view gui/src/terminal/TerminalDisplay.cpp @ 13516:d53287c44e5a

Removed BlockArray class from Konsole code.
author Jacob Dawid <jacob.dawid@googlemail.com>
date Tue, 19 Jul 2011 13:17:18 +0200
parents 7eb8cd35454c
children d3bede98d798
line wrap: on
line source

/*
    This file is part of Konsole, a terminal emulator for KDE.
    
    Copyright 2006-2008 by Robert Knight <robertknight@gmail.com>
    Copyright 1997,1998 by Lars Doelle <lars.doelle@on-line.de>
    
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    02110-1301  USA.
*/

// Own
#include "TerminalDisplay.h"

// Qt
#include <QtGui/QApplication>
#include <QtGui/QBoxLayout>
#include <QtGui/QClipboard>
#include <QtGui/QKeyEvent>
#include <QtCore/QEvent>
#include <QtCore/QTime>
#include <QtCore/QFile>
#include <QtGui/QGridLayout>
#include <QtGui/QLabel>
#include <QtGui/QLayout>
#include <QtGui/QPainter>
#include <QtGui/QPixmap>
#include <QtGui/QScrollBar>
#include <QtGui/QStyle>
#include <QtCore/QTimer>
#include <QtGui/QToolTip>
#include <QtCore/QTextStream>

#include "Filter.h"
#include "konsole_wcwidth.h"
#include "ScreenWindow.h"
#include "TerminalCharacterDecoder.h"

#ifndef loc
#define loc(X,Y) ((Y)*_columns+(X))
#endif

#define yMouseScroll 1

#define REPCHAR   "ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
    "abcdefgjijklmnopqrstuvwxyz" \
    "0123456789./+@"

const ColorEntry base_color_table[TABLE_COLORS] =
// The following are almost IBM standard color codes, with some slight
// gamma correction for the dim colors to compensate for bright X screens.
// It contains the 8 ansiterm/xterm colors in 2 intensities.
{
  // Fixme: could add faint colors here, also.
  // normal
  ColorEntry (QColor (0x00, 0x00, 0x00), 0), ColorEntry (QColor (0xB2, 0xB2, 0xB2), 1),	// Dfore, Dback
  ColorEntry (QColor (0x00, 0x00, 0x00), 0), ColorEntry (QColor (0xB2, 0x18, 0x18), 0),	// Black, Red
  ColorEntry (QColor (0x18, 0xB2, 0x18), 0), ColorEntry (QColor (0xB2, 0x68, 0x18), 0),	// Green, Yellow
  ColorEntry (QColor (0x18, 0x18, 0xB2), 0), ColorEntry (QColor (0xB2, 0x18, 0xB2), 0),	// Blue, Magenta
  ColorEntry (QColor (0x18, 0xB2, 0xB2), 0), ColorEntry (QColor (0xB2, 0xB2, 0xB2), 0),	// Cyan, White
  // intensiv
  ColorEntry (QColor (0x00, 0x00, 0x00), 0),
    ColorEntry (QColor (0xFF, 0xFF, 0xFF), 1),
  ColorEntry (QColor (0x68, 0x68, 0x68), 0),
    ColorEntry (QColor (0xFF, 0x54, 0x54), 0),
  ColorEntry (QColor (0x54, 0xFF, 0x54), 0),
    ColorEntry (QColor (0xFF, 0xFF, 0x54), 0),
  ColorEntry (QColor (0x54, 0x54, 0xFF), 0),
    ColorEntry (QColor (0xFF, 0x54, 0xFF), 0),
  ColorEntry (QColor (0x54, 0xFF, 0xFF), 0),
    ColorEntry (QColor (0xFF, 0xFF, 0xFF), 0)
};

// scroll increment used when dragging selection at top/bottom of window.

// static
bool
  TerminalDisplay::_antialiasText = true;
bool
  TerminalDisplay::HAVE_TRANSPARENCY = false;

// we use this to force QPainter to display text in LTR mode
// more information can be found in: http://unicode.org/reports/tr9/ 
const QChar
LTR_OVERRIDE_CHAR (0x202D);

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                                Colors                                     */
/*                                                                           */
/* ------------------------------------------------------------------------- */

/* Note that we use ANSI color order (bgr), while IBMPC color order is (rgb)

   Code        0       1       2       3       4       5       6       7
   ----------- ------- ------- ------- ------- ------- ------- ------- -------
   ANSI  (bgr) Black   Red     Green   Yellow  Blue    Magenta Cyan    White
   IBMPC (rgb) Black   Blue    Green   Cyan    Red     Magenta Yellow  White
*/

ScreenWindow *
TerminalDisplay::screenWindow () const
{
  return _screenWindow;
}

void
TerminalDisplay::setScreenWindow (ScreenWindow * window)
{
  // disconnect existing screen window if any
  if (_screenWindow)
    {
      disconnect (_screenWindow, 0, this, 0);
    }

  _screenWindow = window;

  if (window)
    {

      // TODO: Determine if this is an issue.
      //#warning "The order here is not specified - does it matter whether updateImage or updateLineProperties comes first?"
      connect (_screenWindow, SIGNAL (outputChanged ()), this,
	       SLOT (updateLineProperties ()));
      connect (_screenWindow, SIGNAL (outputChanged ()), this,
	       SLOT (updateImage ()));
      window->setWindowLines (_lines);
    }
}

const ColorEntry *
TerminalDisplay::colorTable () const
{
  return _colorTable;
}

void
TerminalDisplay::setBackgroundColor (const QColor & color)
{
  _colorTable[DEFAULT_BACK_COLOR].color = color;
  QPalette p = palette ();
  p.setColor (backgroundRole (), color);
  setPalette (p);

  // Avoid propagating the palette change to the scroll bar
  _scrollBar->setPalette (QApplication::palette ());

  update ();
}

void
TerminalDisplay::setForegroundColor (const QColor & color)
{
  _colorTable[DEFAULT_FORE_COLOR].color = color;

  update ();
}

void
TerminalDisplay::setColorTable (const ColorEntry table[])
{
  for (int i = 0; i < TABLE_COLORS; i++)
    _colorTable[i] = table[i];

  setBackgroundColor (_colorTable[DEFAULT_BACK_COLOR].color);
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                                   Font                                    */
/*                                                                           */
/* ------------------------------------------------------------------------- */

/*
   The VT100 has 32 special graphical characters. The usual vt100 extended
   xterm fonts have these at 0x00..0x1f.

   QT's iso mapping leaves 0x00..0x7f without any changes. But the graphicals
   come in here as proper unicode characters.

   We treat non-iso10646 fonts as VT100 extended and do the requiered mapping
   from unicode to 0x00..0x1f. The remaining translation is then left to the
   QCodec.
*/

static inline bool
isLineChar (quint16 c)
{
  return ((c & 0xFF80) == 0x2500);
}

static inline bool
isLineCharString (const QString & string)
{
  return (string.length () > 0) && (isLineChar (string.at (0).unicode ()));
}


// assert for i in [0..31] : vt100extended(vt100_graphics[i]) == i.

unsigned short vt100_graphics[32] = {	// 0/8     1/9    2/10    3/11    4/12    5/13    6/14    7/15
  0x0020, 0x25C6, 0x2592, 0x2409, 0x240c, 0x240d, 0x240a, 0x00b0,
  0x00b1, 0x2424, 0x240b, 0x2518, 0x2510, 0x250c, 0x2514, 0x253c,
  0xF800, 0xF801, 0x2500, 0xF803, 0xF804, 0x251c, 0x2524, 0x2534,
  0x252c, 0x2502, 0x2264, 0x2265, 0x03C0, 0x2260, 0x00A3, 0x00b7
};

void
TerminalDisplay::fontChange (const QFont &)
{
  QFontMetrics fm (font ());
  _fontHeight = fm.height () + _lineSpacing;

  // waba TerminalDisplay 1.123:
  // "Base character width on widest ASCII character. This prevents too wide
  //  characters in the presence of double wide (e.g. Japanese) characters."
  // Get the width from representative normal width characters
  _fontWidth =
    qRound ((double) fm.width (REPCHAR) / (double) strlen (REPCHAR));

  _fixedFont = true;

  int fw = fm.width (REPCHAR[0]);
  for (unsigned int i = 1; i < strlen (REPCHAR); i++)
    {
      if (fw != fm.width (REPCHAR[i]))
	{
	  _fixedFont = false;
	  break;
	}
    }

  if (_fontWidth < 1)
    _fontWidth = 1;

  _fontAscent = fm.ascent ();

  emit changedFontMetricSignal (_fontHeight, _fontWidth);
  propagateSize ();
  update ();
}

void
TerminalDisplay::setVTFont (const QFont & f)
{
  QFont font = f;

  QFontMetrics metrics (font);

  if (!QFontInfo (font).fixedPitch ())
    {
      //kWarning() << "Using an unsupported variable-width font in the terminal.  This may produce display errors.";
    }

  if (metrics.height () < height () && metrics.maxWidth () < width ())
    {
      // hint that text should be drawn without anti-aliasing.
      // depending on the user's font configuration, this may not be respected
      if (!_antialiasText)
	font.setStyleStrategy (QFont::NoAntialias);

      // experimental optimization.  Konsole assumes that the terminal is using a
      // mono-spaced font, in which case kerning information should have an effect.
      // Disabling kerning saves some computation when rendering text.
      font.setKerning (false);

      QWidget::setFont (font);
      fontChange (font);
    }
}

void
TerminalDisplay::setFont (const QFont &)
{
  // ignore font change request if not coming from konsole itself
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                         Constructor / Destructor                          */
/*                                                                           */
/* ------------------------------------------------------------------------- */

TerminalDisplay::TerminalDisplay (QWidget * parent):QWidget (parent), _screenWindow (0), _allowBell (true), _gridLayout (0),
_fontHeight (1), _fontWidth (1), _fontAscent (1), _boldIntense (true),
_lines (1), _columns (1), _usedLines (1), _usedColumns (1),
_contentHeight (1), _contentWidth (1), _image (0), _randomSeed (0),
_resizing (false), _terminalSizeHint (false), _terminalSizeStartup (true),
_bidiEnabled (false), _actSel (0), _wordSelectionMode (false),
_lineSelectionMode (false), _preserveLineBreaks (false),
_columnSelectionMode (false), _scrollbarLocation (NoScrollBar),
_wordCharacters (":@-./_~"), _bellMode (SystemBeepBell), _blinking (false),
_hasBlinker (false), _cursorBlinking (false), _hasBlinkingCursor (false),
_allowBlinkingText (true), _ctrlDrag (true),
_tripleClickMode (SelectWholeLine), _isFixedSize (false),
_possibleTripleClick (false), _resizeWidget (0), _resizeTimer (0),
_flowControlWarningEnabled (false), _outputSuspendedLabel (0),
_lineSpacing (0), _colorsInverted (false),
_blendColor (qRgba (0, 0, 0, 0xff)),
_filterChain (new TerminalImageFilterChain ()), _cursorShape (BlockCursor)
{
  // terminal applications are not designed with Right-To-Left in mind,
  // so the layout is forced to Left-To-Right
  setLayoutDirection (Qt::LeftToRight);

  // The offsets are not yet calculated.
  // Do not calculate these too often to be more smoothly when resizing
  // konsole in opaque mode.
  _topMargin = DEFAULT_TOP_MARGIN;
  _leftMargin = DEFAULT_LEFT_MARGIN;

  // create scroll bar for scrolling output up and down
  // set the scroll bar's slider to occupy the whole area of the scroll bar initially
  _scrollBar = new QScrollBar (this);
  setScroll (0, 0);
  _scrollBar->setCursor (Qt::ArrowCursor);
  connect (_scrollBar, SIGNAL (valueChanged (int)), this,
	   SLOT (scrollBarPositionChanged (int)));

  // setup timers for blinking cursor and text
  _blinkTimer = new QTimer (this);
  connect (_blinkTimer, SIGNAL (timeout ()), this, SLOT (blinkEvent ()));
  _blinkCursorTimer = new QTimer (this);
  connect (_blinkCursorTimer, SIGNAL (timeout ()), this,
	   SLOT (blinkCursorEvent ()));

  //KCursor::setAutoHideCursor( this, true );

  setUsesMouse (true);
  setColorTable (base_color_table);
  setMouseTracking (true);

  // Enable drag and drop
  setAcceptDrops (true);	// attempt
  dragInfo.state = diNone;

  setFocusPolicy (Qt::WheelFocus);

  // enable input method support
  setAttribute (Qt::WA_InputMethodEnabled, true);

  // this is an important optimization, it tells Qt
  // that TerminalDisplay will handle repainting its entire area.
  setAttribute (Qt::WA_OpaquePaintEvent);

  _gridLayout = new QGridLayout (this);
  _gridLayout->setContentsMargins (0, 0, 0, 0);

  setLayout (_gridLayout);

  new
  AutoScrollHandler (this);
}

TerminalDisplay::~TerminalDisplay ()
{
  disconnect (_blinkTimer);
  disconnect (_blinkCursorTimer);
  qApp->removeEventFilter (this);

  delete[]_image;

  delete _gridLayout;
  delete _outputSuspendedLabel;
  delete _filterChain;
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                             Display Operations                            */
/*                                                                           */
/* ------------------------------------------------------------------------- */

/**
 A table for emulating the simple (single width) unicode drawing chars.
 It represents the 250x - 257x glyphs. If it's zero, we can't use it.
 if it's not, it's encoded as follows: imagine a 5x5 grid where the points are numbered
 0 to 24 left to top, top to bottom. Each point is represented by the corresponding bit.

 Then, the pixels basically have the following interpretation:
 _|||_
 -...-
 -...-
 -...-
 _|||_

where _ = none
      | = vertical line.
      - = horizontal line.
 */


enum LineEncode
{
  TopL = (1 << 1),
  TopC = (1 << 2),
  TopR = (1 << 3),

  LeftT = (1 << 5),
  Int11 = (1 << 6),
  Int12 = (1 << 7),
  Int13 = (1 << 8),
  RightT = (1 << 9),

  LeftC = (1 << 10),
  Int21 = (1 << 11),
  Int22 = (1 << 12),
  Int23 = (1 << 13),
  RightC = (1 << 14),

  LeftB = (1 << 15),
  Int31 = (1 << 16),
  Int32 = (1 << 17),
  Int33 = (1 << 18),
  RightB = (1 << 19),

  BotL = (1 << 21),
  BotC = (1 << 22),
  BotR = (1 << 23)
};

void
TerminalDisplay::setKeyboardCursorShape (KeyboardCursorShape shape)
{
  _cursorShape = shape;
}

TerminalDisplay::KeyboardCursorShape TerminalDisplay::keyboardCursorShape () const
{
  return _cursorShape;
}

void
TerminalDisplay::drawBackground (QPainter & painter, const QRect & rect,
				 const QColor & backgroundColor,
				 bool useOpacitySetting)
{
  // the area of the widget showing the contents of the terminal display is drawn
  // using the background color from the color scheme set with setColorTable()
  //
  // the area of the widget behind the scroll-bar is drawn using the background
  // brush from the scroll-bar's palette, to give the effect of the scroll-bar
  // being outside of the terminal display and visual consistency with other KDE
  // applications.
  //
  QRect scrollBarArea = _scrollBar->isVisible ()?
    rect.intersected (_scrollBar->geometry ()) : QRect ();
  QRegion contentsRegion = QRegion (rect).subtracted (scrollBarArea);
  QRect contentsRect = contentsRegion.boundingRect ();

  if (HAVE_TRANSPARENCY && qAlpha (_blendColor) < 0xff && useOpacitySetting)
    {
      QColor color (backgroundColor);
      color.setAlpha (qAlpha (_blendColor));

      painter.save ();
      painter.setCompositionMode (QPainter::CompositionMode_Source);
      painter.fillRect (contentsRect, color);
      painter.restore ();
    }
  else
    painter.fillRect (contentsRect, backgroundColor);

  painter.fillRect (scrollBarArea, _scrollBar->palette ().background ());
}

void
TerminalDisplay::drawCursor (QPainter & painter,
			     const QRect & rect,
			     const QColor & foregroundColor,
			     const QColor & /*backgroundColor */ ,
			     bool & invertCharacterColor)
{
  QRect cursorRect = rect;
  cursorRect.setHeight (_fontHeight - _lineSpacing - 1);

  if (!_cursorBlinking)
    {
      if (_cursorColor.isValid ())
	painter.setPen (_cursorColor);
      else
	painter.setPen (foregroundColor);

      if (_cursorShape == BlockCursor)
	{
	  // draw the cursor outline, adjusting the area so that
	  // it is draw entirely inside 'rect'
	  int penWidth = qMax (1, painter.pen ().width ());

	  painter.drawRect (cursorRect.adjusted (penWidth / 2,
						 penWidth / 2,
						 -penWidth / 2 - penWidth % 2,
						 -penWidth / 2 -
						 penWidth % 2));
	  if (hasFocus ())
	    {
	      painter.fillRect (cursorRect,
				_cursorColor.
				isValid ()? _cursorColor : foregroundColor);

	      if (!_cursorColor.isValid ())
		{
		  // invert the colour used to draw the text to ensure that the character at
		  // the cursor position is readable
		  invertCharacterColor = true;
		}
	    }
	}
      else if (_cursorShape == UnderlineCursor)
	painter.drawLine (cursorRect.left (),
			  cursorRect.bottom (),
			  cursorRect.right (), cursorRect.bottom ());
      else if (_cursorShape == IBeamCursor)
	painter.drawLine (cursorRect.left (),
			  cursorRect.top (),
			  cursorRect.left (), cursorRect.bottom ());

    }
}

void
TerminalDisplay::drawCharacters (QPainter & painter,
				 const QRect & rect,
				 const QString & text,
				 const Character * style,
				 bool invertCharacterColor)
{
  // don't draw text which is currently blinking
  if (_blinking && (style->rendition & RE_BLINK))
    return;

  // setup boldJ and underline
  bool useBold;
  ColorEntry::FontWeight weight = style->fontWeight (_colorTable);
  if (weight == ColorEntry::UseCurrentFormat)
    useBold = ((style->rendition & RE_BOLD) && _boldIntense)
      || font ().bold ();
  else
    useBold = (weight == ColorEntry::Bold) ? true : false;
  bool useUnderline = style->rendition & RE_UNDERLINE || font ().underline ();

  QFont font = painter.font ();
  if (font.bold () != useBold || font.underline () != useUnderline)
    {
      font.setBold (useBold);
      font.setUnderline (useUnderline);
      painter.setFont (font);
    }

  // setup pen
  const CharacterColor & textColor =
    (invertCharacterColor ? style->backgroundColor : style->foregroundColor);
  const QColor color = textColor.color (_colorTable);
  QPen pen = painter.pen ();
  if (pen.color () != color)
    {
      pen.setColor (color);
      painter.setPen (color);
    }

  if (_bidiEnabled)
    painter.drawText (rect, 0, text);
  else
    painter.drawText (rect, 0, LTR_OVERRIDE_CHAR + text);
}

void
TerminalDisplay::drawTextFragment (QPainter & painter,
				   const QRect & rect,
				   const QString & text,
				   const Character * style)
{
  painter.save ();

  // setup painter 
  const QColor foregroundColor = style->foregroundColor.color (_colorTable);
  const QColor backgroundColor = style->backgroundColor.color (_colorTable);

  // draw background if different from the display's background color
  if (backgroundColor != palette ().background ().color ())
    drawBackground (painter, rect, backgroundColor,
		    false /* do not use transparency */ );

  // draw cursor shape if the current character is the cursor
  // this may alter the foreground and background colors
  bool invertCharacterColor = false;
  if (style->rendition & RE_CURSOR)
    drawCursor (painter, rect, foregroundColor, backgroundColor,
		invertCharacterColor);

  // draw text
  drawCharacters (painter, rect, text, style, invertCharacterColor);

  painter.restore ();
}

void
TerminalDisplay::setRandomSeed (uint randomSeed)
{
  _randomSeed = randomSeed;
}

uint
TerminalDisplay::randomSeed () const
{
  return _randomSeed;
}

#if 0
/*!
    Set XIM Position
*/
void
TerminalDisplay::setCursorPos (const int curx, const int cury)
{
  QPoint tL = contentsRect ().topLeft ();
  int tLx = tL.x ();
  int tLy = tL.y ();

  int xpos, ypos;
  ypos = _topMargin + tLy + _fontHeight * (cury - 1) + _fontAscent;
  xpos = _leftMargin + tLx + _fontWidth * curx;
  _cursorLine = cury;
  _cursorCol = curx;
}
#endif

// scrolls the image by 'lines', down if lines > 0 or up otherwise.
//
// the terminal emulation keeps track of the scrolling of the character 
// image as it receives input, and when the view is updated, it calls scrollImage() 
// with the final scroll amount.  this improves performance because scrolling the 
// display is much cheaper than re-rendering all the text for the 
// part of the image which has moved up or down.  
// Instead only new lines have to be drawn
void
TerminalDisplay::scrollImage (int lines, const QRect & screenWindowRegion)
{
  // if the flow control warning is enabled this will interfere with the 
  // scrolling optimizations and cause artifacts.  the simple solution here
  // is to just disable the optimization whilst it is visible
  if (_outputSuspendedLabel && _outputSuspendedLabel->isVisible ())
    return;

  // constrain the region to the display
  // the bottom of the region is capped to the number of lines in the display's
  // internal image - 2, so that the height of 'region' is strictly less
  // than the height of the internal image.
  QRect region = screenWindowRegion;
  region.setBottom (qMin (region.bottom (), this->_lines - 2));

  // return if there is nothing to do
  if (lines == 0
      || _image == 0
      || !region.isValid ()
      || (region.top () + abs (lines)) >= region.bottom ()
      || this->_lines <= region.height ())
    return;

  // hide terminal size label to prevent it being scrolled
  if (_resizeWidget && _resizeWidget->isVisible ())
    _resizeWidget->hide ();

  // Note:  With Qt 4.4 the left edge of the scrolled area must be at 0
  // to get the correct (newly exposed) part of the widget repainted.
  //
  // The right edge must be before the left edge of the scroll bar to 
  // avoid triggering a repaint of the entire widget, the distance is 
  // given by SCROLLBAR_CONTENT_GAP
  //
  // Set the QT_FLUSH_PAINT environment variable to '1' before starting the
  // application to monitor repainting.
  //
  int scrollBarWidth = _scrollBar->isHidden ()? 0 : _scrollBar->width ();
  const int SCROLLBAR_CONTENT_GAP = 1;
  QRect scrollRect;
  if (_scrollbarLocation == ScrollBarLeft)
    {
      scrollRect.setLeft (scrollBarWidth + SCROLLBAR_CONTENT_GAP);
      scrollRect.setRight (width ());
    }
  else
    {
      scrollRect.setLeft (0);
      scrollRect.setRight (width () - scrollBarWidth - SCROLLBAR_CONTENT_GAP);
    }
  void *firstCharPos = &_image[region.top () * this->_columns];
  void *lastCharPos = &_image[(region.top () + abs (lines)) * this->_columns];

  int top = _topMargin + (region.top () * _fontHeight);
  int linesToMove = region.height () - abs (lines);
  int bytesToMove = linesToMove * this->_columns * sizeof (Character);

  Q_ASSERT (linesToMove > 0);
  Q_ASSERT (bytesToMove > 0);

  //scroll internal image
  if (lines > 0)
    {
      // check that the memory areas that we are going to move are valid
      Q_ASSERT ((char *) lastCharPos + bytesToMove <
		(char *) (_image + (this->_lines * this->_columns)));

      Q_ASSERT ((lines * this->_columns) < _imageSize);

      //scroll internal image down
      memmove (firstCharPos, lastCharPos, bytesToMove);

      //set region of display to scroll
      scrollRect.setTop (top);
    }
  else
    {
      // check that the memory areas that we are going to move are valid
      Q_ASSERT ((char *) firstCharPos + bytesToMove <
		(char *) (_image + (this->_lines * this->_columns)));

      //scroll internal image up
      memmove (lastCharPos, firstCharPos, bytesToMove);

      //set region of the display to scroll
      scrollRect.setTop (top + abs (lines) * _fontHeight);
    }
  scrollRect.setHeight (linesToMove * _fontHeight);

  Q_ASSERT (scrollRect.isValid () && !scrollRect.isEmpty ());

  //scroll the display vertically to match internal _image
  scroll (0, _fontHeight * (-lines), scrollRect);
}

QRegion
TerminalDisplay::hotSpotRegion () const
{
  QRegion region;
  foreach (Filter::HotSpot * hotSpot, _filterChain->hotSpots ())
  {
    QRect r;
    if (hotSpot->startLine () == hotSpot->endLine ())
      {
	r.setLeft (hotSpot->startColumn ());
	r.setTop (hotSpot->startLine ());
	r.setRight (hotSpot->endColumn ());
	r.setBottom (hotSpot->endLine ());
	region |= imageToWidget (r);;
      }
    else
      {
	r.setLeft (hotSpot->startColumn ());
	r.setTop (hotSpot->startLine ());
	r.setRight (_columns);
	r.setBottom (hotSpot->startLine ());
	region |= imageToWidget (r);;
	for (int line = hotSpot->startLine () + 1; line < hotSpot->endLine ();
	     line++)
	  {
	    r.setLeft (0);
	    r.setTop (line);
	    r.setRight (_columns);
	    r.setBottom (line);
	    region |= imageToWidget (r);;
	  }
	r.setLeft (0);
	r.setTop (hotSpot->endLine ());
	r.setRight (hotSpot->endColumn ());
	r.setBottom (hotSpot->endLine ());
	region |= imageToWidget (r);;
      }
  }
  return region;
}

void
TerminalDisplay::processFilters ()
{
  if (!_screenWindow)
    return;

  QRegion preUpdateHotSpots = hotSpotRegion ();

  // use _screenWindow->getImage() here rather than _image because
  // other classes may call processFilters() when this display's
  // ScreenWindow emits a scrolled() signal - which will happen before
  // updateImage() is called on the display and therefore _image is 
  // out of date at this point
  _filterChain->setImage (_screenWindow->getImage (),
			  _screenWindow->windowLines (),
			  _screenWindow->windowColumns (),
			  _screenWindow->getLineProperties ());
  _filterChain->process ();

  QRegion postUpdateHotSpots = hotSpotRegion ();

  update (preUpdateHotSpots | postUpdateHotSpots);
}

void
TerminalDisplay::updateImage ()
{
  if (!_screenWindow)
    return;

  // optimization - scroll the existing image where possible and
  // avoid expensive text drawing for parts of the image that
  // can simply be moved up or down
  scrollImage (_screenWindow->scrollCount (), _screenWindow->scrollRegion ());
  _screenWindow->resetScrollCount ();

  if (!_image)
    {
      // Create _image.
      // The emitted changedContentSizeSignal also leads to getImage being recreated, so do this first.
      updateImageSize ();
    }

  Character *const newimg = _screenWindow->getImage ();
  int lines = _screenWindow->windowLines ();
  int columns = _screenWindow->windowColumns ();

  setScroll (_screenWindow->currentLine (), _screenWindow->lineCount ());

  Q_ASSERT (this->_usedLines <= this->_lines);
  Q_ASSERT (this->_usedColumns <= this->_columns);

  int y, x, len;

  QPoint tL = contentsRect ().topLeft ();
  int tLx = tL.x ();
  int tLy = tL.y ();
  _hasBlinker = false;

  CharacterColor cf;		// undefined
  CharacterColor _clipboard;	// undefined
  int cr = -1;			// undefined

  const int linesToUpdate = qMin (this->_lines, qMax (0, lines));
  const int columnsToUpdate = qMin (this->_columns, qMax (0, columns));

  QChar *disstrU = new QChar[columnsToUpdate];
  char *dirtyMask = new char[columnsToUpdate + 2];
  QRegion dirtyRegion;

  // debugging variable, this records the number of lines that are found to
  // be 'dirty' ( ie. have changed from the old _image to the new _image ) and
  // which therefore need to be repainted
  int dirtyLineCount = 0;

  for (y = 0; y < linesToUpdate; ++y)
    {
      const Character *currentLine = &_image[y * this->_columns];
      const Character *const newLine = &newimg[y * columns];

      bool updateLine = false;

      // The dirty mask indicates which characters need repainting. We also
      // mark surrounding neighbours dirty, in case the character exceeds
      // its cell boundaries
      memset (dirtyMask, 0, columnsToUpdate + 2);

      for (x = 0; x < columnsToUpdate; ++x)
	{
	  if (newLine[x] != currentLine[x])
	    {
	      dirtyMask[x] = true;
	    }
	}

      if (!_resizing)		// not while _resizing, we're expecting a paintEvent
	for (x = 0; x < columnsToUpdate; ++x)
	  {
	    _hasBlinker |= (newLine[x].rendition & RE_BLINK);

	    // Start drawing if this character or the next one differs.
	    // We also take the next one into account to handle the situation
	    // where characters exceed their cell width.
	    if (dirtyMask[x])
	      {
		quint16 c = newLine[x + 0].character;
		if (!c)
		  continue;
		int p = 0;
		disstrU[p++] = c;	//fontMap(c);
		bool lineDraw = isLineChar (c);
		bool doubleWidth =
		  (x + 1 ==
		   columnsToUpdate) ? false : (newLine[x + 1].character == 0);
		cr = newLine[x].rendition;
		_clipboard = newLine[x].backgroundColor;
		if (newLine[x].foregroundColor != cf)
		  cf = newLine[x].foregroundColor;
		int lln = columnsToUpdate - x;
		for (len = 1; len < lln; ++len)
		  {
		    const Character & ch = newLine[x + len];

		    if (!ch.character)
		      continue;	// Skip trailing part of multi-col chars.

		    bool nextIsDoubleWidth =
		      (x + len + 1 ==
		       columnsToUpdate) ? false : (newLine[x + len +
							   1].character == 0);

		    if (ch.foregroundColor != cf ||
			ch.backgroundColor != _clipboard ||
			ch.rendition != cr ||
			!dirtyMask[x + len] ||
			isLineChar (c) != lineDraw ||
			nextIsDoubleWidth != doubleWidth)
		      break;

		    disstrU[p++] = c;	//fontMap(c);
		  }

		QString unistr (disstrU, p);

		bool saveFixedFont = _fixedFont;
		if (lineDraw)
		  _fixedFont = false;
		if (doubleWidth)
		  _fixedFont = false;

		updateLine = true;

		_fixedFont = saveFixedFont;
		x += len - 1;
	      }

	  }

      //both the top and bottom halves of double height _lines must always be redrawn
      //although both top and bottom halves contain the same characters, only
      //the top one is actually
      //drawn.
      if (_lineProperties.count () > y)
	updateLine |= (_lineProperties[y] & LINE_DOUBLEHEIGHT);

      // if the characters on the line are different in the old and the new _image
      // then this line must be repainted.
      if (updateLine)
	{
	  dirtyLineCount++;

	  // add the area occupied by this line to the region which needs to be
	  // repainted
	  QRect dirtyRect = QRect (_leftMargin + tLx,
				   _topMargin + tLy + _fontHeight * y,
				   _fontWidth * columnsToUpdate,
				   _fontHeight);

	  dirtyRegion |= dirtyRect;
	}

      // replace the line of characters in the old _image with the
      // current line of the new _image
      memcpy ((void *) currentLine, (const void *) newLine,
	      columnsToUpdate * sizeof (Character));
    }

  // if the new _image is smaller than the previous _image, then ensure that the area
  // outside the new _image is cleared
  if (linesToUpdate < _usedLines)
    {
      dirtyRegion |= QRect (_leftMargin + tLx,
			    _topMargin + tLy + _fontHeight * linesToUpdate,
			    _fontWidth * this->_columns,
			    _fontHeight * (_usedLines - linesToUpdate));
    }
  _usedLines = linesToUpdate;

  if (columnsToUpdate < _usedColumns)
    {
      dirtyRegion |= QRect (_leftMargin + tLx + columnsToUpdate * _fontWidth,
			    _topMargin + tLy,
			    _fontWidth * (_usedColumns - columnsToUpdate),
			    _fontHeight * this->_lines);
    }
  _usedColumns = columnsToUpdate;

  dirtyRegion |= _inputMethodData.previousPreeditRect;

  // update the parts of the display which have changed
  update (dirtyRegion);

  if (_hasBlinker && !_blinkTimer->isActive ())
    _blinkTimer->start (TEXT_BLINK_DELAY);
  if (!_hasBlinker && _blinkTimer->isActive ())
    {
      _blinkTimer->stop ();
      _blinking = false;
    }
  delete[]dirtyMask;
  delete[]disstrU;

}

void
TerminalDisplay::showResizeNotification ()
{
  if (_terminalSizeHint && isVisible ())
    {
      if (_terminalSizeStartup)
	{
	  _terminalSizeStartup = false;
	  return;
	}
      if (!_resizeWidget)
	{
	  _resizeWidget = new QLabel (QString ("Size: XXX x XXX"), this);
	  _resizeWidget->setMinimumWidth (_resizeWidget->fontMetrics ().
					  width (QString
						 ("Size: XXX x XXX")));
	  _resizeWidget->setMinimumHeight (_resizeWidget->sizeHint ().
					   height ());
	  _resizeWidget->setAlignment (Qt::AlignCenter);

	  _resizeWidget->
	    setStyleSheet
	    ("background-color:palette(window);border-style:solid;border-width:1px;border-color:palette(dark)");

	  _resizeTimer = new QTimer (this);
	  _resizeTimer->setSingleShot (true);
	  connect (_resizeTimer, SIGNAL (timeout ()), _resizeWidget,
		   SLOT (hide ()));
	}
      QString sizeStr = QString ("Size: %1 x %2").arg (_columns).arg (_lines);
      _resizeWidget->setText (sizeStr);
      _resizeWidget->move ((width () - _resizeWidget->width ()) / 2,
			   (height () - _resizeWidget->height ()) / 2 + 20);
      _resizeWidget->show ();
      _resizeTimer->start (1000);
    }
}

void
TerminalDisplay::setBlinkingCursor (bool blink)
{
  _hasBlinkingCursor = blink;

  if (blink && !_blinkCursorTimer->isActive ())
    _blinkCursorTimer->start (QApplication::cursorFlashTime () / 2);

  if (!blink && _blinkCursorTimer->isActive ())
    {
      _blinkCursorTimer->stop ();
      if (_cursorBlinking)
	blinkCursorEvent ();
      else
	_cursorBlinking = false;
    }
}

void
TerminalDisplay::setBlinkingTextEnabled (bool blink)
{
  _allowBlinkingText = blink;

  if (blink && !_blinkTimer->isActive ())
    _blinkTimer->start (TEXT_BLINK_DELAY);

  if (!blink && _blinkTimer->isActive ())
    {
      _blinkTimer->stop ();
      _blinking = false;
    }
}

void
TerminalDisplay::focusOutEvent (QFocusEvent *)
{
  // trigger a repaint of the cursor so that it is both visible (in case
  // it was hidden during blinking)
  // and drawn in a focused out state
  _cursorBlinking = false;
  updateCursor ();

  _blinkCursorTimer->stop ();
  if (_blinking)
    blinkEvent ();

  _blinkTimer->stop ();
}

void
TerminalDisplay::focusInEvent (QFocusEvent *)
{
  if (_hasBlinkingCursor)
    {
      _blinkCursorTimer->start ();
    }
  updateCursor ();

  if (_hasBlinker)
    _blinkTimer->start ();
}

void
TerminalDisplay::paintEvent (QPaintEvent * pe)
{
  QPainter paint (this);

  foreach (const QRect & rect, (pe->region () & contentsRect ()).rects ())
  {
    drawBackground (paint, rect, palette ().background ().color (),
		    true /* use opacity setting */ );
    drawContents (paint, rect);
  }
  drawInputMethodPreeditString (paint, preeditRect ());
  paintFilters (paint);
}

QPoint
TerminalDisplay::cursorPosition () const
{
  if (_screenWindow)
    return _screenWindow->cursorPosition ();
  else
    return QPoint (0, 0);
}

QRect
TerminalDisplay::preeditRect () const
{
  const int preeditLength = string_width (_inputMethodData.preeditString);

  if (preeditLength == 0)
    return QRect ();

  return QRect (_leftMargin + _fontWidth * cursorPosition ().x (),
		_topMargin + _fontHeight * cursorPosition ().y (),
		_fontWidth * preeditLength, _fontHeight);
}

void
TerminalDisplay::drawInputMethodPreeditString (QPainter & painter,
					       const QRect & rect)
{
  if (_inputMethodData.preeditString.isEmpty ())
    return;

  const QPoint cursorPos = cursorPosition ();

  bool invertColors = false;
  const QColor background = _colorTable[DEFAULT_BACK_COLOR].color;
  const QColor foreground = _colorTable[DEFAULT_FORE_COLOR].color;
  const Character *style = &_image[loc (cursorPos.x (), cursorPos.y ())];

  drawBackground (painter, rect, background, true);
  drawCursor (painter, rect, foreground, background, invertColors);
  drawCharacters (painter, rect, _inputMethodData.preeditString, style,
		  invertColors);

  _inputMethodData.previousPreeditRect = rect;
}

FilterChain *
TerminalDisplay::filterChain () const
{
  return _filterChain;
}

void
TerminalDisplay::paintFilters (QPainter & painter)
{
  // get color of character under mouse and use it to draw
  // lines for filters
  QPoint cursorPos = mapFromGlobal (QCursor::pos ());
  int cursorLine;
  int cursorColumn;
  int scrollBarWidth =
    (_scrollbarLocation == ScrollBarLeft) ? _scrollBar->width () : 0;

  getCharacterPosition (cursorPos, cursorLine, cursorColumn);
  Character cursorCharacter = _image[loc (cursorColumn, cursorLine)];

  painter.
    setPen (QPen (cursorCharacter.foregroundColor.color (colorTable ())));

  // iterate over hotspots identified by the display's currently active filters 
  // and draw appropriate visuals to indicate the presence of the hotspot

  QList < Filter::HotSpot * >spots = _filterChain->hotSpots ();
  QListIterator < Filter::HotSpot * >iter (spots);
  while (iter.hasNext ())
    {
      Filter::HotSpot * spot = iter.next ();

      QRegion region;
      if (spot->type () == Filter::HotSpot::Link)
	{
	  QRect r;
	  if (spot->startLine () == spot->endLine ())
	    {
	      r.setCoords (spot->startColumn () * _fontWidth + 1 +
			   scrollBarWidth,
			   spot->startLine () * _fontHeight + 1,
			   (spot->endColumn () - 1) * _fontWidth - 1 +
			   scrollBarWidth,
			   (spot->endLine () + 1) * _fontHeight - 1);
	      region |= r;
	    }
	  else
	    {
	      r.setCoords (spot->startColumn () * _fontWidth + 1 +
			   scrollBarWidth,
			   spot->startLine () * _fontHeight + 1,
			   (_columns - 1) * _fontWidth - 1 + scrollBarWidth,
			   (spot->startLine () + 1) * _fontHeight - 1);
	      region |= r;
	      for (int line = spot->startLine () + 1; line < spot->endLine ();
		   line++)
		{
		  r.setCoords (0 * _fontWidth + 1 + scrollBarWidth,
			       line * _fontHeight + 1,
			       (_columns - 1) * _fontWidth - 1 +
			       scrollBarWidth, (line + 1) * _fontHeight - 1);
		  region |= r;
		}
	      r.setCoords (0 * _fontWidth + 1 + scrollBarWidth,
			   spot->endLine () * _fontHeight + 1,
			   (spot->endColumn () - 1) * _fontWidth - 1 +
			   scrollBarWidth,
			   (spot->endLine () + 1) * _fontHeight - 1);
	      region |= r;
	    }
	}

      for (int line = spot->startLine (); line <= spot->endLine (); line++)
	{
	  int startColumn = 0;
	  int endColumn = _columns - 1;	// TODO use number of _columns which are actually 
	  // occupied on this line rather than the width of the
	  // display in _columns

	  // ignore whitespace at the end of the lines
	  while (QChar (_image[loc (endColumn, line)].character).isSpace ()
		 && endColumn > 0)
	    endColumn--;

	  // increment here because the column which we want to set 'endColumn' to
	  // is the first whitespace character at the end of the line
	  endColumn++;

	  if (line == spot->startLine ())
	    startColumn = spot->startColumn ();
	  if (line == spot->endLine ())
	    endColumn = spot->endColumn ();

	  // subtract one pixel from
	  // the right and bottom so that
	  // we do not overdraw adjacent
	  // hotspots
	  //
	  // subtracting one pixel from all sides also prevents an edge case where
	  // moving the mouse outside a link could still leave it underlined 
	  // because the check below for the position of the cursor
	  // finds it on the border of the target area
	  QRect r;
	  r.setCoords (startColumn * _fontWidth + 1 + scrollBarWidth,
		       line * _fontHeight + 1,
		       endColumn * _fontWidth - 1 + scrollBarWidth,
		       (line + 1) * _fontHeight - 1);
	  // Underline link hotspots 
	  if (spot->type () == Filter::HotSpot::Link)
	    {
	      QFontMetrics metrics (font ());

	      // find the baseline (which is the invisible line that the characters in the font sit on,
	      // with some having tails dangling below)
	      int baseline = r.bottom () - metrics.descent ();
	      // find the position of the underline below that
	      int underlinePos = baseline + metrics.underlinePos ();
	      if (region.contains (mapFromGlobal (QCursor::pos ())))
		{
		  painter.drawLine (r.left (), underlinePos,
				    r.right (), underlinePos);
		}
	    }
	  // Marker hotspots simply have a transparent rectanglular shape
	  // drawn on top of them
	  else if (spot->type () == Filter::HotSpot::Marker)
	    {
	      //TODO - Do not use a hardcoded colour for this
	      painter.fillRect (r, QBrush (QColor (255, 0, 0, 120)));
	    }
	}
    }
}

void
TerminalDisplay::drawContents (QPainter & paint, const QRect & rect)
{
  QPoint tL = contentsRect ().topLeft ();
  int tLx = tL.x ();
  int tLy = tL.y ();

  int lux =
    qMin (_usedColumns - 1,
	  qMax (0, (rect.left () - tLx - _leftMargin) / _fontWidth));
  int luy =
    qMin (_usedLines - 1,
	  qMax (0, (rect.top () - tLy - _topMargin) / _fontHeight));
  int rlx =
    qMin (_usedColumns - 1,
	  qMax (0, (rect.right () - tLx - _leftMargin) / _fontWidth));
  int rly =
    qMin (_usedLines - 1,
	  qMax (0, (rect.bottom () - tLy - _topMargin) / _fontHeight));

  const int bufferSize = _usedColumns;
  QString unistr;
  unistr.reserve (bufferSize);
  for (int y = luy; y <= rly; y++)
    {
      quint16 c = _image[loc (lux, y)].character;
      int x = lux;
      if (!c && x)
	x--;			// Search for start of multi-column character
      for (; x <= rlx; x++)
	{
	  int len = 1;
	  int p = 0;

	  // reset our buffer to the maximal size
	  unistr.resize (bufferSize);
	  QChar *disstrU = unistr.data ();

	  // is this a single character or a sequence of characters ?
	  if (_image[loc (x, y)].rendition & RE_EXTENDED_CHAR)
	    {
	      // sequence of characters
	      ushort extendedCharLength = 0;
	      ushort *chars =
		ExtendedCharTable::instance.
		lookupExtendedChar (_image[loc (x, y)].charSequence,
				    extendedCharLength);
	      for (int index = 0; index < extendedCharLength; index++)
		{
		  Q_ASSERT (p < bufferSize);
		  disstrU[p++] = chars[index];
		}
	    }
	  else
	    {
	      // single character
	      c = _image[loc (x, y)].character;
	      if (c)
		{
		  Q_ASSERT (p < bufferSize);
		  disstrU[p++] = c;	//fontMap(c);
		}
	    }

	  bool lineDraw = isLineChar (c);
	  bool doubleWidth =
	    (_image[qMin (loc (x, y) + 1, _imageSize)].character == 0);
	  CharacterColor currentForeground =
	    _image[loc (x, y)].foregroundColor;
	  CharacterColor currentBackground =
	    _image[loc (x, y)].backgroundColor;
	  quint8 currentRendition = _image[loc (x, y)].rendition;

	  while (x + len <= rlx && _image[loc (x + len, y)].foregroundColor == currentForeground && _image[loc (x + len, y)].backgroundColor == currentBackground && _image[loc (x + len, y)].rendition == currentRendition && (_image[qMin (loc (x + len, y) + 1, _imageSize)].character == 0) == doubleWidth && isLineChar (c = _image[loc (x + len, y)].character) == lineDraw)	// Assignment!
	    {
	      if (c)
		disstrU[p++] = c;	//fontMap(c);
	      if (doubleWidth)	// assert((_image[loc(x+len,y)+1].character == 0)), see above if condition
		len++;		// Skip trailing part of multi-column character
	      len++;
	    }
	  if ((x + len < _usedColumns)
	      && (!_image[loc (x + len, y)].character))
	    len++;		// Adjust for trailing part of multi-column character

	  bool save__fixedFont = _fixedFont;
	  if (lineDraw)
	    _fixedFont = false;
	  if (doubleWidth)
	    _fixedFont = false;
	  unistr.resize (p);

	  // Create a text scaling matrix for double width and double height lines.
	  QMatrix textScale;

	  if (y < _lineProperties.size ())
	    {
	      if (_lineProperties[y] & LINE_DOUBLEWIDTH)
		textScale.scale (2, 1);

	      if (_lineProperties[y] & LINE_DOUBLEHEIGHT)
		textScale.scale (1, 2);
	    }

	  //Apply text scaling matrix.
	  paint.setWorldMatrix (textScale, true);

	  //calculate the area in which the text will be drawn
	  QRect textArea =
	    QRect (_leftMargin + tLx + _fontWidth * x,
		   _topMargin + tLy + _fontHeight * y, _fontWidth * len,
		   _fontHeight);

	  //move the calculated area to take account of scaling applied to the painter.
	  //the position of the area from the origin (0,0) is scaled
	  //by the opposite of whatever
	  //transformation has been applied to the painter.  this ensures that
	  //painting does actually start from textArea.topLeft()
	  //(instead of textArea.topLeft() * painter-scale)
	  textArea.moveTopLeft (textScale.inverted ().
				map (textArea.topLeft ()));

	  //paint text fragment
	  drawTextFragment (paint, textArea, unistr, &_image[loc (x, y)]);	//,
	  //0,
	  //!_isPrinting );

	  _fixedFont = save__fixedFont;

	  //reset back to single-width, single-height _lines
	  paint.setWorldMatrix (textScale.inverted (), true);

	  if (y < _lineProperties.size () - 1)
	    {
	      //double-height _lines are represented by two adjacent _lines
	      //containing the same characters
	      //both _lines will have the LINE_DOUBLEHEIGHT attribute.
	      //If the current line has the LINE_DOUBLEHEIGHT attribute,
	      //we can therefore skip the next line
	      if (_lineProperties[y] & LINE_DOUBLEHEIGHT)
		y++;
	    }

	  x += len - 1;
	}
    }
}

void
TerminalDisplay::blinkEvent ()
{
  if (!_allowBlinkingText)
    return;

  _blinking = !_blinking;

  //TODO:  Optimize to only repaint the areas of the widget
  // where there is blinking text
  // rather than repainting the whole widget.
  update ();
}

QRect
TerminalDisplay::imageToWidget (const QRect & imageArea) const
{
  QRect result;
  result.setLeft (_leftMargin + _fontWidth * imageArea.left ());
  result.setTop (_topMargin + _fontHeight * imageArea.top ());
  result.setWidth (_fontWidth * imageArea.width ());
  result.setHeight (_fontHeight * imageArea.height ());

  return result;
}

void
TerminalDisplay::updateCursor ()
{
  QRect cursorRect = imageToWidget (QRect (cursorPosition (), QSize (1, 1)));
  update (cursorRect);
}

void
TerminalDisplay::blinkCursorEvent ()
{
  _cursorBlinking = !_cursorBlinking;
  updateCursor ();
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                                  Resizing                                 */
/*                                                                           */
/* ------------------------------------------------------------------------- */

void
TerminalDisplay::resizeEvent (QResizeEvent *)
{
  updateImageSize ();
}

void
TerminalDisplay::propagateSize ()
{
  if (_isFixedSize)
    {
      setSize (_columns, _lines);
      QWidget::setFixedSize (sizeHint ());
      parentWidget ()->adjustSize ();
      parentWidget ()->setFixedSize (parentWidget ()->sizeHint ());
      return;
    }
  if (_image)
    updateImageSize ();
}

void
TerminalDisplay::updateImageSize ()
{
  Character *oldimg = _image;
  int oldlin = _lines;
  int oldcol = _columns;

  makeImage ();

  // copy the old image to reduce flicker
  int lines = qMin (oldlin, _lines);
  int columns = qMin (oldcol, _columns);

  if (oldimg)
    {
      for (int line = 0; line < lines; line++)
	{
	  memcpy ((void *) &_image[_columns * line],
		  (void *) &oldimg[oldcol * line],
		  columns * sizeof (Character));
	}
      delete[]oldimg;
    }

  if (_screenWindow)
    _screenWindow->setWindowLines (_lines);

  _resizing = (oldlin != _lines) || (oldcol != _columns);

  if (_resizing)
    {
      showResizeNotification ();
      emit changedContentSizeSignal (_contentHeight, _contentWidth);	// expose resizeEvent
    }

  _resizing = false;
}

//showEvent and hideEvent are reimplemented here so that it appears to other classes that the 
//display has been resized when the display is hidden or shown.
//
//TODO: Perhaps it would be better to have separate signals for show and hide instead of using
//the same signal as the one for a content size change 
void
TerminalDisplay::showEvent (QShowEvent *)
{
  emit changedContentSizeSignal (_contentHeight, _contentWidth);
}

void
TerminalDisplay::hideEvent (QHideEvent *)
{
  emit changedContentSizeSignal (_contentHeight, _contentWidth);
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                                Scrollbar                                  */
/*                                                                           */
/* ------------------------------------------------------------------------- */

void
TerminalDisplay::scrollBarPositionChanged (int)
{
  if (!_screenWindow)
    return;

  _screenWindow->scrollTo (_scrollBar->value ());

  // if the thumb has been moved to the bottom of the _scrollBar then set
  // the display to automatically track new output,
  // that is, scroll down automatically
  // to how new _lines as they are added
  const bool atEndOfOutput = (_scrollBar->value () == _scrollBar->maximum ());
  _screenWindow->setTrackOutput (atEndOfOutput);

  updateImage ();
}

void
TerminalDisplay::setScroll (int cursor, int slines)
{
  // update _scrollBar if the range or value has changed,
  // otherwise return
  //
  // setting the range or value of a _scrollBar will always trigger
  // a repaint, so it should be avoided if it is not necessary
  if (_scrollBar->minimum () == 0 &&
      _scrollBar->maximum () == (slines - _lines) &&
      _scrollBar->value () == cursor)
    {
      return;
    }

  disconnect (_scrollBar, SIGNAL (valueChanged (int)), this,
	      SLOT (scrollBarPositionChanged (int)));
  _scrollBar->setRange (0, slines - _lines);
  _scrollBar->setSingleStep (1);
  _scrollBar->setPageStep (_lines);
  _scrollBar->setValue (cursor);
  connect (_scrollBar, SIGNAL (valueChanged (int)), this,
	   SLOT (scrollBarPositionChanged (int)));
}

void
TerminalDisplay::setScrollBarPosition (ScrollBarPosition position)
{
  if (_scrollbarLocation == position)
    return;

  if (position == NoScrollBar)
    _scrollBar->hide ();
  else
    _scrollBar->show ();

  _topMargin = _leftMargin = 1;
  _scrollbarLocation = position;

  propagateSize ();
  update ();
}

void
TerminalDisplay::mousePressEvent (QMouseEvent * ev)
{
  if (_possibleTripleClick && (ev->button () == Qt::LeftButton))
    {
      mouseTripleClickEvent (ev);
      return;
    }

  if (!contentsRect ().contains (ev->pos ()))
    return;

  if (!_screenWindow)
    return;

  int charLine;
  int charColumn;
  getCharacterPosition (ev->pos (), charLine, charColumn);
  QPoint pos = QPoint (charColumn, charLine);

  if (ev->button () == Qt::LeftButton)
    {
      _lineSelectionMode = false;
      _wordSelectionMode = false;

      emit isBusySelecting (true);	// Keep it steady...
      // Drag only when the Control key is hold
      bool selected = false;

      // The receiver of the testIsSelected() signal will adjust
      // 'selected' accordingly.
      //emit testIsSelected(pos.x(), pos.y(), selected);

      selected = _screenWindow->isSelected (pos.x (), pos.y ());

      if ((!_ctrlDrag || ev->modifiers () & Qt::ControlModifier) && selected)
	{
	  // The user clicked inside selected text
	  dragInfo.state = diPending;
	  dragInfo.start = ev->pos ();
	}
      else
	{
	  // No reason to ever start a drag event
	  dragInfo.state = diNone;

	  _preserveLineBreaks = !((ev->modifiers () & Qt::ControlModifier)
				  && !(ev->modifiers () & Qt::AltModifier));
	  _columnSelectionMode = (ev->modifiers () & Qt::AltModifier)
	    && (ev->modifiers () & Qt::ControlModifier);

	  if (_mouseMarks || (ev->modifiers () & Qt::ShiftModifier))
	    {
	      _screenWindow->clearSelection ();

	      //emit clearSelectionSignal();
	      pos.ry () += _scrollBar->value ();
	      _iPntSel = _pntSel = pos;
	      _actSel = 1;	// left mouse button pressed but nothing selected yet.

	    }
	  else
	    {
	      emit mouseSignal (0, charColumn + 1,
				charLine + 1 + _scrollBar->value () -
				_scrollBar->maximum (), 0);
	    }
	}
    }
  else if (ev->button () == Qt::MidButton)
    {
      if (_mouseMarks
	  || (!_mouseMarks && (ev->modifiers () & Qt::ShiftModifier)))
	emitSelection (true, ev->modifiers () & Qt::ControlModifier);
      else
	emit mouseSignal (1, charColumn + 1,
			  charLine + 1 + _scrollBar->value () -
			  _scrollBar->maximum (), 0);
    }
  else if (ev->button () == Qt::RightButton)
    {
      if (_mouseMarks || (ev->modifiers () & Qt::ShiftModifier))
	emit configureRequest (ev->pos ());
      else
      emit mouseSignal (2, charColumn + 1,
			charLine + 1 + _scrollBar->value () -
			_scrollBar->maximum (), 0);
    }
}

QList < QAction * >TerminalDisplay::filterActions (const QPoint & position)
{
  int
    charLine,
    charColumn;
  getCharacterPosition (position, charLine, charColumn);

  Filter::HotSpot * spot = _filterChain->hotSpotAt (charLine, charColumn);

  return spot ? spot->actions () : QList < QAction * >();
}

void
TerminalDisplay::mouseMoveEvent (QMouseEvent * ev)
{
  int charLine = 0;
  int charColumn = 0;
  int scrollBarWidth =
    (_scrollbarLocation == ScrollBarLeft) ? _scrollBar->width () : 0;

  getCharacterPosition (ev->pos (), charLine, charColumn);

  // handle filters
  // change link hot-spot appearance on mouse-over
  Filter::HotSpot * spot = _filterChain->hotSpotAt (charLine, charColumn);
  if (spot && spot->type () == Filter::HotSpot::Link)
    {
      QRegion previousHotspotArea = _mouseOverHotspotArea;
      _mouseOverHotspotArea = QRegion ();
      QRect r;
      if (spot->startLine () == spot->endLine ())
	{
	  r.setCoords (spot->startColumn () * _fontWidth + scrollBarWidth,
		       spot->startLine () * _fontHeight,
		       spot->endColumn () * _fontWidth + scrollBarWidth,
		       (spot->endLine () + 1) * _fontHeight - 1);
	  _mouseOverHotspotArea |= r;
	}
      else
	{
	  r.setCoords (spot->startColumn () * _fontWidth + scrollBarWidth,
		       spot->startLine () * _fontHeight,
		       _columns * _fontWidth - 1 + scrollBarWidth,
		       (spot->startLine () + 1) * _fontHeight);
	  _mouseOverHotspotArea |= r;
	  for (int line = spot->startLine () + 1; line < spot->endLine ();
	       line++)
	    {
	      r.setCoords (0 * _fontWidth + scrollBarWidth,
			   line * _fontHeight,
			   _columns * _fontWidth + scrollBarWidth,
			   (line + 1) * _fontHeight);
	      _mouseOverHotspotArea |= r;
	    }
	  r.setCoords (0 * _fontWidth + scrollBarWidth,
		       spot->endLine () * _fontHeight,
		       spot->endColumn () * _fontWidth + scrollBarWidth,
		       (spot->endLine () + 1) * _fontHeight);
	  _mouseOverHotspotArea |= r;
	}
      // display tooltips when mousing over links
      // TODO: Extend this to work with filter types other than links
      const QString & tooltip = spot->tooltip ();
      if (!tooltip.isEmpty ())
	{
	  QToolTip::showText (mapToGlobal (ev->pos ()), tooltip, this,
			      _mouseOverHotspotArea.boundingRect ());
	}

      update (_mouseOverHotspotArea | previousHotspotArea);
    }
  else if (!_mouseOverHotspotArea.isEmpty ())
    {
      update (_mouseOverHotspotArea);
      // set hotspot area to an invalid rectangle
      _mouseOverHotspotArea = QRegion ();
    }

  // for auto-hiding the cursor, we need mouseTracking
  if (ev->buttons () == Qt::NoButton)
    return;

  // if the terminal is interested in mouse movements
  // then emit a mouse movement signal, unless the shift
  // key is being held down, which overrides this.
  if (!_mouseMarks && !(ev->modifiers () & Qt::ShiftModifier))
    {
      int button = 3;
      if (ev->buttons () & Qt::LeftButton)
	button = 0;
      if (ev->buttons () & Qt::MidButton)
	button = 1;
      if (ev->buttons () & Qt::RightButton)
	button = 2;


      emit mouseSignal (button,
			charColumn + 1,
			charLine + 1 + _scrollBar->value () -
			_scrollBar->maximum (), 1);

      return;
    }

  if (dragInfo.state == diPending)
    {
      // we had a mouse down, but haven't confirmed a drag yet
      // if the mouse has moved sufficiently, we will confirm

      int distance = 10;	//KGlobalSettings::dndEventDelay();
      if (ev->x () > dragInfo.start.x () + distance
	  || ev->x () < dragInfo.start.x () - distance
	  || ev->y () > dragInfo.start.y () + distance
	  || ev->y () < dragInfo.start.y () - distance)
	{
	  // we've left the drag square, we can start a real drag operation now
	  emit isBusySelecting (false);	// Ok.. we can breath again.

	  _screenWindow->clearSelection ();
	  doDrag ();
	}
      return;
    }
  else if (dragInfo.state == diDragging)
    {
      // this isn't technically needed because mouseMoveEvent is suppressed during
      // Qt drag operations, replaced by dragMoveEvent
      return;
    }

  if (_actSel == 0)
    return;

  // don't extend selection while pasting
  if (ev->buttons () & Qt::MidButton)
    return;

  extendSelection (ev->pos ());
}

void
TerminalDisplay::extendSelection (const QPoint & position)
{
  QPoint pos = position;

  if (!_screenWindow)
    return;

  //if ( !contentsRect().contains(ev->pos()) ) return;
  QPoint tL = contentsRect ().topLeft ();
  int tLx = tL.x ();
  int tLy = tL.y ();
  int scroll = _scrollBar->value ();

  // we're in the process of moving the mouse with the left button pressed
  // the mouse cursor will kept caught within the bounds of the text in
  // this widget.

  int linesBeyondWidget = 0;

  QRect textBounds (tLx + _leftMargin,
		    tLy + _topMargin,
		    _usedColumns * _fontWidth - 1,
		    _usedLines * _fontHeight - 1);

  // Adjust position within text area bounds.
  QPoint oldpos = pos;

  pos.setX (qBound (textBounds.left (), pos.x (), textBounds.right ()));
  pos.setY (qBound (textBounds.top (), pos.y (), textBounds.bottom ()));

  if (oldpos.y () > textBounds.bottom ())
    {
      linesBeyondWidget = (oldpos.y () - textBounds.bottom ()) / _fontHeight;
      _scrollBar->setValue (_scrollBar->value () + linesBeyondWidget + 1);	// scrollforward
    }
  if (oldpos.y () < textBounds.top ())
    {
      linesBeyondWidget = (textBounds.top () - oldpos.y ()) / _fontHeight;
      _scrollBar->setValue (_scrollBar->value () - linesBeyondWidget - 1);	// history
    }

  int charColumn = 0;
  int charLine = 0;
  getCharacterPosition (pos, charLine, charColumn);

  QPoint here = QPoint (charColumn, charLine);	//QPoint((pos.x()-tLx-_leftMargin+(_fontWidth/2))/_fontWidth,(pos.y()-tLy-_topMargin)/_fontHeight);
  QPoint ohere;
  QPoint _iPntSelCorr = _iPntSel;
  _iPntSelCorr.ry () -= _scrollBar->value ();
  QPoint _pntSelCorr = _pntSel;
  _pntSelCorr.ry () -= _scrollBar->value ();
  bool swapping = false;

  if (_wordSelectionMode)
    {
      // Extend to word boundaries
      int i;
      QChar selClass;

      bool left_not_right = (here.y () < _iPntSelCorr.y () ||
			     (here.y () == _iPntSelCorr.y ()
			      && here.x () < _iPntSelCorr.x ()));
      bool old_left_not_right = (_pntSelCorr.y () < _iPntSelCorr.y ()
				 || (_pntSelCorr.y () == _iPntSelCorr.y ()
				     && _pntSelCorr.x () <
				     _iPntSelCorr.x ()));
      swapping = left_not_right != old_left_not_right;

      // Find left (left_not_right ? from here : from start)
      QPoint left = left_not_right ? here : _iPntSelCorr;
      i = loc (left.x (), left.y ());
      if (i >= 0 && i <= _imageSize)
	{
	  selClass = charClass (_image[i].character);
	  while (((left.x () > 0)
		  || (left.y () > 0
		      && (_lineProperties[left.y () - 1] & LINE_WRAPPED)))
		 && charClass (_image[i - 1].character) == selClass)
	    {
	      i--;
	      if (left.x () > 0)
		left.rx ()--;
	      else
		{
		  left.rx () = _usedColumns - 1;
		  left.ry ()--;
		}
	    }
	}

      // Find left (left_not_right ? from start : from here)
      QPoint right = left_not_right ? _iPntSelCorr : here;
      i = loc (right.x (), right.y ());
      if (i >= 0 && i <= _imageSize)
	{
	  selClass = charClass (_image[i].character);
	  while (((right.x () < _usedColumns - 1)
		  || (right.y () < _usedLines - 1
		      && (_lineProperties[right.y ()] & LINE_WRAPPED)))
		 && charClass (_image[i + 1].character) == selClass)
	    {
	      i++;
	      if (right.x () < _usedColumns - 1)
		right.rx ()++;
	      else
		{
		  right.rx () = 0;
		  right.ry ()++;
		}
	    }
	}

      // Pick which is start (ohere) and which is extension (here)
      if (left_not_right)
	{
	  here = left;
	  ohere = right;
	}
      else
	{
	  here = right;
	  ohere = left;
	}
      ohere.rx ()++;
    }

  if (_lineSelectionMode)
    {
      // Extend to complete line
      bool above_not_below = (here.y () < _iPntSelCorr.y ());

      QPoint above = above_not_below ? here : _iPntSelCorr;
      QPoint below = above_not_below ? _iPntSelCorr : here;

      while (above.y () > 0
	     && (_lineProperties[above.y () - 1] & LINE_WRAPPED))
	above.ry ()--;
      while (below.y () < _usedLines - 1
	     && (_lineProperties[below.y ()] & LINE_WRAPPED))
	below.ry ()++;

      above.setX (0);
      below.setX (_usedColumns - 1);

      // Pick which is start (ohere) and which is extension (here)
      if (above_not_below)
	{
	  here = above;
	  ohere = below;
	}
      else
	{
	  here = below;
	  ohere = above;
	}

      QPoint newSelBegin = QPoint (ohere.x (), ohere.y ());
      swapping = !(_tripleSelBegin == newSelBegin);
      _tripleSelBegin = newSelBegin;

      ohere.rx ()++;
    }

  int offset = 0;
  if (!_wordSelectionMode && !_lineSelectionMode)
    {
      int i;
      QChar selClass;

      bool left_not_right = (here.y () < _iPntSelCorr.y () ||
			     (here.y () == _iPntSelCorr.y ()
			      && here.x () < _iPntSelCorr.x ()));
      bool old_left_not_right = (_pntSelCorr.y () < _iPntSelCorr.y ()
				 || (_pntSelCorr.y () == _iPntSelCorr.y ()
				     && _pntSelCorr.x () <
				     _iPntSelCorr.x ()));
      swapping = left_not_right != old_left_not_right;

      // Find left (left_not_right ? from here : from start)
      QPoint left = left_not_right ? here : _iPntSelCorr;

      // Find left (left_not_right ? from start : from here)
      QPoint right = left_not_right ? _iPntSelCorr : here;
      if (right.x () > 0 && !_columnSelectionMode)
	{
	  i = loc (right.x (), right.y ());
	  if (i >= 0 && i <= _imageSize)
	    {
	      selClass = charClass (_image[i - 1].character);
	      /* if (selClass == ' ')
	         {
	         while ( right.x() < _usedColumns-1 && charClass(_image[i+1].character) == selClass && (right.y()<_usedLines-1) && 
	         !(_lineProperties[right.y()] & LINE_WRAPPED))
	         { i++; right.rx()++; }
	         if (right.x() < _usedColumns-1)
	         right = left_not_right ? _iPntSelCorr : here;
	         else
	         right.rx()++;  // will be balanced later because of offset=-1;
	         } */
	    }
	}

      // Pick which is start (ohere) and which is extension (here)
      if (left_not_right)
	{
	  here = left;
	  ohere = right;
	  offset = 0;
	}
      else
	{
	  here = right;
	  ohere = left;
	  offset = -1;
	}
    }

  if ((here == _pntSelCorr) && (scroll == _scrollBar->value ()))
    return;			// not moved

  if (here == ohere)
    return;			// It's not left, it's not right.

  if (_actSel < 2 || swapping)
    {
      if (_columnSelectionMode && !_lineSelectionMode && !_wordSelectionMode)
	{
	  _screenWindow->setSelectionStart (ohere.x (), ohere.y (), true);
	}
      else
	{
	  _screenWindow->setSelectionStart (ohere.x () - 1 - offset,
					    ohere.y (), false);
	}

    }

  _actSel = 2;			// within selection
  _pntSel = here;
  _pntSel.ry () += _scrollBar->value ();

  if (_columnSelectionMode && !_lineSelectionMode && !_wordSelectionMode)
    {
      _screenWindow->setSelectionEnd (here.x (), here.y ());
    }
  else
    {
      _screenWindow->setSelectionEnd (here.x () + offset, here.y ());
    }

}

void
TerminalDisplay::mouseReleaseEvent (QMouseEvent * ev)
{
  if (!_screenWindow)
    return;

  int charLine;
  int charColumn;
  getCharacterPosition (ev->pos (), charLine, charColumn);

  if (ev->button () == Qt::LeftButton)
    {
      emit isBusySelecting (false);
      if (dragInfo.state == diPending)
	{
	  // We had a drag event pending but never confirmed.  Kill selection
	  _screenWindow->clearSelection ();
	  //emit clearSelectionSignal();
	}
      else
	{
	  if (_actSel > 1)
	    {
	      setSelection (_screenWindow->
			    selectedText (_preserveLineBreaks));
	    }

	  _actSel = 0;

	  //FIXME: emits a release event even if the mouse is
	  //       outside the range. The procedure used in `mouseMoveEvent'
	  //       applies here, too.

	  if (!_mouseMarks && !(ev->modifiers () & Qt::ShiftModifier))
	    emit mouseSignal (3,	// release
			      charColumn + 1,
			      charLine + 1 + _scrollBar->value () -
			      _scrollBar->maximum (), 0);
	}
      dragInfo.state = diNone;
    }


  if (!_mouseMarks &&
      ((ev->button () == Qt::RightButton
	&& !(ev->modifiers () & Qt::ShiftModifier))
       || ev->button () == Qt::MidButton))
    {
      emit mouseSignal (3,
			charColumn + 1,
			charLine + 1 + _scrollBar->value () -
			_scrollBar->maximum (), 0);
    }
}

void
TerminalDisplay::getCharacterPosition (const QPoint & widgetPoint, int &line,
				       int &column) const
{
  column =
    (widgetPoint.x () + _fontWidth / 2 - contentsRect ().left () -
     _leftMargin) / _fontWidth;
  line =
    (widgetPoint.y () - contentsRect ().top () - _topMargin) / _fontHeight;

  if (line < 0)
    line = 0;
  if (column < 0)
    column = 0;

  if (line >= _usedLines)
    line = _usedLines - 1;

  // the column value returned can be equal to _usedColumns, which
  // is the position just after the last character displayed in a line.
  //
  // this is required so that the user can select characters in the right-most
  // column (or left-most for right-to-left input)
  if (column > _usedColumns)
    column = _usedColumns;
}

void
TerminalDisplay::updateLineProperties ()
{
  if (!_screenWindow)
    return;

  _lineProperties = _screenWindow->getLineProperties ();
}

void
TerminalDisplay::mouseDoubleClickEvent (QMouseEvent * ev)
{
  if (ev->button () != Qt::LeftButton)
    return;
  if (!_screenWindow)
    return;

  int charLine = 0;
  int charColumn = 0;

  getCharacterPosition (ev->pos (), charLine, charColumn);

  QPoint pos (charColumn, charLine);

  // pass on double click as two clicks.
  if (!_mouseMarks && !(ev->modifiers () & Qt::ShiftModifier))
    {
      // Send just _ONE_ click event, since the first click of the double click
      // was already sent by the click handler
      emit mouseSignal (0, pos.x () + 1, pos.y () + 1 + _scrollBar->value () - _scrollBar->maximum (), 0);	// left button
      return;
    }

  _screenWindow->clearSelection ();
  QPoint bgnSel = pos;
  QPoint endSel = pos;
  int i = loc (bgnSel.x (), bgnSel.y ());
  _iPntSel = bgnSel;
  _iPntSel.ry () += _scrollBar->value ();

  _wordSelectionMode = true;

  // find word boundaries...
  QChar selClass = charClass (_image[i].character);
  {
    // find the start of the word
    int x = bgnSel.x ();
    while (((x > 0)
	    || (bgnSel.y () > 0
		&& (_lineProperties[bgnSel.y () - 1] & LINE_WRAPPED)))
	   && charClass (_image[i - 1].character) == selClass)
      {
	i--;
	if (x > 0)
	  x--;
	else
	  {
	    x = _usedColumns - 1;
	    bgnSel.ry ()--;
	  }
      }

    bgnSel.setX (x);
    _screenWindow->setSelectionStart (bgnSel.x (), bgnSel.y (), false);

    // find the end of the word
    i = loc (endSel.x (), endSel.y ());
    x = endSel.x ();
    while (((x < _usedColumns - 1)
	    || (endSel.y () < _usedLines - 1
		&& (_lineProperties[endSel.y ()] & LINE_WRAPPED)))
	   && charClass (_image[i + 1].character) == selClass)
      {
	i++;
	if (x < _usedColumns - 1)
	  x++;
	else
	  {
	    x = 0;
	    endSel.ry ()++;
	  }
      }

    endSel.setX (x);

    // In word selection mode don't select @ (64) if at end of word.
    if ((QChar (_image[i].character) == '@')
	&& ((endSel.x () - bgnSel.x ()) > 0))
      endSel.setX (x - 1);


    _actSel = 2;		// within selection

    _screenWindow->setSelectionEnd (endSel.x (), endSel.y ());

    setSelection (_screenWindow->selectedText (_preserveLineBreaks));
  }

  _possibleTripleClick = true;

  QTimer::singleShot (QApplication::doubleClickInterval (), this,
		      SLOT (tripleClickTimeout ()));
}

void
TerminalDisplay::wheelEvent (QWheelEvent * ev)
{
  if (ev->orientation () != Qt::Vertical)
    return;

  // if the terminal program is not interested mouse events
  // then send the event to the scrollbar if the slider has room to move
  // or otherwise send simulated up / down key presses to the terminal program
  // for the benefit of programs such as 'less'
  if (_mouseMarks)
    {
      bool canScroll = _scrollBar->maximum () > 0;
      if (canScroll)
	_scrollBar->event (ev);
      else
	{
	  // assume that each Up / Down key event will cause the terminal application
	  // to scroll by one line.
	  //
	  // to get a reasonable scrolling speed, scroll by one line for every 5 degrees
	  // of mouse wheel rotation.  Mouse wheels typically move in steps of 15 degrees,
	  // giving a scroll of 3 lines
	  int key = ev->delta () > 0 ? Qt::Key_Up : Qt::Key_Down;

	  // QWheelEvent::delta() gives rotation in eighths of a degree
	  int wheelDegrees = ev->delta () / 8;
	  int linesToScroll = abs (wheelDegrees) / 5;

	  QKeyEvent keyScrollEvent (QEvent::KeyPress, key, Qt::NoModifier);

	  for (int i = 0; i < linesToScroll; i++)
	    emit keyPressedSignal (&keyScrollEvent);
	}
    }
  else
    {
      // terminal program wants notification of mouse activity

      int charLine;
      int charColumn;
      getCharacterPosition (ev->pos (), charLine, charColumn);

      emit mouseSignal (ev->delta () > 0 ? 4 : 5,
			charColumn + 1,
			charLine + 1 + _scrollBar->value () -
			_scrollBar->maximum (), 0);
    }
}

void
TerminalDisplay::tripleClickTimeout ()
{
  _possibleTripleClick = false;
}

void
TerminalDisplay::mouseTripleClickEvent (QMouseEvent * ev)
{
  if (!_screenWindow)
    return;

  int charLine;
  int charColumn;
  getCharacterPosition (ev->pos (), charLine, charColumn);
  _iPntSel = QPoint (charColumn, charLine);

  _screenWindow->clearSelection ();

  _lineSelectionMode = true;
  _wordSelectionMode = false;

  _actSel = 2;			// within selection
  emit isBusySelecting (true);	// Keep it steady...

  while (_iPntSel.y () > 0
	 && (_lineProperties[_iPntSel.y () - 1] & LINE_WRAPPED))
    _iPntSel.ry ()--;

  if (_tripleClickMode == SelectForwardsFromCursor)
    {
      // find word boundary start
      int i = loc (_iPntSel.x (), _iPntSel.y ());
      QChar selClass = charClass (_image[i].character);
      int x = _iPntSel.x ();

      while (((x > 0) ||
	      (_iPntSel.y () > 0
	       && (_lineProperties[_iPntSel.y () - 1] & LINE_WRAPPED)))
	     && charClass (_image[i - 1].character) == selClass)
	{
	  i--;
	  if (x > 0)
	    x--;
	  else
	    {
	      x = _columns - 1;
	      _iPntSel.ry ()--;
	    }
	}

      _screenWindow->setSelectionStart (x, _iPntSel.y (), false);
      _tripleSelBegin = QPoint (x, _iPntSel.y ());
    }
  else if (_tripleClickMode == SelectWholeLine)
    {
      _screenWindow->setSelectionStart (0, _iPntSel.y (), false);
      _tripleSelBegin = QPoint (0, _iPntSel.y ());
    }

  while (_iPntSel.y () < _lines - 1
	 && (_lineProperties[_iPntSel.y ()] & LINE_WRAPPED))
    _iPntSel.ry ()++;

  _screenWindow->setSelectionEnd (_columns - 1, _iPntSel.y ());

  setSelection (_screenWindow->selectedText (_preserveLineBreaks));

  _iPntSel.ry () += _scrollBar->value ();
}


bool
TerminalDisplay::focusNextPrevChild (bool next)
{
  if (next)
    return false;		// This disables changing the active part in konqueror
  // when pressing Tab
  return QWidget::focusNextPrevChild (next);
}


QChar
TerminalDisplay::charClass (QChar qch) const
{
  if (qch.isSpace ())
    return ' ';

  if (qch.isLetterOrNumber ()
      || _wordCharacters.contains (qch, Qt::CaseInsensitive))
    return 'a';

  return qch;
}

void
TerminalDisplay::setWordCharacters (const QString & wc)
{
  _wordCharacters = wc;
}

void
TerminalDisplay::setUsesMouse (bool on)
{
  _mouseMarks = on;
  setCursor (_mouseMarks ? Qt::IBeamCursor : Qt::ArrowCursor);
}

bool
TerminalDisplay::usesMouse () const
{
  return _mouseMarks;
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                               Clipboard                                   */
/*                                                                           */
/* ------------------------------------------------------------------------- */

#undef KeyPress

void
TerminalDisplay::emitSelection (bool useXselection, bool appendReturn)
{
  if (!_screenWindow)
    return;

  // Paste Clipboard by simulating keypress events
  QString text =
    QApplication::clipboard ()->
    text (useXselection ? QClipboard::Selection : QClipboard::Clipboard);
  if (appendReturn)
    text.append ("\r");
  if (!text.isEmpty ())
    {
      text.replace ('\n', '\r');
      QKeyEvent e (QEvent::KeyPress, 0, Qt::NoModifier, text);
      emit keyPressedSignal (&e);	// expose as a big fat keypress event

      _screenWindow->clearSelection ();
    }
}

void
TerminalDisplay::setSelection (const QString & t)
{
  QApplication::clipboard ()->setText (t, QClipboard::Selection);
}

void
TerminalDisplay::copyClipboard ()
{
  if (!_screenWindow)
    return;

  QString text = _screenWindow->selectedText (_preserveLineBreaks);
  if (!text.isEmpty ())
    QApplication::clipboard ()->setText (text);
}

void
TerminalDisplay::pasteClipboard ()
{
  emitSelection (false, false);
}

void
TerminalDisplay::pasteSelection ()
{
  emitSelection (true, false);
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                                Keyboard                                   */
/*                                                                           */
/* ------------------------------------------------------------------------- */

void
TerminalDisplay::setFlowControlWarningEnabled (bool enable)
{
  _flowControlWarningEnabled = enable;

  // if the dialog is currently visible and the flow control warning has 
  // been disabled then hide the dialog
  if (!enable)
    outputSuspended (false);
}

void
TerminalDisplay::keyPressEvent (QKeyEvent * event)
{
  bool emitKeyPressSignal = true;

  if (event->modifiers () == Qt::ControlModifier)
    {
      switch (event->key ())
	{
	case Qt::Key_C:
	  copyClipboard ();
	  break;
	case Qt::Key_V:
	  pasteClipboard ();
	  break;
	};
    }
  else if (event->modifiers () == Qt::ShiftModifier)
    {
      bool update = true;

      if (event->key () == Qt::Key_PageUp)
	{
	  _screenWindow->scrollBy (ScreenWindow::ScrollPages, -1);
	}
      else if (event->key () == Qt::Key_PageDown)
	{
	  _screenWindow->scrollBy (ScreenWindow::ScrollPages, 1);
	}
      else if (event->key () == Qt::Key_Up)
	{
	  _screenWindow->scrollBy (ScreenWindow::ScrollLines, -1);
	}
      else if (event->key () == Qt::Key_Down)
	{
	  _screenWindow->scrollBy (ScreenWindow::ScrollLines, 1);
	}
      else
	update = false;

      if (update)
	{
	  _screenWindow->setTrackOutput (_screenWindow->atEndOfOutput ());

	  updateLineProperties ();
	  updateImage ();

	  // do not send key press to terminal
	  emitKeyPressSignal = false;
	}
    }

  _actSel = 0;			// Key stroke implies a screen update, so TerminalDisplay won't
  // know where the current selection is.

  if (_hasBlinkingCursor)
    {
      _blinkCursorTimer->start (QApplication::cursorFlashTime () / 2);
      if (_cursorBlinking)
	blinkCursorEvent ();
      else
	_cursorBlinking = false;
    }

  if (emitKeyPressSignal)
    emit keyPressedSignal (event);

  event->accept ();
}

void
TerminalDisplay::inputMethodEvent (QInputMethodEvent * event)
{
  QKeyEvent keyEvent (QEvent::KeyPress, 0,
		      (Qt::KeyboardModifiers) Qt::NoModifier,
		      event->commitString ());
  emit keyPressedSignal (&keyEvent);

  _inputMethodData.preeditString = event->preeditString ();
  update (preeditRect () | _inputMethodData.previousPreeditRect);

  event->accept ();
}

QVariant
TerminalDisplay::inputMethodQuery (Qt::InputMethodQuery query) const
{
  const QPoint cursorPos =
    _screenWindow ? _screenWindow->cursorPosition () : QPoint (0, 0);
  switch (query)
    {
    case Qt::ImMicroFocus:
      return imageToWidget (QRect (cursorPos.x (), cursorPos.y (), 1, 1));
      break;
    case Qt::ImFont:
      return font ();
      break;
    case Qt::ImCursorPosition:
      // return the cursor position within the current line
      return cursorPos.x ();
      break;
    case Qt::ImSurroundingText:
      {
	// return the text from the current line
	QString lineText;
	QTextStream stream (&lineText);
	PlainTextDecoder decoder;
	decoder.begin (&stream);
	decoder.decodeLine (&_image[loc (0, cursorPos.y ())], _usedColumns,
			    _lineProperties[cursorPos.y ()]);
	decoder.end ();
	return lineText;
      }
      break;
    case Qt::ImCurrentSelection:
      return QString ();
      break;
    default:
      break;
    }

  return QVariant ();
}

bool
TerminalDisplay::handleShortcutOverrideEvent (QKeyEvent * keyEvent)
{
  int modifiers = keyEvent->modifiers ();

  //  When a possible shortcut combination is pressed, 
  //  emit the overrideShortcutCheck() signal to allow the host
  //  to decide whether the terminal should override it or not.
  if (modifiers != Qt::NoModifier)
    {
      int modifierCount = 0;
      unsigned int currentModifier = Qt::ShiftModifier;

      while (currentModifier <= Qt::KeypadModifier)
	{
	  if (modifiers & currentModifier)
	    modifierCount++;
	  currentModifier <<= 1;
	}
      if (modifierCount < 2)
	{
	  bool override = false;
	  emit overrideShortcutCheck (keyEvent, override);
	  if (override)
	    {
	      keyEvent->accept ();
	      return true;
	    }
	}
    }

  // Override any of the following shortcuts because
  // they are needed by the terminal
  int keyCode = keyEvent->key () | modifiers;
  switch (keyCode)
    {
      // list is taken from the QLineEdit::event() code
    case Qt::Key_Tab:
    case Qt::Key_Delete:
    case Qt::Key_Home:
    case Qt::Key_End:
    case Qt::Key_Backspace:
    case Qt::Key_Left:
    case Qt::Key_Right:
      keyEvent->accept ();
      return true;
    }
  return false;
}

bool
TerminalDisplay::event (QEvent * event)
{
  bool eventHandled = false;
  switch (event->type ())
    {
    case QEvent::ShortcutOverride:
      eventHandled = handleShortcutOverrideEvent ((QKeyEvent *) event);
      break;
    case QEvent::PaletteChange:
    case QEvent::ApplicationPaletteChange:
      _scrollBar->setPalette (QApplication::palette ());
      break;
    default:
      break;
    }
  return eventHandled ? true : QWidget::event (event);
}

void
TerminalDisplay::setBellMode (int mode)
{
  _bellMode = mode;
}

void
TerminalDisplay::enableBell ()
{
  _allowBell = true;
}

void
TerminalDisplay::bell (const QString & message)
{
  Q_UNUSED (message);
  if (_bellMode == NoBell)
    return;

  //limit the rate at which bells can occur
  //...mainly for sound effects where rapid bells in sequence
  //produce a horrible noise
  if (_allowBell)
    {
      _allowBell = false;
      QTimer::singleShot (500, this, SLOT (enableBell ()));

      if (_bellMode == SystemBeepBell)
	{
	  // TODO: This will need added back in at some point
	  //KNotification::beep();
	}
      else if (_bellMode == NotifyBell)
	{
	  // TODO: This will need added back in at some point
	  //KNotification::event("BellVisible", message,QPixmap(),this);
	}
      else if (_bellMode == VisualBell)
	{
	  swapColorTable ();
	  QTimer::singleShot (200, this, SLOT (swapColorTable ()));
	}
    }
}

void
TerminalDisplay::swapColorTable ()
{
  ColorEntry color = _colorTable[1];
  _colorTable[1] = _colorTable[0];
  _colorTable[0] = color;
  _colorsInverted = !_colorsInverted;
  update ();
}

void
TerminalDisplay::clearImage ()
{
  // We initialize _image[_imageSize] too. See makeImage()
  for (int i = 0; i <= _imageSize; i++)
    {
      _image[i].character = ' ';
      _image[i].foregroundColor = CharacterColor (COLOR_SPACE_DEFAULT,
						  DEFAULT_FORE_COLOR);
      _image[i].backgroundColor = CharacterColor (COLOR_SPACE_DEFAULT,
						  DEFAULT_BACK_COLOR);
      _image[i].rendition = DEFAULT_RENDITION;
    }
}

void
TerminalDisplay::calcGeometry ()
{
  _scrollBar->resize (_scrollBar->sizeHint ().width (),
		      contentsRect ().height ());
  switch (_scrollbarLocation)
    {
    case NoScrollBar:
      _leftMargin = DEFAULT_LEFT_MARGIN;
      _contentWidth = contentsRect ().width () - 2 * DEFAULT_LEFT_MARGIN;
      break;
    case ScrollBarLeft:
      _leftMargin = DEFAULT_LEFT_MARGIN + _scrollBar->width ();
      _contentWidth =
	contentsRect ().width () - 2 * DEFAULT_LEFT_MARGIN -
	_scrollBar->width ();
      _scrollBar->move (contentsRect ().topLeft ());
      break;
    case ScrollBarRight:
      _leftMargin = DEFAULT_LEFT_MARGIN;
      _contentWidth =
	contentsRect ().width () - 2 * DEFAULT_LEFT_MARGIN -
	_scrollBar->width ();
      _scrollBar->move (contentsRect ().topRight () -
			QPoint (_scrollBar->width () - 1, 0));
      break;
    }

  _topMargin = DEFAULT_TOP_MARGIN;
  _contentHeight =
    contentsRect ().height () - 2 * DEFAULT_TOP_MARGIN + /* mysterious */ 1;

  if (!_isFixedSize)
    {
      // ensure that display is always at least one column wide
      _columns = qMax (1, _contentWidth / _fontWidth);
      _usedColumns = qMin (_usedColumns, _columns);

      // ensure that display is always at least one line high
      _lines = qMax (1, _contentHeight / _fontHeight);
      _usedLines = qMin (_usedLines, _lines);
    }
}

void
TerminalDisplay::makeImage ()
{
  calcGeometry ();

  // confirm that array will be of non-zero size, since the painting code
  // assumes a non-zero array length
  Q_ASSERT (_lines > 0 && _columns > 0);
  Q_ASSERT (_usedLines <= _lines && _usedColumns <= _columns);

  _imageSize = _lines * _columns;

  // We over-commit one character so that we can be more relaxed in dealing with
  // certain boundary conditions: _image[_imageSize] is a valid but unused position
  _image = new Character[_imageSize + 1];

  clearImage ();
}

// calculate the needed size, this must be synced with calcGeometry()
void
TerminalDisplay::setSize (int columns, int lines)
{
  int scrollBarWidth =
    _scrollBar->isHidden ()? 0 : _scrollBar->sizeHint ().width ();
  int horizontalMargin = 2 * DEFAULT_LEFT_MARGIN;
  int verticalMargin = 2 * DEFAULT_TOP_MARGIN;

  QSize newSize =
    QSize (horizontalMargin + scrollBarWidth + (columns * _fontWidth),
	   verticalMargin + (lines * _fontHeight));

  if (newSize != size ())
    {
      _size = newSize;
      updateGeometry ();
    }
}

void
TerminalDisplay::setFixedSize (int cols, int lins)
{
  _isFixedSize = true;

  //ensure that display is at least one line by one column in size
  _columns = qMax (1, cols);
  _lines = qMax (1, lins);
  _usedColumns = qMin (_usedColumns, _columns);
  _usedLines = qMin (_usedLines, _lines);

  if (_image)
    {
      delete[]_image;
      makeImage ();
    }
  setSize (cols, lins);
  QWidget::setFixedSize (_size);
}

QSize
TerminalDisplay::sizeHint () const
{
  return _size;
}


/* --------------------------------------------------------------------- */
/*                                                                       */
/* Drag & Drop                                                           */
/*                                                                       */
/* --------------------------------------------------------------------- */

void
TerminalDisplay::dragEnterEvent (QDragEnterEvent * event)
{
  if (event->mimeData ()->hasFormat ("text/plain"))
    event->acceptProposedAction ();
}

void
TerminalDisplay::dropEvent (QDropEvent * event)
{
  //KUrl::List urls = KUrl::List::fromMimeData(event->mimeData());

  QString dropText;
  /*
     if (!urls.isEmpty()) 
     {
     for ( int i = 0 ; i < urls.count() ; i++ ) 
     {
     KUrl url = KIO::NetAccess::mostLocalUrl( urls[i] , 0 );
     QString urlText;

     if (url.isLocalFile())
     urlText = url.path(); 
     else
     urlText = url.url();

     // in future it may be useful to be able to insert file names with drag-and-drop
     // without quoting them (this only affects paths with spaces in) 
     urlText = KShell::quoteArg(urlText);

     dropText += urlText;

     if ( i != urls.count()-1 ) 
     dropText += ' ';
     }
     }
     else 
     {
     dropText = event->mimeData()->text();
     }
   */

  if (event->mimeData ()->hasFormat ("text/plain"))
    {
      emit sendStringToEmu (dropText.toLocal8Bit ());
    }
}

void
TerminalDisplay::doDrag ()
{
  dragInfo.state = diDragging;
  dragInfo.dragObject = new QDrag (this);
  QMimeData *mimeData = new QMimeData;
  mimeData->setText (QApplication::clipboard ()->
		     text (QClipboard::Selection));
  dragInfo.dragObject->setMimeData (mimeData);
  dragInfo.dragObject->start (Qt::CopyAction);
  // Don't delete the QTextDrag object.  Qt will delete it when it's done with it.
}

void
TerminalDisplay::outputSuspended (bool suspended)
{
  //create the label when this function is first called
  if (!_outputSuspendedLabel)
    {
      //This label includes a link to an English language website
      //describing the 'flow control' (Xon/Xoff) feature found in almost
      //all terminal emulators.
      //If there isn't a suitable article available in the target language the link
      //can simply be removed.
      _outputSuspendedLabel = new QLabel (QString ("<qt>Output has been "
						   "<a href=\"http://en.wikipedia.org/wiki/Flow_control\">suspended</a>"
						   " by pressing Ctrl+S."
						   "  Press <b>Ctrl+Q</b> to resume.</qt>"),
					  this);

      QPalette palette (_outputSuspendedLabel->palette ());
      //KColorScheme::adjustBackground(palette,KColorScheme::NeutralBackground);
      _outputSuspendedLabel->setPalette (palette);
      _outputSuspendedLabel->setAutoFillBackground (true);
      _outputSuspendedLabel->setBackgroundRole (QPalette::Base);
      _outputSuspendedLabel->setFont (QApplication::font ());
      _outputSuspendedLabel->setContentsMargins (5, 5, 5, 5);

      //enable activation of "Xon/Xoff" link in label
      _outputSuspendedLabel->
	setTextInteractionFlags (Qt::LinksAccessibleByMouse | Qt::
				 LinksAccessibleByKeyboard);
      _outputSuspendedLabel->setOpenExternalLinks (true);
      _outputSuspendedLabel->setVisible (false);

      _gridLayout->addWidget (_outputSuspendedLabel);
      _gridLayout->addItem (new QSpacerItem (0, 0, QSizePolicy::Expanding,
					     QSizePolicy::Expanding), 1, 0);

    }

  _outputSuspendedLabel->setVisible (suspended);
}

uint
TerminalDisplay::lineSpacing () const
{
  return _lineSpacing;
}

void
TerminalDisplay::setLineSpacing (uint i)
{
  _lineSpacing = i;
  setVTFont (font ());		// Trigger an update.
}

AutoScrollHandler::AutoScrollHandler (QWidget * parent):QObject (parent),
_timerId (0)
{
  //parent->installEventFilter(this);
}

void
AutoScrollHandler::timerEvent (QTimerEvent * event)
{
  if (event->timerId () != _timerId)
    return;

  QMouseEvent mouseEvent (QEvent::MouseMove,
			  widget ()->mapFromGlobal (QCursor::pos ()),
			  Qt::NoButton, Qt::LeftButton, Qt::NoModifier);

  QApplication::sendEvent (widget (), &mouseEvent);
}

bool
AutoScrollHandler::eventFilter (QObject * watched, QEvent * event)
{
  Q_ASSERT (watched == parent ());
  Q_UNUSED (watched);

  QMouseEvent *mouseEvent = (QMouseEvent *) event;
  switch (event->type ())
    {
    case QEvent::MouseMove:
      {
	bool mouseInWidget = widget ()->rect ().contains (mouseEvent->pos ());

	if (mouseInWidget)
	  {
	    if (_timerId)
	      killTimer (_timerId);
	    _timerId = 0;
	  }
	else
	  {
	    if (!_timerId && (mouseEvent->buttons () & Qt::LeftButton))
	      _timerId = startTimer (100);
	  }
	break;
      }
    case QEvent::MouseButtonRelease:
      if (_timerId && (mouseEvent->buttons () & ~Qt::LeftButton))
	{
	  killTimer (_timerId);
	  _timerId = 0;
	}
      break;
    default:
      break;
    };

  return false;
}