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diff --git a/src/xml/document.h b/src/xml/document.h
index 8dc286a38979587d8ee79eaa3cf547461e5969cb..2b9ea5cc3c8ebd12648af2d8cdbfbd51ff1747c7 100644 (file)
--- a/src/xml/document.h
+++ b/src/xml/document.h
-/*
- * Inkscape::XML::Document - interface for XML documents
- *
- * Copyright 2005 MenTaLguY <mental@rydia.net>
+/** @file
+ * @brief Interface for XML documents
+ */
+/* Copyright 2005 MenTaLguY <mental@rydia.net>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
#ifndef SEEN_INKSCAPE_XML_SP_REPR_DOC_H
#define SEEN_INKSCAPE_XML_SP_REPR_DOC_H
+#include "xml/xml-forward.h"
#include "xml/node.h"
-#include "xml/session.h"
namespace Inkscape {
namespace XML {
+/**
+ * @brief Interface for XML documents
+ *
+ * This class represents a complete document tree. You have to go through this class
+ * to create new nodes. It also contains transaction support, which forms the base
+ * of the undo system.
+ *
+ * The document is also a node. It usually contains only two child nodes - a processing
+ * instruction node (PINode) containing the XML prolog, and the root node. You can get
+ * the root node of the document by calling the root() method.
+ *
+ * The name "transaction" can be misleading, because they are not atomic. Their main feature
+ * is that they provide rollback. After starting a transaction,
+ * all changes made to the document are stored in an internal event log. At any time
+ * after starting the transaction, you can call the rollback() method, which restores
+ * the document to the state it was before starting the transaction. Calling the commit()
+ * method causes the internal event log to be discarded, and you can estabilish a new
+ * "restore point" by calling beginTransaction() again. There can be only one active
+ * transaction at a time for a given document.
+ */
struct Document : virtual public Node {
public:
- Node *createElementNode(char const *name) {
- return session()->createElementNode(name);
- }
- Node *createTextNode(char const *content) {
- return session()->createTextNode(content);
- }
- Node *createCommentNode(char const *content) {
- return session()->createCommentNode(content);
- }
+ /**
+ * @name Document transactions
+ * @{
+ */
+ /**
+ * @brief Checks whether there is an active transaction for this document
+ * @return true if there's an established transaction for this document, false otherwise
+ */
+ virtual bool inTransaction()=0;
+ /**
+ * @brief Begin a transaction and start recording changes
+ *
+ * By calling this method you effectively establish a resotre point.
+ * You can undo all changes made to the document after this call using rollback().
+ */
+ virtual void beginTransaction()=0;
+ /**
+ * @brief Restore the state of the document prior to the transaction
+ *
+ * This method applies the inverses of all recorded changes in reverse order,
+ * restoring the document state from before the transaction. For some implementations,
+ * this function may do nothing.
+ */
+ virtual void rollback()=0;
+ /**
+ * @brief Commit a transaction and discard change data
+ *
+ * This method finishes the active transaction and discards the recorded changes.
+ */
+ virtual void commit()=0;
+ /**
+ * @brief Commit a transaction and store the events for later use
+ *
+ * This method finishes a transaction and returns an event chain
+ * that describes the changes made to the document. This method may return NULL,
+ * which means that the document implementation doesn't support event logging,
+ * or that no changes were made.
+ *
+ * @return Event chain describing the changes, or NULL
+ */
+ virtual Event *commitUndoable()=0;
+ /*@}*/
+
+ /**
+ * @name Create new nodes
+ * @{
+ */
+ virtual Node *createElement(char const *name)=0;
+ virtual Node *createTextNode(char const *content)=0;
+ virtual Node *createComment(char const *content)=0;
+ virtual Node *createPI(char const *target, char const *content)=0;
+ /*@}*/
+
+ /**
+ * @brief Get the event logger for this document
+ *
+ * This is an implementation detail that should not be used outside of node implementations.
+ * It should be made non-public in the future.
+ */
+ virtual NodeObserver *logger()=0;
};
}