Qt:Документация 4.3.2/qmimedata

Материал из Wiki.crossplatform.ru

Перейти к: навигация, поиск

Внимание: Актуальная версия перевода документации находится здесь

__NOTOC__

Главная · Все классы · Основные классы · Классы по группам · Модули · Функции

Содержание 1 QMimeData Class Reference[модуль QtCore ] 1.1 Открытые функции 1.2 Защищенные функции 1.3 Дополнительные унаследованные члены 1.4 Подробное описание 1.4.1 Platform-Specific MIME Types 1.5 Описание функций-членов 1.5.1 QMimeData::QMimeData () 1.5.2 QMimeData::~QMimeData () 1.5.3 void QMimeData::clear () 1.5.4 QVariant QMimeData::colorData () const 1.5.5 QByteArray QMimeData::data ( const QString & mimeType ) const 1.5.6 QStringList QMimeData::formats () const [virtual] 1.5.7 bool QMimeData::hasColor () const 1.5.8 bool QMimeData::hasFormat ( const QString & mimeType ) const [virtual] 1.5.9 bool QMimeData::hasHtml () const 1.5.10 bool QMimeData::hasImage () const 1.5.11 bool QMimeData::hasText () const 1.5.12 bool QMimeData::hasUrls () const 1.5.13 QString QMimeData::html () const 1.5.14 QVariant QMimeData::imageData () const 1.5.15 QVariant QMimeData::retrieveData ( const QString & mimeType, QVariant::Type type ) const [virtual protected] 1.5.16 void QMimeData::setColorData ( const QVariant & color ) 1.5.17 void QMimeData::setData ( const QString & mimeType, const QByteArray & data ) 1.5.18 void QMimeData::setHtml ( const QString & html ) 1.5.19 void QMimeData::setImageData ( const QVariant & image ) 1.5.20 void QMimeData::setText ( const QString & text ) 1.5.21 void QMimeData::setUrls ( const QList< QUrl> & urls ) 1.5.22 QString QMimeData::text () const 1.5.23 QList< QUrl> QMimeData::urls () const

[править] QMimeData Class Reference
^{[модуль QtCore ]}

The QMimeData class provides a container for data that records information about its MIME type. More...

 #include <QMimeData>

Inherits QObject.

• Список всех членов включая унаследованные

[править] Открытые функции

• QMimeData ()
• ~QMimeData ()
• void clear ()
• QVariant colorData () const
• QByteArray data ( const QString & mimeType ) const
• virtual QStringList formats () const
• bool hasColor () const
• virtual bool hasFormat ( const QString & mimeType ) const
• bool hasHtml () const
• bool hasImage () const
• bool hasText () const
• bool hasUrls () const
• QString html () const
• QVariant imageData () const
• void setColorData ( const QVariant & color )
• void setData ( const QString & mimeType, const QByteArray & data )
• void setHtml ( const QString & html )
• void setImageData ( const QVariant & image )
• void setText ( const QString & text )
• void setUrls ( const QList<QUrl> & urls )
• QString text () const
• QList<QUrl> urls () const

• 29 открытых функций унаследованных от QObject

[править] Защищенные функции

• virtual QVariant retrieveData ( const QString & mimeType, QVariant::Type type ) const

• 7 защищенных функций унаследованных от QObject

[править] Дополнительные унаследованные члены

• 1 свойство унаследованное от QObject
• 1 открытый слот унаследованный от QObject
• 1 сигнал унаследованный от QObject
• 5 статических открытых члена унаследованных от QObject

---

[править] Подробное описание

The QMimeData class provides a container for data that records information about its MIME type.

QMimeData is used to describe information that can be stored in the clipboard, and transferred via the drag and drop mechanism. QMimeData objects associate the data that they hold with the corresponding MIME types to ensure that information can be safely transferred between applications, and copied around within the same application.

QMimeData objects are usually created using new and supplied to QDrag or QClipboard objects. This is to enable Qt to manage the memory that they use.

A single QMimeData object can store the same data using several different formats at the same time. The formats() function returns a list of the available formats in order of preference. The data() function returns the raw data associated with a MIME type, and setData() allows you to set the data for a MIME type.

For the most common MIME types, QMimeData provides convenience functions to access the data:

Tester	Getter	Setter	MIME Types
hasText()	text()	setText()	text/plain
hasHtml()	html()	setHtml()	text/html
hasUrls()	urls()	setUrls()	text/uri-list
hasImage()	imageData()	setImageData()	image/ *
hasColor()	colorData()	setColorData()	application/x-color

For example, if your write a widget that accepts URL drags, you would end up writing code like this:

 void MyWidget::dragEnterEvent(QDragEnterEvent *event)
 {
     if (event->mimeData()->hasUrls())
         event->acceptProposedAction();
 }
 
 void MyWidget::dropEvent(QDropEvent *event)
 {
     if (event->mimeData()->hasUrls()) {
         QUrl url = event->mimeData()->urls();
         ...
     }
 }

There are three appraches for storing custom data in a QMimeData object:

1. Custom data can be stored directly in a QMimeData object as a QByteArray using setData(). For example:

        QByteArray csvData = ...;
   

QMimeData *mimeData = new QMimeData; mimeData->setData("text/csv", csvData);

1. We can subclass QMimeData and reimplement hasFormat(), formats(), and retrieveData().
2. If the drag and drop operation occurs withing a single application, we can subclass QMimeData and add extra data in it, and use a qobject_cast() in the receiver's drop event handler. For example:

    void MyWidget::dropEvent(QDropEvent *event) {
   

const MyMimeData *myData = qobject_cast<const MyMimeData *>(event->mimeData()); if (myData) { // access myData's data directly (not through QMimeData's API) } }

[править] Platform-Specific MIME Types

 application/x-qt-windows-mime;value="<custom type>"

 application/x-qt-windows-mime;value="FileGroupDescriptor" application/x-qt-windows-mime;value="FileContents"

[править] Описание функций-членов

[править]

QMimeData::QMimeData ()

Constructs a new MIME data object with no data in it.

[править]

QMimeData::~QMimeData ()

Destroys the MIME data object.

[править]

void QMimeData::clear ()

Removes all the MIME type and data entries in the object.

[править]

QVariant QMimeData::colorData () const

 if (event->mimeData()->hasColor()) {     QColor color = qvariant_cast<QColor>(event->mimeData()->colorData());     ... }

See also hasColor(), setColorData(), and data().

[править]

QByteArray QMimeData::data ( const QString & mimeType ) const

Returns the data stored in the object in the format described by the MIME type specified by mimeType.
See also setData().

[править]

QStringList QMimeData::formats () const [virtual]

Returns a list of formats supported by the object. This is a list of MIME types for which the object can return suitable data. The formats in the list are in a priority order.
For the most common types of data, you can call the higher-level functions hasText(), hasHtml(), hasUrls(), hasImage(), and hasColor() instead.
See also hasFormat(), setData(), and data().

[править]

bool QMimeData::hasColor () const

Returns true if the object can return a color (MIME type application/x-color); otherwise returns false.
See also setColorData(), colorData(), and hasFormat().

[править]

bool QMimeData::hasFormat ( const QString & mimeType ) const [virtual]

Returns true if the object can return data for the MIME type specified by mimeType; otherwise returns false.
For the most common types of data, you can call the higher-level functions hasText(), hasHtml(), hasUrls(), hasImage(), and hasColor() instead.
See also formats(), setData(), and data().

[править]

bool QMimeData::hasHtml () const

Returns true if the object can return HTML (MIME type text/html); otherwise returns false.
See also setHtml(), html(), and hasFormat().

[править]

bool QMimeData::hasImage () const

Returns true if the object can return an image; otherwise returns false.
See also setImageData(), imageData(), and hasFormat().

[править]

bool QMimeData::hasText () const

Returns true if the object can return plain text (MIME type text/plain); otherwise returns false.
See also setText(), text(), hasHtml(), and hasFormat().

[править]

bool QMimeData::hasUrls () const

Returns true if the object can return a list of urls; otherwise returns false.
URLs correspond to the MIME type text/uri-list.
See also setUrls(), urls(), and hasFormat().

[править]

QString QMimeData::html () const

Returns a string if the data stored in the object is HTML (MIME type text/html); otherwise returns an empty string.
See also setHtml(), hasHtml(), and setData().

[править]

QVariant QMimeData::imageData () const

Returns a QVariant storing a QImage if the object can return an image; otherwise returns a null variant.

 if (event->mimeData()->hasImage()) {     QImage image = qvariant_cast<QImage>(event->mimeData()->imageData());     ... }

See also setImageData() and hasImage().

[править]

QVariant QMimeData::retrieveData ( const QString & mimeType, QVariant::Type type ) const [virtual protected]

Returns a variant with the given type containing data for the MIME type specified by mimeType. If the object does not support the MIME type or variant type given, a null variant is returned instead.
This function is called by the general data() getter and by the convenience getters ( text(), html(), urls(), imageData(), and colorData()). You can reimplement it if you want to store your data using a custom data structure (instead of a QByteArray, which is what setData() provides). You would then also need to reimplement hasFormat() and formats().
See also data().

[править]

void QMimeData::setColorData ( const QVariant & color )

Sets the color data in the object to the given color.
Colors correspond to the MIME type application/x-color.
See also colorData(), hasColor(), and setData().

[править]

void QMimeData::setData ( const QString & mimeType, const QByteArray & data )

Sets the data associated with the MIME type given by mimeType to the specified data.
For the most common types of data, you can call the higher-level functions setText(), setHtml(), setUrls(), setImageData(), and setColorData() instead.
See also data() and hasFormat().

[править]

void QMimeData::setHtml ( const QString & html )

Sets html as the HTML (MIME type text/html) used to represent the data.
See also html(), hasHtml(), setText(), and setData().

[править]

void QMimeData::setImageData ( const QVariant & image )

Sets the data in the object to the given image.

 mimeData->setImageData(QImage("beautifulfjord.png"));

[править]

void QMimeData::setText ( const QString & text )

Sets text as the plain text (MIME type text/plain) used to represent the data.

See also text(), hasText(), setHtml(), and setData().

[править]

void QMimeData::setUrls ( const QList< QUrl> & urls )

Sets the URLs stored in the MIME data object to those specified by urls.

URLs correspond to the MIME type text/uri-list.

See also urls(), hasUrls(), and setData().

[править]

QString QMimeData::text () const

Returns a plain text (MIME type text/plain) representation of the data.

See also setText(), hasText(), html(), and data().

[править]

QList< QUrl> QMimeData::urls () const

Returns a list of URLs contained within the MIME data object.

URLs correspond to the MIME type text/uri-list.

See also setUrls(), hasUrls(), and data().