qcompleter.cpp

奇趣公司比较新的qt/emd版本

        reset();
        return;
    }

    emit layoutAboutToBeChanged();
    QModelIndexList piList = persistentIndexList();
    QModelIndexList empty;
    for (int i = 0; i < piList.size(); i++)
        empty.append(QModelIndex());
    changePersistentIndexList(piList, empty);
    emit layoutChanged();
}

//////////////////////////////////////////////////////////////////////////////
void QCompletionEngine::filter(const QStringList& parts)
{
    const QAbstractItemModel *model = c->proxy->sourceModel();
    curParts = parts;
    if (curParts.isEmpty())
        curParts.append(QString());

    curRow = -1;
    curParent = QModelIndex();
    curMatch = QMatchData();
    historyMatch = filterHistory();

    if (!model)
        return;

    QModelIndex parent;
    for (int i = 0; i < curParts.count() - 1; i++) {
        QString part = curParts[i];
        int emi = filter(part, parent, -1).exactMatchIndex;
        if (emi == -1)
            return;
        parent = model->index(emi, c->column, parent);
    }

    // Note that we set the curParent to a valid parent, even if we have no matches
    // When filtering is disabled, we show all the items under this parent
    curParent = parent;
    if (curParts.last().isEmpty())
        curMatch = QMatchData(QIndexMapper(0, model->rowCount(curParent) - 1), -1, false);
    else
        curMatch = filter(curParts.last(), curParent, 1); // build at least one
    curRow = curMatch.isValid() ? 0 : -1;
}

QMatchData QCompletionEngine::filterHistory()
{
    QAbstractItemModel *source = c->proxy->sourceModel();
    if (curParts.count() <= 1 || c->proxy->showAll || !source)
        return QMatchData();
    bool dirModel = false;
#ifndef QT_NO_DIRMODEL
    dirModel = (qobject_cast<QDirModel *>(source) != 0);
#endif
    QVector<int> v;
    QIndexMapper im(v);
    QMatchData m(im, -1, true);

    for (int i = 0; i < source->rowCount(); i++) {
        QString str = source->index(i, c->column).data().toString();
        if (str.startsWith(c->prefix, c->cs)
#ifndef Q_OS_WIN
            && (!dirModel || str != QDir::separator())
#endif
            )
            m.indices.append(i);
    }
    return m;
}

// Returns a match hint from the cache by chopping the search string
bool QCompletionEngine::matchHint(QString part, const QModelIndex& parent, QMatchData *hint)
{
    if (c->cs == Qt::CaseInsensitive)
        part = part.toLower();

    const CacheItem& map = cache[parent];

    QString key = part;
    while (!key.isEmpty()) {
        key.chop(1);
        if (map.contains(key)) {
            *hint = map[key];
            return true;
        }
    }

    return false;
}

bool QCompletionEngine::lookupCache(QString part, const QModelIndex& parent, QMatchData *m)
{
   if (c->cs == Qt::CaseInsensitive)
        part = part.toLower();
   const CacheItem& map = cache[parent];
   if (!map.contains(part))
       return false;
   *m = map[part];
   return true;
}

// When the cache size exceeds 1MB, it clears out about 1/2 of the cache.
void QCompletionEngine::saveInCache(QString part, const QModelIndex& parent, const QMatchData& m)
{
    QMatchData old = cache[parent].take(part);
    cost = cost + m.indices.cost() - old.indices.cost();
    if (cost * sizeof(int) > 1024 * 1024) {
        QMap<QModelIndex, CacheItem>::iterator it1 ;
        for (it1 = cache.begin(); it1 != cache.end(); ++it1) {
            CacheItem& ci = it1.value();
            int sz = ci.count()/2;
            QMap<QString, QMatchData>::iterator it2 = ci.begin();
            for (int i = 0; it2 != ci.end() && i < sz; i++, ++it2) {
                cost -= it2.value().indices.cost();
                ci.erase(it2);
            }
            if (ci.count() == 0)
                cache.erase(it1);
        }
    }

    if (c->cs == Qt::CaseInsensitive)
        part = part.toLower();
    cache[parent][part] = m;
}

///////////////////////////////////////////////////////////////////////////////////
QIndexMapper QSortedModelEngine::indexHint(QString part, const QModelIndex& parent, Qt::SortOrder order)
{
    const QAbstractItemModel *model = c->proxy->sourceModel();

    if (c->cs == Qt::CaseInsensitive)
        part = part.toLower();

    const CacheItem& map = cache[parent];

    // Try to find a lower and upper bound for the search from previous results
    int to = model->rowCount(parent) - 1;
    int from = 0;
    const CacheItem::const_iterator it = map.lowerBound(part);

    // look backward for first valid hint
    for(CacheItem::const_iterator it1 = it; it1-- != map.constBegin();) {
        const QMatchData& value = it1.value();
        if (value.isValid()) {
            if (order == Qt::AscendingOrder) {
                from = value.indices.last() + 1;
            } else {
                to = value.indices.first() - 1;
            }
            break;
        }
    }

    // look forward for first valid hint
    for(CacheItem::const_iterator it2 = it; it2 != map.constEnd(); ++it2) {
        const QMatchData& value = it2.value();
        if (value.isValid() && !it2.key().startsWith(part)) {
            if (order == Qt::AscendingOrder) {
                to = value.indices.first() - 1;
            } else {
                from = value.indices.first() + 1;
            }
            break;
        }
    }

    return QIndexMapper(from, to);
}

Qt::SortOrder QSortedModelEngine::sortOrder(const QModelIndex &parent) const
{
    const QAbstractItemModel *model = c->proxy->sourceModel();

    int rowCount = model->rowCount(parent);
    if (rowCount < 2)
        return Qt::AscendingOrder;
    QString first = model->data(model->index(0, c->column, parent), c->role).toString();
    QString last = model->data(model->index(rowCount - 1, c->column, parent), c->role).toString();
    return QString::compare(first, last, c->cs) <= 0 ? Qt::AscendingOrder : Qt::DescendingOrder;
}

QMatchData QSortedModelEngine::filter(const QString& part, const QModelIndex& parent, int)
{
    const QAbstractItemModel *model = c->proxy->sourceModel();

    QMatchData hint;
    if (lookupCache(part, parent, &hint))
        return hint;

    QIndexMapper indices;
    Qt::SortOrder order = sortOrder(parent);

    if (matchHint(part, parent, &hint)) {
        if (!hint.isValid())
            return QMatchData();
        indices = hint.indices;
    } else {
        indices = indexHint(part, parent, order);
    }

    // binary search the model within 'indices' for 'part' under 'parent'
    int high = indices.to() + 1;
    int low = indices.from() - 1;
    int probe;
    QModelIndex probeIndex;
    QString probeData;

    while (high - low > 1)
    {
        probe = (high + low) / 2;
        probeIndex = model->index(probe, c->column, parent);
        probeData = model->data(probeIndex, c->role).toString();
        const int cmp = QString::compare(probeData, part, c->cs);
        if ((order == Qt::AscendingOrder && cmp >= 0)
            || (order == Qt::DescendingOrder && cmp < 0)) {
            high = probe;
        } else {
            low = probe;
        }
    }

    if ((order == Qt::AscendingOrder && low == indices.to())
        || (order == Qt::DescendingOrder && high == indices.from())) { // not found
        saveInCache(part, parent, QMatchData());
        return QMatchData();
    }

    probeIndex = model->index(order == Qt::AscendingOrder ? low+1 : high-1, c->column, parent);
    probeData = model->data(probeIndex, c->role).toString();
    if (!probeData.startsWith(part, c->cs)) {
        saveInCache(part, parent, QMatchData());
        return QMatchData();
    }

    const bool exactMatch = QString::compare(probeData, part, c->cs) == 0;
    int emi =  exactMatch ? (order == Qt::AscendingOrder ? low+1 : high-1) : -1;

    int from = 0;
    int to = 0;
    if (order == Qt::AscendingOrder) {
        from = low + 1;
        high = indices.to() + 1;
        low = from;
    } else {
        to = high - 1;
        low = indices.from() - 1;
        high = to;
    }

    while (high - low > 1)
    {
        probe = (high + low) / 2;
        probeIndex = model->index(probe, c->column, parent);
        probeData = model->data(probeIndex, c->role).toString();
        const bool startsWith = probeData.startsWith(part, c->cs);
        if ((order == Qt::AscendingOrder && startsWith)
            || (order == Qt::DescendingOrder && !startsWith)) {
            low = probe;
        } else {
            high = probe;
        }
    }

    QMatchData m(order == Qt::AscendingOrder ? QIndexMapper(from, high - 1) : QIndexMapper(low+1, to), emi, false);
    saveInCache(part, parent, m);
    return m;
}

////////////////////////////////////////////////////////////////////////////////////////
int QUnsortedModelEngine::buildIndices(const QString& str, const QModelIndex& parent, int n,
                                      const QIndexMapper& indices, QMatchData* m)
{
    Q_ASSERT(m->partial);
    Q_ASSERT(n != -1 || m->exactMatchIndex == -1);
    const QAbstractItemModel *model = c->proxy->sourceModel();
    int i, count = 0;

    for (i = 0; i < indices.count() && count != n; ++i) {
        QModelIndex idx = model->index(indices[i], c->column, parent);
        QString data = model->data(idx, c->role).toString();
        if (!data.startsWith(str, c->cs))
            continue;
        m->indices.append(indices[i]);
        ++count;
        if (m->exactMatchIndex == -1 && QString::compare(data, str, c->cs) == 0) {
            m->exactMatchIndex = indices[i];
            if (n == -1)
                return indices[i];
        }
    }
    return indices[i-1];
}

void QUnsortedModelEngine::filterOnDemand(int n)
{
    Q_ASSERT(matchCount());
    if (!curMatch.partial)
        return;
    Q_ASSERT(n >= -1);
    const QAbstractItemModel *model = c->proxy->sourceModel();
    int lastRow = model->rowCount(curParent) - 1;
    QIndexMapper im(curMatch.indices.last() + 1, lastRow);
    int lastIndex = buildIndices(curParts.last(), curParent, n, im, &curMatch);
    curMatch.partial = (lastRow != lastIndex);
    saveInCache(curParts.last(), curParent, curMatch);
}

QMatchData QUnsortedModelEngine::filter(const QString& part, const QModelIndex& parent, int n)
{
    QMatchData hint;

    QVector<int> v;
    QIndexMapper im(v);
    QMatchData m(im, -1, true);

    const QAbstractItemModel *model = c->proxy->sourceModel();
    bool foundInCache = lookupCache(part, parent, &m);

    if (!foundInCache) {
        if (matchHint(part, parent, &hint) && !hint.isValid())
            return QMatchData();
    }

    if (!foundInCache && !hint.isValid()) {
        const int lastRow = model->rowCount(parent) - 1;
        QIndexMapper all(0, lastRow);
        int lastIndex = buildIndices(part, parent, n, all, &m);
        m.partial = (lastIndex != lastRow);
    } else {
        if (!foundInCache) { // build from hint as much as we can
            buildIndices(part, parent, INT_MAX, hint.indices, &m);
            m.partial = hint.partial;
        }
        if (m.partial && ((n == -1 && m.exactMatchIndex == -1) || (m.indices.count() < n))) {
            // need more and have more
            const int lastRow = model->rowCount(parent) - 1;
            QIndexMapper rest(hint.indices.last() + 1, lastRow);
            int want = n == -1 ? -1 : n - m.indices.count();
            int lastIndex = buildIndices(part, parent, want, rest, &m);
            m.partial = (lastRow != lastIndex);
        }
    }

    saveInCache(part, parent, m);
    return m;
}

///////////////////////////////////////////////////////////////////////////////
QCompleterPrivate::QCompleterPrivate()
: widget(0), proxy(0), popup(0), cs(Qt::CaseSensitive), role(Qt::EditRole), column(0),
  sorting(QCompleter::UnsortedModel), wrap(true), eatFocusOut(true)
{
}

void QCompleterPrivate::init(QAbstractItemModel *m)
{
    Q_Q(QCompleter);
    proxy = new QCompletionModel(this, q);
    QObject::connect(proxy, SIGNAL(rowsAdded()), q, SLOT(_q_autoResizePopup()));
    q->setModel(m);
#ifdef QT_NO_LISTVIEW
    q->setCompletionMode(QCompleter::InlineCompletion);
#else
    q->setCompletionMode(QCompleter::PopupCompletion);
#endif // QT_NO_LISTVIEW
}

void QCompleterPrivate::setCurrentIndex(QModelIndex index, bool select)
{
    Q_Q(QCompleter);
    if (!q->popup())
        return;
    if (!select) {
        popup->selectionModel()->setCurrentIndex(index, QItemSelectionModel::NoUpdate);
    } else {
        if (!index.isValid())
            popup->selectionModel()->clear();
        else
            popup->selectionModel()->setCurrentIndex(index, QItemSelectionModel::Select
                                                            | QItemSelectionModel::Rows);
    }
    index = popup->selectionModel()->currentIndex();
    if (!index.isValid())
        popup->scrollToTop();
    else
        popup->scrollTo(index, QAbstractItemView::PositionAtTop);
}

void QCompleterPrivate::_q_completionSelected(const QItemSelection& selection)
{
    QModelIndex index;
    if (!selection.indexes().isEmpty())
        index = selection.indexes().first();

    _q_complete(index, true);
}

void QCompleterPrivate::_q_complete(QModelIndex index, bool highlighted)
{
    Q_Q(QCompleter);
    QString completion;

    if (!index.isValid())
        completion = prefix;
    else {
        QModelIndex si = proxy->mapToSource(index);
        si = si.sibling(si.row(), column); // for clicked()
        completion = q->pathFromIndex(si);
#ifndef QT_NO_DIRMODEL
        // add a trailing separator in inline
        if (mode == QCompleter::InlineCompletion) {
            if (qobject_cast<QDirModel *>(proxy->sourceModel()) && QFileInfo(completion).isDir())
                completion += QDir::separator();
        }
#endif
    }

    if (highlighted) {
        emit q->highlighted(index);
        emit q->highlighted(completion);
    } else {
        emit q->activated(index);
        emit q->activated(completion);
    }
}