q3dragobject.cpp

奇趣公司比较新的qt/emd版本

const char * Q3TextDrag::format(int i) const
{
    if (i > 0)
        return 0;
    return d_func()->fmt.constData();
}

QTextCodec* qt_findcharset(const QByteArray& mimetype)
{
    int i=mimetype.indexOf("charset=");
    if (i >= 0) {
        QByteArray cs = mimetype.mid(i+8);
        stripws(cs);
        i = cs.indexOf(';');
        if (i >= 0)
            cs = cs.left(i);
        // win98 often has charset=utf16, and we need to get the correct codec for
        // it to be able to get Unicode text drops.
        if (cs == "utf16")
            cs = "ISO-10646-UCS-2";
        // May return 0 if unknown charset
        return QTextCodec::codecForName(cs);
    }
    // no charset=, use locale
    return QTextCodec::codecForName("utf-8");
}

static QTextCodec *codecForHTML(const QByteArray &ba)
{
    // determine charset
    int mib = 0;
    int pos;
    QTextCodec *c = 0;

    if (ba.size() > 1 && (((uchar)ba[0] == 0xfe && (uchar)ba[1] == 0xff)
                          || ((uchar)ba[0] == 0xff && (uchar)ba[1] == 0xfe))) {
        mib = 1015; // utf16
    } else if (ba.size() > 2
               && (uchar)ba[0] == 0xef
               && (uchar)ba[1] == 0xbb
               && (uchar)ba[2] == 0xbf) {
        mib = 106; // utf-8
    } else {
        pos = 0;
        while ((pos = ba.indexOf('<', pos)) != -1) {
            int end = ba.indexOf('>', pos+1);
            if (end == -1)
                break;
            const QString str(QString::fromLatin1(ba.mid(pos, end-pos)));
            if (str.contains(QLatin1String("meta http-equiv="), Qt::CaseInsensitive)) {
                pos = str.indexOf(QLatin1String("charset="), 0, Qt::CaseInsensitive) + int(strlen("charset="));
                if (pos != -1) {
                    int pos2 = ba.indexOf('\"', pos+1);
                    QByteArray cs = ba.mid(pos, pos2-pos);
                    c = QTextCodec::codecForName(cs);
                    if (c)
                        return c;
                }
            }
            pos = end;
        }
    }
    if (mib)
        c = QTextCodec::codecForMib(mib);

    return c;
}

static
QTextCodec* findcodec(const QMimeSource* e)
{
    QTextCodec* r = 0;
    const char* f;
    int i;
    for (i=0; (f=e->format(i)); i++) {
        bool html = !qstrnicmp(f, "text/html", 9);
        if (html)
            r = codecForHTML(e->encodedData(f));
        if (!r)
            r = qt_findcharset(QByteArray(f).toLower());
        if (r)
            return r;
    }
    return 0;
}



/*!
    \reimp
*/
QByteArray Q3TextDrag::encodedData(const char* mime) const
{
    Q_D(const Q3TextDrag);
    if (mime != d->fmt)
        return QByteArray();
    return d->txt.toUtf8();
}

/*!
    \fn bool Q3TextDrag::canDecode(const QMimeSource *source)

    Returns true if the information in the MIME \a source can be decoded
    into a QString; otherwise returns false.

    \sa decode()
*/
bool Q3TextDrag::canDecode(const QMimeSource* e)
{
    const char* f;
    for (int i=0; (f=e->format(i)); i++) {
        if (0==qstrnicmp(f,"text/",5)) {
            return findcodec(e) != 0;
        }
    }
    return false;
}

/*!
    \fn bool Q3TextDrag::decode(const QMimeSource *source, QString &string, QString &subtype)

    \overload

    Attempts to decode the dropped information in the MIME \a source into
    the \a string given.
    Returns true if successful; otherwise returns false. If \a subtype
    is null, any text subtype is accepted; otherwise only the
    specified \a subtype is accepted.

    \sa canDecode()
*/
bool Q3TextDrag::decode(const QMimeSource* e, QString& str, QString& subtype)
{
    if(!e)
        return false;

    const char* mime;
    for (int i=0; (mime = e->format(i)); i++) {
        if (0==qstrnicmp(mime,"text/",5)) {
            QByteArray m(mime);
            m = m.toLower();
            int semi = m.indexOf(';');
            if (semi < 0)
                semi = m.length();
            QString foundst(QString::fromLatin1(m.mid(5,semi-5)));
            if (subtype.isNull() || foundst == subtype) {
                bool html = !qstrnicmp(mime, "text/html", 9);
                QTextCodec* codec = 0;
                if (html)
                    // search for the charset tag in the HTML
                    codec = codecForHTML(e->encodedData(mime));
                if (!codec)
                    codec = qt_findcharset(m);
                if (codec) {
                    QByteArray payload;

                    payload = e->encodedData(mime);
                    if (payload.size()) {
                        int l;
                        if (codec->mibEnum() != 1015) {
                            // length is at NUL or payload.size()
                            l = 0;
                            while (l < (int)payload.size() && payload[l])
                                l++;
                        } else {
                            l = payload.size();
                        }

                        str = codec->toUnicode(payload,l);

                        if (subtype.isNull())
                            subtype = foundst;

                        return true;
                    }
                }
            }
        }
    }
    return false;
}

/*!
    \fn bool Q3TextDrag::decode(const QMimeSource *source, QString &string)

    Attempts to decode the dropped information in the MIME \a source into
    the \a string given.
    Returns true if successful; otherwise returns false.

    \sa canDecode()
*/
bool Q3TextDrag::decode(const QMimeSource* e, QString& str)
{
    QString st;
    return decode(e, str, st);
}


/*
  Q3ImageDrag could use an internal MIME type for communicating QPixmaps
  and QImages rather than always converting to raw data. This is available
  for that purpose and others. It is not currently used.
*/

/*!
    \class Q3ImageDrag qdragobject.h

    \brief The Q3ImageDrag class provides a drag and drop object for
    transferring images.

    \compat

    Images are offered to the receiving application in multiple
    formats, determined by Qt's output formats.
*/

/*!
    Constructs an image drag object with the given \a name, and sets its
    data to \a image. The \a dragSource is the widget that the drag operation
    started from.
*/

Q3ImageDrag::Q3ImageDrag(QImage image,
                        QWidget * dragSource, const char * name)
    : Q3DragObject(*(new Q3ImageDragPrivate), dragSource)
{
    setObjectName(QLatin1String(name));
    setImage(image);
}

/*!
    Constructs a default image drag object with the given \a name.
    The \a dragSource is the widget that the drag operation started from.
*/

Q3ImageDrag::Q3ImageDrag(QWidget * dragSource, const char * name)
    : Q3DragObject(*(new Q3ImageDragPrivate), dragSource)
{
    setObjectName(QLatin1String(name));
}

/*! \internal */
Q3ImageDrag::Q3ImageDrag(Q3ImageDragPrivate &dd, QWidget *dragSource)
    : Q3DragObject(dd, dragSource)
{
}

/*!
    Destroys the image drag object.
*/

Q3ImageDrag::~Q3ImageDrag()
{
    // nothing
}


/*!
    Sets the \a image to be dragged. You will need to call this if you did
    not pass the image during construction.
*/
void Q3ImageDrag::setImage(QImage image)
{
    Q_D(Q3ImageDrag);
    d->img = image;
    QList<QByteArray> formats = QImageWriter::supportedImageFormats();
    formats.removeAll("PBM"); // remove non-raw PPM
    if (image.depth()!=32) {
        // BMP better than PPM for paletted images
        if (formats.removeAll("BMP")) // move to front
            formats.insert(0,"BMP");
    }
    // PNG is best of all
    if (formats.removeAll("PNG")) // move to front
        formats.insert(0,"PNG");

    for(int i = 0; i < formats.count(); i++) {
        QByteArray format("image/");
        format += formats.at(i);
        format = format.toLower();
        if (format == "image/pbmraw")
            format = "image/ppm";
        d->ofmts.append(format);
    }
}

/*!
    \reimp
*/
const char * Q3ImageDrag::format(int i) const
{
    Q_D(const Q3ImageDrag);
    return i < d->ofmts.count() ? d->ofmts.at(i).data() : 0;
}

/*!
    \reimp
*/
QByteArray Q3ImageDrag::encodedData(const char* fmt) const
{
    Q_D(const Q3ImageDrag);
    if (qstrnicmp(fmt, "image/", 6)==0) {
        QByteArray f(fmt+6);
        QByteArray dat;
        QBuffer w(&dat);
        w.open(QIODevice::WriteOnly);
        QImageWriter writer(&w, f.toUpper());
        if (!writer.write(d->img))
            return QByteArray();
        w.close();
        return dat;
    } else {
        return QByteArray();
    }
}

/*!
    \fn bool Q3ImageDrag::canDecode(const QMimeSource *source)

    Returns true if the information in the MIME \a source can be decoded
    into an image; otherwise returns false.

    \sa decode()
*/
bool Q3ImageDrag::canDecode(const QMimeSource* e)
{
    const QList<QByteArray> fileFormats = QImageReader::supportedImageFormats();

    for (int i = 0; i < fileFormats.count(); ++i) {
        if (e->provides("image" + fileFormats.at(i).toLower()))
            return true;
    }

    return false;
}

/*!
    \fn bool Q3ImageDrag::decode(const QMimeSource *source, QImage &image)

    Decode the dropped information in the MIME \a source into the \a image.
    Returns true if successful; otherwise returns false.

    \sa canDecode()
*/
bool Q3ImageDrag::decode(const QMimeSource* e, QImage& img)
{
    if (!e)
        return false;

    QByteArray payload;
    QList<QByteArray> fileFormats = QImageReader::supportedImageFormats();

    // PNG is best of all
    // (this is a rather strange hack, but it works now)
    for (int i=0; i < fileFormats.count(); i++) {
        if (fileFormats.at(i).toLower() == "png") {
            fileFormats.prepend("png");
            break ;
        }
    } // move to front

    for (int i = 0; i < fileFormats.count(); ++i) {
        QByteArray type = "image/" + fileFormats.at(i).toLower();
        if (! e->provides(type))
            continue;
        payload = e->encodedData(type);
        if (!payload.isEmpty())
            break;
    }

    if (payload.isEmpty())
        return false;

    img.loadFromData(payload);
    if (img.isNull())
        return false;
    return true;
}

/*!
    \fn bool Q3ImageDrag::decode(const QMimeSource *source, QPixmap &pixmap)

    \overload

    Decodes the dropped information in the MIME \a source into the \a pixmap.
    Returns true if successful; otherwise returns false.

    This is a convenience function that converts the information to a QPixmap
    via a QImage.

    \sa canDecode()
*/
bool Q3ImageDrag::decode(const QMimeSource* e, QPixmap& pm)
{
    if (!e)
        return false;

    QImage img;
    // We avoid dither, since the image probably came from this display
    if (decode(e, img)) {
        pm = QPixmap::fromImage(img, Qt::AvoidDither);
        if (pm.isNull())
            return false;

        return true;
    }
    return false;
}




/*!
    \class Q3StoredDrag qdragobject.h
    \brief The Q3StoredDrag class provides a simple stored-value drag object for arbitrary MIME data.

    \compat

    When a block of data has only one representation, you can use a
    Q3StoredDrag to hold it.

    For more information about drag and drop, see the Q3DragObject
    class and the \link dnd.html drag and drop documentation\endlink.
*/

/*!
    Constructs a Q3StoredDrag. The \a dragSource and \a name are passed
    to the Q3DragObject constructor, and the format is set to \a
    mimeType.

    The data will be unset. Use setEncodedData() to set it.
*/
Q3StoredDrag::Q3StoredDrag(const char* mimeType, QWidget * dragSource, const char * name) :
    Q3DragObject(*new Q3StoredDragPrivate, dragSource)
{
    Q_D(Q3StoredDrag);
    setObjectName(QLatin1String(name));
    d->fmt = qstrdup(mimeType);
}

/*! \internal */
Q3StoredDrag::Q3StoredDrag(Q3StoredDragPrivate &dd, const char* mimeType, QWidget * dragSource)
    : Q3DragObject(dd, dragSource)
{
    d_func()->fmt = qstrdup(mimeType);
}

/*!
    Destroys the drag object.
*/
Q3StoredDrag::~Q3StoredDrag()
{
    delete [] (char*)d_func()->fmt;
}

/*!
    \reimp
*/
const char * Q3StoredDrag::format(int i) const
{
    if (i==0)
        return d_func()->fmt;
    else
        return 0;
}


/*!
    \fn void Q3StoredDrag::setEncodedData(const QByteArray &data)

    Sets the encoded \a data of this drag object. The encoded data is
    delivered to drop sites; it must be in a strictly defined and portable
    format.

    The drag object can't be dropped (by the user) until this function
    has been called.
*/

void Q3StoredDrag::setEncodedData(const QByteArray & encodedData)
{
    d_func()->enc = encodedData;
}

/*!
    \fn QByteArray Q3StoredDrag::encodedData(const char *format) const

    Returns the stored data in the \a format given.

    \sa setEncodedData()
*/
QByteArray Q3StoredDrag::encodedData(const char* m) const
{
    if (!qstricmp(m, d_func()->fmt))
        return d_func()->enc;
    else
        return QByteArray();
}


/*!
    \class Q3UriDrag qdragobject.h
    \brief The Q3UriDrag class provides a drag object for a list of URI references.

    \compat

    URIs are a useful way to refer to files that may be distributed
    across multiple machines. A URI will often refer to a file on a
    machine local to both the drag source and the drop target, so the
    URI can be equivalent to passing a file name but is more
    extensible.

    Use URIs in Unicode form so that the user can comfortably edit and
    view them. For use in HTTP or other protocols, use the correctly
    escaped ASCII form.

    You can convert a list of file names to file URIs using
    setFileNames(), or into human-readable form with setUnicodeUris().

    Static functions are provided to convert between filenames and
    URIs; e.g. uriToLocalFile() and localFileToUri(). Static functions
    are also provided to convert URIs to and from human-readable form;
    e.g. uriToUnicodeUri() and unicodeUriToUri().
    You can also decode URIs from a MIME source into a list with
    decodeLocalFiles() and decodeToUnicodeUris().
*/

/*!