basetexteditor.cpp

/**************************************************************************
**
** This file is part of Qt Creator
**
** Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
**
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** Commercial Usage
**
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
**
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://qt.nokia.com/contact.
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**************************************************************************/

#include "texteditor_global.h"

#include "basetextdocument.h"
#include "basetextdocumentlayout.h"
#include "basetexteditor_p.h"
#include "behaviorsettings.h"
#include "codecselector.h"
#include "completionsettings.h"
#include "completionsupport.h"
#include "tabsettings.h"
#include "texteditorconstants.h"
#include "texteditorplugin.h"

#include <aggregation/aggregate.h>
#include <coreplugin/actionmanager/actionmanager.h>
#include <coreplugin/actionmanager/actioncontainer.h>
#include <coreplugin/actionmanager/command.h>
#include <coreplugin/coreconstants.h>
#include <coreplugin/editormanager/editormanager.h>
#include <coreplugin/icore.h>
#include <coreplugin/manhattanstyle.h>
#include <extensionsystem/pluginmanager.h>
#include <find/basetextfind.h>
#include <utils/linecolumnlabel.h>
#include <utils/qtcassert.h>
#include <utils/stylehelper.h>

#include <QtCore/QCoreApplication>
#include <QtCore/QTextCodec>
#include <QtCore/QFile>
#include <QtCore/QDebug>
#include <QtCore/QTimer>
#include <QtCore/QTimeLine>
#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/QScrollBar>
#include <QtGui/QShortcut>
#include <QtGui/QStyle>
#include <QtGui/QSyntaxHighlighter>
#include <QtGui/QTextCursor>
#include <QtGui/QTextDocumentFragment>
#include <QtGui/QTextBlock>
#include <QtGui/QTextLayout>
#include <QtGui/QToolBar>
#include <QtGui/QToolTip>
#include <QtGui/QInputDialog>
#include <QtGui/QMenu>

using namespace TextEditor;
using namespace TextEditor::Internal;

namespace {
    class Locker {
        bool *m_bool;
    public:
        inline Locker(bool *b):m_bool(b){ *m_bool = true; }
        inline ~Locker() { *m_bool = false; }
    };
}



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);
    }
};

} // namespace Internal
} // namespace TextEditor


ITextEditor *BaseTextEditor::openEditorAt(const QString &fileName,
                                          int line,
                                          int column,
                                          const QString &editorKind,
                                          bool *newEditor)
{
    Core::EditorManager *editorManager = Core::EditorManager::instance();
    editorManager->addCurrentPositionToNavigationHistory();
    Core::IEditor *editor = editorManager->openEditor(fileName, editorKind,
            Core::EditorManager::IgnoreNavigationHistory, newEditor);
    TextEditor::ITextEditor *texteditor = qobject_cast<TextEditor::ITextEditor *>(editor);
    if (texteditor) {
        texteditor->gotoLine(line, column);
        return texteditor;
    }

    return 0;
}

static void convertToPlainText(QString &txt)
{
    QChar *uc = txt.data();
    QChar *e = uc + txt.size();

    for (; uc != e; ++uc) {
        switch (uc->unicode()) {
        case 0xfdd0: // QTextBeginningOfFrame
        case 0xfdd1: // QTextEndOfFrame
        case QChar::ParagraphSeparator:
        case QChar::LineSeparator:
            *uc = QLatin1Char('\n');
            break;
        case QChar::Nbsp:
            *uc = QLatin1Char(' ');
            break;
        default:
            ;
        }
    }
}

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->m_overlay = new TextEditorOverlay(this);
    d->m_snippetOverlay = new TextEditorOverlay(this);
    d->m_searchResultOverlay = new TextEditorOverlay(this);

    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->extraAreaHighlightCollapseColumn
        = -1;

    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_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_highlightBlocksTimer = new QTimer(this);
    d->m_highlightBlocksTimer->setSingleShot(true);
    connect(d->m_highlightBlocksTimer, SIGNAL(timeout()), this, SLOT(_q_highlightBlocks()));

    d->m_animator = 0;

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

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

    d->m_delayedUpdateTimer = new QTimer(this);
    d->m_delayedUpdateTimer->setSingleShot(true);
    connect(d->m_delayedUpdateTimer, SIGNAL(timeout()), viewport(), SLOT(update()));

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

    d->m_inKeyPressEvent = false;
    d->m_moveLineUndoHack = false;
}

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 int collapseBoxWidth(const QFontMetrics &fm)
{
    const int lineSpacing = fm.lineSpacing();
    return lineSpacing + lineSpacing%2 + 1;
}

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;
}


int BaseTextEditorPrivate::visualIndent(const QTextBlock &block) const
{
    if (!block.isValid())
        return 0;
    const QTextDocument *document = block.document();
    int i = 0;
    while (i < block.length()) {
        if (!document->characterAt(block.position() + i).isSpace()) {
            QTextCursor cursor(block);
            cursor.setPosition(block.position() + i);
            return q->cursorRect(cursor).x();
        }
        ++i;
    }

    return 0;
}

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

void BaseTextEditor::maybeEmitContentsChangedBecauseOfUndo()
{
    if (!d->m_inKeyPressEvent) {

        // i.e. the document was changed outside key press event
        // Possible with undo, cut, paste, etc.
        if (d->m_snippetOverlay->isVisible()) {

            d->m_snippetOverlay->hide();
            d->m_snippetOverlay->clear();
            QTextCursor cursor = textCursor();
            cursor.clearSelection();
            setTextCursor(cursor);
            return;
        }

    }
    if (document()->isRedoAvailable()) {
        emit editableInterface()->contentsChangedBecauseOfUndo();
    }
}

BaseTextEditorEditable *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(textChanged()),
                this, SLOT(maybeEmitContentsChangedBecauseOfUndo()));
        connect(this, SIGNAL(changed()),
                d->m_editable, SIGNAL(changed()));
    }
    return d->m_editable;
}


void BaseTextEditor::currentEditorChanged(Core::IEditor *editor)
{
    if (editor == editableInterface()) {
        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 BaseTextEditor::triggerCompletions()
{
    emit requestAutoCompletion(editableInterface(), true);
}

void BaseTextEditor::triggerQuickFix()
{
    emit requestQuickFix(editableInterface());
}

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;
}

/*
  Collapses the first comment in a file, if there is only whitespace above
  */
void BaseTextEditorPrivate::collapseLicenseHeader()
{
    QTextDocument *doc = q->document();
    BaseTextDocumentLayout *documentLayout = qobject_cast<BaseTextDocumentLayout*>(doc->documentLayout());
    QTC_ASSERT(documentLayout, return);
    QTextBlock block = doc->firstBlock();
    const TabSettings &ts = m_document->tabSettings();
    while (block.isValid() && block.isVisible()) {
        TextBlockUserData *data = TextBlockUserData::canCollapse(block);
        if (data && block.next().isVisible()) {
            QChar character;
            static_cast<TextBlockUserData*>(data)->collapseAtPos(&character);
            if (character != QLatin1Char('+'))
                break; // not a comment
            TextBlockUserData::doCollapse(block, false);
            moveCursorVisible();
            documentLayout->requestUpdate();
            documentLayout->emitDocumentSizeChanged();
            break;
        }
        QString text = block.text();
        if (ts.firstNonSpace(text) < text.size())
            break;
        block = block.next();
    }
}

const Utils::ChangeSet &BaseTextEditor::changeSet() const
{
    return d->m_changeSet;
}

void BaseTextEditor::setChangeSet(const Utils::ChangeSet &changeSet)
{
    using namespace Utils;

    d->m_changeSet = changeSet;

    foreach (const ChangeSet::EditOp &op, changeSet.operationList()) {
        // ### TODO: process the edit operation

        switch (op.type) {
        case ChangeSet::EditOp::Replace:
            break;

        case ChangeSet::EditOp::Move:
            break;

        case ChangeSet::EditOp::Insert:
            break;

        case ChangeSet::EditOp::Remove:
            break;

        case ChangeSet::EditOp::Flip:
            break;

        case ChangeSet::EditOp::Copy:
            break;

        default:
            break;
        } // switch
    }
}

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

void BaseTextEditor::editorContentsChange(int position, int charsRemoved, int charsAdded)
{
    if (d->m_animator)
        d->m_animator->finish();


    d->m_contentsChanged = true;
    QTextDocument *doc = document();

    // 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 = doc->findBlock(position);
        const QTextBlock nextBlock = doc->findBlock(position + charsAdded);
        if (posBlock != nextBlock) {
            d->updateMarksLineNumber();
            d->updateMarksBlock(posBlock);
            d->updateMarksBlock(nextBlock);
        } else {
            d->updateMarksBlock(posBlock);
        }
    }

    if (doc->isRedoAvailable())
        emit editableInterface()->contentsChangedBecauseOfUndo();
}


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();

    // Clear any link which might be showing when the selection changes
    clearLink();
}

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

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

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

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


void BaseTextEditor::gotoLineStart()
{
    handleHomeKey(false);
}

void BaseTextEditor::gotoLineStartWithSelection()
{
    handleHomeKey(true);
}

void BaseTextEditor::gotoLineEnd()
{
    moveCursor(QTextCursor::EndOfLine);
}

void BaseTextEditor::gotoLineEndWithSelection()
{
    moveCursor(QTextCursor::EndOfLine, QTextCursor::KeepAnchor);
}

void BaseTextEditor::gotoNextLine()
{
    moveCursor(QTextCursor::NextRow);
}

void BaseTextEditor::gotoNextLineWithSelection()
{
    moveCursor(QTextCursor::NextRow, QTextCursor::KeepAnchor);
}

void BaseTextEditor::gotoPreviousLine()
{
    moveCursor(QTextCursor::PreviousRow);
}

void BaseTextEditor::gotoPreviousLineWithSelection()
{
    moveCursor(QTextCursor::PreviousRow, QTextCursor::KeepAnchor);
}

void BaseTextEditor::gotoPreviousCharacter()
{
    moveCursor(QTextCursor::PreviousCharacter);
}

void BaseTextEditor::gotoPreviousCharacterWithSelection()
{
    moveCursor(QTextCursor::PreviousCharacter, QTextCursor::KeepAnchor);
}

void BaseTextEditor::gotoNextCharacter()
{
    moveCursor(QTextCursor::NextCharacter);
}

void BaseTextEditor::gotoNextCharacterWithSelection()
{
    moveCursor(QTextCursor::NextCharacter, QTextCursor::KeepAnchor);
}

void BaseTextEditor::gotoPreviousWord()
{
    moveCursor(QTextCursor::PreviousWord);
}

void BaseTextEditor::gotoPreviousWordWithSelection()
{
    moveCursor(QTextCursor::PreviousWord, QTextCursor::KeepAnchor);
}

void BaseTextEditor::gotoNextWord()
{
    moveCursor(QTextCursor::NextWord);
}

void BaseTextEditor::gotoNextWordWithSelection()
{
    moveCursor(QTextCursor::NextWord, QTextCursor::KeepAnchor);
}



static QTextCursor flippedCursor(const QTextCursor &cursor)
{
    QTextCursor flipped = cursor;
    flipped.clearSelection();
    flipped.setPosition(cursor.anchor(), QTextCursor::KeepAnchor);
    return flipped;
}

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(flippedCursor(cursor));
    _q_matchParentheses();
}

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(flippedCursor(cursor));
    _q_matchParentheses();
}

void BaseTextEditor::copyLineUp()
{
    copyLineUpDown(true);
}

void BaseTextEditor::copyLineDown()
{
    copyLineUpDown(false);
}

void BaseTextEditor::copyLineUpDown(bool up)
{
    QTextCursor cursor = textCursor();
    QTextCursor move = cursor;
    move.beginEditBlock();

    bool hasSelection = cursor.hasSelection();

    if (hasSelection) {
        move.setPosition(cursor.selectionStart());
        move.movePosition(QTextCursor::StartOfBlock);
        move.setPosition(cursor.selectionEnd(), QTextCursor::KeepAnchor);
        move.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
    } else {
        move.movePosition(QTextCursor::StartOfBlock);
        move.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
    }

    QString text = move.selectedText();

    if (up) {
        move.setPosition(cursor.selectionStart());
        move.movePosition(QTextCursor::StartOfBlock);
        move.insertBlock();
        move.movePosition(QTextCursor::Left);
    } else {
        move.movePosition(QTextCursor::EndOfBlock);
        if (move.atBlockStart()) {
            move.movePosition(QTextCursor::NextBlock);
            move.insertBlock();
            move.movePosition(QTextCursor::Left);
        } else {
            move.insertBlock();
        }
    }

    int start = move.position();
    move.clearSelection();
    move.insertText(text);
    int end = move.position();

    move.setPosition(start);
    move.setPosition(end, QTextCursor::KeepAnchor);

    indent(document(), move, QChar::Null);
    move.endEditBlock();

    setTextCursor(move);
}

void BaseTextEditor::joinLines()
{
    QTextCursor cursor = textCursor();
    QTextCursor start = cursor;
    QTextCursor end = cursor;

    start.setPosition(cursor.selectionStart());
    end.setPosition(cursor.selectionEnd() - 1);

    int lineCount = qMax(1, end.blockNumber() - start.blockNumber());

    cursor.beginEditBlock();
    cursor.setPosition(cursor.selectionStart());
    while (lineCount--) {
        cursor.movePosition(QTextCursor::NextBlock);
        cursor.movePosition(QTextCursor::StartOfBlock);
        cursor.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
        QString cutLine = cursor.selectedText();

        // Collapse leading whitespaces to one or insert whitespace
        cutLine.replace(QRegExp("^\\s*"), " ");
        cursor.movePosition(QTextCursor::Right, QTextCursor::KeepAnchor);
        cursor.removeSelectedText();

        cursor.movePosition(QTextCursor::PreviousBlock);
        cursor.movePosition(QTextCursor::EndOfBlock);

        cursor.insertText(cutLine);
    }
    cursor.endEditBlock();

    setTextCursor(cursor);
}

void BaseTextEditor::moveLineUp()
{
    moveLineUpDown(true);
}

void BaseTextEditor::moveLineDown()
{
    moveLineUpDown(false);
}

void BaseTextEditor::moveLineUpDown(bool up)
{
    QTextCursor cursor = textCursor();
    QTextCursor move = cursor;

    move.setVisualNavigation(false); // this opens collapsed items instead of destroying them

    if (d->m_moveLineUndoHack)
        move.joinPreviousEditBlock();
    else
        move.beginEditBlock();

    bool hasSelection = cursor.hasSelection();

    if (cursor.hasSelection()) {
        move.setPosition(cursor.selectionStart());
        move.movePosition(QTextCursor::StartOfBlock);
        move.setPosition(cursor.selectionEnd(), QTextCursor::KeepAnchor);
        move.movePosition(move.atBlockStart() ? QTextCursor::Left: QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
    } else {
        move.movePosition(QTextCursor::StartOfBlock);
        move.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);
    }
    QString text = move.selectedText();
    move.movePosition(QTextCursor::Right, QTextCursor::KeepAnchor);