basetexteditor.cpp

                                         static_cast<int>(lineRect.top() + line.ascent()), visualArrow);
                    }
                    if (!nextBlock.isValid()) { // paint EOF symbol
                        QTextLine line = layout->lineAt(lineCount-1);
                        QRectF lineRect = line.naturalTextRect().translated(offset.x(), top);
                        int h = 4;
                        lineRect.adjust(0, 0, -1, -1);
                        QPainterPath path;
                        QPointF pos(lineRect.topRight() + QPointF(h+4, line.ascent()));
                        path.moveTo(pos);
                        path.lineTo(pos + QPointF(-h, -h));
                        path.lineTo(pos + QPointF(0, -2*h));
                        path.lineTo(pos + QPointF(h, -h));
                        path.closeSubpath();
                        painter.setBrush(painter.pen().color());
                        painter.drawPath(path);
                    }
                    painter.restore();
                }
            }

            if (nextBlock.isValid() && !nextBlock.isVisible()) {

                bool selectThis = (hasSelection
                                   && nextBlock.position() >= selectionStart
                                   && nextBlock.position() < selectionEnd);
                if (selectThis) {
                    painter.save();
                    painter.setBrush(palette().highlight());
                }

                QTextLayout *layout = block.layout();
                QTextLine line = layout->lineAt(layout->lineCount()-1);
                QRectF lineRect = line.naturalTextRect().translated(offset.x(), top);
                lineRect.adjust(0, 0, -1, -1);

                QRectF collapseRect(lineRect.right() + 12,
                                    lineRect.top(),
                                    fontMetrics().width(QLatin1String(" {...}; ")),
                                    lineRect.height());
                painter.setRenderHint(QPainter::Antialiasing, true);
                painter.translate(.5, .5);
                painter.drawRoundedRect(collapseRect.adjusted(0, 0, 0, -1), 3, 3);
                painter.setRenderHint(QPainter::Antialiasing, false);
                painter.translate(-.5, -.5);

                QString replacement = QLatin1String("...");

                QTextBlock info = block;
                if (block.userData()
                    && static_cast<TextBlockUserData*>(block.userData())->collapseMode() == TextBlockUserData::CollapseAfter)
                    ;
                else if (block.next().userData()
                         && static_cast<TextBlockUserData*>(block.next().userData())->collapseMode()
                         == TextBlockUserData::CollapseThis) {
                    replacement.prepend(nextBlock.text().trimmed().left(1));
                    info = nextBlock;
                }


                block = nextVisibleBlock.previous();
                if (!block.isValid())
                    block = doc->lastBlock();

                if (info.userData()
                    && static_cast<TextBlockUserData*>(info.userData())->collapseIncludesClosure()) {
                    QString right = block.text().trimmed();
                    if (right.endsWith(QLatin1Char(';'))) {
                        right.chop(1);
                        right = right.trimmed();
                        replacement.append(right.right(right.endsWith(QLatin1Char('/')) ? 2 : 1));
                        replacement.append(QLatin1Char(';'));
                    } else {
                        replacement.append(right.right(right.endsWith(QLatin1Char('/')) ? 2 : 1));
                    }
                }
                if (selectThis)
                    painter.setPen(palette().highlightedText().color());
                painter.drawText(collapseRect, Qt::AlignCenter, replacement);
                if (selectThis)
                    painter.restore();
            }
        }

        block = nextVisibleBlock;
        top = bottom;
        bottom = top + (int)blockBoundingRect(block).height();
    }

    if (visibleCollapsedBlock.isValid() ) {
        int margin = doc->documentMargin();
        qreal maxWidth = 0;
        qreal blockHeight = 0;
        QTextBlock b = visibleCollapsedBlock;

        while (!b.isVisible() && visibleCollapsedBlockOffset.y() + blockHeight <= e->rect().bottom()) {
            b.setVisible(true); // make sure block bounding rect works
            QRectF r = blockBoundingRect(b).translated(visibleCollapsedBlockOffset);

            QTextLayout *layout = b.layout();
            for (int i = layout->lineCount()-1; i >= 0; --i)
                maxWidth = qMax(maxWidth, layout->lineAt(i).naturalTextWidth() + margin);

            blockHeight += r.height();

            b.setVisible(false); // restore previous state
            b = b.next();
        }

        painter.save();
        painter.setRenderHint(QPainter::Antialiasing, true);
        painter.translate(.5, .5);
        QColor color = blendColor;
//        color.setAlpha(240); // someone thinks alpha blending looks messy
        painter.setBrush(color);
        painter.drawRoundedRect(QRectF(visibleCollapsedBlockOffset.x(),
                                       visibleCollapsedBlockOffset.y(),
                                       maxWidth, blockHeight).adjusted(0, 0, 0, 0), 3, 3);
        painter.restore();

        QTextBlock end = b;
        b = visibleCollapsedBlock;
        while (b != end) {
            b.setVisible(true); // make sure block bounding rect works
            QRectF r = blockBoundingRect(b).translated(visibleCollapsedBlockOffset);
            QTextLayout *layout = b.layout();
            QVector<QTextLayout::FormatRange> selections;
            d->highlightSearchResults(b, &selections);
            layout->draw(&painter, visibleCollapsedBlockOffset, selections, er);

            b.setVisible(false); // restore previous state
            visibleCollapsedBlockOffset.ry() += r.height();
            b = b.next();
        }
    }


    if (d->m_visibleWrapColumn > 0) {
        qreal lineX = fontMetrics().width('x') * d->m_visibleWrapColumn + offset.x() + 4;
        const QColor bg = palette().base().color();
        QColor col = (bg.value() > 128) ? Qt::black : Qt::white;
        col.setAlpha(32);
        painter.setPen(QPen(col, 0));
        painter.drawLine(QPointF(lineX, 0), QPointF(lineX, viewport()->height()));
    }
}

QWidget *BaseTextEditor::extraArea() const
{
    return d->m_extraArea;
}

int BaseTextEditor::extraAreaWidth(int *markWidthPtr) const
{
    TextEditDocumentLayout *documentLayout = qobject_cast<TextEditDocumentLayout*>(document()->documentLayout());
    if (!documentLayout)
        return 0;

    if (!d->m_marksVisible && documentLayout->hasMarks)
        d->m_marksVisible = true;

    int space = 0;
    const QFontMetrics fm(d->m_extraArea->fontMetrics());

    if (d->m_lineNumbersVisible) {
        int digits = 2;
        int max = qMax(1, blockCount());
        while (max >= 100) {
            max /= 10;
            ++digits;
        }
        space += fm.width(QLatin1Char('9')) * digits;
    }
    int markWidth = 0;

    if (d->m_marksVisible) {
        markWidth += fm.lineSpacing();
//     if (documentLayout->doubleMarkCount)
//         markWidth += fm.lineSpacing() / 3;
        space += markWidth;
    } else {
        space += 2;
    }

    if (markWidthPtr)
        *markWidthPtr = markWidth;

    space += 4;

    if (d->m_codeFoldingVisible)
        space += fm.lineSpacing();
    return space;
}

void BaseTextEditor::slotUpdateExtraAreaWidth()
{
    if (isLeftToRight())
        setViewportMargins(extraAreaWidth(), 0, 0, 0);
    else
        setViewportMargins(0, 0, extraAreaWidth(), 0);
}

void BaseTextEditor::extraAreaPaintEvent(QPaintEvent *e)
{
    QTextDocument *doc = document();
    TextEditDocumentLayout *documentLayout = qobject_cast<TextEditDocumentLayout*>(doc->documentLayout());
    QTC_ASSERT(documentLayout, return);

    int selStart = textCursor().selectionStart();
    int selEnd = textCursor().selectionEnd();

    const QColor baseColor = palette().base().color();
    QPalette pal = d->m_extraArea->palette();
    pal.setCurrentColorGroup(QPalette::Active);
    QPainter painter(d->m_extraArea);
    QFontMetrics fm(painter.fontMetrics());
    int fmLineSpacing = fm.lineSpacing();

    int markWidth = 0;
    if (d->m_marksVisible)
        markWidth += fm.lineSpacing();
//     if (documentLayout->doubleMarkCount)
//         markWidth += fm.lineSpacing() / 3;

    const int collapseBoxWidth = d->m_codeFoldingVisible ? fmLineSpacing + 1: 0;
    const int extraAreaWidth = d->m_extraArea->width() - collapseBoxWidth;

    painter.fillRect(e->rect(), pal.color(QPalette::Base));
    painter.fillRect(e->rect().intersected(QRect(0, 0, extraAreaWidth, INT_MAX)),
                     pal.color(QPalette::Background));

    QTextBlock block = firstVisibleBlock();
    int blockNumber = block.blockNumber();
    int top = (int)blockBoundingGeometry(block).translated(contentOffset()).top();
    int bottom = top;

#if 0
    int extraAreaHighlightCollapseEndBlockNumber = -1;

    int extraAreaHighlightCollapseBlockNumber = d->extraAreaHighlightCollapseBlockNumber;
    if (extraAreaHighlightCollapseBlockNumber < 0) {
        extraAreaHighlightCollapseBlockNumber = d->extraAreaHighlightFadingBlockNumber;
    }

    if (extraAreaHighlightCollapseBlockNumber >= 0 ) {
        QTextBlock highlightBlock = doc->findBlockByNumber(extraAreaHighlightCollapseBlockNumber);
        if (highlightBlock.isValid() && highlightBlock.next().isValid() && highlightBlock.next().isVisible())
            extraAreaHighlightCollapseEndBlockNumber = TextBlockUserData::testCollapse(highlightBlock).blockNumber();
        else
            extraAreaHighlightCollapseEndBlockNumber = extraAreaHighlightCollapseBlockNumber;
    }
#endif

    while (block.isValid() && top <= e->rect().bottom()) {

        top = bottom;
        bottom = top + (int)blockBoundingRect(block).height();
        QTextBlock nextBlock = block.next();

        QTextBlock nextVisibleBlock = nextBlock;
        int nextVisibleBlockNumber = blockNumber + 1;

        if (!nextVisibleBlock.isVisible()) {
            // invisible blocks do have zero line count
            nextVisibleBlock = doc->findBlockByLineNumber(nextVisibleBlock.firstLineNumber());
            nextVisibleBlockNumber = nextVisibleBlock.blockNumber();
        }

        painter.setPen(pal.color(QPalette::Dark));

        if (d->m_codeFoldingVisible || d->m_marksVisible) {
            painter.save();
            painter.setRenderHint(QPainter::Antialiasing, false);

            int previousBraceDepth = block.previous().userState();
            if (previousBraceDepth >= 0)
                previousBraceDepth >>= 8;
            else
                previousBraceDepth = 0;

            int braceDepth = block.userState();
            if (!nextBlock.isVisible()) {
                QTextBlock lastInvisibleBlock = nextVisibleBlock.previous();
                if (!lastInvisibleBlock.isValid())
                    lastInvisibleBlock = doc->lastBlock();
                braceDepth = lastInvisibleBlock.userState();
            }
            if (braceDepth >= 0)
                braceDepth >>= 8;
            else
                braceDepth = 0;

            if (TextBlockUserData *userData = static_cast<TextBlockUserData*>(block.userData())) {
                if (d->m_marksVisible) {
                    int xoffset = 0;
                    foreach (ITextMark *mrk, userData->marks()) {
                        int x = 0;
                        int radius = fmLineSpacing - 1;
                        QRect r(x + xoffset, top, radius, radius);
                        mrk->icon().paint(&painter, r, Qt::AlignCenter);
                        xoffset += 2;
                    }
                }
            }

            if (d->m_codeFoldingVisible) {
                QRect r(extraAreaWidth+2, top, collapseBoxWidth-4, bottom - top);
                bool drawBox = !nextBlock.isVisible();

                int minBraceDepth = qMax(braceDepth, previousBraceDepth);
                if (minBraceDepth > 0) {
                    QColor color = calcBlendColor(baseColor, minBraceDepth);
                    if (!d->m_highlightBlocksInfo.isEmpty()
                        && blockNumber >= d->m_highlightBlocksInfo.open.last()
                        && blockNumber <= d->m_highlightBlocksInfo.close.first())
                        color = calcMixColor(pal.highlight().color(), color);
                    painter.fillRect(r, color);
                }

                bool drawDown = !d->m_highlightBlocksInfo.isEmpty()
                              && blockNumber == d->m_highlightBlocksInfo.open.last();
                bool drawUp = !d->m_highlightBlocksInfo.isEmpty()
                              && blockNumber == d->m_highlightBlocksInfo.close.first();

                if (drawBox || drawDown || drawUp) {
                    painter.setRenderHint(QPainter::Antialiasing, true);
                    painter.translate(.5, .5);
                    painter.setPen(pal.text().color());
                    painter.setBrush(pal.text().color());

                    if (drawBox) {
                        QPointF points1[3] = { QPointF(r.left(), r.center().y()-1),
                                               QPointF(r.center().x(), r.top()),
                                               QPointF(r.right(), r.center().y()-1) };
                        QPointF points2[3] = { QPointF(r.left(), r.center().y()+1),
                                               QPointF(r.center().x(), r.bottom()-1),
                                               QPointF(r.right(), r.center().y()+1) };
                        painter.drawPolygon(points1, 3);
                        painter.drawPolygon(points2, 3);
                    } else if (drawUp) {

                        // check that we are not collapsed
                        QTextBlock open = doc->findBlockByNumber(d->m_highlightBlocksInfo.open.last());
                        if (open.next().isVisible()) {

                            QPointF points[3] = { QPointF(r.left(), r.bottom()-1),
                                                  QPointF(r.center().x(), r.center().y()),
                                                  QPointF(r.right(), r.bottom()-1) };
                            painter.drawPolygon(points, 3);
                        }
                    } else if(drawDown) {
                        QPointF points[3] = { QPointF(r.left(), r.top()),
                                               QPointF(r.center().x(), r.center().y()),
                                               QPointF(r.right(), r.top()) };
                        painter.drawPolygon(points, 3);
                    }
                    painter.translate(-.5, -.5);
                    painter.setRenderHint(QPainter::Antialiasing, false);
                }

            }


            painter.restore();
        }


        if (d->m_revisionsVisible && block.revision() != documentLayout->lastSaveRevision) {
            painter.save();
            painter.setRenderHint(QPainter::Antialiasing, false);
            if (block.revision() < 0)
                painter.setPen(QPen(Qt::darkGreen, 2));
            else
                painter.setPen(QPen(Qt::red, 2));
            painter.drawLine(extraAreaWidth-1, top, extraAreaWidth-1, bottom-1);
            painter.restore();
        }

        if (d->m_lineNumbersVisible) {
            const QString &number = QString::number(blockNumber + 1);
            bool selected = (
                    selStart < block.position() + block.length()
                    && selEnd > block.position()
                    );
            if (selected) {
                painter.save();
                QFont f = painter.font();
                f.setBold(d->m_currentLineNumberFormat.font().bold());
                f.setItalic(d->m_currentLineNumberFormat.font().italic());
                painter.setFont(f);
                painter.setPen(d->m_currentLineNumberFormat.foreground().color());
            }
            painter.drawText(markWidth, top, extraAreaWidth - markWidth - 4, fm.height(), Qt::AlignRight, number);
            if (selected)
                painter.restore();
        }

        block = nextVisibleBlock;
        blockNumber = nextVisibleBlockNumber;
    }

    if (d->m_codeFoldingVisible) {
        painter.drawLine(extraAreaWidth, 0,
                         extraAreaWidth, viewport()->height());
        painter.drawLine(extraAreaWidth + collapseBoxWidth - 1, 0,
                         extraAreaWidth + collapseBoxWidth - 1, viewport()->height());
//        QRect cb = collapseBox();
//        if (!cb.isEmpty()) {
//            QPen pen(baseColor.value() < 128 ? Qt::white : Qt::black);
//            pen.setWidth(2);
//            painter.setPen(pen);
//            painter.setRenderHint(QPainter::Antialiasing, true);
//            painter.translate(.5, .5);
//            painter.drawRoundedRect(QRect(cb.adjusted(0, 0,-2, -2)), 4, 4);
//        }
    }
}

void BaseTextEditor::slotModificationChanged(bool m)
{
    if (m)
        return;

    QTextDocument *doc = document();
    TextEditDocumentLayout *documentLayout = qobject_cast<TextEditDocumentLayout*>(doc->documentLayout());
    QTC_ASSERT(documentLayout, return);
    int oldLastSaveRevision = documentLayout->lastSaveRevision;
    documentLayout->lastSaveRevision = doc->revision();

    if (oldLastSaveRevision != documentLayout->lastSaveRevision) {
        QTextBlock block = doc->begin();
        while (block.isValid()) {
            if (block.revision() < 0 || block.revision() != oldLastSaveRevision) {
                block.setRevision(-documentLayout->lastSaveRevision - 1);
            } else {
                block.setRevision(documentLayout->lastSaveRevision);
            }
            block = block.next();
        }
    }
    d->m_extraArea->update();
}

void BaseTextEditor::slotUpdateRequest(const QRect &r, int dy)
{
    if (dy)
        d->m_extraArea->scroll(0, dy);
    else if (r.width() > 4) { // wider than cursor width, not just cursor blinking
        d->m_extraArea->update(0, r.y(), d->m_extraArea->width(), r.height());
    }

    if (r.contains(viewport()->rect()))
        slotUpdateExtraAreaWidth();
}

void BaseTextEditor::saveCurrentCursorPositionForNavigation()
{
    d->m_lastCursorChangeWasInteresting = true;
    d->m_tempNavigationState = saveState();
}

void BaseTextEditor::slotCursorPositionChanged()
{
    if (!d->m_contentsChanged && d->m_lastCursorChangeWasInteresting) {
        Core::EditorManager::instance()->addCurrentPositionToNavigationHistory(d->m_tempNavigationState);
        d->m_lastCursorChangeWasInteresting = false;
    } else if (d->m_contentsChanged) {
        saveCurrentCursorPositionForNavigation();
    }

    if (d->m_parenthesesMatchingEnabled) {
        // Delay update when no matching is displayed yet, to avoid flicker
        if (extraSelections(ParenthesesMatchingSelection).isEmpty()) {
            d->m_parenthesesMatchingTimer->start(50);
        } else {
            _q_matchParentheses();
        }
    }

    QList<QTextEdit::ExtraSelection> extraSelections;

    if (d->m_highlightCurrentLine) {
        QTextEdit::ExtraSelection sel;
        sel.format.setBackground(d->m_currentLineFormat.background());
        sel.format.setProperty(QTextFormat::FullWidthSelection, true);
        sel.cursor = textCursor();
        sel.cursor.clearSelection();
        extraSelections.append(sel);
    }

    setExtraSelections(CurrentLineSelection, extraSelections);

    if (d->m_highlightBlocks) {
        QTextCursor cursor = textCursor();
        d->extraAreaHighlightCollapseBlockNumber = cursor.blockNumber();
        d->extraAreaHighlightCollapseColumn = cursor.position() - cursor.block().position();
        d->m_highlightBlocksTimer->start(100);
    }
}

void BaseTextEditor::slotUpdateBlockNotify(const QTextBlock &block)
{
    static bool blockRecursion = false;
    if (blockRecursion)
        return;
    if (block.previous().isValid() && block.userState() != block.previous().userState()) {
        /* 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.*/
        blockRecursion = true;
        emit requestBlockUpdate(block.previous());
        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);
    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;
        }
    }
}

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);
        }
    }
    QPlainTextEdit::mousePressEvent(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 (d->m_highlightBlocks) {
            QTextCursor cursor  = textCursor();
            d->extraAreaHighlightCollapseBlockNumber = cursor.blockNumber();
            d->extraAreaHighlightCollapseColumn = cursor.position() - cursor.block().position();
        }

        int collapseBoxWidth = fontMetrics().lineSpacing() + 1;
        if (e->pos().x() > extraArea()->width() - collapseBoxWidth) {
            d->extraAreaHighlightCollapseBlockNumber = cursor.blockNumber();
            if (!TextBlockUserData::hasClosingCollapse(cursor.block()))
                d->extraAreaHighlightCollapseColumn = cursor.block().length()-1;
        }
        if (highlightBlockNumber != d->extraAreaHighlightCollapseBlockNumber
            || highlightColumn != d->extraAreaHighlightCollapseColumn)
            d->m_highlightBlocksTimer->start(40);
    }

    if (e->type() == QEvent::MouseButtonPress || e->type() == QEvent::MouseButtonDblClick) {
        if (e->button() == Qt::LeftButton) {
            int collapseBoxWidth = fontMetrics().lineSpacing() + 1;
            if (d->m_codeFoldingVisible && e->pos().x() > extraArea()->width() - collapseBoxWidth) {
                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::canCollapse(c))
                        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()
        || (doc->findBlock(cursor.selectionStart()) == doc->findBlock(cursor.selectionEnd()) )) {
        cursor.removeSelectedText();
        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 {
        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();
    QTC_ASSERT(!cursor.hasSelection(), return);

    const TextEditor::TabSettings &tabSettings = d->m_document->tabSettings();
    QTextBlock currentBlock = cursor.block();
    int positionInBlock = cursor.position() - 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)
            break;
    }

    if (previousIndent >= indent)
        previousIndent = 0;

    cursor.beginEditBlock();
    cursor.setPosition(currentBlock.position(), QTextCursor::KeepAnchor);
    cursor.insertText(tabSettings.indentationString(0, previousIndent));
    cursor.endEditBlock();
}

void BaseTextEditor::wheelEvent(QWheelEvent *e)
{
  d->clearVisibleCollapsedBlock();
    if (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();
    QFont f = font();
    const int newSize = f.pointSize() + range;
    if (newSize <= 0)
        return;
    f.setPointSize(newSize);
    setFont(f);
}

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

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

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

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