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#include "cppeditoroutline.h"

#include "cppeditor.h"
#include "cppeditorplugin.h"

#include <cpptools/cppmodelmanager.h>

#include <cplusplus/OverviewModel.h>
#include <utils/treeviewcombobox.h>

#include <QSortFilterProxyModel>
#include <QTimer>

/*!
    \class CppEditor::Internal::CppEditorOutline
    \brief A helper class of CppEditorWidget that provides the outline model
           and widget, e.g. for the editor's tool bar.

    \internal

    The caller is responsible for deleting the widget returned by widget().

    \sa CppEditor::Internal::CppEditorWidget
 */

enum { UpdateOutlineIntervalInMs = 500 };

namespace {

class OverviewProxyModel : public QSortFilterProxyModel
{
    Q_OBJECT

public:
    OverviewProxyModel(CPlusPlus::OverviewModel *sourceModel, QObject *parent)
        : QSortFilterProxyModel(parent)
        , m_sourceModel(sourceModel)
    {
        setSourceModel(m_sourceModel);
    }

    bool filterAcceptsRow(int sourceRow,const QModelIndex &sourceParent) const
    {
        // Ignore generated symbols, e.g. by macro expansion (Q_OBJECT)
        const QModelIndex sourceIndex = m_sourceModel->index(sourceRow, 0, sourceParent);
        CPlusPlus::Symbol *symbol = m_sourceModel->symbolFromIndex(sourceIndex);
        if (symbol && symbol->isGenerated())
            return false;

        return QSortFilterProxyModel::filterAcceptsRow(sourceRow, sourceParent);
    }
private:
    CPlusPlus::OverviewModel *m_sourceModel;
};

QTimer *newSingleShotTimer(QObject *parent, int msInternal, const QString &objectName)
{
    QTimer *timer = new QTimer(parent);
    timer->setObjectName(objectName);
    timer->setSingleShot(true);
    timer->setInterval(msInternal);
    return timer;
}

} // anonymous namespace

namespace CppEditor {
namespace Internal {

CppEditorOutline::CppEditorOutline(CppEditorWidget *editorWidget)
    : QObject(editorWidget)
    , m_editorWidget(editorWidget)
    , m_combo(new Utils::TreeViewComboBox)
    , m_model(new CPlusPlus::OverviewModel(this))
    , m_proxyModel(new OverviewProxyModel(m_model, this))
{
    // Set up proxy model
    if (CppEditorPlugin::instance()->sortedOutline())
        m_proxyModel->sort(0, Qt::AscendingOrder);
    else
        m_proxyModel->sort(-1, Qt::AscendingOrder); // don't sort yet, but set column for sortedOutline()
    m_proxyModel->setDynamicSortFilter(true);
    m_proxyModel->setSortCaseSensitivity(Qt::CaseInsensitive);

    // Set up combo box
    m_combo->setModel(m_proxyModel);

    m_combo->setMinimumContentsLength(22);
    QSizePolicy policy = m_combo->sizePolicy();
    policy.setHorizontalPolicy(QSizePolicy::Expanding);
    m_combo->setSizePolicy(policy);
    m_combo->setMaxVisibleItems(40);

    m_combo->setContextMenuPolicy(Qt::ActionsContextMenu);
    m_sortAction = new QAction(tr("Sort Alphabetically"), m_combo);
    m_sortAction->setCheckable(true);
    m_sortAction->setChecked(isSorted());
    connect(m_sortAction, SIGNAL(toggled(bool)),
            CppEditorPlugin::instance(), SLOT(setSortedOutline(bool)));
    m_combo->addAction(m_sortAction);

    connect(m_combo, SIGNAL(activated(int)), this, SLOT(gotoSymbolInEditor()));
    connect(m_combo, SIGNAL(currentIndexChanged(int)), this, SLOT(updateToolTip()));

    // Set up timers
    m_updateTimer = newSingleShotTimer(this, UpdateOutlineIntervalInMs,
                                       QLatin1String("CppEditorOutline::m_updateTimer"));
    connect(m_updateTimer, SIGNAL(timeout()), this, SLOT(updateNow()));

    m_updateIndexTimer = newSingleShotTimer(this, UpdateOutlineIntervalInMs,
                                            QLatin1String("CppEditorOutline::m_updateIndexTimer"));
    connect(m_updateIndexTimer, SIGNAL(timeout()), this, SLOT(updateIndexNow()));
}

void CppEditorOutline::update()
{
    m_updateTimer->start();
}

bool CppEditorOutline::isSorted() const
{
    return m_proxyModel->sortColumn() == 0;
}

void CppEditorOutline::setSorted(bool sort)
{
    if (sort != isSorted()) {
        if (sort)
            m_proxyModel->sort(0, Qt::AscendingOrder);
        else
            m_proxyModel->sort(-1, Qt::AscendingOrder);
        bool block = m_sortAction->blockSignals(true);
        m_sortAction->setChecked(m_proxyModel->sortColumn() == 0);
        m_sortAction->blockSignals(block);
        updateIndexNow();
    }
}

CPlusPlus::OverviewModel *CppEditorOutline::model() const
{
    return m_model;
}

QModelIndex CppEditorOutline::modelIndex()
{
    if (!m_modelIndex.isValid()) {
        int line = 0, column = 0;
        m_editorWidget->convertPosition(m_editorWidget->position(), &line, &column);
        m_modelIndex = indexForPosition(line, column);
        emit modelIndexChanged(m_modelIndex);
    }

    return m_modelIndex;
}

QWidget *CppEditorOutline::widget() const
{
    return m_combo;
}

void CppEditorOutline::updateNow()
{
    CppTools::CppModelManager *cmmi = CppTools::CppModelManager::instance();
    if (!cmmi)
        return;

    const CPlusPlus::Snapshot snapshot = cmmi->snapshot();
    const QString filePath = m_editorWidget->textDocument()->filePath();
    CPlusPlus::Document::Ptr document = snapshot.document(filePath);
    if (!document)
        return;

    if (document->editorRevision() != (unsigned) m_editorWidget->document()->revision()) {
        m_updateTimer->start();
        return;
    }

    m_model->rebuild(document);

    m_combo->view()->expandAll();
    updateIndexNow();
}

void CppEditorOutline::updateIndex()
{
    m_updateIndexTimer->start();
}

void CppEditorOutline::updateIndexNow()
{
    if (!m_model->document())
        return;

    const unsigned revision = m_editorWidget->document()->revision();
    if (m_model->document()->editorRevision() != revision) {
        m_updateIndexTimer->start();
        return;
    }

    m_updateIndexTimer->stop();

    m_modelIndex = QModelIndex(); //invalidate
    QModelIndex comboIndex = modelIndex();

    if (comboIndex.isValid()) {
        bool blocked = m_combo->blockSignals(true);
        m_combo->setCurrentIndex(m_proxyModel->mapFromSource(comboIndex));
        updateToolTip();
        m_combo->blockSignals(blocked);
    }
}

void CppEditorOutline::updateToolTip()
{
    m_combo->setToolTip(m_combo->currentText());
}

void CppEditorOutline::gotoSymbolInEditor()
{
    const QModelIndex modelIndex = m_combo->view()->currentIndex();
    const QModelIndex sourceIndex = m_proxyModel->mapToSource(modelIndex);
    CPlusPlus::Symbol *symbol = m_model->symbolFromIndex(sourceIndex);
    if (!symbol)
        return;

    const TextEditor::TextEditorWidget::Link &link = CppEditorWidget::linkToSymbol(symbol);
    if (!link.hasValidTarget())
        return;

    Core::EditorManager::cutForwardNavigationHistory();
    Core::EditorManager::addCurrentPositionToNavigationHistory();
    m_editorWidget->gotoLine(link.targetLine, link.targetColumn);
    m_editorWidget->activateEditor();
}

QModelIndex CppEditorOutline::indexForPosition(int line, int column,
                                               const QModelIndex &rootIndex) const
{
    QModelIndex lastIndex = rootIndex;

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

    if (lastIndex != rootIndex) {
        // recurse
        lastIndex = indexForPosition(line, column, lastIndex);
    }

    return lastIndex;
}

} // namespace Internal
} // namespace CppEditor

#include <cppeditoroutline.moc>
