TEScreen.cpp

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/* -------------------------------------------------------------------------- */
/*                                                                            */
/* [TEScreen.C]               Screen Data Type                                */
/*                                                                            */
/* -------------------------------------------------------------------------- */
/*                                                                            */
/* Copyright (c) 1997,1998 by Lars Doelle <lars.doelle@on-line.de>            */
/*                                                                            */
/* This file is part of Konsole - an X terminal for KDE                       */
/*                                                                            */
/* -------------------------------------------------------------------------- */
/*                        */
/* Ported Konsole to Qt/Embedded                                              */
/*                        */
/* Copyright (C) 2000 by John Ryland <jryland@trolltech.com>                  */
/*                        */
/* -------------------------------------------------------------------------- */
// enhancements added by L.J. Potter <ljp@llornkcor.com>

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
// #include <kdebug.h>

#include <assert.h>
#include <string.h>
#include <ctype.h>

#include <qpe/config.h>
#include "TEScreen.h"

#define HERE printf("%s(%d): here\n",__FILE__,__LINE__)

//FIXME: this is emulation specific. Use FALSE for xterm, TRUE for ANSI.
//FIXME: see if we can get this from terminfo.
#define BS_CLEARS FALSE

#define loc(X,Y) ((Y) * columns + (X))

TEScreen::TEScreen(int lines, int columns)
{
  this->lines   = lines;
  this->columns = columns;
//  odebug << "Columns " << columns << "" << oendl; 
  
  image      = (ca*) malloc(lines*columns*sizeof(ca));
  tabstops   = NULL; initTabStops();

  histCursor = 0;
  horzCursor = 0;

  clearSelection();
  reset();
}

TEScreen::~TEScreen()
{
  free(image);
  if (tabstops) free(tabstops);
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/* Normalized                    Screen Operations                           */
/*                                                                           */
/* ------------------------------------------------------------------------- */

// Cursor Setting --------------------------------------------------------------

void TEScreen::cursorUp(int n)
//=CUU
{
  if (n == 0) n = 1; // Default
  int stop = cuY < tmargin ? 0 : tmargin;
  cuX = QMIN(columns-1,cuX); // nowrap!
  cuY = QMAX(stop,cuY-n);
}

void TEScreen::cursorDown(int n)
//=CUD
{
  if (n == 0) n = 1; // Default
  int stop = cuY > bmargin ? lines-1 : bmargin;
  cuX = QMIN(columns-1,cuX); // nowrap!
  cuY = QMIN(stop,cuY+n);
}

void TEScreen::cursorLeft(int n)
//=CUB
{
  if (n == 0) n = 1; // Default
  cuX = QMIN(columns-1,cuX); // nowrap!
  cuX = QMAX(0,cuX-n);
}

void TEScreen::cursorRight(int n)
//=CUF
{
  if (n == 0) n = 1; // Default
  cuX = QMIN(columns-1,cuX+n);
}

void TEScreen::setMargins(int top, int bot)
//=STBM
{
  if (top == 0) top = 1;      // Default
  if (bot == 0) bot = lines;  // Default
  top = top - 1;              // Adjust to internal lineno
  bot = bot - 1;              // Adjust to internal lineno
  if ( !( 0 <= top && top < bot && bot < lines ) )
  { fprintf(stderr,"%s(%d) : setRegion(%d,%d) : bad range.\n",
                   __FILE__,__LINE__,top,bot);
    return;                   // Default error action: ignore
  }
  tmargin = top;
  bmargin = bot;
  cuX = 0;
  cuY = getMode(MODE_Origin) ? top : 0;
}

void TEScreen::index()
//=IND
{
  if (cuY == bmargin)
  {
    if (tmargin == 0 && bmargin == lines-1) addHistLine(); // hist.history
    scrollUp(tmargin,1);
  }
  else if (cuY < lines-1)
    cuY += 1;
}

void TEScreen::reverseIndex()
//=RI
{
  if (cuY == tmargin)
     scrollDown(tmargin,1);
  else if (cuY > 0)
    cuY -= 1;
}

void TEScreen::NextLine()
//=NEL
{
  Return(); index();
}

// Line Editing ----------------------------------------------------------------

void TEScreen::eraseChars(int n)
{
  if (n == 0) n = 1; // Default
  int p = QMAX(0,QMIN(cuX+n-1,columns-1));
  clearImage(loc(cuX,cuY),loc(p,cuY),' ');
}

void TEScreen::deleteChars(int n)
{
  if (n == 0) n = 1; // Default
  int p = QMAX(0,QMIN(cuX+n,columns-1));
  moveImage(loc(cuX,cuY),loc(p,cuY),loc(columns-1,cuY));
  clearImage(loc(columns-n,cuY),loc(columns-1,cuY),' ');
}

void TEScreen::insertChars(int n)
{
  if (n == 0) n = 1; // Default
  int p = QMAX(0,QMIN(columns-1-n,columns-1));
  int q = QMAX(0,QMIN(cuX+n,columns-1));
  moveImage(loc(q,cuY),loc(cuX,cuY),loc(p,cuY));
  clearImage(loc(cuX,cuY),loc(q-1,cuY),' ');
}

void TEScreen::deleteLines(int n)
{
  if (n == 0) n = 1; // Default
  scrollUp(cuY,n);
}

void TEScreen::insertLines(int n)
{
  if (n == 0) n = 1; // Default
  scrollDown(cuY,n);
}

// Mode Operations -----------------------------------------------------------

void TEScreen::setMode(int m)
{
  currParm.mode[m] = TRUE;
  switch(m)
  {
    case MODE_Origin : cuX = 0; cuY = tmargin; break; //FIXME: home
  }
}

void TEScreen::resetMode(int m)
{
  currParm.mode[m] = FALSE;
  switch(m)
  {
    case MODE_Origin : cuX = 0; cuY = 0; break; //FIXME: home
  }
}

void TEScreen::saveMode(int m)
{
  saveParm.mode[m] = currParm.mode[m];
}

void TEScreen::restoreMode(int m)
{
  currParm.mode[m] = saveParm.mode[m];
}

//NOTE: this is a helper function
BOOL TEScreen::getMode(int m)
{
  return currParm.mode[m];
}

void TEScreen::saveCursor()
{
  sa_cuX     = cuX;
  sa_cuY     = cuY;
  sa_cu_re   = cu_re;
  sa_cu_fg   = cu_fg;
  sa_cu_bg   = cu_bg;
}

void TEScreen::restoreCursor()
{
  cuX     = QMIN(sa_cuX,columns-1);
  cuY     = QMIN(sa_cuY,lines-1);
  cu_re   = sa_cu_re;
  cu_fg   = sa_cu_fg;
  cu_bg   = sa_cu_bg;
  effectiveRendition();
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                             Screen Operations                             */
/*                                                                           */
/* ------------------------------------------------------------------------- */

void TEScreen::resizeImage(int new_lines, int new_columns)
{
    if (cuY > new_lines-1)  {
// attempt to preserve focus and lines
        bmargin = lines-1; //FIXME: margin lost
        for (int i = 0; i < cuY-(new_lines-1); i++) {
            addHistLine(); scrollUp(horzCursor,1);
        }
    }

      // make new image
    ca* newimg = (ca*)malloc( new_lines * new_columns * sizeof( ca));

    clearSelection();

      // clear new image
    for (int y = 0; y < new_lines; y++)
        for (int x = 0; x < new_columns; x++) {
            newimg[y*new_columns+x].c = ' ';
            newimg[y*new_columns+x].f = DEFAULT_FORE_COLOR;
            newimg[y*new_columns+x].b = DEFAULT_BACK_COLOR;
            newimg[y*new_columns+x].r = DEFAULT_RENDITION;
        }
    int cpy_lines   = QMIN(new_lines,  lines);
    int cpy_columns = QMIN(new_columns,columns);
      // copy to new image
    for (int y = 0; y < cpy_lines; y++)
        for (int x = 0; x < cpy_columns; x++) {
            newimg[y*new_columns+x].c = image[loc(x,y)].c;
            newimg[y*new_columns+x].f = image[loc(x,y)].f;
            newimg[y*new_columns+x].b = image[loc(x,y)].b;
            newimg[y*new_columns+x].r = image[loc(x,y)].r;
        }
    free(image);
    image = newimg;
    lines = new_lines;
    columns = new_columns;
    cuX = QMIN(cuX,columns-1);
    cuY = QMIN(cuY,lines-1);

      // FIXME: try to keep values, evtl.
    tmargin=0;
    bmargin=lines-1;
    initTabStops();
    clearSelection();
}

/*
   Clarifying rendition here and in TEWidget.

   currently, TEWidget's color table is
     0       1       2 .. 9    10 .. 17
     dft_fg, dft_bg, dim 0..7, intensive 0..7

   cu_fg, cu_bg contain values 0..8;
   - 0    = default color
   - 1..8 = ansi specified color

   re_fg, re_bg contain values 0..17
   due to the TEWidget's color table

   rendition attributes are

      attr           widget screen
      -------------- ------ ------
      RE_UNDERLINE     XX     XX    affects foreground only
      RE_BLINK         XX     XX    affects foreground only
      RE_BOLD          XX     XX    affects foreground only
      RE_REVERSE       --     XX
      RE_TRANSPARENT   XX     --    affects background only
      RE_INTENSIVE     XX     --    affects foreground only

   Note that RE_BOLD is used in both widget
   and screen rendition. Since xterm/vt102
   is to poor to distinguish between bold
   (which is a font attribute) and intensive
   (which is a color attribute), we translate
   this and RE_BOLD in falls eventually appart
   into RE_BOLD and RE_INTENSIVE.
*/

void TEScreen::reverseRendition(ca* p)
{ UINT8 f = p->f; UINT8 b = p->b;
  p->f = b; p->b = f; //p->r &= ~RE_TRANSPARENT;
}

void TEScreen::effectiveRendition()
// calculate rendition
{
  ef_re = cu_re & (RE_UNDERLINE | RE_BLINK);
  if (cu_re & RE_REVERSE)
  {
    ef_fg = cu_bg;
    ef_bg = cu_fg;
  }
  else
  {
    ef_fg = cu_fg;
    ef_bg = cu_bg;
  }
  if (cu_re & RE_BOLD)
  {
    if (ef_fg < BASE_COLORS)
      ef_fg += BASE_COLORS;
    else
      ef_fg -= BASE_COLORS;
  }
}

ca* TEScreen::getCookedImage()
{
 int x,y;
  ca* merged = (ca*)malloc(lines*columns*sizeof(ca));
  ca dft(' ',DEFAULT_FORE_COLOR,DEFAULT_BACK_COLOR,DEFAULT_RENDITION);

  if (histCursor > hist.getLines()) {
    histCursor = hist.getLines();
  }

  for (y = 0; (y < lines) && (y < (hist.getLines()-histCursor)); y++)
  {
    int len = QMIN(columns,hist.getLineLen(y+histCursor));
    int yp  = y*columns;
    int yq  = (y+histCursor)*columns;

    hist.getCells(y+histCursor,0,len,merged+yp);
    for (x = len; x < columns; x++) merged[yp+x] = dft;
    for (x = 0; x < columns; x++)
    {   int p=x + yp; int q=x + yq;
        if ( ( q >= sel_TL ) && ( q <= sel_BR ) )
          reverseRendition(&merged[p]); // for selection
    }
  }
  if (lines >= hist.getLines()-histCursor)
  {
    for (y = (hist.getLines()-histCursor); y < lines ; y++)
    {
       int yp  = y*columns;
       int yq  = (y+histCursor)*columns;
       int yr =  (y-hist.getLines()+histCursor)*columns;
       for (x = 0; x < columns; x++)
       { int p = x + yp; int q = x + yq; int r = x + yr;
         merged[p] = image[r];
         if ( q >= sel_TL && q <= sel_BR )
           reverseRendition(&merged[p]); // for selection
       }

    }
  }
  // evtl. inverse display
  if (getMode(MODE_Screen))
  { int i,n = lines*columns;
    for (i = 0; i < n; i++)
      reverseRendition(&merged[i]); // for reverse display
  }
  if (getMode(MODE_Cursor) && (cuY+(hist.getLines()-histCursor) < lines)) // cursor visible
    reverseRendition(&merged[loc(cuX,cuY+(hist.getLines()-histCursor))]);
  return merged;
 
}


void TEScreen::reset()
{
  Config cfg( "Konsole" );
  cfg.setGroup("ScrollBar");
  if( !cfg.readBoolEntry("HorzScroll",0) )
    setMode(MODE_Wrap  ); saveMode(MODE_Wrap  );  // wrap at end of margin

    
  resetMode(MODE_Origin); saveMode(MODE_Origin);  // position refere to [1,1]
  resetMode(MODE_Insert); saveMode(MODE_Insert);  // overstroke
    setMode(MODE_Cursor);                         // cursor visible
  resetMode(MODE_Screen);                         // screen not inverse
  resetMode(MODE_NewLine);

  tmargin=0;
  bmargin=lines-1;

  setDefaultRendition();
  saveCursor();

  clear();
}

void TEScreen::clear()
{
  clearEntireScreen();
  home();
}

void TEScreen::BackSpace()
{
  cuX = QMAX(0,cuX-1);
  if (BS_CLEARS) image[loc(cuX,cuY)].c = ' ';
}

void TEScreen::Tabulate()
{
  // note that TAB is a format effector (does not write ' ');
  cursorRight(1); while(cuX < columns-1 && !tabstops[cuX]) cursorRight(1);
}

void TEScreen::clearTabStops()
{
  for (int i = 0; i < columns; i++) tabstops[i-1] = FALSE;
}

void TEScreen::changeTabStop(bool set)
{
  if (cuX >= columns) return;
  tabstops[cuX] = set;
}

void TEScreen::initTabStops()
{
  if (tabstops) free(tabstops);
  tabstops = (bool*)malloc(columns*sizeof(bool));
  // Arrg! The 1st tabstop has to be one longer than the other.
  // i.e. the kids start counting from 0 instead of 1.
  // Other programs might behave correctly. Be aware.
  for (int i = 0; i < columns; i++) tabstops[i] = (i%8 == 0 && i != 0);
}

void TEScreen::NewLine()
{
  if (getMode(MODE_NewLine)) Return();
  index();
}

void TEScreen::checkSelection(int from, int to)
{
  if (sel_begin == -1) return;
  int scr_TL = loc(0, hist.getLines());
  //Clear entire selection if it overlaps region [from, to]
  if ( (sel_BR > (from+scr_TL) )&&(sel_TL < (to+scr_TL)) )
  {
    clearSelection();
  }
}

void TEScreen::ShowCharacter(unsigned short c)
{
  // Note that VT100 does wrapping BEFORE putting the character.
  // This has impact on the assumption of valid cursor positions.
  // We indicate the fact that a newline has to be triggered by
  // putting the cursor one right to the last column of the screen.

  if (cuX >= columns)
  {
    if (getMode(MODE_Wrap)) NextLine(); else cuX = columns - 1;
       // comment out for no wrap
  }

  if (getMode(MODE_Insert)) insertChars(1);

  int i = loc( cuX, cuY);

  checkSelection(i, i); // check if selection is still valid.

  image[i].c = c;
  image[i].f = ef_fg;
  image[i].b = ef_bg;
  image[i].r = ef_re;

  cuX += 1;
}

// Region commands -------------------------------------------------------------


void TEScreen::scrollUp(int from, int n)
{
 if (n <= 0 || from + n > bmargin) return;
  //FIXME: make sure `tmargin', `bmargin', `from', `n' is in bounds.

    moveImage( loc( 0, from), loc( 0, from + n), loc( columns - 1, bmargin));
    clearImage( loc( 0, bmargin - n + 1), loc( columns - 1, bmargin), ' ');
}

void TEScreen::scrollDown(int from, int n)
{
    
//FIXME: make sure `tmargin', `bmargin', `from', `n' is in bounds.
 if (n <= 0) return;
  if (from > bmargin) return;
  if (from + n > bmargin) n = bmargin - from;

  moveImage( loc(0,from+n), loc(0,from), loc(columns-1,bmargin-n));
  clearImage(loc(0,from),loc(columns-1,from+n-1),' ');
}



void TEScreen::setCursorYX(int y, int x)
{
  setCursorY(y); setCursorX(x);
}

void TEScreen::setCursorX(int x)
{
  if (x == 0) x = 1; // Default
  x -= 1; // Adjust
  cuX = QMAX(0,QMIN(columns-1, x));
}

void TEScreen::setCursorY(int y)
{
  if (y == 0) y = 1; // Default
  y -= 1; // Adjust
  cuY = QMAX(0,QMIN(lines  -1, y + (getMode(MODE_Origin) ? tmargin : 0) ));
}

void TEScreen::home()
{
  cuX = 0;
  cuY = 0;
}

void TEScreen::Return()
{
  cuX = 0;
}

int TEScreen::getCursorX()
{
  return cuX;
}

int TEScreen::getCursorY()
{
  return cuY;
}

// Erasing ---------------------------------------------------------------------

void TEScreen::clearImage(int loca, int loce, char c)
{ int i;
  int scr_TL=loc(0,hist.getLines());
  //FIXME: check positions

  //Clear entire selection if it overlaps region to be moved...
  if ( (sel_BR > (loca+scr_TL) )&&(sel_TL < (loce+scr_TL)) )
  {
    clearSelection();
  }
  for (i = loca; i <= loce; i++)
  {
    image[i].c = c;
    image[i].f = ef_fg; //DEFAULT_FORE_COLOR; //FIXME: xterm and linux/ansi
    image[i].b = ef_bg; //DEFAULT_BACK_COLOR; //       many have different
    image[i].r = ef_re; //DEFAULT_RENDITION;  //       ideas here.
  }
}

void TEScreen::moveImage(int dst, int loca, int loce)
{
//FIXME: check positions
  if (loce < loca) {
    // kdDebug() << "WARNING!!! call to TEScreen:moveImage with loce < loca!" << endl;
    return;
  }
  memmove(&image[dst],&image[loca],(loce-loca+1)*sizeof(ca));
}

void TEScreen::clearToEndOfScreen()
{
  clearImage(loc(cuX,cuY),loc(columns-1,lines-1),' ');
}

void TEScreen::clearToBeginOfScreen()
{
  clearImage(loc(0,0),loc(cuX,cuY),' ');
}

void TEScreen::clearEntireScreen()
{
  clearImage(loc(0,0),loc(columns-1,lines-1),' ');
}

void TEScreen::helpAlign()
{
  clearImage(loc(0,0),loc(columns-1,lines-1),'E');
}

void TEScreen::clearToEndOfLine()
{
  clearImage(loc(cuX,cuY),loc(columns-1,cuY),' ');
}

void TEScreen::clearToBeginOfLine()
{
  clearImage(loc(0,cuY),loc(cuX,cuY),' ');
}

void TEScreen::clearEntireLine()
{
  clearImage( loc( 0, cuY),loc( columns - 1, cuY),' ');
}

// Rendition ------------------------------------------------------------------

void TEScreen::setRendition(int re)
{
  cu_re |= re;
  effectiveRendition();
}

void TEScreen::resetRendition(int re)
{
  cu_re &= ~re;
  effectiveRendition();
}

void TEScreen::setDefaultRendition()
{
  setForeColorToDefault();
  setBackColorToDefault();
  cu_re   = DEFAULT_RENDITION;
  effectiveRendition();
}

void TEScreen::setForeColor(int fgcolor)
{
  cu_fg = (fgcolor&7)+((fgcolor&8) ? 4+8 : 2);
  effectiveRendition();
}

void TEScreen::setBackColor(int bgcolor)
{
  cu_bg = (bgcolor&7)+((bgcolor&8) ? 4+8 : 2);
  effectiveRendition();
}

void TEScreen::setBackColorToDefault()
{
  cu_bg = DEFAULT_BACK_COLOR;
  effectiveRendition();
}

void TEScreen::setForeColorToDefault()
{
  cu_fg = DEFAULT_FORE_COLOR;
  effectiveRendition();
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                            Marking & Selection                            */
/*                                                                           */
/* ------------------------------------------------------------------------- */

void TEScreen::clearSelection()
{
  sel_BR = -1;
  sel_TL = -1;
  sel_begin = -1;
}

void TEScreen::setSelBeginXY(const int x, const int y)
{
  if (histCursor > hist.getLines()) {
    histCursor = hist.getLines();
  }
  sel_begin = loc(x,y+histCursor) ;
  sel_BR = sel_begin;
  sel_TL = sel_begin;
}

void TEScreen::setSelExtentXY(const int x, const int y)
{
  if (sel_begin == -1) return;
  if (histCursor > hist.getLines()) {
    histCursor = hist.getLines();
  }
  int l =  loc(x,y + histCursor);

  if (l < sel_begin)
  {
    sel_TL = l;
    sel_BR = sel_begin;
  }
  else
  {
    /* FIXME, HACK to correct for x too far to the right... */
    if (( x == columns )|| (x == 0)) l--;

    sel_TL = sel_begin;
    sel_BR = l;
  }
}

QString TEScreen::getSelText(const BOOL preserve_line_breaks)
{
  if (sel_begin == -1) 
     return QString::null; // Selection got clear while selecting.

  int *m;     // buffer to fill.
  int s, d;     // source index, dest. index.
  int hist_BR = loc(0, hist.getLines());
  int hY = sel_TL / columns;
  int hX = sel_TL % columns;
  int eol;      // end of line

  s = sel_TL;     // tracks copy in source.

        // allocate buffer for maximum
        // possible size...
  d = (sel_BR - sel_TL) / columns + 1;
  m = new int[d * (columns + 1) + 2];
  d = 0;

  while (s <= sel_BR)
    {
      if (s < hist_BR)
  {     // get lines from hist.history
        // buffer.
    eol = hist.getLineLen(hY);

    if ((hY == (sel_BR / columns)) &&
        (eol >= (sel_BR % columns)))
      {
        eol = sel_BR % columns + 1;
      }
    
    while (hX < eol)
      {
        m[d++] = hist.getCell(hY, hX++).c;
        s++;
      }

    if (s <= sel_BR)
      {
        // The line break handling
        // It's different from the screen
        // image case!
        if (eol % columns == 0)
    {
        // That's either a completely filled
        // line or an empty line
      if (eol == 0)
        {
          m[d++] = '\n';
        }
      else
        {
        // We have a full line.
        // FIXME: How can we handle newlines
        // at this position?!
        }
    }
        else if ((eol + 1) % columns == 0)
    {
        // FIXME: We don't know if this was a
        // space at the last position or a
        // short line!!
      m[d++] = ' ';
    }
        else
    {
        // We have a short line here. Put a
        // newline or a space into the
        // buffer.
      m[d++] = preserve_line_breaks ? '\n' : ' ';
    }
      }

    hY++;
    hX = 0;
    s = hY * columns;
  }
    else
      {       // or from screen image.
  eol = (s / columns + 1) * columns - 1;

  if (eol < sel_BR)
    {
      while ((eol > s) &&
       isspace(image[eol - hist_BR].c))
        {
    eol--;
        }
    }
  else
    {
      eol = sel_BR;
    }

  while (s <= eol)
    {
      m[d++] = image[s++ - hist_BR].c;
    }

  if (eol < sel_BR)
    {
        // eol processing see below ...
      if ((eol + 1) % columns == 0)
        {
    if (image[eol - hist_BR].c == ' ')
      {
        m[d++] = ' ';
      }
        }
      else
        {
    m[d++] = ((preserve_line_breaks ||
         ((eol % columns) == 0)) ?
        '\n' : ' ');
        }
    }

  s = (eol / columns + 1) * columns;
      }
    }

  QChar* qc = new QChar[d];

  for (int i = 0; i < d; i++)
    {
      qc[i] = m[i];
    }
  
  QString res(qc, d);

  delete m;
  delete qc;

  return res;
}
/* above ... end of line processing for selection -- psilva
cases:

1)    (eol+1)%columns == 0 --> the whole line is filled.
   If the last char is a space, insert (preserve) space. otherwise
   leave the text alone, so that words that are broken by linewrap
   are preserved.

FIXME:
  * this suppresses \n for command output that is
    sized to the exact column width of the screen.

2)    eol%columns == 0     --> blank line.
   insert a \n unconditionally.
   Do it either you would because you are in preserve_line_break mode,
   or because it's an ASCII paragraph delimiter, so even when
   not preserving line_breaks, you want to preserve paragraph breaks.

3)    else     --> partially filled line
   insert a \n in preserve line break mode, else a space
   The space prevents concatenation of the last word of one
   line with the first of the next.

*/

void TEScreen::addHistLine()
{
  assert(hasScroll() || histCursor == 0);

  // add to hist buffer
  // we have to take care about scrolling, too...

  if (hasScroll()){
      ca dft;

    int end = columns - 1;
    while (end >= 0 && image[end] == dft)
      end -= 1;

    hist.addCells( image, end + 1);
    hist.addLine();

    // adjust history cursor
    histCursor += ( hist.getLines() - 1 == histCursor);
  }

  if (!hasScroll()) histCursor = 0; //FIXME: a poor workaround
}

void TEScreen::setHistCursor(int cursor)
{
  histCursor = cursor; //FIXME:rangecheck
  if (histCursor > hist.getLines()) {
    histCursor = hist.getLines();
  }
  if (histCursor < 0) {
    histCursor = 0;
  }
}

void TEScreen::setHorzCursor(int cursor)
{
  horzCursor = cursor; 
}

int TEScreen::getHistCursor()
{
  return histCursor;
}

int TEScreen::getHorzCursor()
{
  return horzCursor;
}

int TEScreen::getHistLines()
{
  return hist.getLines();
}

void TEScreen::setScroll(bool on)
{
  histCursor = 0;
  clearSelection();
  hist.setScroll(on);
}

bool TEScreen::hasScroll()
{
  return hist.hasScroll();
}

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