basetexteditor.cpp

/***************************************************************************
**
** This file is part of Qt Creator
**
** Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).
**
** Contact:  Qt Software Information (qt-info@nokia.com)
**
**
** Non-Open Source Usage
**
** Licensees may use this file in accordance with the Qt Beta Version
** License Agreement, Agreement version 2.2 provided with the Software or,
** alternatively, in accordance with the terms contained in a written
** agreement between you and Nokia.
**
** GNU General Public License Usage
**
** Alternatively, this file may be used under the terms of the GNU General
** Public License versions 2.0 or 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the packaging
** of this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
**
** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
** http://www.gnu.org/copyleft/gpl.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt GPL Exception
** version 1.2, included in the file GPL_EXCEPTION.txt in this package.
**
***************************************************************************/

#include "texteditor_global.h"

#include "texteditorconstants.h"
#ifndef TEXTEDITOR_STANDALONE
#include "texteditorplugin.h"
#include "completionsupport.h"
#endif
#include "basetextdocument.h"
#include "basetexteditor_p.h"
#include "codecselector.h"

#ifndef TEXTEDITOR_STANDALONE
#include <coreplugin/icore.h>
#include <coreplugin/manhattanstyle.h>
#include <coreplugin/coreconstants.h>
#include <coreplugin/editormanager/editormanager.h>
#include <find/basetextfind.h>
#include <texteditor/fontsettings.h>
#include <utils/reloadpromptutils.h>
#include <aggregation/aggregate.h>
#endif
#include <utils/linecolumnlabel.h>

#include <QtCore/QCoreApplication>
#include <QtCore/QTextCodec>
#include <QtCore/QFile>
#include <QtCore/QDebug>
#include <QtCore/QTimer>
#include <QtGui/QAbstractTextDocumentLayout>
#include <QtGui/QApplication>
#include <QtGui/QKeyEvent>
#include <QtGui/QLabel>
#include <QtGui/QLayout>
#include <QtGui/QPainter>
#include <QtGui/QPrinter>
#include <QtGui/QPrintDialog>
#include <QtGui/QPainter>
#include <QtGui/QScrollBar>
#include <QtGui/QShortcut>
#include <QtGui/QScrollBar>
#include <QtGui/QStyle>
#include <QtGui/QSyntaxHighlighter>
#include <QtGui/QTextCursor>
#include <QtGui/QTextBlock>
#include <QtGui/QTextLayout>
#include <QtGui/QToolBar>
#include <QtGui/QToolTip>
#include <QtGui/QInputDialog>

using namespace TextEditor;
using namespace TextEditor::Internal;


namespace TextEditor {
    namespace Internal {

class TextEditExtraArea : public QWidget {
    BaseTextEditor *textEdit;
public:
    TextEditExtraArea(BaseTextEditor *edit):QWidget(edit) {
        textEdit = edit;
        setAutoFillBackground(true);
    }
public:

    QSize sizeHint() const {
        return QSize(textEdit->extraAreaWidth(), 0);
    }
protected:
    void paintEvent(QPaintEvent *event){
        textEdit->extraAreaPaintEvent(event);
    }
    void mousePressEvent(QMouseEvent *event){
        textEdit->extraAreaMouseEvent(event);
    }
    void mouseMoveEvent(QMouseEvent *event){
        textEdit->extraAreaMouseEvent(event);
    }
    void mouseReleaseEvent(QMouseEvent *event){
        textEdit->extraAreaMouseEvent(event);
    }
    void leaveEvent(QEvent *event){
        textEdit->extraAreaLeaveEvent(event);
    }

    void wheelEvent(QWheelEvent *event) {
        QCoreApplication::sendEvent(textEdit->viewport(), event);
    }
};

    }
}

ITextEditor *BaseTextEditor::openEditorAt(const QString &fileName,
                                             int line,
                                             int column)
{
    Core::EditorManager *editorManager =
            ExtensionSystem::PluginManager::instance()->getObject<Core::ICore>()->editorManager();
    editorManager->addCurrentPositionToNavigationHistory(true);
    Core::IEditor *editor = editorManager->openEditor(fileName, QString(), true);
    TextEditor::ITextEditor *texteditor = qobject_cast<TextEditor::ITextEditor *>(editor);
    if (texteditor) {
        texteditor->gotoLine(line, column);
        editorManager->addCurrentPositionToNavigationHistory();
        return texteditor;
    }
    return 0;
}

BaseTextEditor::BaseTextEditor(QWidget *parent)
    : QPlainTextEdit(parent)
{
    d = new BaseTextEditorPrivate();
    d->q = this;
    d->m_extraArea = new TextEditExtraArea(this);
    d->m_extraArea->setMouseTracking(true);
    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);

    d->setupDocumentSignals(d->m_document);
    d->setupDocumentSignals(d->m_document);

    d->m_lastScrollPos = -1;
    setCursorWidth(2);


    // from RESEARCH

    setLayoutDirection(Qt::LeftToRight);
    viewport()->setMouseTracking(true);
    d->extraAreaSelectionAnchorBlockNumber
        = d->extraAreaToggleMarkBlockNumber
        = d->extraAreaHighlightCollapseBlockNumber
        = d->extraAreaHighlightFadingBlockNumber
        = -1;
    d->extraAreaCollapseAlpha = 255;

    d->visibleCollapsedBlockNumber = d->suggestedVisibleCollapsedBlockNumber = -1;

    connect(this, SIGNAL(blockCountChanged(int)), this, SLOT(slotUpdateExtraAreaWidth()));
    connect(this, SIGNAL(modificationChanged(bool)), this, SLOT(slotModificationChanged(bool)));
    connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(slotCursorPositionChanged()));
    connect(this, SIGNAL(updateRequest(QRect, int)), this, SLOT(slotUpdateRequest(QRect, int)));
    connect(this, SIGNAL(selectionChanged()), this, SLOT(slotSelectionChanged()));

//     (void) new QShortcut(tr("CTRL+L"), this, SLOT(centerCursor()), 0, Qt::WidgetShortcut);
//     (void) new QShortcut(tr("F9"), this, SLOT(slotToggleMark()), 0, Qt::WidgetShortcut);
//     (void) new QShortcut(tr("F11"), this, SLOT(slotToggleBlockVisible()));


    // parentheses matcher
    d->m_parenthesesMatchingEnabled = false;
    d->m_formatRange = true;
    d->m_matchFormat.setForeground(Qt::red);
    d->m_rangeFormat.setBackground(QColor(0xb4, 0xee, 0xb4));
    d->m_mismatchFormat.setBackground(Qt::magenta);
    d->m_parenthesesMatchingTimer = new QTimer(this);
    d->m_parenthesesMatchingTimer->setSingleShot(true);
    connect(d->m_parenthesesMatchingTimer, SIGNAL(timeout()), this, SLOT(_q_matchParentheses()));


    d->m_searchResultFormat.setBackground(QColor(0xffef0b));

    slotUpdateExtraAreaWidth();
    slotCursorPositionChanged();
    setFrameStyle(QFrame::NoFrame);


    d->extraAreaTimeLine = new QTimeLine(150, this);
    d->extraAreaTimeLine->setFrameRange(0, 255);
    connect(d->extraAreaTimeLine, SIGNAL(frameChanged(int)), this,
            SLOT(setCollapseIndicatorAlpha(int)));


    connect(Core::EditorManager::instance(), SIGNAL(currentEditorChanged(Core::IEditor*)),
            this, SLOT(currentEditorChanged(Core::IEditor*)));
}

BaseTextEditor::~BaseTextEditor()
{
    delete d;
    d = 0;
}

QString BaseTextEditor::mimeType() const
{
    return d->m_document->mimeType();
}

void BaseTextEditor::setMimeType(const QString &mt)
{
    d->m_document->setMimeType(mt);
}

void BaseTextEditor::print(QPrinter *printer)
{
    const bool oldFullPage =  printer->fullPage();
    printer->setFullPage(true);
    QPrintDialog *dlg = new QPrintDialog(printer, this);
    dlg->setWindowTitle(tr("Print Document"));
    if (dlg->exec() == QDialog::Accepted) {
        d->print(printer);
    }
    printer->setFullPage(oldFullPage);
    delete dlg;
}

static void printPage(int index, QPainter *painter, const QTextDocument *doc,
                      const QRectF &body, const QRectF &titleBox,
                      const QString &title)
{
    painter->save();

    painter->translate(body.left(), body.top() - (index - 1) * body.height());
    QRectF view(0, (index - 1) * body.height(), body.width(), body.height());

    QAbstractTextDocumentLayout *layout = doc->documentLayout();
    QAbstractTextDocumentLayout::PaintContext ctx;

    painter->setFont(QFont(doc->defaultFont()));
    QRectF box = titleBox.translated(0, view.top());
    int dpix = painter->device()->logicalDpiX();
    int dpiy = painter->device()->logicalDpiY();
    int mx = 5 * dpix / 72.0;
    int my = 2 * dpiy / 72.0;
    painter->fillRect(box.adjusted(-mx, -my, mx, my), QColor(210, 210, 210));
    if (!title.isEmpty())
        painter->drawText(box, Qt::AlignCenter, title);
    const QString pageString = QString::number(index);
    painter->drawText(box, Qt::AlignRight, pageString);

    painter->setClipRect(view);
    ctx.clip = view;
    // don't use the system palette text as default text color, on HP/UX
    // for example that's white, and white text on white paper doesn't
    // look that nice
    ctx.palette.setColor(QPalette::Text, Qt::black);

    layout->draw(painter, ctx);

    painter->restore();
}

void BaseTextEditorPrivate::print(QPrinter *printer)
{

    QTextDocument *doc = q->document();

    QString title = q->displayName();
    if (title.isEmpty())
        printer->setDocName(title);


    QPainter p(printer);

    // Check that there is a valid device to print to.
    if (!p.isActive())
        return;

    doc = doc->clone(doc);

    QTextOption opt = doc->defaultTextOption();
    opt.setWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
    doc->setDefaultTextOption(opt);

    (void)doc->documentLayout(); // make sure that there is a layout


    QColor background = q->palette().color(QPalette::Base);
    bool backgroundIsDark = background.value() < 128;

    for (QTextBlock srcBlock = q->document()->firstBlock(), dstBlock = doc->firstBlock();
         srcBlock.isValid() && dstBlock.isValid();
         srcBlock = srcBlock.next(), dstBlock = dstBlock.next()) {


        QList<QTextLayout::FormatRange> formatList = srcBlock.layout()->additionalFormats();
        if (backgroundIsDark) {
            // adjust syntax highlighting colors for better contrast
            for (int i = formatList.count() - 1; i >=0; --i) {
                QTextCharFormat &format = formatList[i].format;
                if (format.background().color() == background) {
                    QBrush brush = format.foreground();
                    QColor color = brush.color();
                    int h,s,v,a;
                    color.getHsv(&h, &s, &v, &a);
                    color.setHsv(h, s, qMin(128, v), a);
                    brush.setColor(color);
                    format.setForeground(brush);
                }
                format.setBackground(Qt::white);
            }
        }

        dstBlock.layout()->setAdditionalFormats(formatList);
    }

    QAbstractTextDocumentLayout *layout = doc->documentLayout();
    layout->setPaintDevice(p.device());

    int dpiy = p.device()->logicalDpiY();
    int margin = (int) ((2/2.54)*dpiy); // 2 cm margins

    QTextFrameFormat fmt = doc->rootFrame()->frameFormat();
    fmt.setMargin(margin);
    doc->rootFrame()->setFrameFormat(fmt);

    QRectF pageRect(printer->pageRect());
    QRectF body = QRectF(0, 0, pageRect.width(), pageRect.height());
    QFontMetrics fontMetrics(doc->defaultFont(), p.device());

    QRectF titleBox(margin,
                    body.top() + margin
                    - fontMetrics.height()
                    - 6 * dpiy / 72.0,
                    body.width() - 2*margin,
                    fontMetrics.height());
    doc->setPageSize(body.size());

    int docCopies;
    int pageCopies;
    if (printer->collateCopies() == true){
        docCopies = 1;
        pageCopies = printer->numCopies();
    } else {
        docCopies = printer->numCopies();
        pageCopies = 1;
    }

    int fromPage = printer->fromPage();
    int toPage = printer->toPage();
    bool ascending = true;

    if (fromPage == 0 && toPage == 0) {
        fromPage = 1;
        toPage = doc->pageCount();
    }
    // paranoia check
    fromPage = qMax(1, fromPage);
    toPage = qMin(doc->pageCount(), toPage);

    if (printer->pageOrder() == QPrinter::LastPageFirst) {
        int tmp = fromPage;
        fromPage = toPage;
        toPage = tmp;
        ascending = false;
    }

    for (int i = 0; i < docCopies; ++i) {

        int page = fromPage;
        while (true) {
            for (int j = 0; j < pageCopies; ++j) {
                if (printer->printerState() == QPrinter::Aborted
                    || printer->printerState() == QPrinter::Error)
                    goto UserCanceled;
                printPage(page, &p, doc, body, titleBox, title);
                if (j < pageCopies - 1)
                    printer->newPage();
            }

            if (page == toPage)
                break;

            if (ascending)
                ++page;
            else
                --page;

            printer->newPage();
        }

        if ( i < docCopies - 1)
            printer->newPage();
    }

UserCanceled:
    delete doc;
}


bool DocumentMarker::addMark(TextEditor::ITextMark *mark, int line)
{
    Q_ASSERT(line >= 1);
    int blockNumber = line - 1;
    TextEditDocumentLayout *documentLayout = qobject_cast<TextEditDocumentLayout*>(document->documentLayout());
    Q_ASSERT(documentLayout);
    QTextBlock block = document->findBlockByNumber(blockNumber);

    if (block.isValid()) {
        TextBlockUserData *userData = TextEditDocumentLayout::userData(block);
        userData->addMark(mark);
        mark->updateLineNumber(blockNumber + 1);
        mark->updateBlock(block);
        documentLayout->hasMarks = true;
        documentLayout->requestUpdate();
        return true;
    }
    return false;
}


TextEditor::TextMarks DocumentMarker::marksAt(int line) const
{
    Q_ASSERT(line >= 1);
    int blockNumber = line - 1;
    QTextBlock block = document->findBlockByNumber(blockNumber);

    if (block.isValid()) {
        if (TextBlockUserData *userData = TextEditDocumentLayout::testUserData(block))
            return userData->marks();
    }
    return TextMarks();
}

void DocumentMarker::removeMark(TextEditor::ITextMark *mark)
{
    bool needUpdate = false;
    QTextBlock block = document->begin();
    while (block.isValid()) {
        if (TextBlockUserData *data = static_cast<TextBlockUserData *>(block.userData())) {
            needUpdate |= data->removeMark(mark);
        }
        block = block.next();
    }
    if (needUpdate)
        updateMark(0);
}


bool DocumentMarker::hasMark(TextEditor::ITextMark *mark) const
{
    QTextBlock block = document->begin();
    while (block.isValid()) {
        if (TextBlockUserData *data = static_cast<TextBlockUserData *>(block.userData())) {
            if (data->hasMark(mark))
                return true;
        }
        block = block.next();
    }
    return false;
}

ITextMarkable *BaseTextEditor::markableInterface() const
{
    return baseTextDocument()->documentMarker();
}

ITextEditable *BaseTextEditor::editableInterface() const
{
    if (!d->m_editable) {
        d->m_editable = const_cast<BaseTextEditor*>(this)->createEditableInterface();
        connect(this, SIGNAL(textChanged()),
                d->m_editable, SIGNAL(contentsChanged()));
        connect(this, SIGNAL(changed()),
                d->m_editable, SIGNAL(changed()));
        connect(this,
                SIGNAL(markRequested(TextEditor::ITextEditor *, int)),
                d->m_editable,
                SIGNAL(markRequested(TextEditor::ITextEditor *, int)));
    }
    return d->m_editable;
}


void BaseTextEditor::currentEditorChanged(Core::IEditor *editor)
{
    if (editor == d->m_editable) {
        if (d->m_document->hasDecodingError()) {
            Core::EditorManager::instance()->showEditorInfoBar(QLatin1String(Constants::SELECT_ENCODING),
                tr("<b>Error:</b> Could not decode \"%1\" with \"%2\"-encoding. Editing not possible.").arg(displayName()).arg(QString::fromLatin1(d->m_document->codec()->name())),
                tr("Select Encoding"),
                this, SLOT(selectEncoding()));
        }
    }
}

void BaseTextEditor::selectEncoding()
{
    BaseTextDocument *doc = d->m_document;
    CodecSelector codecSelector(this, doc);

    switch (codecSelector.exec()) {
    case CodecSelector::Reload:
        doc->reload(codecSelector.selectedCodec());
        setReadOnly(d->m_document->hasDecodingError());
        if (doc->hasDecodingError())
            currentEditorChanged(Core::EditorManager::instance()->currentEditor());
        else
            Core::EditorManager::instance()->hideEditorInfoBar(QLatin1String(Constants::SELECT_ENCODING));
        break;
    case CodecSelector::Save:
        doc->setCodec(codecSelector.selectedCodec());
        Core::EditorManager::instance()->saveEditor(editableInterface());
        break;
    case CodecSelector::Cancel:
        break;
    }
}

void DocumentMarker::updateMark(ITextMark *mark)
{
    TextEditDocumentLayout *documentLayout = qobject_cast<TextEditDocumentLayout*>(document->documentLayout());
    Q_ASSERT(documentLayout);
    Q_UNUSED(mark);
    documentLayout->requestUpdate();
}


void BaseTextEditor::triggerCompletions()
{
    emit requestAutoCompletion(editableInterface(), true);
}

bool BaseTextEditor::createNew(const QString &contents)
{
    setPlainText(contents);
    document()->setModified(false);
    return true;
}

bool BaseTextEditor::open(const QString &fileName)
{
    if (d->m_document->open(fileName)) {
        moveCursor(QTextCursor::Start);
        setReadOnly(d->m_document->hasDecodingError());
        return true;
    }
    return false;
}

Core::IFile * BaseTextEditor::file()
{
    return d->m_document;
}

void BaseTextEditor::editorContentsChange(int position, int charsRemoved, int charsAdded)
{
    d->m_contentsChanged = true;

    // Keep the line numbers and the block information for the text marks updated
    if (charsRemoved != 0) {
        d->updateMarksLineNumber();
        d->updateMarksBlock(document()->findBlock(position));
    } else {
        const QTextBlock posBlock = document()->findBlock(position);
        const QTextBlock nextBlock = document()->findBlock(position + charsAdded);
        if (posBlock != nextBlock) {
            d->updateMarksLineNumber();
            d->updateMarksBlock(posBlock);
            d->updateMarksBlock(nextBlock);
        } else {
            d->updateMarksBlock(posBlock);
        }
    }
}


void BaseTextEditor::slotSelectionChanged()
{
    bool changed = (d->m_inBlockSelectionMode != d->m_lastEventWasBlockSelectionEvent);
    d->m_inBlockSelectionMode = d->m_lastEventWasBlockSelectionEvent;
    if (changed || d->m_inBlockSelectionMode)
        viewport()->update();
    if (!d->m_inBlockSelectionMode)
        d->m_blockSelectionExtraX = 0;
    if (!d->m_selectBlockAnchor.isNull() && !textCursor().hasSelection())
        d->m_selectBlockAnchor = QTextCursor();
}

void BaseTextEditor::gotoBlockStart()
{
    QTextCursor cursor = textCursor();
    if (TextBlockUserData::findPreviousOpenParenthesis(&cursor, false))
        setTextCursor(cursor);
}

void BaseTextEditor::gotoBlockEnd()
{
    QTextCursor cursor = textCursor();
    if (TextBlockUserData::findNextClosingParenthesis(&cursor, false))
        setTextCursor(cursor);
}

void BaseTextEditor::gotoBlockStartWithSelection()
{
    QTextCursor cursor = textCursor();
    if (TextBlockUserData::findPreviousOpenParenthesis(&cursor, true))
        setTextCursor(cursor);
}

void BaseTextEditor::gotoBlockEndWithSelection()
{
    QTextCursor cursor = textCursor();
    if (TextBlockUserData::findNextClosingParenthesis(&cursor, true))
        setTextCursor(cursor);
}

void BaseTextEditor::selectBlockUp()
{
    QTextCursor cursor = textCursor();
    if (!cursor.hasSelection())
        d->m_selectBlockAnchor = cursor;
    else
        cursor.setPosition(cursor.selectionStart());


    if (!TextBlockUserData::findPreviousOpenParenthesis(&cursor, false))
        return;
    if (!TextBlockUserData::findNextClosingParenthesis(&cursor, true))
        return;
    setTextCursor(cursor);
}

void BaseTextEditor::selectBlockDown()
{
    QTextCursor tc = textCursor();
    QTextCursor cursor = d->m_selectBlockAnchor;

    if (!tc.hasSelection() || cursor.isNull())
        return;
    tc.setPosition(tc.selectionStart());

    forever {
        QTextCursor ahead = cursor;
        if (!TextBlockUserData::findPreviousOpenParenthesis(&ahead, false))
            break;
        if (ahead.position() <= tc.position())
            break;
        cursor = ahead;
    }
    if ( cursor != d->m_selectBlockAnchor)
        TextBlockUserData::findNextClosingParenthesis(&cursor, true);

    setTextCursor(cursor);
}



void BaseTextEditor::keyPressEvent(QKeyEvent *e)
{

    d->clearVisibleCollapsedBlock();

    QKeyEvent *original_e = e;
    d->m_lastEventWasBlockSelectionEvent = false;

    if (e->key() == Qt::Key_Escape) {
        e->accept();
        QTextCursor cursor = textCursor();
        cursor.clearSelection();
        setTextCursor(cursor);
        return;
    }

    d->m_contentsChanged = false;

    bool ro = isReadOnly();

    if (d->m_inBlockSelectionMode) {
        if (e == QKeySequence::Cut) {
            if (!ro) {
                cut();
                e->accept();
                return;
            }
        } else if (e == QKeySequence::Delete) {
            if (!ro) {
                d->removeBlockSelection();
                e->accept();
                return;
            }
        } else if (e == QKeySequence::Paste) {
            if (!ro) {
                d->removeBlockSelection();
                // continue
            }
        }
    }


    if (!ro
        && (e == QKeySequence::InsertParagraphSeparator
            || (!d->m_lineSeparatorsAllowed && e == QKeySequence::InsertLineSeparator))
        ) {

        QTextCursor cursor = textCursor();
        if (d->m_inBlockSelectionMode)
            cursor.clearSelection();
        cursor.insertBlock();
        if (d->m_document->tabSettings().m_autoIndent) {
            indent(document(), cursor, QChar::Null);
        }
        e->accept();
        setTextCursor(cursor);
        return;
    } else switch (e->key()) {


#if 0
    case Qt::Key_sterling: {

        static bool toggle = false;
        if ((toggle = !toggle)) {
            QList<BaseTextEditor::BlockRange> rangeList;
            rangeList += BaseTextEditor::BlockRange(4, 12);
            rangeList += BaseTextEditor::BlockRange(15, 19);
            setIfdefedOutBlocks(rangeList);
        } else {
            setIfdefedOutBlocks(QList<BaseTextEditor::BlockRange>());
        }
        e->accept();
        return;

    } break;
#endif
    case Qt::Key_Tab:
    case Qt::Key_Backtab:
        if (ro) break;
        indentOrUnindent(e->key() == Qt::Key_Tab);
        e->accept();
        return;
    case Qt::Key_Backspace:
        if (ro) break;
        if (d->m_document->tabSettings().m_smartBackspace
            && (e->modifiers() & (Qt::ControlModifier
                               | Qt::ShiftModifier
                               | Qt::AltModifier
                               | Qt::MetaModifier)) == Qt::NoModifier
            && !textCursor().hasSelection()) {
            handleBackspaceKey();
            e->accept();
            return;
        }
        break;
    case Qt::Key_Home:
        if (!(e == QKeySequence::MoveToStartOfDocument) && !(e == QKeySequence::SelectStartOfDocument)) {
            if ((e->modifiers() & (Qt::AltModifier | Qt::ShiftModifier)) == (Qt::AltModifier | Qt::ShiftModifier))
                d->m_lastEventWasBlockSelectionEvent = true;
            handleHomeKey(e->modifiers() & Qt::ShiftModifier);
            e->accept();
            return;
        }
        break;
    case Qt::Key_Up:
    case Qt::Key_Down:
        if (e->modifiers() & Qt::ControlModifier) {
            verticalScrollBar()->triggerAction(
                    e->key() == Qt::Key_Up ? QAbstractSlider::SliderSingleStepSub :
                                             QAbstractSlider::SliderSingleStepAdd);
            e->accept();
            return;
        }
        // fall through
    case Qt::Key_End:
    case Qt::Key_Right:
    case Qt::Key_Left:
#ifndef Q_OS_MAC
        if ((e->modifiers() & (Qt::AltModifier | Qt::ShiftModifier)) == (Qt::AltModifier | Qt::ShiftModifier)) {

            d->m_lastEventWasBlockSelectionEvent = true;

            if (d->m_inBlockSelectionMode) {
                if (e->key() == Qt::Key_Right && textCursor().atBlockEnd()) {
                    d->m_blockSelectionExtraX++;
                    viewport()->update();
                    e->accept();
                    return;
                } else if (e->key() == Qt::Key_Left && d->m_blockSelectionExtraX > 0) {
                    d->m_blockSelectionExtraX--;
                    e->accept();
                    viewport()->update();
                    return;
                }
            }

            e = new QKeyEvent(
                e->type(),
                e->key(),
                e->modifiers() & ~Qt::AltModifier,
                e->text(),
                e->isAutoRepeat(),
                e->count()
                );
        }
#endif
        break;
    case Qt::Key_PageUp:
    case Qt::Key_PageDown:
        if (e->modifiers() == Qt::ControlModifier) {
            verticalScrollBar()->triggerAction(
                    e->key() == Qt::Key_PageUp ? QAbstractSlider::SliderPageStepSub :
                                                 QAbstractSlider::SliderPageStepAdd);
            e->accept();
            return;
        }
        break;

    default:
        if (! ro && d->m_document->tabSettings().m_autoIndent
            && ! e->text().isEmpty() && isElectricCharacter(e->text().at(0))) {
            QTextCursor cursor = textCursor();
            const QString text = e->text();
            cursor.insertText(text);
            const QString leftText = cursor.block().text().left(cursor.position() - 1 - cursor.block().position());
            if (leftText.simplified().isEmpty()) {
                const QChar typedChar = e->text().at(0);
                indent(document(), cursor, typedChar);
            }
#if 0
            TextEditDocumentLayout *documentLayout = qobject_cast<TextEditDocumentLayout*>(document()->documentLayout());
            Q_ASSERT(documentLayout);
            documentLayout->requestUpdate(); // a bit drastic
            e->accept();
#endif
            setTextCursor(cursor);
            return;
        }
        break;
    }

    if (d->m_inBlockSelectionMode) {
        QString text = e->text();
        if (!text.isEmpty() && (text.at(0).isPrint() || text.at(0) == QLatin1Char('\t'))) {
            d->removeBlockSelection(text);
            goto skip_event;
        }
    }

    QPlainTextEdit::keyPressEvent(e);

skip_event:
    if (!ro && e->key() == Qt::Key_Delete && d->m_parenthesesMatchingEnabled)
        slotCursorPositionChanged(); // parentheses matching

    if (!ro && d->m_contentsChanged && !e->text().isEmpty() && e->text().at(0).isPrint())
        emit requestAutoCompletion(editableInterface(), false);

    if (e != original_e)
        delete e;
}

void BaseTextEditor::setTextCursor(const QTextCursor &cursor)
{
    // workaround for QTextControl bug
    bool selectionChange = cursor.hasSelection() || textCursor().hasSelection();
    QPlainTextEdit::setTextCursor(cursor);
    if (selectionChange)
        slotSelectionChanged();
}

void BaseTextEditor::gotoLine(int line, int column)
{
    const int blockNumber = line - 1;
    const QTextBlock &block = document()->findBlockByNumber(blockNumber);
    if (block.isValid()) {
        QTextCursor cursor(block);
        if (column > 0) {
            cursor.movePosition(QTextCursor::Right, QTextCursor::MoveAnchor, column);
        } else {
            int pos = cursor.position();
            while (characterAt(pos).category() == QChar::Separator_Space) {
                ++pos;
            }
            cursor.setPosition(pos);
        }
        setTextCursor(cursor);
        centerCursor();
    }
}

int BaseTextEditor::position(ITextEditor::PositionOperation posOp, int at) const
{
    QTextCursor tc = textCursor();

    if (at != -1)
        tc.setPosition(at);

    if (posOp == ITextEditor::Current)
        return tc.position();

    switch (posOp) {
    case ITextEditor::EndOfLine:
        tc.movePosition(QTextCursor::EndOfLine);
        return tc.position();
    case ITextEditor::StartOfLine:
        tc.movePosition(QTextCursor::StartOfLine);
        return tc.position();
    case ITextEditor::Anchor:
        if (tc.hasSelection())
            return tc.anchor();
        break;
    case ITextEditor::EndOfDoc:
        tc.movePosition(QTextCursor::End);
        return tc.position();
    default:
        break;
    }

    return -1;
}

void BaseTextEditor::convertPosition(int pos, int *line, int *column) const
{
    QTextBlock block = document()->findBlock(pos);
    if (!block.isValid()) {
        (*line) = -1;
        (*column) = -1;
    } else {
        (*line) = block.blockNumber() + 1;
        (*column) = pos - block.position();
    }
}

QChar BaseTextEditor::characterAt(int pos) const
{
    return document()->characterAt(pos);
}

bool BaseTextEditor::event(QEvent *e)
{
    switch (e->type()) {
    case QEvent::ShortcutOverride:
        e->ignore(); // we are a really nice citizen
        return true;
    default:
        break;
    }

    return QPlainTextEdit::event(e);
}

void BaseTextEditor::duplicateFrom(BaseTextEditor *editor)
{
    if (this == editor)
        return;
    setDisplayName(editor->displayName());
    d->m_revisionsVisible = editor->d->m_revisionsVisible;
    if (d->m_document == editor->d->m_document)
        return;
    d->setupDocumentSignals(editor->d->m_document);
    d->m_document = editor->d->m_document;
}

QString BaseTextEditor::displayName() const
{
    return d->m_displayName;
}

void BaseTextEditor::setDisplayName(const QString &title)
{
    d->m_displayName = title;
}

BaseTextDocument *BaseTextEditor::baseTextDocument() const
{
    return d->m_document;
}

void BaseTextEditor::setBaseTextDocument(BaseTextDocument *doc)
{
    if (doc) {
        d->setupDocumentSignals(doc);
        d->m_document = doc;
    }
}