The QClipboard class provides access to the window system clipboard. More...

Inheritance diagram for QClipboard:

Public Types
enum	Mode

Public Signals
void	changed (QClipboard::Mode mode)

void	dataChanged ()

void	findBufferChanged ()

void	selectionChanged ()

Public Signals inherited from QObject
void	destroyed (QObject *obj=nullptr)

void	objectNameChanged (const QString &objectName)

Public Methods
void	clear (Mode mode=Clipboard)

QImage	image (Mode mode=Clipboard) const

const QMimeData *	mimeData (Mode mode=Clipboard) const

bool	ownsClipboard () const

bool	ownsFindBuffer () const

bool	ownsSelection () const

QPixmap	pixmap (Mode mode=Clipboard) const

void	setImage (const QImage &image, Mode mode=Clipboard)

void	setMimeData (QMimeData *data, Mode mode=Clipboard)

void	setPixmap (const QPixmap &pixmap, Mode mode=Clipboard)

void	setText (const QString &text, Mode mode=Clipboard)

bool	supportsFindBuffer () const

bool	supportsSelection () const

QString	text (Mode mode=Clipboard) const

QString	text (QString &subtype, Mode mode=Clipboard) const

Public Methods inherited from QObject
	QObject (QObject *parent=nullptr)

	~QObject ()

bool	blockSignals (bool block)

const QList< QObject * > &	children () const

bool	connect (const QObject *sender, const QString &signalMethod, const QString &location, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

bool	connect (const QObject *sender, const QString &signalMethod, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

bool	disconnect (const QObject *receiver, const QString &slotMethod=QString ()) const

bool	disconnect (const QString &signalMethod, const QString &location, const QObject *receiver=nullptr, const QString &slotMethod=QString ()) const

bool	disconnect (const QString &signalMethod=QString (), const QObject *receiver=nullptr, const QString &slotMethod=QString ()) const

void	dumpObjectInfo ()

void	dumpObjectTree ()

QList< QString >	dynamicPropertyNames () const

virtual bool	event (QEvent *event)

virtual bool	eventFilter (QObject watched, QEvent event)

template<typename T >
T	findChild (const QString &childName=QString ()) const

template<class T >
QList< T >	findChildren (const QRegularExpression &regExp, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

template<class T >
QList< T >	findChildren (const QString &childName=QString (), Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

bool	inherits (const QString &className) const

void	installEventFilter (QObject *filterObj)

bool	isWidgetType () const

bool	isWindowType () const

void	killTimer (int id)

const QMetaObject *	metaObject () const

void	moveToThread (QThread *targetThread)

QString	objectName () const

QObject *	parent () const

template<class T = QVariant>
T	property (const QString &name) const

void	removeEventFilter (QObject *obj)

void	setObjectName (const QString &name)

void	setParent (QObject *parent)

bool	setProperty (const QString &name, const QVariant &value)

bool	signalsBlocked () const

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)

QThread *	thread () const

Friends
class	QApplication

class	QPlatformClipboard

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()

Static Public Methods inherited from QObject
static bool	connect (const QObject sender, const QMetaMethod &signalMethod, const QObject receiver, const QMetaMethod &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

static bool	connect (const QObject sender, const QString &signalMethod, const QObject receiver, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection, const QString &location=QString ())

static bool	connect (const QObject sender, const QString &signalMethod, const QString &location, const QObject receiver, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class SlotClass , class... SlotArgs, class SlotReturn >
static bool	connect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver receiver, SlotReturn (SlotClass::slotMethod)(SlotArgs...), Qt::ConnectionType type=Qt::AutoConnection)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class T >
static bool	connect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, T slotLambda, Qt::ConnectionType type=Qt::AutoConnection)

static bool	disconnect (const QObject sender, const QMetaMethod &signalMethod, const QObject receiver, const QMetaMethod &slotMethod)

static bool	disconnect (const QObject sender, const QString &signalMethod, const QObject receiver, const QString &slotMethod)

static bool	disconnect (const QObject sender, const QString &signalMethod, const QString &location, const QObject receiver, const QString &slotMethod)

static bool	disconnect (const QObject sender, std::nullptr_t, const QObject receiver, std::nullptr_t)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class SlotClass , class... SlotArgs, class SlotReturn >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver receiver, SlotReturn (SlotClass::slotMethod)(SlotArgs...))

template<class Sender , class SignalClass , class... SignalArgs, class Receiver >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, std::nullptr_t slotMethod=nullptr)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class T >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, T slotMethod)

static QMetaObject &	staticMetaObject ()

static QString	tr (const char text, const char comment=nullptr, std::optional< int > numArg=std::optional< int >())

Protected Methods inherited from QObject
virtual void	childEvent (QChildEvent *event)

virtual void	connectNotify (const QMetaMethod &signalMethod) const

virtual void	customEvent (QEvent *event)

virtual void	disconnectNotify (const QMetaMethod &signalMethod) const

bool	isSignalConnected (const QMetaMethod &signalMethod) const

int	receivers (const QString &signal) const

QObject *	sender () const

int	senderSignalIndex () const

virtual void	timerEvent (QTimerEvent *event)

Properties inherited from QObject
	objectName

Related Functions inherited from QObject
T	qobject_cast (QObject *object)

	QObjectList

Detailed Description

The QClipboard class provides access to the window system clipboard.

The clipboard offers a simple mechanism to copy and paste data between applications.QClipboard supports the same data types that QDrag does, and uses similar mechanisms. For advanced clipboard usage read Drag and Drop. There is a single QClipboard object in an application, accessible as QApplication::clipboard().

QClipboard *clipboard = QApplication::clipboard();
QString originalText = clipboard->text();
 
// ...
 
clipboard->setText(newText);

QClipboard has several methods to access common data types: setText() allows the exchange of Unicode text and setPixmap() and setImage() allows the exchange of QPixmaps and QImages between applications. The setMimeData() function is the ultimate in flexibility: it allows you to add any QMimeData into the clipboard. There are corresponding getters for each of these, e.g. text(), image() and pixmap(). You can clear the clipboard by calling clear().

A typical example is shown below.

void DropArea::paste()
{
    const QClipboard *clipboard = QApplication::clipboard();
    const QMimeData *mimeData = clipboard->mimeData();
 
    if (mimeData->hasImage()) {
        setPixmap(qvariant_cast<QPixmap>(mimeData->imageData()));
 
    } else if (mimeData->hasHtml()) {
        setText(mimeData->html());
        setTextFormat(Qt::RichText);
 
    } else if (mimeData->hasText()) {
        setText(mimeData->text());
        setTextFormat(Qt::PlainText);
 
    } else {
        setText(tr("Unable to display data"));
 
    }

Notes for X11 Users

The X11 Window System has the concept of a separate selection and clipboard. When text is selected, it is immediately available as the global mouse selection. The global mouse selection may later be copied to the clipboard. By convention, the middle mouse button is used to paste the global mouse selection.
X11 also has the concept of ownership; if you change the selection within a window, X11 will only notify the owner and the previous owner of the change, i.e. it will not notify all applications that the selection or clipboard data changed.
Lastly, the X11 clipboard is event driven, i.e. the clipboard will not function properly if the event loop is not running. Similarly, it is recommended that the contents of the clipboard are stored or retrieved in direct response to user-input events, e.g. mouse button or key presses and releases. You should not store or retrieve the clipboard contents in response to timer or non-user-input events.
Since there is no standard way to copy and paste files between applications on X11, various MIME types and conventions are currently in use. For instance, Nautilus expects files to be supplied with a x-special/gnome-copied-files MIME type with data beginning with the cut/copy action, a newline character, and the URL of the file.

Notes for Mac OS X Users

Mac OS X supports a separate find buffer that holds the current search string in Find operations. This find clipboard can be accessed by specifying the FindBuffer mode.

Windows and Mac OS X Users

Windows and Mac OS X do not support the global mouse selection, they only support the global clipboard, this means they only add text to the clipboard when an explicit copy or cut is made.
Windows and Mac OS X does not have the concept of ownership, the clipboard is a fully global resource so all applications are notified of changes.

See also: QApplication

Member Enumeration Documentation

enum QClipboard::Mode

This enum type is used to control which part of the system clipboard is used by QClipboard::mimeData(), QClipboard::setMimeData() and related functions.

Constant	Value	Description
`QClipboard::Clipboard`	`0`	Indicates data should be stored and retrieved from the global clipboard.
`QClipboard::Selection`	`1`	Indicates that data should be stored and retrieved from the global mouse selection. Support for this enum is provided only on systems with a global mouse selection like X11.
`QClipboard::FindBuffer`	`2`	Indicates the data should be stored and retrieved from the Find buffer. This mode is used for holding search strings on Mac OS X.

See also: QClipboard::supportsSelection()

Method Documentation

void QClipboard::changed ( QClipboard::Mode mode )

signal

This signal is emitted when the data for the given clipboard mode is changed.

See also: dataChanged(), selectionChanged(), findBufferChanged()

void QClipboard::clear ( Mode mode = Clipboard )

Clear the clipboard contents.

The mode argument is used to control which part of the system clipboard is used. If mode is QClipboard::Clipboard, this function clears the global clipboard contents. If mode is QClipboard::Selection, this function clears the global mouse selection contents. If mode is QClipboard::FindBuffer, this function clears the search string buffer.

See also: QClipboard::Mode, supportsSelection()

void QClipboard::dataChanged ( )

signal

This signal is emitted when the clipboard data is changed.

Clipboard changes made by other applications will only be detected when the application is activated.

See also: findBufferChanged(), selectionChanged(), changed()

void QClipboard::findBufferChanged ( )

signal

This signal is emitted when the find buffer is changed. This only applies to Mac OS X. Clipboard changes made by other applications will only be detected when the application is activated.

See also: dataChanged(), selectionChanged(), changed()

QImage QClipboard::image ( Mode mode = Clipboard ) const

Returns the clipboard image, or returns a null image if the clipboard does not contain an image or if it contains an image in an unsupported image format.

The mode argument is used to control which part of the system clipboard is used. If mode is QClipboard::Clipboard, the image is retrieved from the global clipboard. If mode is QClipboard::Selection, the image is retrieved from the global mouse selection.

See also: setImage(), pixmap(), mimeData(), QImage::isNull()

const QMimeData * QClipboard::mimeData ( Mode mode = Clipboard ) const

Returns a reference to a QMimeData representation of the current clipboard data.

The mode argument is used to control which part of the system clipboard is used. If mode is QClipboard::Clipboard, the data is retrieved from the global clipboard. If mode is QClipboard::Selection, the data is retrieved from the global mouse selection. If mode is QClipboard::FindBuffer, the data is retrieved from the search string buffer.

The text(), image(), and pixmap() functions are simpler wrappers for retrieving text, image, and pixmap data.

See also: setMimeData()

bool QClipboard::ownsClipboard ( ) const

Returns true if this clipboard object owns the clipboard data, otherwise returns false.

bool QClipboard::ownsFindBuffer ( ) const

Returns true if this clipboard object owns the find buffer data, otherwise returns false.

bool QClipboard::ownsSelection ( ) const

Returns true if this clipboard object owns the mouse selection data, otherwise returns false.

QPixmap QClipboard::pixmap ( Mode mode = Clipboard ) const

The mode is used to control which part of the system clipboard is used. If mode is Mode::Clipboard, the pixmap is retrieved from the global clipboard. If mode is Mode::Selection the pixmap is retrieved from the global mouse selection. Returns the clipboard pixmap or a null QPixMap if the clipboard does not contain a pixmap.

This method may need to convert the clipboard data and could lose information.For example, if the image is 24-bit and the display is 8-bit the result is converted to 8 bits.

See also: setPixmap(), image(), mimeData(), QPixmap::convertFromImage()

void QClipboard::selectionChanged ( )

signal

This signal is emitted when the selection is changed. This only applies to windowing systems that support selections, like X11. Windows and Mac OS X do not support selections.

See also: dataChanged(), findBufferChanged(), changed()

void QClipboard::setImage	(	const QImage &	image,
		Mode	mode = `Clipboard`
	)

Copies the image into the clipboard.

The mode argument is used to control which part of the system clipboard is used. If mode is QClipboard::Clipboard, the image is stored in the global clipboard. If mode is QClipboard::Selection the data is stored in the global mouse selection.

Calling this method is equivalent to the following example.

QMimeData *data = new QMimeData;
data->setImageData(image);
clipboard->setMimeData(data, mode);

See also: image(), setPixmap(), setMimeData()

void QClipboard::setMimeData	(	QMimeData *	data,
		Mode	mode = `Clipboard`
	)

Sets the clipboard data to data. Ownership of the data is transferred to the clipboard. If you want to remove the data either call clear() or call setMimeData() again with new data.

The mode argument is used to control which part of the system clipboard is used. If mode is QClipboard::Clipboard, the data is stored in the global clipboard. If mode is QClipboard::Selection, the data is stored in the global mouse selection. If mode is QClipboard::FindBuffer, the data is stored in the search string buffer.

The setText(), setImage() and setPixmap() functions are simpler wrappers for setting text, image and pixmap data respectively.

See also: mimeData()

void QClipboard::setPixmap	(	const QPixmap &	pixmap,
		Mode	mode = `Clipboard`
	)

Copies pixmap into the clipboard. This is slower than calling setImage() because it needs to convert the QPixmap to a QImage first.

The mode argument is used to control which part of the system clipboard is used. If mode is QClipboard::Clipboard, the pixmap is stored in the global clipboard. If mode is QClipboard::Selection, the pixmap is stored in the global mouse selection.

See also: pixmap(), setImage(), setMimeData()

void QClipboard::setText	(	const QString &	text,
		Mode	mode = `Clipboard`
	)

Copies text into the clipboard as plain text. The mode argument is used to control which part of the system clipboard is used. If mode is QClipboard::Clipboard, the text is stored in the global clipboard. If mode is QClipboard::Selection, the text is stored in the global mouse selection. If mode is QClipboard::FindBuffer, the text is stored in the search string buffer.

See also: text(), setMimeData()

bool QClipboard::supportsFindBuffer ( ) const

Returns true if the clipboard supports a separate search buffer, otherwise returns false.

bool QClipboard::supportsSelection ( ) const

Returns true if the clipboard supports mouse selection, otherwise returns false.

QString QClipboard::text ( Mode mode = Clipboard ) const

Returns the clipboard text as plain text, or an empty string if the clipboard does not contain any text.

The mode argument is used to control which part of the system clipboard is used. If mode is QClipboard::Clipboard, the text is retrieved from the global clipboard. If mode is QClipboard::Selection, the text is retrieved from the global mouse selection. If mode is QClipboard::FindBuffer, the text is retrieved from the search string buffer.

See also: setText(), mimeData()

QString QClipboard::text	(	QString &	subtype,
		Mode	mode = `Clipboard`
	)		const

Returns the contents of the clipboard for the given subtype or an empty string if the clipboard does not contain text of the request subtype. Common values for subtype are "plain" or "html". If this specified subtype is empty then text for any subtype will be returned. In this case the subtype parameter will be updated to reflect the subtype which was used.

The mode argument is used to control which part of the system clipboard is used. If mode is QClipboard::Clipboard, the text is retrieved from the global clipboard. If mode is QClipboard::Selection the text is retrieved from the global mouse selection.

Calling this method repeatedly may be slow. In such cases use the dataChanged() signal.

See also: setText(), mimeData()

Public Types

Public Signals

Public Methods

Friends

Additional Inherited Members

Detailed Description

Notes for X11 Users

Notes for Mac OS X Users

Windows and Mac OS X Users

Member Enumeration Documentation

Method Documentation