q3mimefactory.cpp

奇趣公司比较新的qt/emd版本

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#include "q3mimefactory.h"

#ifndef QT_NO_MIMEFACTORY

#include "qmap.h"
#include "qmime.h"
#include "qstringlist.h"
#include "qfileinfo.h"
#include "qdir.h"
#include "q3dragobject.h"
#include "qpixmap.h"
#include "qimagereader.h"
#include "q3cleanuphandler.h"
#include "private/qtextimagehandler_p.h"

static Q3MimeSourceFactory* defaultfactory = 0;
static Q3SingleCleanupHandler<Q3MimeSourceFactory> qmime_cleanup_factory;

class Q3MimeSourceFactoryData {
public:
    Q3MimeSourceFactoryData() :
        last(0)
    {
    }

    ~Q3MimeSourceFactoryData()
    {
        QMap<QString, QMimeSource*>::Iterator it = stored.begin();
        while (it != stored.end()) {
            delete *it;
            ++it;
        }
        delete last;
    }

    QMap<QString, QMimeSource*> stored;
    QMap<QString, QString> extensions;
    QStringList path;
    QMimeSource* last;
    QList<Q3MimeSourceFactory*> factories;
};

static QImage richTextImageLoader(const QString &name, const QString &context)
{
    QImage img;

    const QMimeSource *src = Q3MimeSourceFactory::defaultFactory()->data(name, context);
    if (src && Q3ImageDrag::decode(src, img))
        return img;

    return QImage();
}

/*!
    \class Q3MimeSourceFactory
    \brief The Q3MimeSourceFactory class is an extensible provider of mime-typed data.

    \compat

    A Q3MimeSourceFactory provides an abstract interface to a
    collection of information. Each piece of information is
    represented by a QMimeSource object which can be examined and
    converted to concrete data types by functions such as
    Q3ImageDrag::canDecode() and Q3ImageDrag::decode().

    The base Q3MimeSourceFactory can be used in two ways: as an
    abstraction of a collection of files or as specifically stored
    data. For it to access files, call setFilePath() before accessing
    data. For stored data, call setData() for each item (there are
    also convenience functions, e.g. setText(), setImage() and
    setPixmap(), that simply call setData() with appropriate
    parameters).

    The rich text widgets, QTextEdit and QTextBrowser, use
    Q3MimeSourceFactory to resolve references such as images or links
    within rich text documents. They either access the default factory
    (see \l{defaultFactory()}) or their own. Other classes that are
    capable of displaying rich text (such as QLabel, QWhatsThis or
    QMessageBox) always use the default factory.

    A factory can also be used as a container to store data associated
    with a name. This technique is useful whenever rich text contains
    images that are stored in the program itself, not loaded from the
    hard disk. Your program may, for example, define some image data
    as:
    \code
    static const char* myimage_data[]={
    "...",
    ...
    "..."};
    \endcode

    To be able to use this image within some rich text, for example
    inside a QLabel, you must create a QImage from the raw data and
    insert it into the factory with a unique name:
    \code
    Q3MimeSourceFactory::defaultFactory()->setImage("myimage", QImage(myimage_data));
    \endcode

    Now you can create a rich text QLabel with

    \code
    QLabel* label = new QLabel(
        "Rich text with embedded image:<img source=\"myimage\">"
        "Isn't that <em>cute</em>?");
    \endcode

    When no longer needed, you can clear the data from the factory:

    \code
    delete label;
    Q3MimeSourceFactory::defaultFactory()->setData("myimage", 0);
    \endcode
*/


/*!
    Constructs a Q3MimeSourceFactory that has no file path and no
    stored content.
*/
Q3MimeSourceFactory::Q3MimeSourceFactory() :
    d(new Q3MimeSourceFactoryData)
{
    addFilePath(QLatin1String(":/qt/q3mimesourcefactory/")); //to get from the resources
    // add some reasonable defaults
    setExtensionType(QLatin1String("htm"), "text/html;charset=iso8859-1");
    setExtensionType(QLatin1String("html"), "text/html;charset=iso8859-1");
    setExtensionType(QLatin1String("txt"), "text/plain");
    setExtensionType(QLatin1String("xml"), "text/xml;charset=UTF-8");
    setExtensionType(QLatin1String("jpg"), "image/jpeg"); // support misspelled jpeg files
}

/*!
    Destroys the Q3MimeSourceFactory, deleting all stored content.
*/
Q3MimeSourceFactory::~Q3MimeSourceFactory()
{
    if (defaultFactory() == this)
        defaultfactory = 0;
    delete d;
}

QMimeSource* Q3MimeSourceFactory::dataInternal(const QString& abs_name, const QMap<QString, QString> &extensions) const
{
    QMimeSource* r = 0;
    QStringList attempted_names(abs_name);
    QFileInfo fi(abs_name);
    if (fi.isReadable()) {
        // get the right mimetype
        QString e = fi.extension(false);
        QByteArray mimetype("application/octet-stream");
        if (extensions.contains(e))
            mimetype = extensions[e].latin1();
        QByteArray imgfmt = QImageReader::imageFormat(abs_name);
        if (!imgfmt.isEmpty())
            mimetype = "image/" + imgfmt.toLower();

        QFile f(abs_name);
        if (f.open(QIODevice::ReadOnly) && f.size()) {
            QByteArray ba;
            ba.resize(f.size());
            f.readBlock(ba.data(), ba.size());
            Q3StoredDrag* sr = new Q3StoredDrag(mimetype);
            sr->setEncodedData(ba);
            delete d->last;
            d->last = r = sr;
        }
    }

    // we didn't find the mime-source, so ask the default factory for
    // the mime-source (this one will iterate over all installed ones)
    //
    // this looks dangerous, as this dataInternal() function will be
    // called again when the default factory loops over all installed
    // factories (including this), but the static bool looping in
    // data() avoids endless recursions
    if (!r && this != defaultFactory())
        r = (QMimeSource*)defaultFactory()->data(abs_name);

    return r;
}


/*!
    Returns a reference to the data associated with \a abs_name. The
    return value remains valid only until the next data() or setData()
    call, so you should immediately decode the result.

    If there is no data associated with \a abs_name in the factory's
    store, the factory tries to access the local filesystem. If \a
    abs_name isn't an absolute file name, the factory will search for
    it in all defined paths (see \l{setFilePath()}).

    The factory understands all the image formats supported by
    QImageReader. Any other mime types are determined by the file name
    extension. The default settings are
    \code
    setExtensionType("html", "text/html;charset=iso8859-1");
    setExtensionType("htm", "text/html;charset=iso8859-1");
    setExtensionType("txt", "text/plain");
    setExtensionType("xml", "text/xml;charset=UTF-8");
    \endcode
    The effect of these is that file names ending in "txt" will be
    treated as text encoded in the local encoding; those ending in
    "xml" will be treated as text encoded in Unicode UTF-8 encoding.
    The text/html type is treated specially, since the encoding can be
    specified in the html file itself. "html" or "htm" will be treated
    as text encoded in the encoding specified by the html meta tag, if
    none could be found, the charset of the mime type will be used.
    The text subtype ("html", "plain", or "xml") does not affect the
    factory, but users of the factory may behave differently. We
    recommend creating "xml" files where practical. These files can be
    viewed regardless of the runtime encoding and can encode any
    Unicode characters without resorting to encoding definitions
    inside the file.

    Any file data that is not recognized will be retrieved as a
    QMimeSource providing the "application/octet-stream" mime type,
    meaning uninterpreted binary data.

    You can add further extensions or change existing ones with
    subsequent calls to setExtensionType(). If the extension mechanism
    is not sufficient for your problem domain, you can inherit
    Q3MimeSourceFactory and reimplement this function to perform some
    more specialized mime-type detection. The same applies if you want
    to use the mime source factory to access URL referenced data over
    a network.
*/
const QMimeSource *Q3MimeSourceFactory::data(const QString& abs_name) const
{
    if (d->stored.contains(abs_name))
        return d->stored[abs_name];

    const QMimeSource *r = 0;
    if (abs_name.isEmpty())
        return r;
    QStringList::Iterator it;
    if (abs_name[0] == QLatin1Char('/')
#ifdef Q_WS_WIN
            || (abs_name[0].isLetter() && abs_name[1] == QLatin1Char(':')) || abs_name.startsWith(QLatin1String("\\\\"))
#endif
   )
    {