path: root/src/plugins/cppeditor/cppeditor.cpp

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

#include "cppeditor.h"
#include "cppeditorconstants.h"
#include "cppplugin.h"
#include "cpphighlighter.h"

#include <AST.h>
#include <Token.h>
#include <Scope.h>
#include <Symbols.h>
#include <Names.h>
#include <Control.h>
#include <CoreTypes.h>
#include <Literals.h>
#include <Semantic.h>
#include <cplusplus/ExpressionUnderCursor.h>
#include <cplusplus/LookupContext.h>
#include <cplusplus/Overview.h>
#include <cplusplus/OverviewModel.h>
#include <cplusplus/SimpleLexer.h>
#include <cplusplus/TypeOfExpression.h>
#include <cpptools/cppmodelmanagerinterface.h>

#include <coreplugin/icore.h>
#include <coreplugin/uniqueidmanager.h>
#include <coreplugin/actionmanager/actionmanagerinterface.h>
#include <coreplugin/editormanager/ieditor.h>
#include <coreplugin/editormanager/editormanager.h>
#include <projectexplorer/projectexplorerconstants.h>
#include <texteditor/basetextdocument.h>
#include <texteditor/fontsettings.h>
#include <texteditor/texteditorconstants.h>
#include <texteditor/textblockiterator.h>
#include <indenter.h>

#include <QtCore/QFileInfo>
#include <QtCore/QTextStream>
#include <QtCore/QDebug>
#include <QtCore/QTime>
#include <QtCore/QTimer>
#include <QtGui/QAction>
#include <QtGui/QKeyEvent>
#include <QtGui/QLayout>
#include <QtGui/QMenu>
#include <QtGui/QShortcut>
#include <QtGui/QTextEdit>
#include <QtGui/QComboBox>
#include <QtGui/QTreeView>
#include <QtGui/QHeaderView>
#include <QtGui/QStringListModel>

using namespace CPlusPlus;
using namespace CppEditor::Internal;

namespace {

class OverviewTreeView : public QTreeView
{
public:
    OverviewTreeView(QWidget *parent = 0)
        : QTreeView(parent)
    {
        // TODO: Disable the root for all items (with a custom delegate?)
        setRootIsDecorated(false);
    }

    void sync()
    {
        expandAll();
        setMinimumWidth(qMax(sizeHintForColumn(0), minimumSizeHint().width()));
    }
};

} // end of anonymous namespace

QualifiedNameId *qualifiedNameIdForSymbol(Symbol *s, const LookupContext &context)
{
    Name *symbolName = s->name();
    if (! symbolName)
        return 0; // nothing to do.

    QVector<Name *> names;

    for (Scope *scope = s->scope(); scope; scope = scope->enclosingScope()) {
        if (scope->isClassScope() || scope->isNamespaceScope()) {
            if (scope->owner() && scope->owner()->name()) {
                Name *ownerName = scope->owner()->name();
                if (QualifiedNameId *q = ownerName->asQualifiedNameId()) {
                    for (unsigned i = 0; i < q->nameCount(); ++i) {
                        names.prepend(q->nameAt(i));
                    }
                } else {
                    names.prepend(ownerName);
                }
            }
        }
    }

    if (QualifiedNameId *q = symbolName->asQualifiedNameId()) {
        for (unsigned i = 0; i < q->nameCount(); ++i) {
            names.append(q->nameAt(i));
        }
    } else {
        names.append(symbolName);
    }

    return context.control()->qualifiedNameId(names.constData(), names.size());
}

CPPEditorEditable::CPPEditorEditable(CPPEditor *editor)
    : BaseTextEditorEditable(editor)
{
    Core::ICore *core = CppPlugin::core();
    m_context << core->uniqueIDManager()->uniqueIdentifier(CppEditor::Constants::C_CPPEDITOR);
    m_context << core->uniqueIDManager()->uniqueIdentifier(ProjectExplorer::Constants::LANG_CXX);
    m_context << core->uniqueIDManager()->uniqueIdentifier(TextEditor::Constants::C_TEXTEDITOR);
}

CPPEditor::CPPEditor(QWidget *parent) :
    TextEditor::BaseTextEditor(parent),
    m_core(CppPlugin::core())
{
    setParenthesesMatchingEnabled(true);
    setMarksVisible(true);
    setCodeFoldingVisible(true);
    baseTextDocument()->setSyntaxHighlighter(new CPPHighlighter);
//    new QShortcut(QKeySequence("Ctrl+Alt+M"), this, SLOT(foo()), 0, Qt::WidgetShortcut);

#ifdef WITH_TOKEN_MOVE_POSITION
    new QShortcut(QKeySequence::MoveToPreviousWord, this, SLOT(moveToPreviousToken()),
                  /*ambiguousMember=*/ 0, Qt::WidgetShortcut);

    new QShortcut(QKeySequence::MoveToNextWord, this, SLOT(moveToNextToken()),
                  /*ambiguousMember=*/ 0, Qt::WidgetShortcut);

    new QShortcut(QKeySequence::DeleteStartOfWord, this, SLOT(deleteStartOfToken()),
                  /*ambiguousMember=*/ 0, Qt::WidgetShortcut);

    new QShortcut(QKeySequence::DeleteEndOfWord, this, SLOT(deleteEndOfToken()),
                  /*ambiguousMember=*/ 0, Qt::WidgetShortcut);
#endif

    m_modelManager = m_core->pluginManager()->getObject<CppTools::CppModelManagerInterface>();

    if (m_modelManager) {
        connect(m_modelManager, SIGNAL(documentUpdated(CPlusPlus::Document::Ptr)),
                this, SLOT(onDocumentUpdated(CPlusPlus::Document::Ptr)));
    }
}

CPPEditor::~CPPEditor()
{
}

TextEditor::BaseTextEditorEditable *CPPEditor::createEditableInterface()
{
    CPPEditorEditable *editable = new CPPEditorEditable(this);
    createToolBar(editable);
    return editable;
}

void CPPEditor::createToolBar(CPPEditorEditable *editable)
{
    m_methodCombo = new QComboBox;
    m_methodCombo->setMinimumContentsLength(22);
    m_methodCombo->setSizeAdjustPolicy(QComboBox::AdjustToContents);
    QTreeView *methodView = new OverviewTreeView();
    methodView->header()->hide();
    methodView->setItemsExpandable(false);
    m_methodCombo->setView(methodView);
    m_methodCombo->setMaxVisibleItems(20);

    m_overviewModel = new OverviewModel(this);
    m_methodCombo->setModel(m_overviewModel);

    connect(m_methodCombo, SIGNAL(activated(int)), this, SLOT(jumpToMethod(int)));
    connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(updateMethodBoxIndex()));
    connect(m_methodCombo, SIGNAL(currentIndexChanged(int)), this, SLOT(updateMethodBoxToolTip()));

    connect(file(), SIGNAL(changed()), this, SLOT(updateFileName()));

    QToolBar *toolBar = editable->toolBar();
    QList<QAction*> actions = toolBar->actions();
    toolBar->insertWidget(actions.first(), m_methodCombo);
}

int CPPEditor::previousBlockState(QTextBlock block) const
{
    block = block.previous();
    if (block.isValid()) {
        int state = block.userState();

        if (state != -1)
            return state;
    }
    return 0;
}

QTextCursor CPPEditor::moveToPreviousToken(QTextCursor::MoveMode mode) const
{
    SimpleLexer tokenize;
    QTextCursor c(textCursor());
    QTextBlock block = c.block();
    int column = c.columnNumber();

    for (; block.isValid(); block = block.previous()) {
        const QString textBlock = block.text();
        QList<SimpleToken> tokens = tokenize(textBlock, previousBlockState(block));

        if (! tokens.isEmpty()) {
            tokens.prepend(SimpleToken());

            for (int index = tokens.size() - 1; index != -1; --index) {
                const SimpleToken &tk = tokens.at(index);
                if (tk.position() < column) {
                    c.setPosition(block.position() + tk.position(), mode);
                    return c;
                }
            }
        }

        column = INT_MAX;
    }

    c.movePosition(QTextCursor::Start, mode);
    return c;
}

QTextCursor CPPEditor::moveToNextToken(QTextCursor::MoveMode mode) const
{
    SimpleLexer tokenize;
    QTextCursor c(textCursor());
    QTextBlock block = c.block();
    int column = c.columnNumber();

    for (; block.isValid(); block = block.next()) {
        const QString textBlock = block.text();
        QList<SimpleToken> tokens = tokenize(textBlock, previousBlockState(block));

        if (! tokens.isEmpty()) {
            for (int index = 0; index < tokens.size(); ++index) {
                const SimpleToken &tk = tokens.at(index);
                if (tk.position() > column) {
                    c.setPosition(block.position() + tk.position(), mode);
                    return c;
                }
            }
        }

        column = -1;
    }

    c.movePosition(QTextCursor::End, mode);
    return c;
}

void CPPEditor::moveToPreviousToken()
{
    setTextCursor(moveToPreviousToken(QTextCursor::MoveAnchor));
}

void CPPEditor::moveToNextToken()
{
    setTextCursor(moveToNextToken(QTextCursor::MoveAnchor));
}

void CPPEditor::deleteStartOfToken()
{
    QTextCursor c = moveToPreviousToken(QTextCursor::KeepAnchor);
    c.removeSelectedText();
    setTextCursor(c);
}

void CPPEditor::deleteEndOfToken()
{
    QTextCursor c = moveToNextToken(QTextCursor::KeepAnchor);
    c.removeSelectedText();
    setTextCursor(c);
}

void CPPEditor::onDocumentUpdated(Document::Ptr doc)
{
    if (doc->fileName() != file()->fileName())
        return;

    m_overviewModel->rebuild(doc);
    OverviewTreeView *treeView = static_cast<OverviewTreeView *>(m_methodCombo->view());
    treeView->sync();
    updateMethodBoxIndex();
}

void CPPEditor::updateFileName()
{ }

void CPPEditor::jumpToMethod(int)
{
    QModelIndex index = m_methodCombo->view()->currentIndex();
    Symbol *symbol = m_overviewModel->symbolFromIndex(index);
    if (! symbol)
        return;

    m_core->editorManager()->addCurrentPositionToNavigationHistory(true);
    int line = symbol->line();
    gotoLine(line);
    m_core->editorManager()->addCurrentPositionToNavigationHistory();
    setFocus();
}

void CPPEditor::updateMethodBoxIndex()
{
    int line = 0, column = 0;
    convertPosition(position(), &line, &column);

    QModelIndex lastIndex;

    const int rc = m_overviewModel->rowCount();
    for (int row = 0; row < rc; ++row) {
        const QModelIndex index = m_overviewModel->index(row, 0, QModelIndex());
        Symbol *symbol = m_overviewModel->symbolFromIndex(index);
        if (symbol && symbol->line() > unsigned(line))
            break;
        lastIndex = index;
    }

    if (lastIndex.isValid()) {
        bool blocked = m_methodCombo->blockSignals(true);
        m_methodCombo->setCurrentIndex(lastIndex.row());
        updateMethodBoxToolTip();
        (void) m_methodCombo->blockSignals(blocked);
    }
}

void CPPEditor::updateMethodBoxToolTip()
{
    m_methodCombo->setToolTip(m_methodCombo->currentText());
}

static bool isCompatible(Name *name, Name *otherName)
{
    if (NameId *nameId = name->asNameId()) {
        if (TemplateNameId *otherTemplId = otherName->asTemplateNameId())
            return nameId->identifier()->isEqualTo(otherTemplId->identifier());
    } else if (TemplateNameId *templId = name->asTemplateNameId()) {
        if (NameId *otherNameId = otherName->asNameId())
            return templId->identifier()->isEqualTo(otherNameId->identifier());
    }

    return name->isEqualTo(otherName);
}

static bool isCompatible(Function *definition, Symbol *declaration, QualifiedNameId *declarationName)
{
    Function *declTy = declaration->type()->asFunction();
    if (! declTy)
        return false;

    Name *definitionName = definition->name();
    if (QualifiedNameId *q = definitionName->asQualifiedNameId()) {
        if (! isCompatible(q->unqualifiedNameId(), declaration->name()))
            return false;
        else if (q->nameCount() > declarationName->nameCount())
            return false;
        else if (declTy->argumentCount() != definition->argumentCount())
            return false;
        else if (declTy->isConst() != definition->isConst())
            return false;
        else if (declTy->isVolatile() != definition->isVolatile())
            return false;

        for (unsigned i = 0; i < definition->argumentCount(); ++i) {
            Symbol *arg = definition->argumentAt(i);
            Symbol *otherArg = declTy->argumentAt(i);
            if (! arg->type().isEqualTo(otherArg->type()))
                return false;
        }

        for (unsigned i = 0; i != q->nameCount(); ++i) {
            Name *n = q->nameAt(q->nameCount() - i - 1);
            Name *m = declarationName->nameAt(declarationName->nameCount() - i - 1);
            if (! isCompatible(n, m))
                return false;
        }
        return true;
    } else {
        // ### TODO: implement isCompatible for unqualified name ids.
    }
    return false;
}

void CPPEditor::switchDeclarationDefinition()
{
    int line = 0, column = 0;
    convertPosition(position(), &line, &column);

    if (!m_modelManager)
        return;

    const Snapshot snapshot = m_modelManager->snapshot();

    Document::Ptr doc = snapshot.value(file()->fileName());
    if (!doc)
        return;
    Symbol *lastSymbol = doc->findSymbolAt(line, column);
    if (!lastSymbol || !lastSymbol->scope())
        return;

    Function *f = lastSymbol->asFunction();
    if (! f) {
        Scope *fs = lastSymbol->scope();
        if (! fs->isFunctionScope())
            fs = fs->enclosingFunctionScope();
        if (fs)
            f = fs->owner()->asFunction();
    }

    if (f) {
        TypeOfExpression typeOfExpression;
        typeOfExpression.setSnapshot(m_modelManager->snapshot());
        QList<TypeOfExpression::Result> resolvedSymbols = typeOfExpression(QString(), doc, lastSymbol);
        const LookupContext &context = typeOfExpression.lookupContext();

        QualifiedNameId *q = qualifiedNameIdForSymbol(f, context);
        QList<Symbol *> symbols = context.resolve(q);

        Symbol *declaration = 0;
        foreach (declaration, symbols) {
            if (isCompatible(f, declaration, q))
                break;
        }

        if (! declaration && ! symbols.isEmpty())
            declaration = symbols.first();

        if (declaration)
            openEditorAt(declaration);
    } else if (lastSymbol->type()->isFunction()) {
        if (Symbol *def = findDefinition(lastSymbol))
            openEditorAt(def);
    }
}

void CPPEditor::jumpToDefinition()
{
    if (!m_modelManager)
        return;

    const Snapshot snapshot = m_modelManager->snapshot();

    // Find the last symbol up to the cursor position
    int line = 0, column = 0;
    convertPosition(position(), &line, &column);
    Document::Ptr doc = snapshot.value(file()->fileName());
    if (!doc)
        return;

    QTextCursor tc = textCursor();
    unsigned lineno = tc.blockNumber() + 1;
    foreach (const Document::Include &incl, doc->includes()) {
        if (incl.line() == lineno) {
            if (openCppEditorAt(incl.fileName(), 0, 0))
                return; // done
            break;
        }
    }

    Symbol *lastSymbol = doc->findSymbolAt(line, column);
    if (!lastSymbol)
        return;

    // Get the expression under the cursor
    const int endOfName = endOfNameUnderCursor();
    tc.setPosition(endOfName);
    ExpressionUnderCursor expressionUnderCursor;
    const QString expression = expressionUnderCursor(tc);

    // Evaluate the type of the expression
    TypeOfExpression typeOfExpression;
    typeOfExpression.setSnapshot(m_modelManager->snapshot());
    QList<TypeOfExpression::Result> resolvedSymbols =
            typeOfExpression(expression, doc, lastSymbol);

    if (!resolvedSymbols.isEmpty()) {
        Symbol *symbol = resolvedSymbols.first().second;
        if (symbol) {
            Symbol *def = 0;
            if (!lastSymbol->isFunction())
                def = findDefinition(symbol);

            if (def)
                openEditorAt(def);
            else
                openEditorAt(symbol);

        // This would jump to the type of a name
#if 0
        } else if (NamedType *namedType = firstType->asNamedType()) {
            QList<Symbol *> candidates = context.resolve(namedType->name());
            if (!candidates.isEmpty()) {
                Symbol *s = candidates.takeFirst();
                openCppEditorAt(s->fileName(), s->line(), s->column());
            }
#endif
        }
    } else {
        foreach (const Document::MacroUse use, doc->macroUses()) {
            if (use.contains(endOfName - 1)) {
                const Macro &macro = use.macro();
                const QString fileName = QString::fromUtf8(macro.fileName);
                if (openCppEditorAt(fileName, macro.line, 0))
                    return; // done
            }
        }

        qDebug() << "No results for expression:" << expression;
    }
}

Symbol *CPPEditor::findDefinition(Symbol *lastSymbol)
{
    // Currently only functions are supported
    if (!lastSymbol->type()->isFunction())
        return 0;

    QVector<Name *> qualifiedName;
    Scope *scope = lastSymbol->scope();
    for (; scope; scope = scope->enclosingScope()) {
        if (scope->isClassScope() || scope->isNamespaceScope()) {
            if (scope->owner() && scope->owner()->name()) {
                Name *scopeOwnerName = scope->owner()->name();
                if (QualifiedNameId *q = scopeOwnerName->asQualifiedNameId()) {
                    for (unsigned i = 0; i < q->nameCount(); ++i) {
                        qualifiedName.prepend(q->nameAt(i));
                    }
                } else {
                    qualifiedName.prepend(scopeOwnerName);
                }
            }
        }
    }

    qualifiedName.append(lastSymbol->name());

    Control control;
    QualifiedNameId *q = control.qualifiedNameId(&qualifiedName[0], qualifiedName.size());
    LookupContext context(&control);

    const Snapshot documents = m_modelManager->snapshot();
    foreach (Document::Ptr doc, documents) {
        QList<Scope *> visibleScopes;
        visibleScopes.append(doc->globalSymbols());
        visibleScopes = context.expand(visibleScopes);
        //qDebug() << "** doc:" << doc->fileName() << "visible scopes:" << visibleScopes.count();
        foreach (Scope *visibleScope, visibleScopes) {
            Symbol *symbol = 0;
            if (NameId *nameId = q->unqualifiedNameId()->asNameId())
                symbol = visibleScope->lookat(nameId->identifier());
            else if (DestructorNameId *dtorId = q->unqualifiedNameId()->asDestructorNameId())
                symbol = visibleScope->lookat(dtorId->identifier());
            else if (TemplateNameId *templNameId = q->unqualifiedNameId()->asTemplateNameId())
                symbol = visibleScope->lookat(templNameId->identifier());
            else if (OperatorNameId *opId = q->unqualifiedNameId()->asOperatorNameId())
                symbol = visibleScope->lookat(opId->kind());
            // ### cast operators
            for (; symbol; symbol = symbol->next()) {
                if (! symbol->isFunction())
                    continue;
                else if (! isCompatible(symbol->asFunction(), lastSymbol, q))
                    continue;
                return symbol;
            }
        }
    }

    return 0;
}

bool CPPEditor::isElectricCharacter(const QChar &ch) const
{
    if (ch == QLatin1Char('{') ||
        ch == QLatin1Char('}') ||
        ch == QLatin1Char('#')) {
        return true;
    }
    return false;
}

// Indent a code line based on previous
template <class Iterator>
static void indentCPPBlock(const CPPEditor::TabSettings &ts,
                           const QTextBlock &block,
                           const Iterator &programBegin,
                           const Iterator &programEnd,
                           QChar typedChar)
{
    typedef typename SharedTools::Indenter<Iterator> Indenter;
    Indenter &indenter = Indenter::instance();
    indenter.setIndentSize(ts.m_indentSize);
    indenter.setTabSize(ts.m_tabSize);

    const TextEditor::TextBlockIterator current(block);
    const int indent = indenter.indentForBottomLine(current, programBegin, programEnd, typedChar);
    ts.indentLine(block, indent);
}

void CPPEditor::indentBlock(QTextDocument *doc, QTextBlock block, QChar typedChar)
{
    const TextEditor::TextBlockIterator begin(doc->begin());
    const TextEditor::TextBlockIterator end(block.next());

    indentCPPBlock(tabSettings(), block, begin, end, typedChar);
}

void CPPEditor::contextMenuEvent(QContextMenuEvent *e)
{
    QMenu *menu = createStandardContextMenu();

    // Remove insert unicode control character
    QAction *lastAction = menu->actions().last();
    if (lastAction->menu() && QLatin1String(lastAction->menu()->metaObject()->className()) == QLatin1String("QUnicodeControlCharacterMenu"))
        menu->removeAction(lastAction);

    Core::IActionContainer *mcontext =
        m_core->actionManager()->actionContainer(CppEditor::Constants::M_CONTEXT);
    QMenu *contextMenu = mcontext->menu();

    foreach (QAction *action, contextMenu->actions())
        menu->addAction(action);

    menu->exec(e->globalPos());
    delete menu;
}

QList<int> CPPEditorEditable::context() const
{
    return m_context;
}

Core::IEditor *CPPEditorEditable::duplicate(QWidget *parent)
{
    CPPEditor *newEditor = new CPPEditor(parent);
    newEditor->duplicateFrom(editor());
    CppPlugin::instance()->initializeEditor(newEditor);
    return newEditor->editableInterface();
}

const char *CPPEditorEditable::kind() const
{
    return CppEditor::Constants::CPPEDITOR_KIND;
}

void CPPEditor::setFontSettings(const TextEditor::FontSettings &fs)
{
    TextEditor::BaseTextEditor::setFontSettings(fs);
    CPPHighlighter *highlighter = qobject_cast<CPPHighlighter*>(baseTextDocument()->syntaxHighlighter());
    if (!highlighter)
        return;

    static QVector<QString> categories;
    if (categories.isEmpty()) {
        categories << QLatin1String(TextEditor::Constants::C_NUMBER)
                   << QLatin1String(TextEditor::Constants::C_STRING)
                   << QLatin1String(TextEditor::Constants::C_TYPE)
                   << QLatin1String(TextEditor::Constants::C_KEYWORD)
                   << QLatin1String(TextEditor::Constants::C_OPERATOR)
                   << QLatin1String(TextEditor::Constants::C_PREPROCESSOR)
                   << QLatin1String(TextEditor::Constants::C_LABEL)
                   << QLatin1String(TextEditor::Constants::C_COMMENT);
    }

    const QVector<QTextCharFormat> formats = fs.toTextCharFormats(categories);
    highlighter->setFormats(formats.constBegin(), formats.constEnd());
    highlighter->rehighlight();
}


void CPPEditor::unCommentSelection()
{
    QTextCursor cursor = textCursor();
    cursor.beginEditBlock();

    int pos = cursor.position();
    int anchor = cursor.anchor();
    int start = qMin(anchor, pos);
    int end = qMax(anchor, pos);
    bool anchorIsStart = (anchor == start);

    QTextBlock startBlock = document()->findBlock(start);
    QTextBlock endBlock = document()->findBlock(end);

    if (end > start && endBlock.position() == end) {
        --end;
        endBlock = endBlock.previous();
    }

    bool doCStyleUncomment = false;
    bool doCStyleComment = false;
    bool doCppStyleUncomment = false;

    bool hasSelection = cursor.hasSelection();

    if (hasSelection) {
        QString startText = startBlock.text();
        int startPos = start - startBlock.position();
        bool hasLeadingCharacters = !startText.left(startPos).trimmed().isEmpty();
        if ((startPos >= 2
            && startText.at(startPos-2) == QLatin1Char('/')
             && startText.at(startPos-1) == QLatin1Char('*'))) {
            startPos -= 2;
            start -= 2;
        }

        bool hasSelStart = (startPos < startText.length() - 2
                            && startText.at(startPos) == QLatin1Char('/')
                            && startText.at(startPos+1) == QLatin1Char('*'));


        QString endText = endBlock.text();
        int endPos = end - endBlock.position();
        bool hasTrailingCharacters = !endText.left(endPos).remove(QLatin1String("//")).trimmed().isEmpty()
                                     && !endText.mid(endPos).trimmed().isEmpty();
        if ((endPos <= endText.length() - 2
            && endText.at(endPos) == QLatin1Char('*')
             && endText.at(endPos+1) == QLatin1Char('/'))) {
            endPos += 2;
            end += 2;
        }

        bool hasSelEnd = (endPos >= 2
                          && endText.at(endPos-2) == QLatin1Char('*')
                          && endText.at(endPos-1) == QLatin1Char('/'));

        doCStyleUncomment = hasSelStart && hasSelEnd;
        doCStyleComment = !doCStyleUncomment && (hasLeadingCharacters || hasTrailingCharacters);
    }

    if (doCStyleUncomment) {
        cursor.setPosition(end);
        cursor.movePosition(QTextCursor::PreviousCharacter, QTextCursor::KeepAnchor, 2);
        cursor.removeSelectedText();
        cursor.setPosition(start);
        cursor.movePosition(QTextCursor::NextCharacter, QTextCursor::KeepAnchor, 2);
        cursor.removeSelectedText();
    } else if (doCStyleComment) {
        cursor.setPosition(end);
        cursor.insertText(QLatin1String("*/"));
        cursor.setPosition(start);
        cursor.insertText(QLatin1String("/*"));
    } else {
        endBlock = endBlock.next();
        doCppStyleUncomment = true;
        for (QTextBlock block = startBlock; block != endBlock; block = block.next()) {
            QString text = block.text();
            if (!text.trimmed().startsWith(QLatin1String("//"))) {
                doCppStyleUncomment = false;
                break;
            }
        }
        for (QTextBlock block = startBlock; block != endBlock; block = block.next()) {
            if (doCppStyleUncomment) {
                QString text = block.text();
                int i = 0;
                while (i < text.size() - 1) {
                    if (text.at(i) == QLatin1Char('/')
                        && text.at(i + 1) == QLatin1Char('/')) {
                        cursor.setPosition(block.position() + i);
                        cursor.movePosition(QTextCursor::NextCharacter, QTextCursor::KeepAnchor, 2);
                        cursor.removeSelectedText();
                        break;
                    }
                    if (!text.at(i).isSpace())
                        break;
                    ++i;
                }
            } else {
                cursor.setPosition(block.position());
                cursor.insertText(QLatin1String("//"));
            }
        }
    }

    // adjust selection when commenting out
    if (hasSelection && !doCStyleUncomment && !doCppStyleUncomment) {
        cursor = textCursor();
        if (!doCStyleComment)
            start = startBlock.position(); // move the double slashes into the selection
        int lastSelPos = anchorIsStart ? cursor.position() : cursor.anchor();
        if (anchorIsStart) {
            cursor.setPosition(start);
            cursor.setPosition(lastSelPos, QTextCursor::KeepAnchor);
        } else {
            cursor.setPosition(lastSelPos);
            cursor.setPosition(start, QTextCursor::KeepAnchor);
        }
        setTextCursor(cursor);
    }

    cursor.endEditBlock();
}

int CPPEditor::endOfNameUnderCursor()
{
    int pos = position();
    QChar chr = characterAt(pos);

    // Skip to the start of a name
    while (chr.isLetterOrNumber() || chr == QLatin1Char('_'))
        chr = characterAt(++pos);

    return pos;
}

TextEditor::ITextEditor *CPPEditor::openCppEditorAt(const QString &fileName,
                                                    int line, int column)
{
    return TextEditor::BaseTextEditor::openEditorAt(fileName, line, column,
                                                    Constants::C_CPPEDITOR);
}

bool CPPEditor::openEditorAt(Symbol *s)
{
    const QString fileName = QString::fromUtf8(s->fileName(), s->fileNameLength());
    return openCppEditorAt(fileName, s->line(), s->column());
}