basetexteditor.cpp

        /* The syntax highlighting state changes. This opens up for
           the possibility that the paragraph has braces that support
           code folding. In this case, do the save thing and also
           update the previous block, which might contain a collapse
           box which now is invalid.*/
            emit requestBlockUpdate(block.previous());
        }
        if (!d->m_findScope.isNull()) {
            if (block.position() < d->m_findScope.selectionEnd()
                && block.position()+block.length() >= d->m_findScope.selectionStart() ) {
                QTextBlock b = block.document()->findBlock(d->m_findScope.selectionStart());
                do {
                    emit requestBlockUpdate(b);
                    b = b.next();
                } while (b.isValid() && b.position() < d->m_findScope.selectionEnd());
            }
        }
    }
    blockRecursion = false;
}

void BaseTextEditor::timerEvent(QTimerEvent *e)
{
    if (e->timerId() == d->autoScrollTimer.timerId()) {
        const QPoint globalPos = QCursor::pos();
        const QPoint pos = d->m_extraArea->mapFromGlobal(globalPos);
        QRect visible = d->m_extraArea->rect();
        verticalScrollBar()->triggerAction( pos.y() < visible.center().y() ?
                                            QAbstractSlider::SliderSingleStepSub
                                            : QAbstractSlider::SliderSingleStepAdd);
        QMouseEvent ev(QEvent::MouseMove, pos, globalPos, Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
        extraAreaMouseEvent(&ev);
        int delta = qMax(pos.y() - visible.top(), visible.bottom() - pos.y()) - visible.height();
        if (delta < 7)
            delta = 7;
        int timeout = 4900 / (delta * delta);
        d->autoScrollTimer.start(timeout, this);

    } else if (e->timerId() == d->collapsedBlockTimer.timerId()) {
        d->visibleCollapsedBlockNumber = d->suggestedVisibleCollapsedBlockNumber;
        d->suggestedVisibleCollapsedBlockNumber = -1;
        d->collapsedBlockTimer.stop();
        viewport()->update();
    }
    QPlainTextEdit::timerEvent(e);
}


void BaseTextEditorPrivate::clearVisibleCollapsedBlock()
{
    if (suggestedVisibleCollapsedBlockNumber) {
        suggestedVisibleCollapsedBlockNumber = -1;
        collapsedBlockTimer.stop();
    }
    if (visibleCollapsedBlockNumber >= 0) {
        visibleCollapsedBlockNumber = -1;
        q->viewport()->update();
    }
}

void BaseTextEditor::mouseMoveEvent(QMouseEvent *e)
{
    d->m_lastEventWasBlockSelectionEvent = (e->modifiers() & Qt::AltModifier);

    updateLink(e);

    if (e->buttons() == Qt::NoButton) {
        const QTextBlock collapsedBlock = collapsedBlockAt(e->pos());
        const int blockNumber = collapsedBlock.next().blockNumber();
        if (blockNumber < 0) {
            d->clearVisibleCollapsedBlock();
        } else if (blockNumber != d->visibleCollapsedBlockNumber) {
            d->suggestedVisibleCollapsedBlockNumber = blockNumber;
            d->collapsedBlockTimer.start(40, this);
        }

        // Update the mouse cursor
        if (collapsedBlock.isValid() && !d->m_mouseOnCollapsedMarker) {
            d->m_mouseOnCollapsedMarker = true;
            viewport()->setCursor(Qt::PointingHandCursor);
        } else if (!collapsedBlock.isValid() && d->m_mouseOnCollapsedMarker) {
            d->m_mouseOnCollapsedMarker = false;
            viewport()->setCursor(Qt::IBeamCursor);
        }
    } else {
        QPlainTextEdit::mouseMoveEvent(e);
    }
    if (d->m_lastEventWasBlockSelectionEvent && d->m_inBlockSelectionMode) {
        if (textCursor().atBlockEnd()) {
            d->m_blockSelectionExtraX = qMax(0, e->pos().x() - cursorRect().center().x()) / fontMetrics().averageCharWidth();
        } else {
            d->m_blockSelectionExtraX = 0;
        }
    }
    if (viewport()->cursor().shape() == Qt::BlankCursor)
        viewport()->setCursor(Qt::IBeamCursor);
}

void BaseTextEditor::mousePressEvent(QMouseEvent *e)
{
    if (e->button() == Qt::LeftButton) {
        d->clearBlockSelection(); // just in case, otherwise we might get strange drag and drop

        QTextBlock collapsedBlock = collapsedBlockAt(e->pos());
        if (collapsedBlock.isValid()) {
            toggleBlockVisible(collapsedBlock);
            viewport()->setCursor(Qt::IBeamCursor);
        }

        updateLink(e);

        if (d->m_currentLink.isValid())
            d->m_linkPressed = true;
    }
    QPlainTextEdit::mousePressEvent(e);
}

void BaseTextEditor::mouseReleaseEvent(QMouseEvent *e)
{
    if (mouseNavigationEnabled()
        && d->m_linkPressed
        && e->modifiers() & Qt::ControlModifier
        && !(e->modifiers() & Qt::ShiftModifier)
        && e->button() == Qt::LeftButton
        ) {
        const QTextCursor cursor = cursorForPosition(e->pos());
        if (openLink(findLinkAt(cursor))) {
            clearLink();
            return;
        }
    }

    QPlainTextEdit::mouseReleaseEvent(e);
}

void BaseTextEditor::leaveEvent(QEvent *e)
{
    // Clear link emulation when the mouse leaves the editor
    clearLink();
    QPlainTextEdit::leaveEvent(e);
}

void BaseTextEditor::keyReleaseEvent(QKeyEvent *e)
{
    // Clear link emulation when Ctrl is released
    if (e->key() == Qt::Key_Control)
        clearLink();

    QPlainTextEdit::keyReleaseEvent(e);
}

void BaseTextEditor::extraAreaLeaveEvent(QEvent *)
{
    // fake missing mouse move event from Qt
    QMouseEvent me(QEvent::MouseMove, QPoint(-1, -1), Qt::NoButton, 0, 0);
    extraAreaMouseEvent(&me);
}

void BaseTextEditor::extraAreaMouseEvent(QMouseEvent *e)
{
    QTextCursor cursor = cursorForPosition(QPoint(0, e->pos().y()));
    cursor.setPosition(cursor.block().position());

    int markWidth;
    extraAreaWidth(&markWidth);

    if (d->m_codeFoldingVisible
        && e->type() == QEvent::MouseMove && e->buttons() == 0) { // mouse tracking
        // Update which folder marker is highlighted
        const int highlightBlockNumber = d->extraAreaHighlightCollapseBlockNumber;
        const int highlightColumn = d->extraAreaHighlightCollapseColumn;
        d->extraAreaHighlightCollapseBlockNumber = -1;
        d->extraAreaHighlightCollapseColumn = -1;

        if (e->pos().x() > extraArea()->width() - collapseBoxWidth(fontMetrics())) {
            d->extraAreaHighlightCollapseBlockNumber = cursor.blockNumber();
            if (TextBlockUserData::canCollapse(cursor.block())
                || !TextBlockUserData::hasClosingCollapse(cursor.block()))
                d->extraAreaHighlightCollapseColumn = cursor.block().length()-1;
            if (TextBlockUserData::hasCollapseAfter(cursor.block())) {
                d->extraAreaHighlightCollapseBlockNumber++;
                d->extraAreaHighlightCollapseColumn = -1;
                if (TextBlockUserData::canCollapse(cursor.block().next())
                    || !TextBlockUserData::hasClosingCollapse(cursor.block().next()))
                    d->extraAreaHighlightCollapseColumn = cursor.block().next().length()-1;
            }
        } else if (d->m_displaySettings.m_highlightBlocks) {
            QTextCursor cursor = textCursor();
            d->extraAreaHighlightCollapseBlockNumber = cursor.blockNumber();
            d->extraAreaHighlightCollapseColumn = cursor.position() - cursor.block().position();
        }

        if (highlightBlockNumber != d->extraAreaHighlightCollapseBlockNumber
            || highlightColumn != d->extraAreaHighlightCollapseColumn) {
            d->m_highlightBlocksTimer->start(d->m_highlightBlocksInfo.isEmpty() ? 120 : 0);
        }
    }

    // Set whether the mouse cursor is a hand or normal arrow
    if (e->type() == QEvent::MouseMove) {
        bool hand = (e->pos().x() <= markWidth);
        if (hand != (d->m_extraArea->cursor().shape() == Qt::PointingHandCursor))
            d->m_extraArea->setCursor(hand ? Qt::PointingHandCursor : Qt::ArrowCursor);
    }

    if (e->type() == QEvent::MouseButtonPress || e->type() == QEvent::MouseButtonDblClick) {
        if (e->button() == Qt::LeftButton) {
            int boxWidth = collapseBoxWidth(fontMetrics());
            if (d->m_codeFoldingVisible && e->pos().x() > extraArea()->width() - boxWidth) {
                if (!cursor.block().next().isVisible()) {
                    toggleBlockVisible(cursor.block());
                    d->moveCursorVisible(false);
                } else if (collapseBox().contains(e->pos())) {
                    cursor.setPosition(
                            document()->findBlockByNumber(d->m_highlightBlocksInfo.open.last()).position()
                            );
                    QTextBlock c = cursor.block();
                    if (TextBlockUserData::hasCollapseAfter(c.previous()))
                        c = c.previous();
                    toggleBlockVisible(c);
                    d->moveCursorVisible(false);
                }
            } else if (d->m_marksVisible && e->pos().x() > markWidth) {
                QTextCursor selection = cursor;
                selection.setVisualNavigation(true);
                d->extraAreaSelectionAnchorBlockNumber = selection.blockNumber();
                selection.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
                selection.movePosition(QTextCursor::Right, QTextCursor::KeepAnchor);
                setTextCursor(selection);
            } else {
                d->extraAreaToggleMarkBlockNumber = cursor.blockNumber();
            }
        } else if (d->m_marksVisible && e->button() == Qt::RightButton) {
            QMenu * contextMenu = new QMenu(this);
            emit d->m_editable->markContextMenuRequested(editableInterface(), cursor.blockNumber() + 1, contextMenu);
            if (!contextMenu->isEmpty())
                contextMenu->exec(e->globalPos());
            delete contextMenu;
        }
    } else if (d->extraAreaSelectionAnchorBlockNumber >= 0) {
        QTextCursor selection = cursor;
        selection.setVisualNavigation(true);
        if (e->type() == QEvent::MouseMove) {
            QTextBlock anchorBlock = document()->findBlockByNumber(d->extraAreaSelectionAnchorBlockNumber);
            selection.setPosition(anchorBlock.position());
            if (cursor.blockNumber() < d->extraAreaSelectionAnchorBlockNumber) {
                selection.movePosition(QTextCursor::EndOfBlock);
                selection.movePosition(QTextCursor::Right);
            }
            selection.setPosition(cursor.block().position(), QTextCursor::KeepAnchor);
            if (cursor.blockNumber() >= d->extraAreaSelectionAnchorBlockNumber) {
                selection.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
                selection.movePosition(QTextCursor::Right, QTextCursor::KeepAnchor);
            }

            if (e->pos().y() >= 0 && e->pos().y() <= d->m_extraArea->height())
                d->autoScrollTimer.stop();
            else if (!d->autoScrollTimer.isActive())
                d->autoScrollTimer.start(100, this);

        } else {
            d->autoScrollTimer.stop();
            d->extraAreaSelectionAnchorBlockNumber = -1;
            return;
        }
        setTextCursor(selection);
    } else if (d->extraAreaToggleMarkBlockNumber >= 0 && d->m_marksVisible && d->m_requestMarkEnabled) {
        if (e->type() == QEvent::MouseButtonRelease && e->button() == Qt::LeftButton) {
            int n = d->extraAreaToggleMarkBlockNumber;
            d->extraAreaToggleMarkBlockNumber = -1;
            if (cursor.blockNumber() == n) {
                int line = n + 1;
                emit d->m_editable->markRequested(editableInterface(), line);
            }
        }
    }
}

QTextBlock TextBlockUserData::testCollapse(const QTextBlock& block)
{
    QTextBlock info = block;
    if (block.userData() && static_cast<TextBlockUserData*>(block.userData())->collapseMode() == CollapseAfter)
        ;
    else if (block.next().userData()
             && static_cast<TextBlockUserData*>(block.next().userData())->collapseMode()
             == TextBlockUserData::CollapseThis)
        info = block.next();
    else
        return QTextBlock();
    int pos = static_cast<TextBlockUserData*>(info.userData())->collapseAtPos();
    if (pos < 0)
        return QTextBlock();
    QTextCursor cursor(info);
    cursor.setPosition(cursor.position() + pos);
    matchCursorForward(&cursor);
    return cursor.block();
}

void TextBlockUserData::doCollapse(const QTextBlock& block, bool visible)
{
    QTextBlock info = block;
    if (block.userData() && static_cast<TextBlockUserData*>(block.userData())->collapseMode() == CollapseAfter)
        ;
    else if (block.next().userData()
             && static_cast<TextBlockUserData*>(block.next().userData())->collapseMode()
             == TextBlockUserData::CollapseThis)
        info = block.next();
    else {
        if (visible && !block.next().isVisible()) {
            // no match, at least unfold!
            QTextBlock b = block.next();
            while (b.isValid() && !b.isVisible()) {
                b.setVisible(true);
                b.setLineCount(visible ? qMax(1, b.layout()->lineCount()) : 0);
                b = b.next();
            }
        }
        return;
    }
    int pos = static_cast<TextBlockUserData*>(info.userData())->collapseAtPos();
    if (pos < 0)
        return;
    QTextCursor cursor(info);
    cursor.setPosition(cursor.position() + pos);
    if (matchCursorForward(&cursor) != Match) {
        if (visible) {
            // no match, at least unfold!
            QTextBlock b = block.next();
            while (b.isValid() && !b.isVisible()) {
                b.setVisible(true);
                b.setLineCount(visible ? qMax(1, b.layout()->lineCount()) : 0);
                b = b.next();
            }
        }
        return;
    }

    QTextBlock b = block.next();
    while (b < cursor.block()) {
        b.setVisible(visible);
        b.setLineCount(visible ? qMax(1, b.layout()->lineCount()) : 0);
        if (visible) {
            TextBlockUserData *data = canCollapse(b);
            if (data && data->collapsed()) {
                QTextBlock end =  testCollapse(b);
                if (data->collapseIncludesClosure())
                    end = end.next();
                if (end.isValid()) {
                    b = end;
                    continue;
                }
            }
        }
        b = b.next();
    }

    bool collapseIncludesClosure = hasClosingCollapseAtEnd(b);
    if (collapseIncludesClosure) {
        b.setVisible(visible);
        b.setLineCount(visible ? qMax(1, b.layout()->lineCount()) : 0);
    }
    static_cast<TextBlockUserData*>(info.userData())->setCollapseIncludesClosure(collapseIncludesClosure);
    static_cast<TextBlockUserData*>(info.userData())->setCollapsed(!block.next().isVisible());

}


void BaseTextEditor::ensureCursorVisible()
{
    QTextBlock block = textCursor().block();
    if (!block.isVisible()) {
        while (!block.isVisible() && block.previous().isValid())
            block = block.previous();
        toggleBlockVisible(block);
    }
    QPlainTextEdit::ensureCursorVisible();
}

void BaseTextEditor::toggleBlockVisible(const QTextBlock &block)
{
    TextEditDocumentLayout *documentLayout = qobject_cast<TextEditDocumentLayout*>(document()->documentLayout());
    QTC_ASSERT(documentLayout, return);

    bool visible = block.next().isVisible();
    TextBlockUserData::doCollapse(block, !visible);
    documentLayout->requestUpdate();
    documentLayout->emitDocumentSizeChanged();
}


const TabSettings &BaseTextEditor::tabSettings() const
{
    return d->m_document->tabSettings();
}

const DisplaySettings &BaseTextEditor::displaySettings() const
{
    return d->m_displaySettings;
}


void BaseTextEditor::indentOrUnindent(bool doIndent)
{
    QTextCursor cursor = textCursor();
    cursor.beginEditBlock();

    int pos = cursor.position();
    const TextEditor::TabSettings &tabSettings = d->m_document->tabSettings();

    QTextDocument *doc = document();

    if (!cursor.hasSelection() && doIndent) {
        // Insert tab if there is no selection and indent is requested
        QTextBlock block = cursor.block();
        QString text = block.text();
        int indentPosition = (cursor.position() - block.position());;
        int spaces = tabSettings.spacesLeftFromPosition(text, indentPosition);
        int startColumn = tabSettings.columnAt(text, indentPosition - spaces);
        int targetColumn = tabSettings.indentedColumn(tabSettings.columnAt(text, indentPosition), doIndent);

        cursor.setPosition(block.position() + indentPosition);
        cursor.setPosition(block.position() + indentPosition - spaces, QTextCursor::KeepAnchor);
        cursor.removeSelectedText();
        cursor.insertText(tabSettings.indentationString(startColumn, targetColumn));
    } else {
        // Indent or unindent the selected lines
        int anchor = cursor.anchor();
        int start = qMin(anchor, pos);
        int end = qMax(anchor, pos);

        QTextBlock startBlock = doc->findBlock(start);
        QTextBlock endBlock = doc->findBlock(end-1).next();

        for (QTextBlock block = startBlock; block != endBlock; block = block.next()) {
            QString text = block.text();
            int indentPosition = tabSettings.lineIndentPosition(text);
            if (!doIndent && !indentPosition)
                indentPosition = tabSettings.firstNonSpace(text);
            int targetColumn = tabSettings.indentedColumn(tabSettings.columnAt(text, indentPosition), doIndent);
            cursor.setPosition(block.position() + indentPosition);
            cursor.insertText(tabSettings.indentationString(0, targetColumn));
            cursor.setPosition(block.position());
            cursor.setPosition(block.position() + indentPosition, QTextCursor::KeepAnchor);
            cursor.removeSelectedText();
        }
    }

    cursor.endEditBlock();
}

void BaseTextEditor::handleHomeKey(bool anchor)
{
    QTextCursor cursor = textCursor();
    QTextCursor::MoveMode mode = QTextCursor::MoveAnchor;

    if (anchor)
        mode = QTextCursor::KeepAnchor;

    const int initpos = cursor.position();
    int pos = cursor.block().position();
    QChar character = characterAt(pos);
    const QLatin1Char tab = QLatin1Char('\t');

    while (character == tab || character.category() == QChar::Separator_Space) {
        ++pos;
        if (pos == initpos)
            break;
        character = characterAt(pos);
    }

    // Go to the start of the block when we're already at the start of the text
    if (pos == initpos)
        pos = cursor.block().position();

    cursor.setPosition(pos, mode);
    setTextCursor(cursor);
}

void BaseTextEditor::handleBackspaceKey()
{
    QTextCursor cursor = textCursor();
    int pos = cursor.position();
    QTC_ASSERT(!cursor.hasSelection(), return);

    const TextEditor::TabSettings &tabSettings = d->m_document->tabSettings();

    if (tabSettings.m_autoIndent && autoBackspace(cursor))
        return;

    if (!tabSettings.m_smartBackspace) {
        cursor.deletePreviousChar();
        return;
    }

    QTextBlock currentBlock = cursor.block();
    int positionInBlock = pos - currentBlock.position();
    const QString blockText = currentBlock.text();
    if (cursor.atBlockStart() || tabSettings.firstNonSpace(blockText) < positionInBlock) {
        cursor.deletePreviousChar();
        return;
    }

    int previousIndent = 0;
    const int indent = tabSettings.columnAt(blockText, positionInBlock);

    for (QTextBlock previousNonEmptyBlock = currentBlock.previous();
         previousNonEmptyBlock.isValid();
         previousNonEmptyBlock = previousNonEmptyBlock.previous()) {
        QString previousNonEmptyBlockText = previousNonEmptyBlock.text();
        if (previousNonEmptyBlockText.trimmed().isEmpty())
            continue;
        previousIndent = tabSettings.columnAt(previousNonEmptyBlockText,
                                              tabSettings.firstNonSpace(previousNonEmptyBlockText));
        if (previousIndent < indent) {
            cursor.beginEditBlock();
            cursor.setPosition(currentBlock.position(), QTextCursor::KeepAnchor);
            cursor.insertText(tabSettings.indentationString(previousNonEmptyBlockText));
            cursor.endEditBlock();
            break;
        }
    }
}

void BaseTextEditor::wheelEvent(QWheelEvent *e)
{
    d->clearVisibleCollapsedBlock();
    if (scrollWheelZoomingEnabled() && e->modifiers() & Qt::ControlModifier) {
        const int delta = e->delta();
        if (delta < 0)
            zoomOut();
        else if (delta > 0)
            zoomIn();
        return;
    }
    QPlainTextEdit::wheelEvent(e);
}

void BaseTextEditor::zoomIn(int range)
{
    d->clearVisibleCollapsedBlock();
    emit requestFontZoom(range*10);
}

void BaseTextEditor::zoomOut(int range)
{
    zoomIn(-range);
}

void BaseTextEditor::zoomReset()
{
    emit requestZoomReset();
}

bool BaseTextEditor::isElectricCharacter(const QChar &) const
{
    return false;
}

void BaseTextEditor::countBracket(QChar open, QChar close, QChar c, int *errors, int *stillopen)
{
    if (c == open)
        ++*stillopen;
    else if (c == close)
        --*stillopen;

    if (*stillopen < 0) {
        *errors += -1 * (*stillopen);
        *stillopen = 0;
    }
}

void BaseTextEditor::countBrackets(QTextCursor cursor, int from, int end, QChar open, QChar close, int *errors, int *stillopen)
{
    cursor.setPosition(from);
    QTextBlock block = cursor.block();
    while (block.isValid() && block.position() < end) {
        TextEditor::Parentheses parenList = TextEditor::TextEditDocumentLayout::parentheses(block);
        if (!parenList.isEmpty() && !TextEditor::TextEditDocumentLayout::ifdefedOut(block)) {
            for (int i = 0; i < parenList.count(); ++i) {
                TextEditor::Parenthesis paren = parenList.at(i);
                int position = block.position() + paren.pos;
                if (position < from || position >= end)
                    continue;
                countBracket(open, close, paren.chr, errors, stillopen);
            }
        }
        block = block.next();
    }
}

bool BaseTextEditor::contextAllowsAutoParentheses(const QTextCursor &cursor,
                                                  const QString &textToInsert) const
{
    Q_UNUSED(cursor);
    Q_UNUSED(textToInsert);
    return false;
}

bool BaseTextEditor::isInComment(const QTextCursor &cursor) const
{
    Q_UNUSED(cursor);
    return false;
}

QString BaseTextEditor::insertMatchingBrace(const QTextCursor &tc, const QString &text,
                                            const QChar &la, int *skippedChars) const
{
    Q_UNUSED(tc);
    Q_UNUSED(text);
    Q_UNUSED(la);
    Q_UNUSED(skippedChars);
    return QString();
}

QString BaseTextEditor::insertParagraphSeparator(const QTextCursor &tc) const
{
    Q_UNUSED(tc);
    return QString();
}

QString BaseTextEditor::autoComplete(QTextCursor &cursor, const QString &textToInsert) const
{
    const bool checkBlockEnd = d->m_allowSkippingOfBlockEnd;
    d->m_allowSkippingOfBlockEnd = false; // consume blockEnd.

    if (!contextAllowsAutoParentheses(cursor, textToInsert))
        return QString();

    const QString text = textToInsert;
    const QChar lookAhead = characterAt(cursor.selectionEnd());

    QChar character = textToInsert.at(0);
    const QString parentheses = QLatin1String("()");
    const QString brackets = QLatin1String("[]");
    if (parentheses.contains(character) || brackets.contains(character)) {
        QTextCursor tmp= cursor;
        TextEditor::TextBlockUserData::findPreviousBlockOpenParenthesis(&tmp);
        int blockStart = tmp.isNull() ? 0 : tmp.position();
        tmp = cursor;
        TextEditor::TextBlockUserData::findNextBlockClosingParenthesis(&tmp);
        int blockEnd = tmp.isNull() ? (cursor.document()->characterCount()-1) : tmp.position();
        const QChar openChar = parentheses.contains(character) ? QLatin1Char('(') : QLatin1Char('[');
        const QChar closeChar = parentheses.contains(character) ? QLatin1Char(')') : QLatin1Char(']');

        int errors = 0;
        int stillopen = 0;
        countBrackets(cursor, blockStart, blockEnd, openChar, closeChar, &errors, &stillopen);
        int errorsBeforeInsertion = errors + stillopen;
        errors = 0;
        stillopen = 0;
        countBrackets(cursor, blockStart, cursor.position(), openChar, closeChar, &errors, &stillopen);
        countBracket(openChar, closeChar, character, &errors, &stillopen);
        countBrackets(cursor, cursor.position(), blockEnd, openChar, closeChar, &errors, &stillopen);
        int errorsAfterInsertion = errors + stillopen;
        if (errorsAfterInsertion < errorsBeforeInsertion)
            return QString(); // insertion fixes parentheses or bracket errors, do not auto complete
    }

    int skippedChars = 0;
    const QString autoText = insertMatchingBrace(cursor, text, lookAhead, &skippedChars);

    if (checkBlockEnd && textToInsert.at(0) == QLatin1Char('}')) {
        if (textToInsert.length() > 1)
            qWarning() << "*** handle event compression";

        int startPos = cursor.selectionEnd(), pos = startPos;
        while (characterAt(pos).isSpace())
            ++pos;

        if (characterAt(pos) == QLatin1Char('}'))
            skippedChars += (pos - startPos) + 1;
    }

    if (skippedChars) {
        const int pos = cursor.position();
        cursor.setPosition(pos + skippedChars);
        cursor.setPosition(pos, QTextCursor::KeepAnchor);
    }

    return autoText;
}

bool BaseTextEditor::autoBackspace(QTextCursor &cursor)
{
    d->m_allowSkippingOfBlockEnd = false;

    int pos = cursor.position();
    QTextCursor c = cursor;
    c.setPosition(pos - 1);

    QChar lookAhead = characterAt(pos);
    QChar lookBehind = characterAt(pos-1);
    QChar lookFurtherBehind = characterAt(pos-2);

    QChar character = lookBehind;
    if (character == QLatin1Char('(') || character == QLatin1Char('[')) {
        QTextCursor tmp = cursor;
        TextEditor::TextBlockUserData::findPreviousBlockOpenParenthesis(&tmp);
        int blockStart = tmp.isNull() ? 0 : tmp.position();
        tmp = cursor;
        TextEditor::TextBlockUserData::findNextBlockClosingParenthesis(&tmp);
        int blockEnd = tmp.isNull() ? (cursor.document()->characterCount()-1) : tmp.position();
        QChar openChar = character;
        QChar closeChar = (character == QLatin1Char('(')) ? QLatin1Char(')') : QLatin1Char(']');

        int errors = 0;
        int stillopen = 0;
        countBrackets(cursor, blockStart, blockEnd, openChar, closeChar, &errors, &stillopen);
        int errorsBeforeDeletion = errors + stillopen;
        errors = 0;
        stillopen = 0;
        countBrackets(cursor, blockStart, pos - 1, openChar, closeChar, &errors, &stillopen);
        countBrackets(cursor, pos, blockEnd, openChar, closeChar, &errors, &stillopen);
        int errorsAfterDeletion = errors + stillopen;

        if (errorsAfterDeletion < errorsBeforeDeletion)
            return false; // insertion fixes parentheses or bracket errors, do not auto complete
    }

    // ### this code needs to be generalized
    if    ((lookBehind == QLatin1Char('(') && lookAhead == QLatin1Char(')'))
        || (lookBehind == QLatin1Char('[') && lookAhead == QLatin1Char(']'))
        || (lookBehind == QLatin1Char('"') && lookAhead == QLatin1Char('"')
            && lookFurtherBehind != QLatin1Char('\\'))
        || (lookBehind == QLatin1Char('\'') && lookAhead == QLatin1Char('\'')
            && lookFurtherBehind != QLatin1Char('\\'))) {
        if (! isInComment(c)) {
            cursor.beginEditBlock();
            cursor.deleteChar();
            cursor.deletePreviousChar();
            cursor.endEditBlock();
            return true;
        }
    }
    return false;
}

int BaseTextEditor::paragraphSeparatorAboutToBeInserted(QTextCursor &cursor)
{
    if (characterAt(cursor.position()-1) != QLatin1Char('{'))
        return 0;

    if (!contextAllowsAutoParentheses(cursor))
        return 0;

    // verify that we indeed do have an extra opening brace in the document
    int braceDepth = document()->lastBlock().userState();
    if (braceDepth >= 0)
        braceDepth >>= 8;
    else
        braceDepth= 0;

    if (braceDepth <= 0)
        return 0; // braces are all balanced or worse, no need to do anything

    // we have an extra brace , let's see if we should close it


    /* verify that the next block is not further intended compared to the current block.
       This covers the following case:

            if (condition) {|
                statement;
    */
    const TabSettings &ts = tabSettings();
    QTextBlock block = cursor.block();
    int indentation = ts.indentationColumn(block.text());
    if (block.next().isValid()
        && ts.indentationColumn(block.next().text()) > indentation)
        return 0;

    int pos = cursor.position();

    const QString textToInsert = insertParagraphSeparator(cursor);

    cursor.insertText(textToInsert);
    cursor.setPosition(pos);
    if (ts.m_autoIndent) {
        cursor.insertBlock();
        indent(document(), cursor, QChar::Null);
    } else {
        QString previousBlockText = cursor.block().text();
        cursor.insertBlock();
        cursor.insertText(ts.indentationString(previousBlockText));
    }
    cursor.setPosition(pos);
    d->m_allowSkippingOfBlockEnd = true;
    return 1;
}

void BaseTextEditor::indentBlock(QTextDocument *, QTextBlock, QChar)
{
}

void BaseTextEditor::indent(QTextDocument *doc, const QTextCursor &cursor, QChar typedChar)
{
    if (cursor.hasSelection()) {
        QTextBlock block = doc->findBlock(cursor.selectionStart());
        const QTextBlock end = doc->findBlock(cursor.selectionEnd()).next();
        do {
            indentBlock(doc, block, typedChar);
            block = block.next();
        } while (block.isValid() && block != end);
    } else {
        indentBlock(doc, cursor.block(), typedChar);
    }
}

void BaseTextEditor::reindent(QTextDocument *doc, const QTextCursor &cursor)
{
    if (cursor.hasSelection()) {
        QTextBlock block = doc->findBlock(cursor.selectionStart());
        const QTextBlock end = doc->findBlock(cursor.selectionEnd()).next();

        const TabSettings &ts = d->m_document->tabSettings();

        // skip empty blocks
        while (block.isValid() && block != end) {
            QString bt = block.text();
            if (ts.firstNonSpace(bt) < bt.size())
                break;
            indentBlock(doc, block, QChar::Null);
            block = block.next();
        }

        int previousIndentation = ts.indentationColumn(block.text());
        indentBlock(doc, block, QChar::Null);
        int currentIndentation = ts.indentationColumn(block.text());
        int delta = currentIndentation - previousIndentation;

        block = block.next();
        while (block.isValid() && block != end) {
            ts.reindentLine(block, delta);
            block = block.next();
        }
    } else {
        indentBlock(doc, cursor.block(), QChar::Null);
    }
}


BaseTextEditor::Link BaseTextEditor::findLinkAt(const QTextCursor &, bool)
{
    return Link();
}

bool BaseTextEditor::openLink(const Link &link)
{
    if (link.fileName.isEmpty())
        return false;

    if (baseTextDocument()->fileName() == link.fileName) {
        Core::EditorManager *editorManager = Core::EditorManager::instance();
        editorManager->addCurrentPositionToNavigationHistory();
        gotoLine(link.line, link.column);
        setFocus();
        return true;
    }

    return openEditorAt(link.fileName, link.line, link.column);
}

void BaseTextEditor::updateLink(QMouseEvent *e)
{
    bool linkFound = false;

    if (mouseNavigationEnabled() && e->modifiers() & Qt::ControlModifier) {
        // Link emulation behaviour for 'go to definition'
        const QTextCursor cursor = cursorForPosition(e->pos());

        // Check that the mouse was actually on the text somewhere
        bool onText = cursorRect(cursor).right() >= e->x();
        if (!onText) {
            QTextCursor nextPos = cursor;
            nextPos.movePosition(QTextCursor::Right);
            onText = cursorRect(nextPos).right() >= e->x();
        }

        const Link link = findLinkAt(cursor, false);

        if (onText && link.isValid()) {
            showLink(link);
            linkFound = true;
        }
    }

    if (!linkFound)
        clearLink();
}

void BaseTextEditor::showLink(const Link &link)
{
    if (d->m_currentLink == link)
        return;

    QTextEdit::ExtraSelection sel;
    sel.cursor = textCursor();
    sel.cursor.setPosition(link.pos);
    sel.cursor.setPosition(link.pos + link.length, QTextCursor::KeepAnchor);
    sel.format = d->m_linkFormat;
    sel.format.setFontUnderline(true);
    setExtraSelections(OtherSelection, QList<QTextEdit::ExtraSelection>() << sel);
    viewport()->setCursor(Qt::PointingHandCursor);
    d->m_currentLink = link;
    d->m_linkPressed = false;
}

void BaseTextEditor::clearLink()
{
    if (!d->m_currentLink.isValid())
        return;

    setExtraSelections(OtherSelection, QList<QTextEdit::ExtraSelection>());
    viewport()->setCursor(Qt::IBeamCursor);
    d->m_currentLink = Link();
    d->m_linkPressed = false;
}

void BaseTextEditorPrivate::updateMarksBlock(const QTextBlock &block)
{
    if (const TextBlockUserData *userData = TextEditDocumentLayout::testUserData(block))
        foreach (ITextMark *mrk, userData->marks())
            mrk->updateBlock(block);
}

void BaseTextEditorPrivate::updateMarksLineNumber()
{
    QTextDocument *doc = q->document();
    QTextBlock block = doc->begin();
    int blockNumber = 0;
    while (block.isValid()) {
        if (const TextBlockUserData *userData = TextEditDocumentLayout::testUserData(block))
            foreach (ITextMark *mrk, userData->marks()) {
                mrk->updateLineNumber(blockNumber + 1);
            }
        block = block.next();
        ++blockNumber;
    }
}

void BaseTextEditor::markBlocksAsChanged(QList<int> blockNumbers)
{
    QTextBlock block = document()->begin();
    while (block.isValid()) {
        if (block.revision() < 0)
            block.setRevision(-block.revision() - 1);
        block = block.next();
    }
    foreach (const int blockNumber, blockNumbers) {
        QTextBlock block = document()->findBlockByNumber(blockNumber);
        if (block.isValid())
            block.setRevision(-block.revision() - 1);
    }
}



TextBlockUserData::MatchType TextBlockUserData::checkOpenParenthesis(QTextCursor *cursor, QChar c)
{
    QTextBlock block = cursor->block();
    if (!TextEditDocumentLayout::hasParentheses(block) || TextEditDocumentLayout::ifdefedOut(block))
        return NoMatch;

    Parentheses parenList = TextEditDocumentLayout::parentheses(block);
    Parenthesis openParen, closedParen;
    QTextBlock closedParenParag = block;

    const int cursorPos = cursor->position() - closedParenParag.position();
    int i = 0;
    int ignore = 0;
    bool foundOpen = false;
    for (;;) {
        if (!foundOpen) {
            if (i >= parenList.count())
                return NoMatch;
            openParen = parenList.at(i);
            if (openParen.pos != cursorPos) {
                ++i;
                continue;
            } else {
                foundOpen = true;
                ++i;
            }
        }

        if (i >= parenList.count()) {
            for (;;) {
                closedParenParag = closedParenParag.next();
                if (!closedParenParag.isValid())
                    return NoMatch;
                if (TextEditDocumentLayout::hasParentheses(closedParenParag)
                    && !TextEditDocumentLayout::ifdefedOut(closedParenParag)) {
                    parenList = TextEditDocumentLayout::parentheses(closedParenParag);
                    break;
                }
            }
            i = 0;
        }

        closedParen = parenList.at(i);