << fMain->GetName() << ")";

    }