virtual bool writeXml(QDomElement &parentElement, QDomDocument &document, const QgsReadWriteContext &context) const =0
Stores the objects's state in a DOM element.
virtual bool readXml(const QDomElement &element, const QDomDocument &document, const QgsReadWriteContext &context)=0
Sets the objects's state from a DOM element.
virtual QgsAbstractLayoutUndoCommand * createCommand(const QString &text, int id=0, QUndoCommand *parent=nullptr)=0
Creates a new layout undo command with the specified text and parent.
The class is used as a container of context for various read/write operations on other objects.