Qt实现文件树

#include 
#include 
#include 
#include "filetree.h"

FileTree::FileTree(const QXmlNamePool& pool)
  : QSimpleXmlNodeModel(pool),
    m_filterAllowAll(QDir::AllEntries |
                     QDir::AllDirs |
                     QDir::NoDotAndDotDot |
                     QDir::Hidden),
    m_sortFlags(QDir::Name)
{
    QXmlNamePool np = namePool();
    m_names.resize(7);
    m_names[File]               = QXmlName(np, QLatin1String("file"));
    m_names[Directory]          = QXmlName(np, QLatin1String("directory"));
    m_names[AttributeFileName]  = QXmlName(np, QLatin1String("fileName"));
    m_names[AttributeFilePath]  = QXmlName(np, QLatin1String("filePath"));
    m_names[AttributeSize]      = QXmlName(np, QLatin1String("size"));
    m_names[AttributeMIMEType]  = QXmlName(np, QLatin1String("mimeType"));
    m_names[AttributeSuffix]    = QXmlName(np, QLatin1String("suffix"));
}

QXmlNodeModelIndex FileTree::nodeFor(const QString& dirName) const
{
    QFileInfo dirInfo(QDir::cleanPath(dirName));
    Q_ASSERT(dirInfo.exists());
    return toNodeIndex(dirInfo);
}

const QFileInfo&
FileTree::toFileInfo(const QXmlNodeModelIndex &nodeIndex) const
{
    return m_fileInfos.at(nodeIndex.data());
}

QXmlNodeModelIndex
FileTree::toNodeIndex(const QFileInfo &fileInfo, Type attributeName) const
{
    const int indexOf = m_fileInfos.indexOf(fileInfo);

    if (indexOf == -1) {
        m_fileInfos.append(fileInfo);
        return createIndex(m_fileInfos.count()-1, attributeName);
    }
    else
        return createIndex(indexOf, attributeName);
}

QXmlNodeModelIndex FileTree::toNodeIndex(const QFileInfo &fileInfo) const
{
    return toNodeIndex(fileInfo, fileInfo.isDir() ? Directory : File);
}

QXmlNodeModelIndex FileTree::nextSibling(const QXmlNodeModelIndex &nodeIndex,
                                         const QFileInfo &fileInfo,
                                         qint8 offset) const
{
    Q_ASSERT(offset == -1 || offset == 1);

    // Get the context node's parent.
    const QXmlNodeModelIndex parent(nextFromSimpleAxis(Parent, nodeIndex));

    if (parent.isNull())
        return QXmlNodeModelIndex();

    // Get the parent's child list.
    const QFileInfo parentFI(toFileInfo(parent));
    Q_ASSERT(Type(parent.additionalData()) == Directory);
    const QFileInfoList siblings(QDir(parentFI.absoluteFilePath()).entryInfoList(QStringList(),
                                                                                 m_filterAllowAll,
                                                                                 m_sortFlags));
    Q_ASSERT_X(!siblings.isEmpty(), Q_FUNC_INFO, "Can't happen! We started at a child.");

    // Find the index of the child where we started.
    const int indexOfMe = siblings.indexOf(fileInfo);

    // Apply the offset.
    const int siblingIndex = indexOfMe + offset;
    if (siblingIndex < 0 || siblingIndex > siblings.count() - 1)
        return QXmlNodeModelIndex();
    else
        return toNodeIndex(siblings.at(siblingIndex));
}
//! [5]


QXmlNodeModelIndex
FileTree::nextFromSimpleAxis(SimpleAxis axis, const QXmlNodeModelIndex &nodeIndex) const
{
    const QFileInfo fi(toFileInfo(nodeIndex));
    const Type type = Type(nodeIndex.additionalData());

    if (type != File && type != Directory) {
        Q_ASSERT_X(axis == Parent, Q_FUNC_INFO, "An attribute only has a parent!");
        return toNodeIndex(fi, Directory);
    }

    switch (axis) {
        case Parent:
            return toNodeIndex(QFileInfo(fi.path()), Directory);

        case FirstChild:
        {
            if (type == File) // A file has no children.
                return QXmlNodeModelIndex();
            else {
                Q_ASSERT(type == Directory);
                Q_ASSERT_X(fi.isDir(), Q_FUNC_INFO, "It isn't really a directory!");
                const QDir dir(fi.absoluteFilePath());
                Q_ASSERT(dir.exists());

                const QFileInfoList children(dir.entryInfoList(QStringList(),
                                                               m_filterAllowAll,
                                                               m_sortFlags));
                if (children.isEmpty())
                    return QXmlNodeModelIndex();
                const QFileInfo firstChild(children.first());
                return toNodeIndex(firstChild);
            }
        }

        case PreviousSibling:
            return nextSibling(nodeIndex, fi, -1);

        case NextSibling:
            return nextSibling(nodeIndex, fi, 1);
    }

    Q_ASSERT_X(false, Q_FUNC_INFO, "Don't ever get here!");
    return QXmlNodeModelIndex();
}

QUrl FileTree::documentUri(const QXmlNodeModelIndex &node) const
{
    Q_UNUSED(node);
    return QUrl("file:///");
}

QXmlNodeModelIndex::NodeKind
FileTree::kind(const QXmlNodeModelIndex &node) const
{
    switch (Type(node.additionalData())) {
        case Directory:
        case File:
            return QXmlNodeModelIndex::Element;
        default:
            return QXmlNodeModelIndex::Attribute;
    }
}


QXmlNodeModelIndex::DocumentOrder
FileTree::compareOrder(const QXmlNodeModelIndex&,
                       const QXmlNodeModelIndex&) const
{
    return QXmlNodeModelIndex::Is;
}

QXmlName FileTree::name(const QXmlNodeModelIndex &node) const
{
    return m_names.at(node.additionalData());
}

QXmlNodeModelIndex FileTree::root(const QXmlNodeModelIndex &node) const
{
    Q_UNUSED(node);
    return toNodeIndex(QFileInfo(QLatin1String("/")));
}

QVariant FileTree::typedValue(const QXmlNodeModelIndex &node) const
{
    const QFileInfo &fi = toFileInfo(node);

    switch (Type(node.additionalData())) {
        case Directory:
            // deliberate fall through.
        case File:
            return QString();
        case AttributeFileName:
            return fi.fileName();
        case AttributeFilePath:
            return fi.filePath();
        case AttributeSize:
            return fi.size();
        case AttributeMIMEType:
            {
                /* We don't have any MIME detection code currently, so return
                 * the most generic one. */
                return QLatin1String("application/octet-stream");
            }
        case AttributeSuffix:
            return fi.suffix();
    }

    Q_ASSERT_X(false, Q_FUNC_INFO, "This line should never be reached.");
    return QString();
}


QVector<QXmlNodeModelIndex>
FileTree::attributes(const QXmlNodeModelIndex &element) const
{
    QVector<QXmlNodeModelIndex> result;

    /* Both elements has this attribute. */
    const QFileInfo &forElement = toFileInfo(element);
    result.append(toNodeIndex(forElement, AttributeFilePath));
    result.append(toNodeIndex(forElement, AttributeFileName));

    if (Type(element.additionalData() == File)) {
        result.append(toNodeIndex(forElement, AttributeSize));
        result.append(toNodeIndex(forElement, AttributeSuffix));
        //result.append(toNodeIndex(forElement, AttributeMIMEType));
    }
    else {
        Q_ASSERT(element.additionalData() == Directory);
    }

    return result;
}