/*
    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/QClipboard>
#include <QtGui/QKeyEvent>
#include <QtCore/QEvent>
#include <QtCore/QFileInfo>
#include <QtGui/QGridLayout>
#include <QtGui/QAction>
#include <QtGui/QLabel>
#include <QtGui/QPainter>
#include <QtGui/QPixmap>
#include <QtGui/QScrollBar>
#include <QtGui/QStyle>
#include <QtCore/QTimer>
#include <QtGui/QToolTip>

// KDE
#include <KShell>
#include <KColorScheme>
#include <KCursor>
#include <KDebug>
#include <KLocalizedString>
#include <KNotification>
#include <KGlobalSettings>
#include <KIO/NetAccess>
#include <konq_operations.h>
#include <KFileItem>

// Konsole
#include "Filter.h"
#include "konsole_wcwidth.h"
#include "TerminalCharacterDecoder.h"
#include "Screen.h"
#include "ScreenWindow.h"
#include "LineFont.h"
#include "SessionController.h"
#include "WindowSystemInfo.h"
#include "ExtendedCharTable.h"

using namespace Konsole;

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

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

// 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.
const ColorEntry Konsole::base_color_table[TABLE_COLORS] = {
    // 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)
};

// 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 (_screenWindow) {
        connect(_screenWindow , SIGNAL(outputChanged()) , this , SLOT(updateLineProperties()));
        connect(_screenWindow , SIGNAL(outputChanged()) , this , SLOT(updateImage()));
        _screenWindow->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                                    */
/*                                                                           */
/* ------------------------------------------------------------------------- */

static inline bool isLineCharString(const QString& string)
{
    if (string.length() == 0)
        return false;

    return isSupportedLineChar(string.at(0).unicode());
}

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)qstrlen(REPCHAR));

    _fixedFont = true;

    const int fw = fm.width(REPCHAR[0]);
    for (unsigned int i = 1; i < qstrlen(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);

        // Konsole cannot handle non-integer font metrics
        font.setStyleStrategy(QFont::StyleStrategy(font.styleStrategy() | QFont::ForceIntegerMetrics));

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

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

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

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

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                         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)
    , _showTerminalSizeHint(true)
    , _bidiEnabled(false)
    , _actSel(0)
    , _wordSelectionMode(false)
    , _lineSelectionMode(false)
    , _preserveLineBreaks(false)
    , _columnSelectionMode(false)
    , _scrollbarLocation(Enum::ScrollBarRight)
    , _wordCharacters(":@-./_~")
    , _bellMode(Enum::NotifyBell)
    , _allowBlinkingText(true)
    , _allowBlinkingCursor(false)
    , _textBlinking(false)
    , _cursorBlinking(false)
    , _hasTextBlinker(false)
    , _underlineLinks(true)
    , _isFixedSize(false)
    , _ctrlDrag(true)
    , _tripleClickMode(Enum::SelectWholeLine)
    , _possibleTripleClick(false)
    , _resizeWidget(0)
    , _resizeTimer(0)
    , _flowControlWarningEnabled(false)
    , _outputSuspendedLabel(0)
    , _lineSpacing(0)
    , _blendColor(qRgba(0, 0, 0, 0xff))
    , _filterChain(new TerminalImageFilterChain())
    , _cursorShape(Enum::BlockCursor)
    , _antialiasText(true)
    , _sessionController(0)
{
    // terminal applications are not designed with Right-To-Left in mind,
    // so the layout is forced to Left-To-Right
    setLayoutDirection(Qt::LeftToRight);

    _topMargin = DEFAULT_TOP_MARGIN;
    _leftMargin = DEFAULT_LEFT_MARGIN;

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

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

    // hide mouse cursor on keystroke or idle
    KCursor::setAutoHideCursor(this, true);
    setMouseTracking(true);

    setUsesMouse(true);

    setColorTable(base_color_table);

    // Enable drag and drop support
    setAcceptDrops(true);
    _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(_blinkTextTimer);
    disconnect(_blinkCursorTimer);

    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)
};

static void drawLineChar(QPainter& paint, int x, int y, int w, int h, uchar code)
{
    //Calculate cell midpoints, end points.
    const int cx = x + w / 2;
    const int cy = y + h / 2;
    const int ex = x + w - 1;
    const int ey = y + h - 1;

    const quint32 toDraw = LineChars[code];

    //Top _lines:
    if (toDraw & TopL)
        paint.drawLine(cx - 1, y, cx - 1, cy - 2);
    if (toDraw & TopC)
        paint.drawLine(cx, y, cx, cy - 2);
    if (toDraw & TopR)
        paint.drawLine(cx + 1, y, cx + 1, cy - 2);

    //Bot _lines:
    if (toDraw & BotL)
        paint.drawLine(cx - 1, cy + 2, cx - 1, ey);
    if (toDraw & BotC)
        paint.drawLine(cx, cy + 2, cx, ey);
    if (toDraw & BotR)
        paint.drawLine(cx + 1, cy + 2, cx + 1, ey);

    //Left _lines:
    if (toDraw & LeftT)
        paint.drawLine(x, cy - 1, cx - 2, cy - 1);
    if (toDraw & LeftC)
        paint.drawLine(x, cy, cx - 2, cy);
    if (toDraw & LeftB)
        paint.drawLine(x, cy + 1, cx - 2, cy + 1);

    //Right _lines:
    if (toDraw & RightT)
        paint.drawLine(cx + 2, cy - 1, ex, cy - 1);
    if (toDraw & RightC)
        paint.drawLine(cx + 2, cy, ex, cy);
    if (toDraw & RightB)
        paint.drawLine(cx + 2, cy + 1, ex, cy + 1);

    //Intersection points.
    if (toDraw & Int11)
        paint.drawPoint(cx - 1, cy - 1);
    if (toDraw & Int12)
        paint.drawPoint(cx, cy - 1);
    if (toDraw & Int13)
        paint.drawPoint(cx + 1, cy - 1);

    if (toDraw & Int21)
        paint.drawPoint(cx - 1, cy);
    if (toDraw & Int22)
        paint.drawPoint(cx, cy);
    if (toDraw & Int23)
        paint.drawPoint(cx + 1, cy);

    if (toDraw & Int31)
        paint.drawPoint(cx - 1, cy + 1);
    if (toDraw & Int32)
        paint.drawPoint(cx, cy + 1);
    if (toDraw & Int33)
        paint.drawPoint(cx + 1, cy + 1);

}

void TerminalDisplay::drawLineCharString(QPainter& painter, int x, int y, const QString& str,
        const Character* attributes)
{
    const QPen& originalPen = painter.pen();

    if ((attributes->rendition & RE_BOLD) && _boldIntense) {
        QPen boldPen(originalPen);
        boldPen.setWidth(3);
        painter.setPen(boldPen);
    }

    for (int i = 0 ; i < str.length(); i++) {
        const uchar code = str[i].cell();
        if (LineChars[code])
            drawLineChar(painter, x + (_fontWidth * i), y, _fontWidth, _fontHeight, code);
    }

    painter.setPen(originalPen);
}

void TerminalDisplay::setKeyboardCursorShape(Enum::CursorShapeEnum shape)
{
    _cursorShape = shape;
}
Enum::CursorShapeEnum TerminalDisplay::keyboardCursorShape() const
{
    return _cursorShape;
}
void TerminalDisplay::setKeyboardCursorColor(bool useForegroundColor, const QColor& color)
{
    if (useForegroundColor) {
        // use an invalid color to indicate that the foreground color of
        // the current character should be used to draw the cursor
        _cursorColor = QColor();
    } else {
        _cursorColor = color;
    }
}
QColor TerminalDisplay::keyboardCursorColor() const
{
    return _cursorColor;
}

void TerminalDisplay::setOpacity(qreal opacity)
{
    QColor color(_blendColor);
    color.setAlphaF(opacity);

    // enable automatic background filling to prevent the display
    // flickering if there is no transparency
    /*if ( color.alpha() == 255 )
    {
        setAutoFillBackground(true);
    }
    else
    {
        setAutoFillBackground(false);
    }*/

    _blendColor = color.rgba();
}

void TerminalDisplay::setWallpaper(ColorSchemeWallpaper::Ptr p)
{
    _wallpaper = p;
}

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 (useOpacitySetting && !_wallpaper->isNull() &&
            _wallpaper->draw(painter, contentsRect)) {
    } else if (WindowSystemInfo::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)
{
    // don't draw cursor which is currently blinking
    if (_cursorBlinking)
        return;

    QRect cursorRect = rect;
    cursorRect.setHeight(_fontHeight - _lineSpacing - 1);

    QColor cursorColor = _cursorColor.isValid() ? _cursorColor : foregroundColor;
    painter.setPen(cursorColor);

    if (_cursorShape == Enum::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));

        // draw the cursor body only when the widget has focus
        if (hasFocus()) {
            painter.fillRect(cursorRect, cursorColor);

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

    else if (_cursorShape == Enum::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 (_textBlinking && (style->rendition & RE_BLINK))
        return;

    // setup bold 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;
    const 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);
    }

    // draw text
    if (isLineCharString(text)) {
        drawLineCharString(painter, rect.x(), rect.y(), text, style);
    } else {
        // Force using LTR as the document layout for the terminal area, because
        // there is no use cases for RTL emulator and RTL terminal application.
        //
        // This still allows RTL characters to be rendered in the RTL way.
        painter.setLayoutDirection(Qt::LeftToRight);

        // the drawText(rect,flags,string) overload is used here with null flags
        // instead of drawText(rect,string) because the (rect,string) overload causes
        // the application's default layout direction to be used instead of
        // the widget-specific layout direction, which should always be
        // Qt::LeftToRight for this widget
        //
        // This was discussed in: http://lists.kde.org/?t=120552223600002&r=1&w=2
        if (_bidiEnabled) {
            painter.drawText(rect, 0, text);
        } else {
            // See bug 280896 for more info
#if QT_VERSION >= 0x040800
            painter.drawText(rect, Qt::AlignBottom, LTR_OVERRIDE_CHAR + text);
#else
            painter.drawText(rect, 0, LTR_OVERRIDE_CHAR + text);
#endif
        }
    }
}

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;
}

// 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.
    //
    const int scrollBarWidth = _scrollBar->isHidden() ? 0 : _scrollBar->width();
    const int SCROLLBAR_CONTENT_GAP = 1;
    QRect scrollRect;
    if (_scrollbarLocation == Enum::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 ];

    const int top = _topMargin + (region.top() * _fontHeight);
    const int linesToMove = region.height() - abs(lines);
    const 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
    if (_wallpaper->isNull()) {
        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();
    const int lines = _screenWindow->windowLines();
    const 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;

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

    CharacterColor cf;       // undefined

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

    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) {
                _hasTextBlinker |= (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]) {
                    if (!newLine[x + 0].character)
                        continue;
                    const bool lineDraw = newLine[x + 0].isLineChar();
                    const bool doubleWidth = (x + 1 == columnsToUpdate) ? false : (newLine[x + 1].character == 0);
                    const quint8 cr = newLine[x].rendition;
                    const CharacterColor clipboard = newLine[x].backgroundColor;
                    if (newLine[x].foregroundColor != cf) cf = newLine[x].foregroundColor;
                    const 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.

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

                        if (ch.foregroundColor != cf ||
                                ch.backgroundColor != clipboard ||
                                (ch.rendition & ~RE_EXTENDED_CHAR) != (cr & ~RE_EXTENDED_CHAR) ||
                                !dirtyMask[x + len] ||
                                ch.isLineChar() != lineDraw ||
                                nextIsDoubleWidth != doubleWidth)
                            break;
                    }

                    const 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 (_hasTextBlinker && !_blinkTextTimer->isActive()) _blinkTextTimer->start(TEXT_BLINK_DELAY);
    if (!_hasTextBlinker && _blinkTextTimer->isActive()) {
        _blinkTextTimer->stop();
        _textBlinking = false;
    }
    delete[] dirtyMask;

}

void TerminalDisplay::showResizeNotification()
{
    static bool resizeForTheFirstTime = true;
    if (resizeForTheFirstTime) {
        // Do not display size hint when resizing for the first time.
        // That first resizing mostly happens on startup
        resizeForTheFirstTime = false;
        return;
    }

    if (_showTerminalSizeHint && isVisible()) {
        if (!_resizeWidget) {
            _resizeWidget = new QLabel(i18n("Size: XXX x XXX"), this);
            _resizeWidget->setMinimumWidth(_resizeWidget->fontMetrics().width(i18n("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 = i18n("Size: %1 x %2", _columns, _lines);
        _resizeWidget->setText(sizeStr);
        _resizeWidget->move((width() - _resizeWidget->width()) / 2,
                            (height() - _resizeWidget->height()) / 2 + 20);
        _resizeWidget->show();
        _resizeTimer->start(1000);
    }
}

void TerminalDisplay::setBlinkingCursorEnabled(bool blink)
{
    _allowBlinkingCursor = 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 && !_blinkTextTimer->isActive())
        _blinkTextTimer->start(TEXT_BLINK_DELAY);

    if (!blink && _blinkTextTimer->isActive()) {
        _blinkTextTimer->stop();
        _textBlinking = 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 (_textBlinking)
        blinkTextEvent();

    _blinkTextTimer->stop();
}
void TerminalDisplay::focusInEvent(QFocusEvent*)
{
    if (_allowBlinkingCursor)
        _blinkCursorTimer->start();

    updateCursor();

    if (_hasTextBlinker)
        _blinkTextTimer->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);
}

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;
    const int scrollBarWidth = (_scrollbarLocation == Enum::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();
    foreach ( Filter::HotSpot* spot, spots ) {

        QRegion region;
        if (_underlineLinks && 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 (_image[loc(endColumn, line)].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 (_underlineLinks && 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)
                const int baseline = r.bottom() - metrics.descent();
                // find the position of the underline below that
                const 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 color for this
                painter.fillRect(r, QBrush(QColor(255, 0, 0, 120)));
            }
        }
    }
}
void TerminalDisplay::drawContents(QPainter& paint, const QRect& rect)
{
    const QPoint tL  = contentsRect().topLeft();
    const int    tLx = tL.x();
    const int    tLy = tL.y();

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

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

            // reset our buffer to the number of columns
            int bufferSize = numberOfColumns;
            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;
                const ushort* chars = ExtendedCharTable::instance.lookupExtendedChar(_image[loc(x, y)].character, extendedCharLength);
                if (chars) {
                    Q_ASSERT(extendedCharLength > 1);
                    bufferSize += extendedCharLength - 1;
                    unistr.resize(bufferSize);
                    disstrU = unistr.data();
                    for (int index = 0 ; index < extendedCharLength ; index++) {
                        Q_ASSERT(p < bufferSize);
                        disstrU[p++] = chars[index];
                    }
                }
            } else {
                // single character
                const quint16 c = _image[loc(x, y)].character;
                if (c) {
                    Q_ASSERT(p < bufferSize);
                    disstrU[p++] = c; //fontMap(c);
                }
            }

            const bool lineDraw = _image[loc(x, y)].isLineChar();
            const bool doubleWidth = (_image[ qMin(loc(x, y) + 1, _imageSize) ].character == 0);
            const CharacterColor currentForeground = _image[loc(x, y)].foregroundColor;
            const CharacterColor currentBackground = _image[loc(x, y)].backgroundColor;
            const 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 & ~RE_EXTENDED_CHAR) == (currentRendition & ~RE_EXTENDED_CHAR) &&
                    (_image[ qMin(loc(x + len, y) + 1, _imageSize) ].character == 0) == doubleWidth &&
                    _image[loc(x + len, y)].isLineChar() == lineDraw) {
                const quint16 c = _image[loc(x + len, y)].character;
                if (_image[loc(x + len, y)].rendition & RE_EXTENDED_CHAR) {
                    // sequence of characters
                    ushort extendedCharLength = 0;
                    const ushort* chars = ExtendedCharTable::instance.lookupExtendedChar(c, extendedCharLength);
                    if (chars) {
                        Q_ASSERT(extendedCharLength > 1);
                        bufferSize += extendedCharLength - 1;
                        unistr.resize(bufferSize);
                        disstrU = unistr.data();
                        for (int index = 0 ; index < extendedCharLength ; index++) {
                            Q_ASSERT(p < bufferSize);
                            disstrU[p++] = chars[index];
                        }
                    }
                } else {
                    // single character
                    if (c) {
                        Q_ASSERT(p < bufferSize);
                        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

            const 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::blinkTextEvent()
{
    if (!_allowBlinkingText)
        return;

    _textBlinking = !_textBlinking;

    // 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();
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                          Geometry & 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* oldImage = _image;
    const int oldLines = _lines;
    const int oldColumns = _columns;

    makeImage();

    if (oldImage) {
        // copy the old image to reduce flicker
        int lines = qMin(oldLines, _lines);
        int columns = qMin(oldColumns, _columns);
        for (int line = 0; line < lines; line++) {
            memcpy((void*)&_image[_columns * line],
                   (void*)&oldImage[oldColumns * line],
                   columns * sizeof(Character));
        }
        delete[] oldImage;
    }

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

    _resizing = (oldLines != _lines) || (oldColumns != _columns);

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

    _resizing = false;
}

void TerminalDisplay::makeImage()
{
    _wallpaper->load();

    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();
}

void TerminalDisplay::clearImage()
{
    for (int i = 0; i <= _imageSize; ++i)
        _image[i] = Screen::defaultChar;
}

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

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

//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::setScrollBarPosition(Enum::ScrollBarPositionEnum position)
{
    if (_scrollbarLocation == position)
        return;

    if (position == Enum::ScrollBarHidden)
        _scrollBar->hide();
    else
        _scrollBar->show();

    _topMargin = _leftMargin = 1;
    _scrollbarLocation = position;

    propagateSize();
    update();
}

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)));
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                                  Mouse                                    */
/*                                                                           */
/* ------------------------------------------------------------------------- */
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) {
        // request the software keyboard, if any
        if (qApp->autoSipEnabled()) {
            QStyle::RequestSoftwareInputPanel behavior = QStyle::RequestSoftwareInputPanel(
                        style()->styleHint(QStyle::SH_RequestSoftwareInputPanel));
            if (hasFocus() || behavior == QStyle::RSIP_OnMouseClick) {
                QEvent event(QEvent::RequestSoftwareInputPanel);
                QApplication::sendEvent(this, &event);
            }
        }

        _lineSelectionMode = false;
        _wordSelectionMode = false;

        bool selected = false;
        // The user clicked inside selected text
        selected =  _screenWindow->isSelected(pos.x(), pos.y());

        // Drag only when the Control key is hold
        if ((!_ctrlDrag || ev->modifiers() & Qt::ControlModifier) && selected) {
            _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();

                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 || (ev->modifiers() & Qt::ShiftModifier))
            doPaste(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;
    getCharacterPosition(ev->pos(), charLine, charColumn);

    const int scrollBarWidth = (_scrollbarLocation == Enum::ScrollBarLeft) ? _scrollBar->width() : 0;

    // handle filters
    // change link hot-spot appearance on mouse-over
    Filter::HotSpot* spot = _filterChain->hotSpotAt(charLine, charColumn);
    if (_underlineLinks && 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;
        }

        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

        const int distance = 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

            _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)
{
    if (!_screenWindow)
        return;

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

    QPoint pos = position;

    // Adjust position within text area bounds.
    const 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 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;

        const bool left_not_right = (here.y() < _iPntSelCorr.y() ||
                               (here.y() == _iPntSelCorr.y() && here.x() < _iPntSelCorr.x()));
        const 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]);
            while (((left.x() > 0) || (left.y() > 0 && (_lineProperties[left.y() - 1] & LINE_WRAPPED)))
                    && charClass(_image[i - 1]) == 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]);
            while (((right.x() < _usedColumns - 1) || (right.y() < _usedLines - 1 && (_lineProperties[right.y()] & LINE_WRAPPED)))
                    && charClass(_image[i + 1]) == 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
        const 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;
        }

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

        ohere.rx()++;
    }

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

        const bool left_not_right = (here.y() < _iPntSelCorr.y() ||
                               (here.y() == _iPntSelCorr.y() && here.x() < _iPntSelCorr.x()));
        const 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)
        const 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]);
                /* 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) {
        if (_dragInfo.state == diPending) {
            // We had a drag event pending but never confirmed.  Kill selection
            _screenWindow->clearSelection();
        } else {
            if (_actSel > 1) {
                setXSelection(_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...
    const QChar selClass = charClass(_image[i]);
    {
        // 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]) == 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]) == 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 (((_image[i].rendition & RE_EXTENDED_CHAR) == 0) &&
                (QChar(_image[i].character) == '@') &&
                ((endSel.x() - bgnSel.x()) > 0)) {
            endSel.setX(x - 1);
        }

        _actSel = 2; // within selection

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

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

    _possibleTripleClick = true;

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

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

    // ctrl+<wheel> for zomming, like in konqueror and firefox
    if (ev->modifiers() & Qt::ControlModifier) {
        if (ev->delta() > 0)
            // wheel-up
            _sessionController->increaseTextSize();
        else
            // wheel-down
            _sessionController->decreaseTextSize();

        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

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

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

        while (((x > 0) ||
                (_iPntSel.y() > 0 && (_lineProperties[_iPntSel.y() - 1] & LINE_WRAPPED))
               )
                && charClass(_image[i - 1]) == 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 == Enum::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());

    setXSelection(_screenWindow->selectedText(_preserveLineBreaks));

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

bool TerminalDisplay::focusNextPrevChild(bool next)
{
    // for 'Tab', always disable focus switching among widgets
    // for 'Shift+Tab', leave the decision to higher level
    if (next)
        return false;
    else
        return QWidget::focusNextPrevChild(next);
}

QChar TerminalDisplay::charClass(const Character& ch) const
{
    if (ch.rendition & RE_EXTENDED_CHAR) {
        ushort extendedCharLength = 0;
        const ushort* chars = ExtendedCharTable::instance.lookupExtendedChar(ch.character, extendedCharLength);
        if (chars && extendedCharLength > 0) {
            const QString s = QString::fromUtf16(chars, extendedCharLength);
            if (_wordCharacters.contains(s, Qt::CaseInsensitive))
                return 'a';
            bool allLetterOrNumber = true;
            for (int i = 0; allLetterOrNumber && i < s.size(); ++i)
                allLetterOrNumber = s.at(i).isLetterOrNumber();
            return allLetterOrNumber ? 'a' : s.at(0);
        }
        return 0;
    } else {
        const QChar qch(ch.character);
        if (qch.isSpace()) return ' ';

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

        return qch;
    }
}

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

// FIXME: the actual value of _mouseMarks is the opposite of its semantic.
// When using programs not interested with mouse(shell, less), it is true.
// When using programs interested with mouse(vim,mc), it is false.
void TerminalDisplay::setUsesMouse(bool on)
{
    _mouseMarks = on;
    setCursor(_mouseMarks ? Qt::IBeamCursor : Qt::ArrowCursor);
}
bool TerminalDisplay::usesMouse() const
{
    return _mouseMarks;
}

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

void TerminalDisplay::doPaste(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::setXSelection(const QString& text)
{
    QApplication::clipboard()->setText(text, QClipboard::Selection);
}

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

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

void TerminalDisplay::pasteFromClipboard()
{
    doPaste(false, false);
}

void TerminalDisplay::pasteFromXSelection()
{
    doPaste(true, false);
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                                Input Method                               */
/*                                                                           */
/* ------------------------------------------------------------------------- */

void TerminalDisplay::inputMethodEvent(QInputMethodEvent* event)
{
    if (!event->commitString().isEmpty()) {
        QKeyEvent keyEvent(QEvent::KeyPress, 0, 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 = cursorPosition();
    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();
}

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;
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                                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::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(i18n("<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);
}

void TerminalDisplay::scrollScreenWindow(enum ScreenWindow::RelativeScrollMode mode, int amount)
{
    _screenWindow->scrollBy(mode, amount);
    _screenWindow->setTrackOutput(_screenWindow->atEndOfOutput());
    updateLineProperties();
    updateImage();
}

void TerminalDisplay::keyPressEvent(QKeyEvent* event)
{
    _screenWindow->screen()->setCurrentTerminalDisplay(this);

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

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

    emit keyPressedSignal(event);

    event->accept();
}

bool TerminalDisplay::handleShortcutOverrideEvent(QKeyEvent* keyEvent)
{
    const 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:
    case Qt::Key_Slash:
    case Qt::Key_Period:
    case Qt::Key_Space:
        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::contextMenuEvent(QContextMenuEvent* )
{
// FIXME: On Mac OSX opening some dialogs cause the context menu to
//  get displayed.  Example: Scrollback dialog via context menu.
#if !defined(Q_OS_MAC)
    emit configureRequest(mapFromGlobal(QCursor::pos()));
#endif
}

/* --------------------------------------------------------------------- */
/*                                                                       */
/*                                  Bell                                 */
/*                                                                       */
/* --------------------------------------------------------------------- */

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

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

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

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

        if (_bellMode == Enum::SystemBeepBell) {
            KNotification::beep();
        } else if (_bellMode == Enum::NotifyBell) {
            KNotification::event(hasFocus() ? "BellVisible" : "BellInvisible",
                                 message, QPixmap(), this);
        } else if (_bellMode == Enum::VisualBell) {
            visualBell();
        }
    }
}

void TerminalDisplay::visualBell()
{
    swapColorTable();
    QTimer::singleShot(200, this, SLOT(swapColorTable()));
}

void TerminalDisplay::swapColorTable()
{
    // swap the default foreground & backround color
    ColorEntry color = _colorTable[DEFAULT_BACK_COLOR];
    _colorTable[DEFAULT_BACK_COLOR] = _colorTable[DEFAULT_FORE_COLOR];
    _colorTable[DEFAULT_FORE_COLOR] = color;

    update();
}

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

void TerminalDisplay::dragEnterEvent(QDragEnterEvent* event)
{
    // text/plain alone is enough for KDE-apps
    // text/uri-list is for supporting some non-KDE apps, such as thunar
    //   and pcmanfm
    // That also applies in dropEvent()
    if (event->mimeData()->hasFormat("text/plain") ||
            event->mimeData()->hasFormat("text/uri-list")) {
        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;

            // Each filename(including the last) should be followed by one space.
            dropText += ' ';
        }

        // If our target is local we will open a popup - otherwise the fallback kicks
        // in and the URLs will simply be pasted as text.
        if (_sessionController && _sessionController->url().isLocalFile()) {
            // A standard popup with Copy, Move and Link as options -
            // plus an additional Paste option.

            QAction* pasteAction = new QAction(i18n("&Paste Location"), this);
            pasteAction->setData(dropText);
            connect(pasteAction, SIGNAL(triggered()), this, SLOT(dropMenuPasteActionTriggered()));

            QList<QAction*> additionalActions;
            additionalActions.append(pasteAction);

            if ( urls.count() == 1 ) {

                const KUrl url = KIO::NetAccess::mostLocalUrl(urls[0] , 0);

                if ( url.isLocalFile() ) {
                    const QFileInfo fileInfo(url.path());

                    if ( fileInfo.isDir() ) {
                        QAction* cdAction = new QAction(i18n("Change &Directory To"), this);
                        dropText = QLatin1String(" cd ") + dropText + QChar('\n');
                        cdAction->setData(dropText);
                        connect(cdAction, SIGNAL(triggered()), this, SLOT(dropMenuCdActionTriggered()));
                        additionalActions.append(cdAction);
                    }
                }
            }

            KUrl target(_sessionController->currentDir());

            KonqOperations::doDrop(KFileItem(), target, event, this, additionalActions);

            return;
        }

    } else {
        dropText = event->mimeData()->text();
    }

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

void TerminalDisplay::dropMenuPasteActionTriggered()
{
    if (sender()) {
        const QAction* action = qobject_cast<const QAction*>(sender());
        if (action) {
            emit sendStringToEmu(action->data().toString().toLocal8Bit());
        }
    }
}

void TerminalDisplay::dropMenuCdActionTriggered()
{
    if (sender()) {
        const QAction* action = qobject_cast<const QAction*>(sender());
        if (action) {
            emit sendStringToEmu(action->data().toString().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->exec(Qt::CopyAction);
    // Don't delete the QTextDrag object.  Qt will delete it when it's done with it.
}

void TerminalDisplay::setSessionController(SessionController* controller)
{
    _sessionController = controller;
}

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;
}

#include "TerminalDisplay.moc"