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#include "qhelpcontentwidget.h"

#include "qhelpenginecore.h"

#include "qhelpengine_p.h"

#include "qhelpdbreader_p.h"

#include <QtCore/QDir>

#include <QtCore/QStack>

#include <QtCore/QThread>

#include <QtCore/QMutex>

#include <QtGui/QHeaderView>

QT_BEGIN_NAMESPACE

class QHelpContentItemPrivate

{

public:

    QHelpContentItemPrivate(const QString &t, const QString &l,

                            QHelpDBReader *r, QHelpContentItem *p)

    {

        parent = p;

        title = t;

        link = l;

        helpDBReader = r;

    }

    QList<QHelpContentItem*> childItems;

    QHelpContentItem *parent;

    QString title;

    QString link;

    QHelpDBReader *helpDBReader;

};

class QHelpContentProvider : public QThread

{

public:

    QHelpContentProvider(QHelpEnginePrivate *helpEngine);

    ~QHelpContentProvider();

    void collectContents(const QString &customFilterName);

    void stopCollecting();

    QHelpContentItem *rootItem();

    int nextChildCount() const;

private:

    void run();

    QHelpEnginePrivate *m_helpEngine;

    QHelpContentItem *m_rootItem;

    QStringList m_filterAttributes;

    QQueue<QHelpContentItem*> m_rootItems;

    QMutex m_mutex;

    bool m_abort;

};

class QHelpContentModelPrivate

{

public:

    QHelpContentItem *rootItem;

    QHelpContentProvider *qhelpContentProvider;

};

/*!

    \class QHelpContentItem

    \inmodule QtHelp

    \brief The QHelpContentItem class provides an item for use with QHelpContentModel.

    \since 4.4

*/

QHelpContentItem::QHelpContentItem(const QString &name, const QString &link,

                                   QHelpDBReader *reader, QHelpContentItem *parent)

{

    d = new QHelpContentItemPrivate(name, link, reader, parent);

}

/*!

    Destroys the help content item.

*/

QHelpContentItem::~QHelpContentItem()

{

    qDeleteAll(d->childItems);

    delete d;

}

void QHelpContentItem::appendChild(QHelpContentItem *item)

{

    d->childItems.append(item);

}

/*!

    Returns the child of the content item in the give \a row.

    \sa parent()

*/

QHelpContentItem *QHelpContentItem::child(int row) const

{

    if (row >= childCount())

        return 0;

    return d->childItems.value(row);

}

/*!

    Returns the number of child items.

*/

int QHelpContentItem::childCount() const

{

    return d->childItems.count();

}

/*!

    Returns the row of this item from its parents view.

*/

int QHelpContentItem::row() const

{

    if (d->parent)

        return d->parent->d->childItems.indexOf(const_cast<QHelpContentItem*>(this));

    return 0;

}

/*!

    Returns the title of the content item.

*/

QString QHelpContentItem::title() const

{

    return d->title;

}

/*!

    Returns the URL of this content item.

*/

QUrl QHelpContentItem::url() const

{

    return d->helpDBReader->urlOfPath(d->link);

}

/*!

    Returns the parent content item.

*/

QHelpContentItem *QHelpContentItem::parent() const

{

    return d->parent;

}

/*!

    Returns the position of a given \a child.

*/

int QHelpContentItem::childPosition(QHelpContentItem *child) const

{

    return d->childItems.indexOf(child);

}

QHelpContentProvider::QHelpContentProvider(QHelpEnginePrivate *helpEngine)

    : QThread(helpEngine)

{

    m_helpEngine = helpEngine;

    m_rootItem = 0;

    m_abort = false;

}

QHelpContentProvider::~QHelpContentProvider()

{

    stopCollecting();

}

void QHelpContentProvider::collectContents(const QString &customFilterName)

{

    m_mutex.lock();

    m_filterAttributes = m_helpEngine->q->filterAttributes(customFilterName);

    m_mutex.unlock();

    if (!isRunning()) {

        start(LowPriority);

    } else {

        stopCollecting();

        start(LowPriority);

    }

}

void QHelpContentProvider::stopCollecting()

{

    if (!isRunning())

        return;

    m_mutex.lock();

    m_abort = true;

    m_mutex.unlock();

    wait();

}

QHelpContentItem *QHelpContentProvider::rootItem()

{

    QMutexLocker locker(&m_mutex);

    return m_rootItems.dequeue();

}

int QHelpContentProvider::nextChildCount() const

{

    return m_rootItems.head()->childCount();

}

void QHelpContentProvider::run()

{

    QString title;

    QString link;

    int depth = 0;

    QHelpContentItem *item = 0;

    m_mutex.lock();

    m_rootItem = new QHelpContentItem(QString(), QString(), 0);

    m_rootItems.enqueue(m_rootItem);

    QStringList atts = m_filterAttributes;

    const QStringList fileNames = m_helpEngine->orderedFileNameList;

    m_mutex.unlock();

    foreach (const QString &dbFileName, fileNames) {

        m_mutex.lock();

        if (m_abort) {

            m_abort = false;

            m_mutex.unlock();

            break;

        }

        m_mutex.unlock();

        QHelpDBReader reader(dbFileName,

            QHelpGlobal::uniquifyConnectionName(dbFileName +

            QLatin1String("FromQHelpContentProvider"),

            QThread::currentThread()), 0);

        if (!reader.init())

            continue;

        foreach (const QByteArray& ba, reader.contentsForFilter(atts)) {

            if (ba.size() < 1)

                continue;

            int _depth = 0;

            bool _root = false;

            QStack<QHelpContentItem*> stack;

            QDataStream s(ba);

            for (;;) {

                s >> depth;

                s >> link;

                s >> title;

                if (title.isEmpty())

                    break;

CHECK_DEPTH:

                if (depth == 0) {

                    m_mutex.lock();

                    item = new QHelpContentItem(title, link,

                        m_helpEngine->fileNameReaderMap.value(dbFileName), m_rootItem);

                    m_rootItem->appendChild(item);

                    m_mutex.unlock();

                    stack.push(item);

                    _depth = 1;

                    _root = true;

                } else {

                    if (depth > _depth && _root) {

                        _depth = depth;

                        stack.push(item);

                    }

                    if (depth == _depth) {

                        item = new QHelpContentItem(title, link,

                            m_helpEngine->fileNameReaderMap.value(dbFileName), stack.top());

                        stack.top()->appendChild(item);

                    } else if (depth < _depth) {

                        stack.pop();

                        --_depth;

                        goto CHECK_DEPTH;

                    }

                }

            }

        }

    }

    m_mutex.lock();

    m_abort = false;

    m_mutex.unlock();

}

/*!

    \class QHelpContentModel

    \inmodule QtHelp

    \brief The QHelpContentModel class provides a model that supplies content to views.

    \since 4.4

*/

/*!

    \fn void QHelpContentModel::contentsCreationStarted()

    This signal is emitted when the creation of the contents has

    started. The current contents are invalid from this point on

    until the signal contentsCreated() is emitted.

    \sa isCreatingContents()

*/

/*!

    \fn void QHelpContentModel::contentsCreated()

    This signal is emitted when the contents have been created.

*/

QHelpContentModel::QHelpContentModel(QHelpEnginePrivate *helpEngine)

    : QAbstractItemModel(helpEngine)

{

    d = new QHelpContentModelPrivate();

    d->rootItem = 0;

    d->qhelpContentProvider = new QHelpContentProvider(helpEngine);

    connect(d->qhelpContentProvider, SIGNAL(finished()),

        this, SLOT(insertContents()), Qt::QueuedConnection);

    connect(helpEngine->q, SIGNAL(setupStarted()), this, SLOT(invalidateContents()));

}

/*!

    Destroys the help content model.

*/

QHelpContentModel::~QHelpContentModel()

{

    delete d->rootItem;

    delete d;

}

void QHelpContentModel::invalidateContents(bool onShutDown)

{

    if (onShutDown)

        disconnect(this, SLOT(insertContents()));

    d->qhelpContentProvider->stopCollecting();

    if (d->rootItem) {

        delete d->rootItem;

        d->rootItem = 0;

    }

    if (!onShutDown)

        reset();

}

/*!

    Creates new contents by querying the help system

    for contents specified for the \a customFilterName.

*/

void QHelpContentModel::createContents(const QString &customFilterName)

{

    d->qhelpContentProvider->collectContents(customFilterName);

    emit contentsCreationStarted();

}

void QHelpContentModel::insertContents()

{

    int count;

    if (d->rootItem) {

        count = d->rootItem->childCount() - 1;

        beginRemoveRows(QModelIndex(), 0, count > 0 ? count : 0);

        delete d->rootItem;

        d->rootItem = 0;

        endRemoveRows();

    }

    count = d->qhelpContentProvider->nextChildCount() - 1;

    beginInsertRows(QModelIndex(), 0, count > 0 ? count : 0);

    d->rootItem = d->qhelpContentProvider->rootItem();

    endInsertRows();

    reset();

    emit contentsCreated();

}

/*!

    Returns true if the contents are currently rebuilt, otherwise

    false.

*/

bool QHelpContentModel::isCreatingContents() const

{

    return d->qhelpContentProvider->isRunning();

}

/*!

    Returns the help content item at the model index position

    \a index.

*/

QHelpContentItem *QHelpContentModel::contentItemAt(const QModelIndex &index) const

{

    if (index.isValid())

        return static_cast<QHelpContentItem*>(index.internalPointer());

    else

        return d->rootItem;

}

/*!

    Returns the index of the item in the model specified by

    the given \a row, \a column and \a parent index.

*/

QModelIndex QHelpContentModel::index(int row, int column, const QModelIndex &parent) const

{

    if (!d->rootItem)

        return QModelIndex();

    QHelpContentItem *parentItem = contentItemAt(parent);

    QHelpContentItem *item = parentItem->child(row);

    if (!item)

        return QModelIndex();

    return createIndex(row, column, item);

}

/*!

    Returns the parent of the model item with the given

    \a index, or QModelIndex() if it has no parent.

*/

QModelIndex QHelpContentModel::parent(const QModelIndex &index) const

{

    QHelpContentItem *item = contentItemAt(index);

    if (!item)

        return QModelIndex();

    QHelpContentItem *parentItem = static_cast<QHelpContentItem*>(item->parent());

    if (!parentItem)

        return QModelIndex();

    QHelpContentItem *grandparentItem = static_cast<QHelpContentItem*>(parentItem->parent());

    if (!grandparentItem)

        return QModelIndex();

    int row = grandparentItem->childPosition(parentItem);

    return createIndex(row, index.column(), parentItem);

}

/*!

    Returns the number of rows under the given \a parent.

*/

int QHelpContentModel::rowCount(const QModelIndex &parent) const

{

    QHelpContentItem *parentItem = contentItemAt(parent);

    if (!parentItem)

        return 0;

    return parentItem->childCount();

}

/*!

    Returns the number of columns under the given \a parent. Currently returns always 1.

*/

int QHelpContentModel::columnCount(const QModelIndex &parent) const

{

    Q_UNUSED(parent)

    return 1;

}

/*!

    Returns the data stored under the given \a role for

    the item referred to by the \a index.

*/

QVariant QHelpContentModel::data(const QModelIndex &index, int role) const

{

    if (role != Qt::DisplayRole)

        return QVariant();

    QHelpContentItem *item = contentItemAt(index);

    if (!item)

        return QVariant();

    return item->title();

}

/*!

    \class QHelpContentWidget

    \inmodule QtHelp

    \brief The QHelpContentWidget class provides a tree view for displaying help content model items.

    \since 4.4

*/

/*!

    \fn void QHelpContentWidget::linkActivated(const QUrl &link)

    This signal is emitted when a content item is activated and

    its associated \a link should be shown.

*/

QHelpContentWidget::QHelpContentWidget()

    : QTreeView(0)

{

    header()->hide();

    setUniformRowHeights(true);

    connect(this, SIGNAL(activated(QModelIndex)),

        this, SLOT(showLink(QModelIndex)));

}

/*!

    Returns the index of the content item with the \a link.

    An invalid index is returned if no such an item exists.