    // @(#)root/gui:$Name:  $:$Id: TGView.cxx,v 1.11 2003/05/28 11:55:32 rdm Exp $
    // Author: Fons Rademakers   30/6/2000

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

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

    //////////////////////////////////////////////////////////////////////////
    //                                                                      //
    // TGView                                                               //
    //                                                                      //
    // A TGView provides the infrastructure for text viewer and editor      //
    // widgets. It provides a canvas (TGViewFrame) and (optionally) a       //
    // vertical and horizontal scrollbar and methods for marking and        //
    // scrolling.                                                           //
    //                                                                      //
    // The TGView (and derivatives) will generate the following             //
    // event messages:                                                      //
    // kC_TEXTVIEW, kTXT_ISMARKED, widget id, [true|false]                  //
    // kC_TEXTVIEW, kTXT_DATACHANGE, widget id, 0                           //
    // kC_TEXTVIEW, kTXT_CLICK2, widget id, position (y << 16) | x)         //
    // kC_TEXTVIEW, kTXT_CLICK3, widget id, position (y << 16) | x)         //
    // kC_TEXTVIEW, kTXT_F3, widget id, true                                //
    // kC_TEXTVIEW, kTXT_OPEN, widget id, 0                                 //
    // kC_TEXTVIEW, kTXT_CLOSE, widget id, 0                                //
    // kC_TEXTVIEW, kTXT_SAVE, widget id, 0                                 //
    //                                                                      //
    //////////////////////////////////////////////////////////////////////////

    #include "TGView.h"
    #include "TGScrollBar.h"
    #include "TGResourcePool.h"
    #include "TSystem.h"
    #include "TMath.h"
    #include "KeySymbols.h"

    //______________________________________________________________________________
    Bool_t TViewTimer::Notify()
    {
       fView->HandleTimer(this);
       Reset();
       return kFALSE;
    }

    ClassImp(TGViewFrame)

    //______________________________________________________________________________
     TGViewFrame::TGViewFrame(TGView *v, UInt_t w, UInt_t h, UInt_t options,
                             ULong_t back) :
       TGCompositeFrame(v, w, h, options | kOwnBackground, back)
    {
       // Create a editor frame.

       fView = v;

       SetBackgroundColor(back);

       gVirtualX->GrabButton(fId, kAnyButton, kAnyModifier,
                             kButtonPressMask | kButtonReleaseMask |
                             kButtonMotionMask, kNone, kNone);

       AddInput(kKeyPressMask | kEnterWindowMask | kLeaveWindowMask |
                kFocusChangeMask | kStructureNotifyMask);
    }

    ClassImp(TGView)

    //______________________________________________________________________________
    TGView::TGView(const TGWindow *p, UInt_t w, UInt_t h, Int_t id,
                   UInt_t xMargin, UInt_t yMargin, UInt_t options,
                   UInt_t sboptions, ULong_t back)
           : TGCompositeFrame(p, w, h, options, GetDefaultFrameBackground())
    {
       // Create an editor view, containing an TGEditorFrame and (optionally)
       // a horizontal and vertical scrollbar.

       fWidgetId    = id;
       fMsgWindow   = p;
       fWidgetFlags = kWidgetWantFocus;

       SetLayoutManager(new TGHorizontalLayout(this));

       fXMargin = xMargin;
       fYMargin = yMargin;
       fScrollVal.fX = 1;
       fScrollVal.fY = 1;

       fClipboard = fClient->GetResourcePool()->GetClipboard();

       fCanvas = new TGViewFrame(this, 10, 10, kChildFrame, back);
       AddFrame(fCanvas);

       if (!(sboptions & kNoHSB)) {
          fHsb = new TGHScrollBar(this, 10, 10, kChildFrame);
          AddFrame(fHsb);
          fHsb->Associate(this);
       } else
          fHsb = 0;

       if (!(sboptions & kNoVSB)) {
          fVsb = new TGVScrollBar(this, 10, 10, kChildFrame);
          AddFrame(fVsb);
          fVsb->Associate(this);
       } else
          fVsb = 0;

       fWhiteGC = GetWhiteGC();
       fWhiteGC.SetGraphicsExposures(kTRUE);

       Clear();
       Layout();

       fScrollTimer = new TViewTimer(this, 75);
       gSystem->AddTimer(fScrollTimer);
    }

    //______________________________________________________________________________
    TGView::~TGView()
    {
       // Delete view.

       delete fScrollTimer;
       delete fCanvas;
       delete fHsb;
       delete fVsb;
    }

    //______________________________________________________________________________
    void TGView::Clear(Option_t *)
    {
       // Clear view.

       fIsMarked  = kFALSE;
       fIsSaved   = kTRUE;
       fScrolling = -1;
       fIsMarking = kFALSE;
       fMarkedStart.fX = fMarkedStart.fY = 0;
       fMarkedEnd.fX   = fMarkedEnd.fY   = 0;
       fMousePos.fX    = fMousePos.fY    = -1;
       fVisible.fX     = fVisible.fY     = 0;
       SetVsbPosition(0);
       SetHsbPosition(0);
    }

    //______________________________________________________________________________
    void TGView::SetVisibleStart(Int_t newTop, Int_t direction)
    {
       // Scroll view in specified direction to make newTop the visible location.

       if (direction == kHorizontal) {
          if (newTop / fScrollVal.fX == fVisible.fX / fScrollVal.fX)
             return;
          ScrollCanvas(newTop, kHorizontal);
       } else {
          if (newTop / fScrollVal.fY == fVisible.fY / fScrollVal.fY)
             return;
          ScrollCanvas(newTop, kVertical);
       }
    }

    //______________________________________________________________________________
    Bool_t TGView::HandleExpose(Event_t *event)
    {
       // Handle expose events.

       if (event->fWindow == fCanvas->GetId()) {
          DrawRegion(event->fX, event->fY, event->fWidth, event->fHeight);
       } else
          TGCompositeFrame::HandleExpose(event);

       return kTRUE;
    }

    //______________________________________________________________________________
    Bool_t TGView::HandleCrossing(Event_t *event)
    {
       // Handle mouse crossing event.

       if (event->fWindow != fCanvas->GetId())
          return kTRUE;

       fMousePos.fY = ToObjYCoord(fVisible.fY + event->fY);
       if (ToScrYCoord(fMousePos.fY+1) >= (Int_t)fCanvas->GetHeight())
          fMousePos.fY--;
       fMousePos.fX = ToObjXCoord(fVisible.fX + event->fX, fMousePos.fY);
       if (fMousePos.fX >= ReturnLineLength(fMousePos.fY))
          fMousePos.fX--;
       if ((event->fState & kButton1Mask) && fIsMarked && fIsMarking) {
          if (event->fType == kLeaveNotify) {
             if (event->fX < 0) {
                fScrolling = 0;
                return kFALSE;
             }
             if (event->fX >= (Int_t)fCanvas->GetWidth()) {
                fScrolling = 1;
                return kFALSE;
             }
             if (event->fY < 0) {
                fScrolling = 2;
                return kFALSE;
             }
             if (event->fY >= (Int_t)fCanvas->GetHeight()) {
                fScrolling = 3;
                return kFALSE;
             }
          } else {
             fScrolling = -1;
             Mark(fMousePos.fX, fMousePos.fY);
          }
       } else
          fIsMarking = kFALSE;

       return kTRUE;
    }

    //______________________________________________________________________________
    Bool_t TGView::HandleTimer(TTimer *)
    {
       // Handle scroll timer.

       TGLongPosition size;

       if (fIsMarked) {
          size.fY = ToObjYCoord(fVisible.fY + fCanvas->GetHeight()) - 1;
          size.fX = ToObjXCoord(fVisible.fX + fCanvas->GetWidth(), fMousePos.fY) - 1;
          switch (fScrolling) {
             case -1:
                break;
             case 0:
                if (fVisible.fX == 0) {
                   fScrolling = -1;
                   break;
                } else {
                   SetHsbPosition(fVisible.fX / fScrollVal.fX - 1);
                   Mark(ToObjXCoord(fVisible.fX, fMousePos.fY) - 1, fMousePos.fY);
                }
                break;
             case 1:
                if ((Int_t)fCanvas->GetWidth() >= ToScrXCoord(ReturnLineLength(fMousePos.fY), fMousePos.fY)) {
                   fScrolling = -1;
                   break;
                } else {
                   SetHsbPosition(fVisible.fX / fScrollVal.fX + 1);
                   Mark(size.fX+1, fMousePos.fY);
                }
                break;
             case 2:
                if (fVisible.fY == 0) {
                   fScrolling = -1;
                   break;
                } else {
                   SetVsbPosition(fVisible.fY / fScrollVal.fY - 1);
                   Mark(fMousePos.fX, fMarkedStart.fY - 1);
                }
                break;
             case 3:
                if ((Int_t)fCanvas->GetHeight() >= ToScrYCoord(ReturnLineCount())) {
                   fScrolling = -1;
                   break;
                } else {
                   SetVsbPosition(fVisible.fY / fScrollVal.fY + 1);
                   Mark(fMousePos.fX, size.fY + 1);
                }
                break;
             default:
                break;
          }
       }
       return kTRUE;
    }

    //______________________________________________________________________________
    Bool_t TGView::HandleButton(Event_t *event)
    {
       // Handle mouse button event in text editor.

       if (event->fWindow != fCanvas->GetId())
          return kTRUE;

       if (event->fCode == kButton1) {
          if (event->fType == kButtonPress) {
             if (fIsMarked) {
                if (event->fState & kKeyShiftMask) {
                   fIsMarking = kTRUE;
                   TGView::HandleMotion(event);
                   return kTRUE;
                }
                fIsMarked = kFALSE;
                UnMark();
             }
             fIsMarked = kTRUE;
             fIsMarking = kTRUE;
             fMousePos.fY = ToObjYCoord(fVisible.fY + event->fY);
             fMousePos.fX = ToObjXCoord(fVisible.fX + event->fX, fMousePos.fY);
             fMarkedStart.fX = fMarkedEnd.fX = fMousePos.fX;
             fMarkedStart.fY = fMarkedEnd.fY = fMousePos.fY;
          } else {
             fScrolling = -1;
             if ((fMarkedStart.fX == fMarkedEnd.fX) &&
                 (fMarkedStart.fY == fMarkedEnd.fY)) {
                fIsMarked = kFALSE;
                SendMessage(fMsgWindow, MK_MSG(kC_TEXTVIEW, kTXT_ISMARKED),
                            fWidgetId, kFALSE);
                Marked(kFALSE);
             } else {
                SendMessage(fMsgWindow, MK_MSG(kC_TEXTVIEW, kTXT_ISMARKED),
                            fWidgetId, kTRUE);
                Marked(kTRUE);
             }
             fIsMarking = kFALSE;
          }
       } else if (event->fCode == kButton4) {
          // move three lines up
          if (fVisible.fY > 0) {
             SetVsbPosition(fVisible.fY / fScrollVal.fY - 3);
             Mark(fMousePos.fX, fMarkedStart.fY - 3);
          }
       } else if (event->fCode == kButton5) {
          // move three lines down
          if ((Int_t)fCanvas->GetHeight() < ToScrYCoord(ReturnLineCount())) {
             TGLongPosition size;
             size.fY = ToObjYCoord(fVisible.fY + fCanvas->GetHeight()) - 1;
             SetVsbPosition(fVisible.fY / fScrollVal.fY + 3);
             Mark(fMousePos.fX, size.fY + 3);
          }
       } else if (event->fType == kButtonPress) {
          if (event->fCode == kButton2) {
             SendMessage(fMsgWindow, MK_MSG(kC_TEXTVIEW, kTXT_CLICK2),
                         fWidgetId, (event->fYRoot << 16) | event->fXRoot);
          } else if (event->fCode == kButton3) {
             SendMessage(fMsgWindow, MK_MSG(kC_TEXTVIEW, kTXT_CLICK3),
                         fWidgetId, (event->fYRoot << 16) | event->fXRoot);
          }
       }
       return kTRUE;
    }

    //______________________________________________________________________________
    Bool_t TGView::HandleMotion(Event_t *event)
    {
       // Handle mouse motion event in the text editor widget.

       if ((ToObjYCoord(fVisible.fY+event->fY) == fMousePos.fY) &&
           (ToObjXCoord(fVisible.fX+event->fX, ToObjYCoord(fVisible.fY+event->fY)) == fMousePos.fX))
          return kTRUE;

       if (fScrolling != -1)
          return kTRUE;

       fMousePos.fY = ToObjYCoord(fVisible.fY+event->fY);
       if (fMousePos.fY >= ReturnLineCount())
          fMousePos.fY = ReturnLineCount()-1;
       fMousePos.fX = ToObjXCoord(fVisible.fX+event->fX, fMousePos.fY);
       if (fMousePos.fX > ReturnLineLength(fMousePos.fY))
          fMousePos.fX = ReturnLineLength(fMousePos.fY);
       if (event->fWindow != fCanvas->GetId())
          return kTRUE;
       if (!fIsMarked || !fIsMarking)
          return kTRUE;
       if (event->fX < 0)
          return kTRUE;
       if (event->fX >= (Int_t)fCanvas->GetWidth())
          return kTRUE;
       if (event->fY < 0)
          return kTRUE;
       if (event->fY >= (Int_t)fCanvas->GetHeight())
          return kTRUE;
       Mark(fMousePos.fX, fMousePos.fY);
       return kTRUE;
    }

    //______________________________________________________________________________
    Bool_t TGView::ProcessMessage(Long_t msg, Long_t parm1, Long_t)
    {
       // Process scrollbar messages.

       switch(GET_MSG(msg)) {
          case kC_HSCROLL:
             switch(GET_SUBMSG(msg)) {
                case kSB_SLIDERTRACK:
                case kSB_SLIDERPOS:
                   SetVisibleStart(Int_t(parm1 * fScrollVal.fX), kHorizontal);
                   break;
             }
             break;

          case kC_VSCROLL:
             switch(GET_SUBMSG(msg)) {
                case kSB_SLIDERTRACK:
                case kSB_SLIDERPOS:
                   SetVisibleStart(Int_t(parm1 * fScrollVal.fY), kVertical);
                   break;
             }
             break;

          default:
             break;
       }
       return kTRUE;
    }

    //______________________________________________________________________________
    void TGView::Layout()
    {
       // Layout the components of view.

       HLayout();
       VLayout();
    }

    //______________________________________________________________________________
    void TGView::HLayout()
    {
       // Horizontal layout of widgets (canvas, scrollbar).

       if (!fHsb) return;

       Int_t tcw, tch;
       Long_t cols;
       tch = fHeight - (fBorderWidth << 1) - fYMargin-1;
       tcw = fWidth - (fBorderWidth << 1) - fXMargin-1;
       if (fVsb && fVsb->IsMapped()) {
          tcw -= fVsb->GetDefaultWidth();
          if (tcw < 0) tcw = 0;
       }
       fCanvas->SetHeight(tch);
       fCanvas->SetWidth(tcw);
       cols = ReturnLongestLineWidth();
       if (cols <= tcw) {
          if (fHsb && fHsb->IsMapped()) {
             SetVisibleStart(0, kHorizontal);
             fHsb->UnmapWindow();
             VLayout();
          }
          fCanvas->MoveResize(fBorderWidth + fXMargin, fBorderWidth + fYMargin, tcw, tch);
       } else {
          if (fHsb) {
             tch -= fHsb->GetDefaultHeight();
             if (tch < 0) tch = 0;
             fHsb->MoveResize(fBorderWidth, fHeight - fHsb->GetDefaultHeight()-fBorderWidth,
                              tcw+1+fBorderWidth, fHsb->GetDefaultHeight());
             fHsb->MapWindow();
             fHsb->SetRange(Int_t(cols/fScrollVal.fX), Int_t(tcw/fScrollVal.fX));
          }
          fCanvas->MoveResize(fBorderWidth + fXMargin, fBorderWidth + fYMargin, tcw, tch);
       }
    }

    //______________________________________________________________________________
    void TGView::VLayout()
    {
       // Vertical layout of widgets (canvas, scrollbar).

       Int_t  tcw, tch;
       Long_t lines;

       tch = fHeight - (fBorderWidth << 1) - fYMargin-1;
       tcw = fWidth - (fBorderWidth << 1) - fXMargin-1;
       if (fHsb && fHsb->IsMapped()) {
          tch -= fHsb->GetDefaultHeight();
          if (tch < 0) tch = 0;
       }
       fCanvas->SetHeight(tch);
       fCanvas->SetWidth(tcw);
       lines = ReturnHeighestColHeight();
       if (lines <= tch) {
          if (fVsb && fVsb->IsMapped()) {
             SetVisibleStart(0, kVertical);
             fVsb->UnmapWindow();
             HLayout();
          }
          fCanvas->MoveResize(fBorderWidth + fXMargin, fBorderWidth + fYMargin, tcw, tch);
       } else {
          if (fVsb) {
             tcw -= fVsb->GetDefaultWidth();
             if (tcw < 0) tcw = 0;
             fVsb->MoveResize(fWidth - fVsb->GetDefaultWidth() - fBorderWidth, fBorderWidth,
                              fVsb->GetDefaultWidth(), tch+1+fBorderWidth);
             fVsb->MapWindow();
             fVsb->SetRange(Int_t(lines/fScrollVal.fY), Int_t(tch/fScrollVal.fY));
          }
          fCanvas->MoveResize(fBorderWidth + fXMargin, fBorderWidth + fYMargin, tcw, tch);
       }
    }

    //______________________________________________________________________________
    void TGView::SetSBRange(Int_t direction)
    {
       // Set the range for the kVertical or kHorizontal scrollbar.

       if (direction == kVertical) {
          if (!fVsb)
             return;
          if (ReturnHeighestColHeight() <= (Int_t)fCanvas->GetHeight()) {
             if (fVsb->IsMapped())
                VLayout();
             else
                return;
          }
          if (!fVsb->IsMapped())
             VLayout();
          fVsb->SetRange(Int_t(ReturnHeighestColHeight()/fScrollVal.fY),
                         Int_t(fCanvas->GetHeight()/fScrollVal.fY));
       } else {
          if (!fHsb)
             return;
          if (ReturnLongestLineWidth() <= (Int_t)fCanvas->GetWidth()) {
             if (fHsb->IsMapped())
                HLayout();
             else
                return;
          }
          if (!fHsb->IsMapped())
             HLayout();
          fHsb->SetRange(Int_t(ReturnLongestLineWidth()/fScrollVal.fX),
                         Int_t(fCanvas->GetWidth()/fScrollVal.fX));
       }
    }

    //______________________________________________________________________________
    void TGView::SetHsbPosition(Long_t newPos)
    {
       // Set position of horizontal scrollbar.

       if (fHsb && fHsb->IsMapped())
         fHsb->SetPosition(Int_t(newPos));
       else
         SetVisibleStart(Int_t(newPos * fScrollVal.fX), kHorizontal);
    }

    //______________________________________________________________________________
    void TGView::SetVsbPosition(Long_t newPos)
    {
       // Set position of vertical scrollbar.

       if (fVsb && fVsb->IsMapped())
          fVsb->SetPosition(Int_t(newPos));
       else
          SetVisibleStart(Int_t(newPos * fScrollVal.fY), kVertical);
    }

    //______________________________________________________________________________
    void TGView::DrawBorder()
    {
       // Draw the border of the text edit 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:
             TGFrame::DrawBorder();
             break;
       }
    }

    //______________________________________________________________________________
    void TGView::ScrollCanvas(Int_t new_top, Int_t direction)
    {
       // Scroll the canvas to new_top in the kVertical or kHorizontal direction.

       Point_t points[4];
       Int_t xsrc, ysrc, xdest, ydest, cpyheight, cpywidth;

       if (direction == kVertical) {
          points[0].fX = points[3].fX = 0;
          points[1].fX = points[2].fX = fCanvas->GetWidth();
          xsrc = xdest = 0;
          cpywidth = 0;
          if (new_top < fVisible.fY) {
             ysrc = 0;
             ydest = Int_t(fVisible.fY - new_top);
             cpyheight = ydest;
             if (ydest > (Int_t)fCanvas->GetHeight())
                ydest = fCanvas->GetHeight();
             points[1].fY = points[0].fY = 0;
             points[3].fY = points[2].fY = ydest ; // -1;
          } else {
             ydest = 0;
             ysrc = Int_t(new_top - fVisible.fY);
             cpyheight= ysrc;
             if (ysrc > (Int_t)fCanvas->GetHeight())
                ysrc = fCanvas->GetHeight();
             points[1].fY = points[0].fY = fCanvas->GetHeight()-ysrc; // +1;
             points[3].fY = points[2].fY = fCanvas->GetHeight();
          }
          fVisible.fY = new_top;
          if (fVisible.fY < 0)
             fVisible.fY = 0;
       } else {
          points[0].fY = points[1].fY = 0;
          points[2].fY = points[3].fY = fCanvas->GetHeight();
          ysrc = ydest = 0;
          cpyheight = 0;
          if (new_top < fVisible.fX) {
             xsrc = 0;
             xdest = Int_t(fVisible.fX - new_top);
             cpywidth = xdest;
             if (xdest < 0)
                xdest = fCanvas->GetWidth();
             points[0].fX = points[3].fX = 0;
             points[1].fX = points[2].fX = xdest ; // -1;
          } else {
             xdest = 0;
             xsrc =  Int_t(new_top - fVisible.fX);
             cpywidth = xsrc;
             if (xsrc > (Int_t)fCanvas->GetWidth())
                xsrc = fCanvas->GetWidth();
             points[0].fX = points[3].fX = fCanvas->GetWidth()-xsrc; // +1;
             points[1].fX = points[2].fX = fCanvas->GetWidth();
          }
          fVisible.fX = new_top;
          if (fVisible.fX < 0)
             fVisible.fX = 0;
       }
       // Copy the scrolled region to its new position
       gVirtualX->CopyArea(fCanvas->GetId(), fCanvas->GetId(), fWhiteGC(),
                           xsrc, ysrc, fCanvas->GetWidth()-cpywidth,
                           fCanvas->GetHeight()-cpyheight, xdest, ydest);
       // Clear the remaining area of any old text
       gVirtualX->ClearArea(fCanvas->GetId(), points[0].fX, points[0].fY,
                            points[2].fX - points[0].fX,
                            points[2].fY - points[0].fY);

       DrawRegion(points[0].fX, points[0].fY,
                  points[2].fX - points[0].fX, points[2].fY - points[0].fY);
    }