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diff --git a/src/xml/node.h b/src/xml/node.h
index ab7e2ba2f97ed34e40eb8d005ac1ae80a0da5235..abcccdb9a68483123cbc293fb2d366b8d6c572bf 100644 (file)
--- a/src/xml/node.h
+++ b/src/xml/node.h
-/*
- * Node - interface for XML nodes
+/** @file
+ * @brief Interface for XML nodes
+ */
+/* Authors:
+ * MenTaLguY <mental@rydia.net>
+ * Krzysztof Kosiński <tweenk.pl@gmail.com> (documentation)
*
- * Copyright 2005 MenTaLguY <mental@rydia.net>
+ * Copyright 2005-2008 Authors
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* of the License, or (at your option) any later version.
*
* See the file COPYING for details.
- *
*/
#ifndef SEEN_INKSCAPE_XML_NODE_H
#include <glib/gtypes.h>
#include "gc-anchored.h"
#include "util/list.h"
+#include "xml/xml-forward.h"
namespace Inkscape {
namespace XML {
-class AttributeRecord;
-class Document;
-class NodeEventVector;
-class NodeObserver;
-
+/**
+ * @brief Enumeration containing all supported node types.
+ */
enum NodeType {
- DOCUMENT_NODE,
- ELEMENT_NODE,
- TEXT_NODE,
- COMMENT_NODE,
- PI_NODE
+ DOCUMENT_NODE, ///< Top-level document node. Do not confuse with the root node.
+ ELEMENT_NODE, ///< Regular element node, e.g. <group />.
+ TEXT_NODE, ///< Text node, e.g. "Some text" in <group>Some text</group> is represented by a text node.
+ COMMENT_NODE, ///< Comment node, e.g. <!-- some comment -->
+ PI_NODE ///< Processing instruction node, e.g. <?xml version="1.0" encoding="utf-8" standalone="no"?>
};
// careful; GC::Anchored should only appear once in the inheritance
-// hierarcy; else there will be leaks
+// hierarchy; otherwise there will be leaks
+
+/**
+ * @brief Interface for refcounted XML nodes
+ *
+ * This class is an abstract base type for all nodes in an XML document - this includes
+ * everything except attributes. An XML document is also a node itself. This is the main
+ * class used for interfacing with Inkscape's documents. Everything that has to be stored
+ * in the SVG has to go through this class at some point.
+ *
+ * Each node unconditionally has to belong to a document. There no "documentless" nodes,
+ * and it's not possible to move nodes between documents - they have to be duplicated.
+ * Each node can only refer to the nodes in the same document. Name of the node is immutable,
+ * it cannot be changed after its creation. Same goes for the type of the node. To simplify
+ * the use of this class, you can perform all operations on all nodes, but only some of them
+ * make any sense. For example, only element nodes can have attributes, only element and
+ * document nodes can have children, and all nodes except element and document nodes can
+ * have content. Although you can set content for element nodes, it won't make any difference
+ * in the XML output.
+ *
+ * To create new nodes, use the methods of the Inkscape::XML::Document class. You can obtain
+ * the nodes' document using the document() method. To destroy a node, just unparent it
+ * by calling sp_repr_unparent() or node->parent->removeChild() and release any references
+ * to it. The garbage collector will reclaim the memory in the next pass. There are additional
+ * convenience functions defined in @ref xml/repr.h
+ *
+ * In addition to regular DOM manipulations, you can register observer objects that will
+ * receive notifications about changes made to the node. See the NodeObserver class.
+ *
+ * @see Inkscape::XML::Document
+ * @see Inkscape::XML::NodeObserver
+ */
class Node : public Inkscape::GC::Anchored {
public:
Node() {}
-
virtual ~Node() {}
+ /**
+ * @name Retrieve information about the node
+ * @{
+ */
+
+ /**
+ * @brief Get the type of the node
+ * @return NodeType enumeration member corresponding to the type of the node.
+ */
virtual NodeType type() const=0;
+ /**
+ * @brief Get the name of the element node
+ *
+ * This method only makes sense for element nodes. Names are stored as
+ * GQuarks to accelerate conversions.
+ *
+ * @return Name for element nodes, NULL for others
+ */
virtual gchar const *name() const=0;
+ /**
+ * @brief Get the integer code corresponding to the node's name
+ * @return GQuark code corresponding to the name
+ */
virtual int code() const=0;
+
+ /**
+ * @brief Get the index of this node in parent's child order
+ *
+ * If this method is used on a node that doesn't have a parent, the method will return 0,
+ * and a warning will be printed on the console.
+ *
+ * @return The node's index, or 0 if the node does not have a parent
+ */
+ virtual unsigned position() const=0;
+
+ /**
+ * @brief Get the number of children of this node
+ * @return The number of children
+ */
+ virtual unsigned childCount() const=0;
+
+ /**
+ * @brief Get the content of a text or comment node
+ *
+ * This method makes no sense for element nodes. To retrieve the element node's name,
+ * use the name() method.
+ *
+ * @return The node's content
+ */
+ virtual gchar const *content() const=0;
+
+ /**
+ * @brief Get the string representation of a node's attribute
+ *
+ * If there is no attribute with the given name, the method will return NULL.
+ * All strings returned by this method are owned by the node and may not be freed.
+ * The returned pointer will become invalid when the attribute changes. If you need
+ * to store the return value, use g_strdup(). To parse the string, use methods
+ * in repr.h
+ *
+ * @param key The name of the node's attribute
+ */
+ virtual gchar const *attribute(gchar const *key) const=0;
+
+ /**
+ * @brief Get a list of the node's attributes
+ *
+ * The returned list is a functional programming style list rather than a standard one.
+ *
+ * @return A list of AttributeRecord structures describing the attributes
+ * @todo This method should return std::map<Glib::Quark const, gchar const *>
+ * or something similar with a custom allocator
+ */
+ virtual Inkscape::Util::List<AttributeRecord const> attributeList() const=0;
+
+ /**
+ * @brief Check whether this node has any attribute that matches a string
+ *
+ * This method checks whether this node has any attributes whose names
+ * have @c partial_name as their substrings. The check is done using
+ * the strstr() function of the C library. I don't know what would require that
+ * functionality, because matchAttributeName("id") matches both "identity" and "hidden".
+ *
+ * @param partial_name The string to match against all attributes
+ * @return true if there is such an attribute, false otherwise
+ */
+ virtual bool matchAttributeName(gchar const *partial_name) const=0;
+
+ /*@}*/
+
+ /**
+ * @name Modify the node
+ * @{
+ */
+
+ /**
+ * @brief Set the position of this node in parent's child order
+ *
+ * To move the node to the end of the parent's child order, pass a negative argument.
+ *
+ * @param pos The new position in parent's child order
+ */
+ virtual void setPosition(int pos)=0;
+
+ /**
+ * @brief Set the content of a text or comment node
+ *
+ * This method doesn't make sense for element nodes.
+ *
+ * @param value The node's new content
+ */
+ virtual void setContent(gchar const *value)=0;
+
+ /**
+ * @brief Change an attribute of this node
+ *
+ * The strings passed to this method are copied, so you can free them after use.
+ *
+ * @param key Name of the attribute to change
+ * @param value The new value of the attribute
+ * @param is_interactive Ignored
+ */
+ virtual void setAttribute(gchar const *key, gchar const *value, bool is_interactive=false)=0;
+
+ /**
+ * @brief Directly set the integer GQuark code for the name of the node
+ *
+ * This function is a hack to easily move elements with no namespace to the SVG namespace.
+ * Do not use this function unless you really have a good reason.
+ *
+ * @param code The integer value corresponding to the string to be set as the name of this node
+ */
virtual void setCodeUnsafe(int code)=0;
+
+ /*@}*/
+
+ /**
+ * @name Traverse the XML tree
+ * @{
+ */
+
+ //@{
+ /**
+ * @brief Get the node's associated document
+ * @return The document to which the node belongs. Never NULL.
+ */
virtual Document *document()=0;
virtual Document const *document() const=0;
+ //@}
- virtual Node *duplicate(Document *doc) const=0;
-
+ //@{
+ /**
+ * @brief Get the root node of this node's document
+ *
+ * This method works on any node that is part of an XML document, and returns
+ * the root node of the document in which it resides. For detached node hierarchies
+ * (i.e. nodes that are not descendants of a document node) this method
+ * returns the highest-level element node. For detached non-element nodes this method
+ * returns NULL.
+ *
+ * @return A pointer to the root element node, or NULL if the node is detached
+ */
virtual Node *root()=0;
virtual Node const *root() const=0;
+ //@}
+ //@{
+ /**
+ * @brief Get the parent of this node
+ *
+ * This method will return NULL for detached nodes.
+ *
+ * @return Pointer to the parent, or NULL
+ */
virtual Node *parent()=0;
virtual Node const *parent() const=0;
+ //@}
+ //@{
+ /**
+ * @brief Get the next sibling of this node
+ *
+ * This method will return NULL if the node is the last sibling element of the parent.
+ * The nodes form a singly-linked list, so there is no "prev()" method. Use the provided
+ * external function for that.
+ *
+ * @return Pointer to the next sibling, or NULL
+ * @see Inkscape::XML::previous_node()
+ */
virtual Node *next()=0;
virtual Node const *next() const=0;
+ //@}
+ //@{
+ /**
+ * @brief Get the first child of this node
+ *
+ * For nodes without any children, this method returns NULL.
+ *
+ * @return Pointer to the first child, or NULL
+ */
virtual Node *firstChild()=0;
virtual Node const *firstChild() const=0;
+ //@}
+
+ //@{
+ /**
+ * @brief Get the last child of this node
+ *
+ * For nodes without any children, this method returns NULL.
+ *
+ * @return Pointer to the last child, or NULL
+ */
virtual Node *lastChild()=0;
virtual Node const *lastChild() const=0;
-
- virtual unsigned childCount() const=0;
+ //@}
+
+ //@{
+ /**
+ * @brief Get the child of this node with a given index
+ *
+ * If there is no child with the specified index number, this method will return NULL.
+ *
+ * @param index The zero-based index of the child to retrieve
+ * @return Pointer to the appropriate child, or NULL
+ */
virtual Node *nthChild(unsigned index)=0;
virtual Node const *nthChild(unsigned index) const=0;
+ //@}
+
+ /*@}*/
+
+ /**
+ * @name Manipulate the XML tree
+ * @{
+ */
- virtual void addChild(Node *child, Node *ref)=0;
+ /**
+ * @brief Create a duplicate of this node
+ *
+ * The newly created node has no parent, and a refcount equal 1.
+ * You need to manually insert it into the document, using e.g. appendChild().
+ * Afterwards, call Inkscape::GC::release on it, so that it will be
+ * automatically collected when the parent is collected.
+ *
+ * @param doc The document in which the duplicate should be created
+ * @return A pointer to the duplicated node
+ */
+ virtual Node *duplicate(Document *doc) const=0;
+
+ /**
+ * @brief Insert another node as a child of this node
+ *
+ * When @c after is NULL, the inserted node will be placed as the first child
+ * of this node. @c after must be a child of this node.
+ *
+ * @param child The node to insert
+ * @param after The node after which the inserted node should be placed, or NULL
+ */
+ virtual void addChild(Node *child, Node *after)=0;
+
+ /**
+ * @brief Append a node as the last child of this node
+ * @param child The node to append
+ */
virtual void appendChild(Node *child)=0;
+
+ /**
+ * @brief Remove a child of this node
+ *
+ * Once the pointer to the removed node disappears from the stack, the removed node
+ * will be collected in the next GC pass, but only as long as its refcount is zero.
+ * You should keep a refcount of zero for all nodes in the document except for
+ * the document node itself, because they will be held in memory by the parent.
+ *
+ * @param child The child to remove
+ */
virtual void removeChild(Node *child)=0;
- virtual void changeOrder(Node *child, Node *ref)=0;
-
- virtual unsigned position() const=0;
- virtual void setPosition(int pos)=0;
-
- virtual gchar const *attribute(gchar const *key) const=0;
- virtual void setAttribute(gchar const *key, gchar const *value, bool is_interactive=false)=0;
- virtual bool matchAttributeName(gchar const *partial_name) const=0;
-
- virtual gchar const *content() const=0;
- virtual void setContent(gchar const *value)=0;
+
+ /**
+ * @brief Move a given node in this node's child order
+ *
+ * Both @c child and @c after must be children of this node for the method to work.
+ *
+ * @param child The node to move in the order
+ * @param after The sibling node after which the moved node should be placed
+ */
+ virtual void changeOrder(Node *child, Node *after)=0;
+ /**
+ * @brief Merge all children of another node with the current
+ *
+ * This method merges two node hierarchies, where @c src takes precedence.
+ * @c key is the name of the attribute that determines whether two nodes are
+ * corresponding (it must be the same for both, and all of their ancestors). If there is
+ * a corresponding node in @c src hierarchy, their attributes and content override the ones
+ * already present in this node's hierarchy. If there is no corresponding node,
+ * it is copied from @c src to this node. This method is used when merging the user's
+ * preferences file with the defaults, and has little use beyond that.
+ *
+ * @param src The node to merge into this node
+ * @param key The attribute to use as the identity attribute
+ */
virtual void mergeFrom(Node const *src, gchar const *key)=0;
+
+ /*@}*/
- virtual Inkscape::Util::List<AttributeRecord const> attributeList() const=0;
- virtual void synthesizeEvents(NodeEventVector const *vector, void *data)=0;
- virtual void synthesizeEvents(NodeObserver &observer)=0;
+ /**
+ * @name Notify observers about operations on the node
+ * @{
+ */
+
+ /**
+ * @brief Add an object that will be notified of the changes to this node
+ *
+ * @c observer must be an object deriving from the NodeObserver class.
+ * The virtual methods of this object will be called when a corresponding change
+ * happens to this node. You can also notify the observer of the node's current state
+ * using synthesizeEvents(NodeObserver &).
+ *
+ * @param observer The observer object
+ */
virtual void addObserver(NodeObserver &observer)=0;
- virtual void addListener(NodeEventVector const *vector, void *data)=0;
+ /**
+ * @brief Remove an object from the list of observers
+ * @param observer The object to be removed
+ */
virtual void removeObserver(NodeObserver &observer)=0;
- virtual void removeListenerByData(void *data)=0;
+ /**
+ * @brief Generate a sequence of events corresponding to the state of this node
+ *
+ * This function notifies the specified observer of all the events that would
+ * recreate the current state of this node; e.g. the observer is notified of
+ * all the attributes, children and content like they were just created.
+ * This function can greatly simplify observer logic.
+ *
+ * @param observer The node observer to notify of the events
+ */
+ virtual void synthesizeEvents(NodeObserver &observer)=0;
+ /**
+ * @brief Add an object that will be notified of the changes to this node and its descendants
+ *
+ * The difference between adding a regular observer and a subtree observer is that
+ * the subtree observer will also be notified if a change occurs to any of the node's
+ * descendants, while a regular observer will only be notified of changes to the node
+ * it was assigned to.
+ *
+ * @param observer The observer object
+ */
virtual void addSubtreeObserver(NodeObserver &observer)=0;
+
+ /**
+ * @brief Remove an object from the subtree observers list
+ * @param observer The object to be removed
+ */
virtual void removeSubtreeObserver(NodeObserver &observer)=0;
+ /**
+ * @brief Add a set node change callbacks with an associated data
+ * @deprecated Use addObserver(NodeObserver &) instead
+ */
+ virtual void addListener(NodeEventVector const *vector, void *data)=0;
+ /**
+ * @brief Remove a set of node change callbacks by their associated data
+ * @deprecated Use removeObserver(NodeObserver &) instead
+ */
+ virtual void removeListenerByData(void *data)=0;
+ /**
+ * @brief Generate a sequence of events corresponding to the state of this node
+ * @deprecated Use synthesizeEvents(NodeObserver &) instead
+ */
+ virtual void synthesizeEvents(NodeEventVector const *vector, void *data)=0;
+
+ /*@}*/
+
protected:
Node(Node const &) : Anchored() {}
-
-public: // ideally these should be protected too somehow...
- virtual NodeObserver &_subtreeObservers()=0;
- virtual void _setParent(Node *parent)=0;
- virtual void _setNext(Node *next)=0;
- virtual void _bindDocument(Document &document)=0;
-
- virtual unsigned _childPosition(Node const &child) const=0;
- virtual unsigned _cachedPosition() const=0;
- virtual void _setCachedPosition(unsigned position) const=0;
};
}