source: trunk/src/gui/kernel/qmime_pm.cpp@ 324

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#include "qmime.h"

#include "qimagereader.h"
#include "qimagewriter.h"
#include "qdatastream.h"
#include "qbuffer.h"
#include "qt_os2.h"
#include "qapplication_p.h"
#include "qtextcodec.h"
#include "qregexp.h"
#include "qalgorithms.h"
#include "qmap.h"
#include "qdnd_p.h"
#include "qurl.h"
#include "qvariant.h"
#include "qtextdocument.h"
#include "qdir.h"

#define QMIME_DEBUG

QT_BEGIN_NAMESPACE

class QPMMimeList
{
public:
    QPMMimeList();
    ~QPMMimeList();
    void addMime(QPMMime *mime);
    void removeMime(QPMMime *mime);
    QList<QPMMime*> mimes();

private:
    void init();
    bool initialized;
    QList<QPMMime*> list;
};

Q_GLOBAL_STATIC(QPMMimeList, theMimeList);


/*!
    \class QPMMime
    \brief The QMPMime class maps open-standard MIME to OS/2 PM Clipboard
    formats.
    \ingroup io
    \ingroup draganddrop
    \ingroup misc

    Qt's drag-and-drop and clipboard facilities use the MIME standard.
    On X11, this maps trivially to the Xdnd protocol, but on OS/2
    although some applications use MIME types to describe clipboard
    formats, others use arbitrary non-standardized naming conventions,
    or unnamed built-in formats of the Presentation Manager.

    By instantiating subclasses of QPMMime that provide conversions between OS/2
    PM Clipboard and MIME formats, you can convert proprietary clipboard formats
    to MIME formats.

    Qt has predefined support for the following PM Clipboard formats:

    \table
    \header \o PM Format \o Equivalent MIME type
    \row \o \c CF_TEXT        \o \c text/plain
    \row \o \c CF_BITMAP      \o \c{image/xyz}, where \c xyz is
                                 a \l{QImageWriter::supportedImageFormats()}{Qt image format}
    \endtable

    An example use of this class would be to map the PM Metafile
    clipboard format (\c CF_METAFILE) to and from the MIME type
    \c{image/x-metafile}. This conversion might simply be adding or removing a
    header, or even just passing on the data. See \l{Drag and Drop} for more
    information on choosing and definition MIME types.
*/

/*!
Constructs a new conversion object, adding it to the globally accessed
list of available converters.
*/
QPMMime::QPMMime()
{
    theMimeList()->addMime(this);
}

/*!
Destroys a conversion object, removing it from the global
list of available converters.
*/
QPMMime::~QPMMime()
{
    theMimeList()->removeMime(this);
}

/*!
    Registers the MIME type \a mime, and returns an ID number
    identifying the format on OS/2.
*/
ULONG QPMMime::registerMimeType(const QString &mime)
{
    QString atom = QLatin1String("mime:") + mime;

    ULONG cf = WinAddAtom(WinQuerySystemAtomTable(), atom.toLocal8Bit());
    if (!cf) {
#ifndef QT_NO_DEBUG
        qWarning("QPMMime: WinAddAtom failed with %lX",
                 WinGetLastError(NULLHANDLE));
#endif
        return 0;
    }

    return cf;
}

/*!
    \fn QList<ULONG> QPMMime::formatsForMimeData(const QMimeData *mimeData) const

    Returns a list of ULONG values representing the different OS/2 PM
    clipboard formats that can be provided for the \a mimeData, in order of
    precedence (the most suitable format goes first), or an empty list if
    neither of the mime types provided by \a mimeData is supported by this
    converter.

    All subclasses must reimplement this pure virtual function.
*/

/*!
    \fn bool QPMMime::convertFromMimeData(const QMimeData *mimeData, ULONG format,
                                          ULONG &flags, ULONG *data) const

    Converts the \a mimeData to the specified \a format.

    If \a data is not NULL, a handle to the converted data should then be placed
    in a variable pointed to by \a data and with the necessary flags describing
    the handle returned in the \a flags variable.

    The following flags describing the data type are recognized:

    \table
    \row \o \c CFI_POINTER        \o \a data is a pointer to a block of memory
                                      allocated with QPMMime::allocMem()
    \row \o \c CFI_HANDLE         \o \a data is a handle to the appropriate
                                      PM resource
    \endtable

    If \a data is NULL then a delayed conversion is requested by the caller.
    The implementation should return the appropriate flags in the \a flags
    variable and may perform the real data conversion later when this method is
    called again with \a data being non-NULL.

    Return true if the conversion was successful.

    All subclasses must reimplement this pure virtual function.
*/

/*!
    \fn QStringList QPMMime::mimesForFormats(const QList<ULONG> &formats) const

    Returns a list of mime types that will be created form the specified \a list
    of \a formats, in order of precedence (the most suitable mime type comes
    first), or an empty list if neither of the \a formats is supported by this
    converter.

    All subclasses must reimplement this pure virtual function.
*/

/*!
    \fn QVariant QPMMime::convertFromFormat(ULONG format, ULONG flags, ULONG data,
                                            const QString &mimeType,
                                            QVariant::Type preferredType) const

    Returns a QVariant containing the converted from the \a data in the
    specified \a format with the given \a flags to the requested \a mimeType. If
    possible the QVariant should be of the \a preferredType to avoid needless
    conversions.

    All subclasses must reimplement this pure virtual function.
*/

// static
QList<QPMMime::Match> QPMMime::allConvertersFromFormats(const QList<ULONG> &formats)
{
    QList<Match> matches;

    QList<QPMMime*> mimes = theMimeList()->mimes();
    for (int i = mimes.size()-1; i >= 0; --i) {
        QStringList fmts = mimes[i]->mimesForFormats(formats);
        int priority = 0;
        foreach (QString fmt, fmts) {
            ++priority;
            QList<Match>::iterator it = matches.begin();
            for (; it != matches.end(); ++it) {
                Match &match = *it;
                if (match.mime == fmt) {
                    // replace if priority is higher, ignore otherwise
                    if (priority < match.priority) {
                        match.converter = mimes[i];
                        match.priority = priority;
                    }
                    break;
                }
            }
            if (it == matches.end()) {
                matches += Match(mimes[i], fmt, priority);
            }
        }
    }

    return matches;
}

// static
QList<QPMMime::Match> QPMMime::allConvertersFromMimeData(const QMimeData *mimeData)
{
    QList<Match> matches;

    QList<QPMMime*> mimes = theMimeList()->mimes();
    for (int i = mimes.size()-1; i >= 0; --i) {
        QList<ULONG> cfs = mimes[i]->formatsForMimeData(mimeData);
        int priority = 0;
        foreach (ULONG cf, cfs) {
            ++priority;
            QList<Match>::iterator it = matches.begin();
            for (; it != matches.end(); ++it) {
                Match &match = *it;
                if (match.format == cf) {
                    // replace if priority is higher, ignore otherwise
                    if (priority < match.priority) {
                        match.converter = mimes[i];
                        match.priority = priority;
                    }
                    break;
                }
            }
            if (it == matches.end()) {
                matches += Match(mimes[i], cf, priority);
            }
        }
    }

    return matches;
}

////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////

QPMMimeList::QPMMimeList()
    : initialized(false)
{
}

QPMMimeList::~QPMMimeList()
{
    while (list.size())
        delete list.first();
}


void QPMMimeList::init()
{
    if (!initialized) {
        initialized = true;
        // @todo new QPMMimeXXX;
    }
}

void QPMMimeList::addMime(QPMMime *mime)
{
    init();
    list.append(mime);
}

void QPMMimeList::removeMime(QPMMime *mime)
{
    init();
    list.removeAll(mime);
}

QList<QPMMime*> QPMMimeList::mimes()
{
    init();
    return list;
}

QT_END_NAMESPACE