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QUtiMimeConverter Class

The QUtiMimeConverter class converts between a MIME type and a Uniform Type Identifier (UTI) format. More...

Header: #include <QUtiMimeConverter>
CMake: find_package(Qt6 REQUIRED COMPONENTS Gui)
target_link_libraries(mytarget PRIVATE Qt6::Gui)
qmake: QT += gui
Since: Qt 6.5

Public Types

flags HandlerScope

Public Functions

QUtiMimeConverter()
virtual ~QUtiMimeConverter()
bool canConvert(const QString &mime, const QString &uti) const
virtual QList<QByteArray> convertFromMime(const QString &mime, const QVariant &data, const QString &uti) const = 0
virtual QVariant convertToMime(const QString &mime, const QList<QByteArray> &data, const QString &uti) const = 0
virtual int count(const QMimeData *mimeData) const
virtual QString mimeForUti(const QString &uti) const = 0
virtual QString utiForMime(const QString &mime) const = 0

Detailed Description

Qt's drag and drop and clipboard facilities use the MIME standard. On X11, this maps trivially to the Xdnd protocol. On Mac, although some applications use MIME to describe clipboard contents, it is more common to use Apple's UTI format.

QUtiMimeConverter's role is to bridge the gap between MIME and UTI; By subclasses this class, one can extend Qt's drag and drop and clipboard handling to convert to and from unsupported, or proprietary, UTI formats.

Construct an instance of your converter implementation after instantiating QGuiApplication:

int main(int argc, char **argv)
{
    QGuiApplication app(argc, argv);
    JsonMimeConverter jsonConverter;
}

Destroying the instance will unregister the converter and remove support for the conversion. It is also valid to heap-allocate the converter instance; Qt takes ownership and will delete the converter object during QGuiApplication shut-down.

Qt has predefined support for the following UTIs:

  • public.utf8-plain-text - converts to "text/plain"
  • public.utf16-plain-text - converts to "text/plain"
  • public.text - converts to "text/plain"
  • public.html - converts to "text/html"
  • public.url - converts to "text/uri-list"
  • public.file-url - converts to "text/uri-list"
  • public.tiff - converts to "application/x-qt-image"
  • public.vcard - converts to "text/plain"
  • com.apple.traditional-mac-plain-text - converts to "text/plain"
  • com.apple.pict - converts to "application/x-qt-image"

When working with MIME data, Qt will iterate through all instances of QUtiMimeConverter to find find an instance that can convert to, or from, a specific MIME type. It will do this by calling mimeForUti() or utiForMime() on each instance, starting with (and choosing) the last created instance first. The actual conversions will be done by using convertToMime() and convertFromMime().

Member Function Documentation

QUtiMimeConverter::QUtiMimeConverter()

Constructs a new conversion object and adds it to the globally accessed list of available converters.

Call this constructor after QGuiApplication has been created.

[virtual noexcept] QUtiMimeConverter::~QUtiMimeConverter()

Destroys a conversion object, removing it from the global list of available converters.

bool QUtiMimeConverter::canConvert(const QString &mime, const QString &uti) const

Returns true if the converter can convert (both ways) between mime and uti; otherwise returns false.

[pure virtual] QList<QByteArray> QUtiMimeConverter::convertFromMime(const QString &mime, const QVariant &data, const QString &uti) const

Returns data converted from MIME type mime to Mac UTI uti.

Note that Mac UTIs must all be self-terminating. The return value may contain trailing data.

All subclasses must reimplement this pure virtual function.

[pure virtual] QVariant QUtiMimeConverter::convertToMime(const QString &mime, const QList<QByteArray> &data, const QString &uti) const

Returns data converted from Mac UTI uti to MIME type mime.

Note that Mac UTIs must all be self-terminating. The input data may contain trailing data.

All subclasses must reimplement this pure virtual function.

[virtual] int QUtiMimeConverter::count(const QMimeData *mimeData) const

Returns the item count for the given mimeData

[pure virtual] QString QUtiMimeConverter::mimeForUti(const QString &uti) const

Returns the MIME type used for Mac UTI uti, or an empty string if this converter does not support converting from uti.

All subclasses must reimplement this pure virtual function.

[pure virtual] QString QUtiMimeConverter::utiForMime(const QString &mime) const

Returns the Mac UTI used for MIME type mime, or an empty string if this converter does not support converting from mime.

All subclasses must reimplement this pure virtual function.

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