QDrag Class

        QDrag *drag = new QDrag(this);
        QMimeData *mimeData = new QMimeData;

        mimeData->setText(commentEdit->toPlainText());
        drag->setMimeData(mimeData);

    drag->setHotSpot(QPoint(drag->pixmap().width()/2,
                            drag->pixmap().height()));

Member Function Documentation

[explicit] QDrag::QDrag(QObject *dragSource)

Constructs a new drag object for the widget specified by dragSource.

[virtual noexcept] QDrag::~QDrag()

Destroys the drag object.

[signal] void QDrag::actionChanged(Qt::DropAction action)

This signal is emitted when the action associated with the drag changes.

See also targetChanged().

[static] void QDrag::cancel()

Cancels a drag operation initiated by Qt.

See also exec().

Qt::DropAction QDrag::defaultAction() const

Returns the default proposed drop action for this drag operation.

See also exec() and supportedActions().

QPixmap QDrag::dragCursor(Qt::DropAction action) const

Returns the drag cursor for the action.

See also setDragCursor().

Qt::DropAction QDrag::exec(Qt::DropActions supportedActions = Qt::MoveAction)

Starts the drag and drop operation and returns a value indicating the requested drop action when it is completed. The drop actions that the user can choose from are specified in supportedActions. The default proposed action will be selected among the allowed actions in the following order: Move, Copy and Link.

Note: On Linux and macOS, the drag and drop operation can take some time, but this function does not block the event loop. Other events are still delivered to the application while the operation is performed. On Windows, the Qt event loop is blocked during the operation.

See also cancel().

Qt::DropAction QDrag::exec(Qt::DropActions supportedActions, Qt::DropAction defaultDropAction)

Starts the drag and drop operation and returns a value indicating the requested drop action when it is completed. The drop actions that the user can choose from are specified in supportedActions.

The defaultDropAction determines which action will be proposed when the user performs a drag without using modifier keys.

Note: On Linux and macOS, the drag and drop operation can take some time, but this function does not block the event loop. Other events are still delivered to the application while the operation is performed. On Windows, the Qt event loop is blocked during the operation. However, QDrag::exec() on Windows causes processEvents() to be called frequently to keep the GUI responsive. If any loops or operations are called while a drag operation is active, it will block the drag operation.

QPoint QDrag::hotSpot() const

Returns the position of the hot spot relative to the top-left corner of the cursor.

See also setHotSpot().

QMimeData *QDrag::mimeData() const

Returns the MIME data that is encapsulated by the drag object.

See also setMimeData().

QPixmap QDrag::pixmap() const

Returns the pixmap used to represent the data in a drag and drop operation.

See also setPixmap().

void QDrag::setDragCursor(const QPixmap &cursor, Qt::DropAction action)

Sets the drag cursor for the action. This allows you to override the default native cursors. To revert to using the native cursor for action pass in a null QPixmap as cursor.

Note: setting the drag cursor for IgnoreAction may not work on all platforms. X11 and macOS has been tested to work. Windows does not support it.

See also dragCursor().

void QDrag::setHotSpot(const QPoint &hotspot)

Sets the position of the hot spot relative to the top-left corner of the pixmap used to the point specified by hotspot.

Note: on X11, the pixmap may not be able to keep up with the mouse movements if the hot spot causes the pixmap to be displayed directly under the cursor.

See also hotSpot().

void QDrag::setMimeData(QMimeData *data)

Sets the data to be sent to the given MIME data. Ownership of the data is transferred to the QDrag object.

See also mimeData().

void QDrag::setPixmap(const QPixmap &pixmap)

Sets pixmap as the pixmap used to represent the data in a drag and drop operation. You can only set a pixmap before the drag is started.

See also pixmap().

QObject *QDrag::source() const

Returns the source of the drag object. This is the widget where the drag and drop operation originated.

Qt::DropActions QDrag::supportedActions() const

Returns the set of possible drop actions for this drag operation.

See also exec() and defaultAction().

QObject *QDrag::target() const

Returns the target of the drag and drop operation. This is the widget where the drag object was dropped.

[signal] void QDrag::targetChanged(QObject *newTarget)

This signal is emitted when the target of the drag and drop operation changes, with newTarget the new target.

See also target() and actionChanged().