regina::NPacket Class Reference
[Basic Packet Types]

Represents a packet of information that may be individually edited or operated upon. More...

#include <npacket.h>

Inheritance diagram for regina::NPacket:
regina::ShareableObject regina::boost::noncopyable regina::NAngleStructureList regina::NContainer regina::NNormalSurfaceList regina::NPDF regina::NScript regina::NSurfaceFilter regina::NText regina::NTriangulation

List of all members.

Classes

class  ChangeEventBlock
 An object that temporarily blocks listeners from being notified of packet change events. More...

Public Member Functions

Constructors and Destructors



 NPacket (NPacket *parent=0)
 Constructor that inserts the new packet into the overall tree structure.
virtual ~NPacket ()
 Destructor that also orphans this packet and destroys all of its descendants.
Packet Identification

(end: Constructors and Destructors)



virtual int getPacketType () const =0
 Returns the integer ID representing this type of packet.
virtual std::string getPacketTypeName () const =0
 Returns an English name for this type of packet.
const std::string & getPacketLabel () const
 Returns the label associated with this individual packet.
void setPacketLabel (const std::string &newLabel)
 Sets the label associated with this individual packet.
std::string getFullName () const
 Returns a descriptive text string for the packet.
std::string makeUniqueLabel (const std::string &base) const
 Returns a new label that cannot be found anywhere in the entire tree structure.
bool makeUniqueLabels (NPacket *reference)
 Ensures that all packet labels in both this and the given packet tree combined are distinct.
Tags

(end: Packet Identification)



bool hasTag (const std::string &tag) const
 Determines whether this packet has the given associated tag.
bool hasTags () const
 Determines whether this packet has any associated tags at all.
bool addTag (const std::string &tag)
 Associates the given tag with this packet.
bool removeTag (const std::string &tag)
 Removes the association of the given tag with this packet.
void removeAllTags ()
 Removes all associated tags from this packet.
const std::set< std::string > & getTags () const
 Returns the set of all tags associated with this packet.
Event Handling

(end: Tags)



bool listen (NPacketListener *listener)
 Registers the given packet listener to listen for events on this packet.
bool isListening (NPacketListener *listener)
 Determines whether the given packet listener is currently listening for events on this packet.
bool unlisten (NPacketListener *listener)
 Unregisters the given packet listener so that it no longer listens for events on this packet.
Tree Queries

(end: Event Handling)



NPacketgetTreeParent () const
 Determines the parent packet in the tree structure.
NPacketgetFirstTreeChild () const
 Determines the first child of this packet in the tree structure.
NPacketgetLastTreeChild () const
 Determines the last child of this packet in the tree structure.
NPacketgetNextTreeSibling () const
 Determines the next sibling of this packet in the tree structure.
NPacketgetPrevTreeSibling () const
 Determines the previous sibling of this packet in the tree structure.
NPacketgetTreeMatriarch () const
 Determines the matriarch (the root) of the tree to which this packet belongs.
unsigned levelsDownTo (const NPacket *descendant) const
 Counts the number of levels between this packet and its given descendant in the tree structure.
unsigned levelsUpTo (const NPacket *ancestor) const
 Counts the number of levels between this packet and its given ancestor in the tree structure.
bool isGrandparentOf (const NPacket *descendant) const
 Determines if this packet is equal to or an ancestor of the given packet in the tree structure.
unsigned long getNumberOfChildren () const
 Returns the number of immediate children of this packet.
unsigned long getNumberOfDescendants () const
 Returns the total number of descendants of this packet.
unsigned long getTotalTreeSize () const
 Determines the total number of packets in the tree or subtree for which this packet is matriarch.
Tree Manipulation

(end: Tree Queries)



void insertChildFirst (NPacket *child)
 Inserts the given packet as the first child of this packet.
void insertChildLast (NPacket *child)
 Inserts the given packet as the last child of this packet.
void insertChildAfter (NPacket *newChild, NPacket *prevChild)
 Inserts the given packet as a child of this packet at the given location in this packet's child list.
void makeOrphan ()
 Cuts this packet away from its parent in the tree structure and instead makes it matriarch of its own tree.
void reparent (NPacket *newParent, bool first=false)
 Cuts this packet away from its parent in the tree structure, and inserts it as a child of the given packet instead.
void swapWithNextSibling ()
 Swaps this packet with its next sibling in the sequence of children beneath their common parent packet.
void moveUp (unsigned steps=1)
 Moves this packet the given number of steps towards the beginning of its sibling list.
void moveDown (unsigned steps=1)
 Moves this packet the given number of steps towards the end of its sibling list.
void moveToFirst ()
 Moves this packet to be the first in its sibling list.
void moveToLast ()
 Moves this packet to be the last in its sibling list.
void sortChildren ()
 Sorts the immediate children of this packet according to their packet labels.
Searching and Iterating

(end: Tree Manipulation)



NPacketnextTreePacket ()
 Finds the next packet after this in a complete depth-first iteration of the entire tree structure to which this packet belongs.
const NPacketnextTreePacket () const
 Finds the next packet after this in a complete depth-first iteration of the entire tree structure to which this packet belongs.
NPacketfirstTreePacket (const std::string &type)
 Finds the first packet of the requested type in a complete depth-first iteration of the tree structure.
const NPacketfirstTreePacket (const std::string &type) const
 Finds the first packet of the requested type in a complete depth-first iteration of the tree structure.
NPacketnextTreePacket (const std::string &type)
 Finds the next packet after this of the requested type in a complete depth-first iteration of the entire tree structure.
const NPacketnextTreePacket (const std::string &type) const
 Finds the next packet after this of the requested type in a complete depth-first iteration of the entire tree structure.
NPacketfindPacketLabel (const std::string &label)
 Finds the packet with the requested label in the tree or subtree for which this packet is matriarch.
const NPacketfindPacketLabel (const std::string &label) const
 Finds the packet with the requested label in the tree or subtree for which this packet is matriarch.
Packet Dependencies

(end: Searching and Iterating)



virtual bool dependsOnParent () const =0
 Determines if this packet depends upon its parent.
bool isPacketEditable () const
 Determines whether this packet can be altered without invalidating or otherwise upsetting any of its immediate children.
Cloning

(end: Packet Dependencies)



NPacketclone (bool cloneDescendants=false, bool end=true) const
 Clones this packet (and possibly its descendants), assigns to it a suitable unused label and inserts the clone into the tree as a sibling of this packet.
File I/O

(end: Cloning)



void writeXMLFile (std::ostream &out) const
 Writes a complete XML file containing the subtree with this packet as matriarch.
virtual void writePacket (NFile &out) const
 Writes the packet details to the given old-style binary file.

Static Public Member Functions

static NXMLPacketReadergetXMLReader (NPacket *parent)
 (end: File I/O)
static NPacketreadPacket (NFile &in, NPacket *parent)
 Reads a single packet from the specified file and returns a newly created object containing that information.

Static Public Attributes

static const int packetType
 Contains the integer ID for this packet.

Protected Member Functions

virtual NPacketinternalClonePacket (NPacket *parent) const =0
 Makes a newly allocated copy of this packet.
void fireChangedEvent ()
 Notifies all registered packet listeners that this packet has changed.
void writeXMLPacketTree (std::ostream &out) const
 Writes a chunk of XML containing the subtree with this packet as matriarch.
virtual void writeXMLPacketData (std::ostream &out) const =0
 Writes a chunk of XML containing the data for this packet only.

Detailed Description

Represents a packet of information that may be individually edited or operated upon.

Packets are stored in a dependency tree, where child packets fit within the context of (or otherwise cannot live without) parent packets.

When deriving classes from NPacket:

Note that external objects can listen for events on packets, such as when packets are changed or about to be destroyed. See the NPacketListener class notes for details.

Todo:
Feature: Provide automatic name selection/specification upon child packet insertion.

Constructor & Destructor Documentation

regina::NPacket::NPacket ( NPacket parent = 0  )  [inline]

Constructor that inserts the new packet into the overall tree structure.

The new packet will be inserted as the last child of the given parent, and will be initialised with no children of its own.

Note that NPacket is an abstract class and cannot be instantiated directly.

Python:
Not present.
Parameters:
parent the parent beneath which to insert this packet, or 0 if this packet is to be the matriarch of a new tree.
virtual regina::NPacket::~NPacket (  )  [virtual]

Destructor that also orphans this packet and destroys all of its descendants.


Member Function Documentation

bool regina::NPacket::addTag ( const std::string &  tag  ) 

Associates the given tag with this packet.

Each packet can have an arbitrary set of string tags associated with it. The tags are not used by this calculation engine; the feature is provided for whatever use a developer or user chooses to make of it.

Tags are case-sensitive. Tags associated with a single packet must be distinct, i.e., a particular tag cannot be associated more than once with the same packet.

Precondition:
The given tag is not the empty string.
Parameters:
tag the tag to add.
Returns:
true if the given tag was successfully added, or false if the given tag was already present beforehand.
NPacket* regina::NPacket::clone ( bool  cloneDescendants = false,
bool  end = true 
) const

Clones this packet (and possibly its descendants), assigns to it a suitable unused label and inserts the clone into the tree as a sibling of this packet.

Note that any string tags associated with this packet will not be cloned.

If this packet has no parent in the tree structure, no clone will be created and 0 will be returned.

Parameters:
cloneDescendants true if the descendants of this packet should also be cloned and inserted as descendants of the new packet. If this is passed as false (the default), only this packet will be cloned.
end true if the new packet should be inserted at the end of the parent's list of children (the default), or false if the new packet should be inserted as the sibling immediately after this packet.
Returns:
the newly inserted packet, or 0 if this packet has no parent.
virtual bool regina::NPacket::dependsOnParent (  )  const [pure virtual]

Determines if this packet depends upon its parent.

This is true if the parent cannot be altered without invalidating or otherwise upsetting this packet.

Returns:
true if and only if this packet depends on its parent.

Implemented in regina::NAngleStructureList, regina::NContainer, regina::NPDF, regina::NScript, regina::NText, regina::NNormalSurfaceList, regina::NSurfaceFilter, and regina::NTriangulation.

const NPacket* regina::NPacket::findPacketLabel ( const std::string &  label  )  const

Finds the packet with the requested label in the tree or subtree for which this packet is matriarch.

Note that label comparisons are case sensitive.

Parameters:
label the label to search for.
Returns:
the packet with the requested label, or 0 if there is no such packet.
NPacket* regina::NPacket::findPacketLabel ( const std::string &  label  ) 

Finds the packet with the requested label in the tree or subtree for which this packet is matriarch.

Note that label comparisons are case sensitive.

Parameters:
label the label to search for.
Returns:
the packet with the requested label, or 0 if there is no such packet.
void regina::NPacket::fireChangedEvent (  )  [protected]

Notifies all registered packet listeners that this packet has changed.

That is, the routine NPacketListener::packetWasChanged() will be called upon all registered listeners.

If change events are currently blocked, this routine will do nothing at all. You may wish to temporarily block change events during large modifications that are likely to call fireChangedEvents() at inopportune times during processing.

Change events can be blocked by creating a local ChangeEventBlock object; the block will be removed when the object is destroyed (goes out of scope). Note that these blocks are cumulative, i.e., if k blocks are created then all k blocks must be destroyed before fireChangeEvents() will notify listeners again.

const NPacket* regina::NPacket::firstTreePacket ( const std::string &  type  )  const

Finds the first packet of the requested type in a complete depth-first iteration of the tree structure.

Note that this packet must be the matriarch of the entire tree.

A parent packet is always reached before its children. The tree matriarch will be the first packet visited in a complete depth-first iteration.

Parameters:
type the type of packet to search for, as returned by getPacketTypeName(). Note that string comparisons are case sensitive.
Returns:
the first such packet, or 0 if there are no packets of the requested type.
NPacket* regina::NPacket::firstTreePacket ( const std::string &  type  ) 

Finds the first packet of the requested type in a complete depth-first iteration of the tree structure.

Note that this packet must be the matriarch of the entire tree.

A parent packet is always reached before its children. The tree matriarch will be the first packet visited in a complete depth-first iteration.

Parameters:
type the type of packet to search for, as returned by getPacketTypeName(). Note that string comparisons are case sensitive.
Returns:
the first such packet, or 0 if there are no packets of the requested type.
NPacket * regina::NPacket::getFirstTreeChild (  )  const [inline]

Determines the first child of this packet in the tree structure.

This routine takes small constant time.

Returns:
the first child packet, or 0 if there is none.
std::string regina::NPacket::getFullName (  )  const [inline]

Returns a descriptive text string for the packet.

The string is of the form label (packet-type).

Returns:
the descriptive text string.
NPacket * regina::NPacket::getLastTreeChild (  )  const [inline]

Determines the last child of this packet in the tree structure.

This routine takes small constant time.

Returns:
the last child packet, or 0 if there is none.
NPacket * regina::NPacket::getNextTreeSibling (  )  const [inline]

Determines the next sibling of this packet in the tree structure.

This is the child of the parent that follows this packet.

This routine takes small constant time.

Returns:
the next sibling of this packet, or 0 if there is none.
unsigned long regina::NPacket::getNumberOfChildren (  )  const

Returns the number of immediate children of this packet.

Grandchildren and so on are not counted.

Returns:
the number of immediate children.
unsigned long regina::NPacket::getNumberOfDescendants (  )  const [inline]

Returns the total number of descendants of this packet.

This includes children, grandchildren and so on. This packet is not included in the count.

Returns:
the total number of descendants.
const std::string & regina::NPacket::getPacketLabel (  )  const [inline]

Returns the label associated with this individual packet.

An example is MyTriangulation. Each individual packet in the overall tree structure must have a unique label.

Returns:
this individual packet's label.
virtual int regina::NPacket::getPacketType (  )  const [pure virtual]

Returns the integer ID representing this type of packet.

This is the same for all packets of this class.

Returns:
the packet type ID.

Implemented in regina::NAngleStructureList, regina::NContainer, regina::NPDF, regina::NScript, regina::NText, regina::NNormalSurfaceList, regina::NSurfaceFilter, and regina::NTriangulation.

virtual std::string regina::NPacket::getPacketTypeName (  )  const [pure virtual]

Returns an English name for this type of packet.

An example is NTriangulation. This is the same for all packets of this class.

Returns:
the packet type name.

Implemented in regina::NAngleStructureList, regina::NContainer, regina::NPDF, regina::NScript, regina::NText, regina::NNormalSurfaceList, regina::NSurfaceFilter, and regina::NTriangulation.

NPacket * regina::NPacket::getPrevTreeSibling (  )  const [inline]

Determines the previous sibling of this packet in the tree structure.

This is the child of the parent that precedes this packet.

This routine takes small constant time.

Returns:
the previous sibling of this packet, or 0 if there is none.
const std::set< std::string > & regina::NPacket::getTags (  )  const [inline]

Returns the set of all tags associated with this packet.

Each packet can have an arbitrary set of string tags associated with it. The tags are not used by this calculation engine; the feature is provided for whatever use a developer or user chooses to make of it.

Tags are case-sensitive. Tags associated with a single packet must be distinct, i.e., a particular tag cannot be associated more than once with the same packet.

Python:
This routine returns a python list of strings.
Returns:
the set of all tags associated with this packet.
unsigned long regina::NPacket::getTotalTreeSize (  )  const

Determines the total number of packets in the tree or subtree for which this packet is matriarch.

This packet is included in the count.

Returns:
the total tree or subtree size.
NPacket* regina::NPacket::getTreeMatriarch (  )  const

Determines the matriarch (the root) of the tree to which this packet belongs.

Returns:
the matriarch of the packet tree.
NPacket * regina::NPacket::getTreeParent (  )  const [inline]

Determines the parent packet in the tree structure.

This routine takes small constant time.

Returns:
the parent packet, or 0 if there is none.
static NXMLPacketReader* regina::NPacket::getXMLReader ( NPacket parent  )  [static]

(end: File I/O)

Returns a newly created XML element reader that will read the contents of a single XML packet element. You may assume that the packet to be read is of the same type as the class in which you are implementing this routine.

The XML element reader should read exactly what writeXMLPacketData() writes, and vice versa.

parent represents the packet which will become the new packet's parent in the tree structure, and may be assumed to have already been read from the file. This information is for reference only, and does not need to be used. The XML element reader can either insert or not insert the new packet beneath parent in the tree structure as it pleases. Note however that parent will be 0 if the new packet is to become a tree matriarch.

This routine is not actually provided for NPacket itself, but must be declared and implemented for every packet subclass that will be instantiated.

Python:
Not present.
Parameters:
parent the packet which will become the new packet's parent in the tree structure, or 0 if the new packet is to be tree matriarch.
Returns:
the newly created XML element reader.
bool regina::NPacket::hasTag ( const std::string &  tag  )  const [inline]

Determines whether this packet has the given associated tag.

Each packet can have an arbitrary set of string tags associated with it. The tags are not used by this calculation engine; the feature is provided for whatever use a developer or user chooses to make of it.

Tags are case-sensitive. Tags associated with a single packet must be distinct, i.e., a particular tag cannot be associated more than once with the same packet.

Parameters:
tag the tag to search for.
Returns:
true if the given tag is found, false otherwise.
bool regina::NPacket::hasTags (  )  const [inline]

Determines whether this packet has any associated tags at all.

Each packet can have an arbitrary set of string tags associated with it. The tags are not used by this calculation engine; the feature is provided for whatever use a developer or user chooses to make of it.

Tags are case-sensitive. Tags associated with a single packet must be distinct, i.e., a particular tag cannot be associated more than once with the same packet.

Returns:
true if this packet has any tags, false otherwise.
void regina::NPacket::insertChildAfter ( NPacket newChild,
NPacket prevChild 
)

Inserts the given packet as a child of this packet at the given location in this packet's child list.

This routine takes small constant time.

Precondition:
Parameter newChild has no parent packet.
Parameter prevChild is already a child of this packet.
This packet is not a descendant of newChild.
Python:
Since this packet takes ownership of the given child packet, the python object containing the given child packet becomes a null object and should no longer be used. See reparent() for a way of avoiding these problems in some cases.
Parameters:
newChild the child to insert.
prevChild the preexisting child of this packet after which newChild will be inserted, or 0 if newChild is to be the first child of this packet.
void regina::NPacket::insertChildFirst ( NPacket child  ) 

Inserts the given packet as the first child of this packet.

This routine takes small constant time.

Precondition:
The given child has no parent packet.
This packet is not a descendant of the given child.
Python:
Since this packet takes ownership of the given child packet, the python object containing the given child packet becomes a null object and should no longer be used. See reparent() for a way of avoiding these problems in some cases.
Parameters:
child the child to insert.
void regina::NPacket::insertChildLast ( NPacket child  ) 

Inserts the given packet as the last child of this packet.

This routine takes small constant time.

Precondition:
The given child has no parent packet.
This packet is not a descendant of the given child.
Python:
Since this packet takes ownership of the given child packet, the python object containing the given child packet becomes a null object and should no longer be used. See reparent() for a way of avoiding these problems in some cases.
Parameters:
child the child to insert.
virtual NPacket* regina::NPacket::internalClonePacket ( NPacket parent  )  const [protected, pure virtual]

Makes a newly allocated copy of this packet.

This routine should not insert the new packet into the tree structure, clone the packet's associated tags or give the packet a label. It should also not clone any descendants of this packet.

You may assume that the new packet will eventually be inserted into the tree beneath either the same parent as this packet or a clone of that parent.

Parameters:
parent the parent beneath which the new packet will eventually be inserted.
Returns:
the newly allocated packet.
bool regina::NPacket::isGrandparentOf ( const NPacket descendant  )  const

Determines if this packet is equal to or an ancestor of the given packet in the tree structure.

Parameters:
descendant the other packet whose relationships we are examining.
Returns:
true if and only if this packet is equal to or an ancestor of descendant.
bool regina::NPacket::isListening ( NPacketListener listener  )  [inline]

Determines whether the given packet listener is currently listening for events on this packet.

See the NPacketListener class notes for details.

Python:
Not present.
Parameters:
listener the listener to search for.
Returns:
true if the given listener is currently registered with this packet, or false otherwise.
bool regina::NPacket::isPacketEditable (  )  const

Determines whether this packet can be altered without invalidating or otherwise upsetting any of its immediate children.

Descendants further down the packet tree are not (and should not need to be) considered.

Returns:
true if and only if this packet may be edited.
unsigned regina::NPacket::levelsDownTo ( const NPacket descendant  )  const

Counts the number of levels between this packet and its given descendant in the tree structure.

If descendant is this packet, the number of levels is zero.

Precondition:
This packet is equal to descendant, or can be obtained from descendant using only child-to-parent steps.
Parameters:
descendant the packet whose relationship with this packet we are examining.
Returns:
the number of levels difference.
unsigned regina::NPacket::levelsUpTo ( const NPacket ancestor  )  const [inline]

Counts the number of levels between this packet and its given ancestor in the tree structure.

If ancestor is this packet, the number of levels is zero.

Precondition:
This packet is equal to ancestor, or can be obtained from ancestor using only parent-to-child steps.
Parameters:
ancestor the packet whose relationship with this packet we are examining.
Returns:
the number of levels difference.
bool regina::NPacket::listen ( NPacketListener listener  ) 

Registers the given packet listener to listen for events on this packet.

See the NPacketListener class notes for details.

Python:
Not present.
Parameters:
listener the listener to register.
Returns:
true if the given listener was successfully registered, or false if the given listener was already registered beforehand.
void regina::NPacket::makeOrphan (  ) 

Cuts this packet away from its parent in the tree structure and instead makes it matriarch of its own tree.

The tree information for both this packet and its parent will be updated.

This routine takes small constant time.

Precondition:
This packet has a parent.
This packet does not depend on its parent; see dependsOnParent() for details.
std::string regina::NPacket::makeUniqueLabel ( const std::string &  base  )  const

Returns a new label that cannot be found anywhere in the entire tree structure.

This packet need not be the tree matriarch; this routine will search the entire tree to which this packet belongs.

The new label will consist of the given base, possibly followed by a space and a number.

Parameters:
base a string upon which the new label will be based.
Returns:
a new unique label.
bool regina::NPacket::makeUniqueLabels ( NPacket reference  ) 

Ensures that all packet labels in both this and the given packet tree combined are distinct.

If two packets have the same label, one will be renamed by adding a space and a number.

Packets in the given packet tree will be given priority over the labels; that is, if a packet in this tree has the same label as a packet in the given tree, it will be the packet in this tree that is renamed.

The given packet tree may be null, in which case only this tree will be examined.

Precondition:
This and the given packet belong to different packet trees, and are each matriarchs in their respective trees.
Parameters:
reference the packet tree with which to compare this tree.
Returns:
true if and only if any of the packets were relabelled.
void regina::NPacket::moveDown ( unsigned  steps = 1  ) 

Moves this packet the given number of steps towards the end of its sibling list.

If the number of steps is larger than the greatest possible movement, the packet will be moved to the very end of its sibling list.

This routine takes time proportional to the number of steps.

Precondition:
The given number of steps is strictly positive.
void regina::NPacket::moveToFirst (  ) 

Moves this packet to be the first in its sibling list.

This routine takes small constant time.

void regina::NPacket::moveToLast (  ) 

Moves this packet to be the last in its sibling list.

This routine takes small constant time.

void regina::NPacket::moveUp ( unsigned  steps = 1  ) 

Moves this packet the given number of steps towards the beginning of its sibling list.

If the number of steps is larger than the greatest possible movement, the packet will be moved to the very beginning of its sibling list.

This routine takes time proportional to the number of steps.

Precondition:
The given number of steps is strictly positive.
const NPacket* regina::NPacket::nextTreePacket ( const std::string &  type  )  const

Finds the next packet after this of the requested type in a complete depth-first iteration of the entire tree structure.

Note that this packet need not be the tree matriarch. The order of tree searching is described in firstTreePacket().

Parameters:
type the type of packet to search for, as returned by getPacketTypeName(). Note that string comparisons are case sensitive.
Returns:
the next such packet, or 0 if this is the last packet of the requested type in such an iteration.
NPacket* regina::NPacket::nextTreePacket ( const std::string &  type  ) 

Finds the next packet after this of the requested type in a complete depth-first iteration of the entire tree structure.

Note that this packet need not be the tree matriarch. The order of tree searching is described in firstTreePacket().

Parameters:
type the type of packet to search for, as returned by getPacketTypeName(). Note that string comparisons are case sensitive.
Returns:
the next such packet, or 0 if this is the last packet of the requested type in such an iteration.
const NPacket* regina::NPacket::nextTreePacket (  )  const

Finds the next packet after this in a complete depth-first iteration of the entire tree structure to which this packet belongs.

Note that this packet need not be the tree matriarch.

A parent packet is always reached before its children. The tree matriarch will be the first packet visited in a complete depth-first iteration.

Returns:
the next packet, or 0 if this is the last packet in such an iteration.
NPacket* regina::NPacket::nextTreePacket (  ) 

Finds the next packet after this in a complete depth-first iteration of the entire tree structure to which this packet belongs.

Note that this packet need not be the tree matriarch.

A parent packet is always reached before its children. The tree matriarch will be the first packet visited in a complete depth-first iteration.

Returns:
the next packet, or 0 if this is the last packet in such an iteration.
static NPacket* regina::NPacket::readPacket ( NFile in,
NPacket parent 
) [static]

Reads a single packet from the specified file and returns a newly created object containing that information.

You may assume that the packet to be read is of the same type as the class in which you are implementing this routine. The newly created object must also be of this type.

For instance, NTriangulation::readPacket() may assume that the packet is of type NTriangulation, and must return a pointer to a newly created NTriangulation. Deallocation of the newly created packet is the responsibility of whoever calls this routine.

The packet type and label may be assumed to have already been read from the file, and should not be reread. The readPacket() routine should read exactly what writePacket() writes, and vice versa.

parent represents the packet which will become the new packet's parent in the tree structure, and may be assumed to have already been read from the file. This information is for reference only, and does not need to be used. This routine can either insert or not insert the new packet beneath parent in the tree structure as it pleases. Note however that parent will be 0 if the new packet is to become a tree matriarch.

This routine is not actually provided for NPacket itself, but must be declared and implemented for every packet subclass that will be instantiated. Within each such subclass the function must be declared to return a pointer to an object of that subclass. For instance, NTriangulation::readPacket() must be declared to return an NTriangulation*, not simply an NPacket*.

New packet types should make this routine simply return 0 since this file format is now obsolete, and older calculation engines will not understand newer packet types anyway.

Deprecated:
For the preferred way to read packets from file, see getXMLReader() and class NXMLPacketReader instead.
Precondition:
The given file is open for reading and all above conditions have been satisfied.
Python:
Not present.
Parameters:
in the file from which to read the packet.
parent the packet which will become the new packet's parent in the tree structure, or 0 if the new packet is to be tree matriarch.
Returns:
the packet read from file, or 0 if an error occurred.
void regina::NPacket::removeAllTags (  ) 

Removes all associated tags from this packet.

Each packet can have an arbitrary set of string tags associated with it. The tags are not used by this calculation engine; the feature is provided for whatever use a developer or user chooses to make of it.

Tags are case-sensitive. Tags associated with a single packet must be distinct, i.e., a particular tag cannot be associated more than once with the same packet.

bool regina::NPacket::removeTag ( const std::string &  tag  ) 

Removes the association of the given tag with this packet.

Each packet can have an arbitrary set of string tags associated with it. The tags are not used by this calculation engine; the feature is provided for whatever use a developer or user chooses to make of it.

Tags are case-sensitive. Tags associated with a single packet must be distinct, i.e., a particular tag cannot be associated more than once with the same packet.

Parameters:
tag the tag to remove.
Returns:
true if the given tag was removed, or false if the given tag was not actually associated with this packet.
void regina::NPacket::reparent ( NPacket newParent,
bool  first = false 
)

Cuts this packet away from its parent in the tree structure, and inserts it as a child of the given packet instead.

This routine is essentially a combination of makeOrphan() followed by either insertChildFirst() or insertChildLast().

This routine takes small constant time. It is safe to use regardless of whether this packet has a parent or not.

Precondition:
This packet does not depend on its parent; see dependsOnParent() for details.
The given parent is not a descendant of this packet.
Python:
This routine is much simpler than combinations of makeOrphan() and insertChildFirst() / insertChildLast(), since there are no unpleasant ownership issues to deal with. However, if this packet currently has no parent then the ownership issues are unavoidable; in this case reparent() will do nothing, and one of the insertChild...() routines must be used instead.
Parameters:
newParent the new parent of this packet, i.e., the packet beneath which this packet will be inserted.
first true if this packet should be inserted as the first child of the given parent, or false (the default) if it should be inserted as the last child.
void regina::NPacket::setPacketLabel ( const std::string &  newLabel  ) 

Sets the label associated with this individual packet.

Precondition:
No other packet in the overall tree structure has the same label.
Parameters:
newLabel the new label to give this packet.
void regina::NPacket::sortChildren (  ) 

Sorts the immediate children of this packet according to their packet labels.

Note that this routine is not recursive (for instance, grandchildren will not be sorted within each child packet).

This routine takes quadratic time in the number of immediate children (and it's slow quadratic at that).

void regina::NPacket::swapWithNextSibling (  ) 

Swaps this packet with its next sibling in the sequence of children beneath their common parent packet.

Calling this routine is equivalent to calling moveDown().

This routine takes small constant time.

If this packet has no next sibling then this routine does nothing.

bool regina::NPacket::unlisten ( NPacketListener listener  ) 

Unregisters the given packet listener so that it no longer listens for events on this packet.

See the NPacketListener class notes for details.

Python:
Not present.
Parameters:
listener the listener to unregister.
Returns:
true if the given listener was successfully unregistered, or false if the given listener was not registered in the first place.
void regina::NPacket::writePacket ( NFile out  )  const [inline, virtual]

Writes the packet details to the given old-style binary file.

You may assume that the packet type and label have already been written. Only the actual data stored in the packet need be written.

The default implementation for this routine does nothing; new packet types should not implement this routine since this file format is now obsolete, and older calculation engines will simply skip unknown packet types when reading from binary files.

Deprecated:
For the preferred way to write packets to file, see writeXMLFile() and writeXMLPacketData() instead.
Precondition:
The given file is open for writing and satisfies the assumptions listed above.
Python:
Not present.
Parameters:
out the file to be written to.

Reimplemented in regina::NAngleStructureList, regina::NContainer, regina::NPDF, regina::NScript, regina::NText, regina::NNormalSurfaceList, regina::NSurfaceFilter, and regina::NTriangulation.

void regina::NPacket::writeXMLFile ( std::ostream &  out  )  const

Writes a complete XML file containing the subtree with this packet as matriarch.

This is the preferred way of writing a packet tree to file.

The output from this routine cannot be used as a piece of an XML file; it must be the entire XML file. For a piece of an XML file, see routine writeXMLPacketTree() instead.

For a handy wrapper to this routine that handles file I/O and compression, see regina::writeXMLFile().

Precondition:
This packet does not depend upon its parent.
Python:
Not present.
Parameters:
out the output stream to which the XML should be written.
virtual void regina::NPacket::writeXMLPacketData ( std::ostream &  out  )  const [protected, pure virtual]

Writes a chunk of XML containing the data for this packet only.

You may assume that the packet opening tag (including the packet type and label) has already been written, and that all child packets followed by the corresponding packet closing tag will be written immediately after this routine is called. This routine need only write the internal data stored in this specific packet.

Parameters:
out the output stream to which the XML should be written.

Implemented in regina::NAngleStructureList, regina::NContainer, regina::NPDF, regina::NScript, regina::NText, regina::NNormalSurfaceList, regina::NSurfaceFilter, and regina::NTriangulation.

void regina::NPacket::writeXMLPacketTree ( std::ostream &  out  )  const [protected]

Writes a chunk of XML containing the subtree with this packet as matriarch.

This is the preferred way of writing a packet tree to file.

The output from this routine is only a piece of XML; it should not be used as a complete XML file. For a complete XML file, see routine writeXMLFile() instead.

Parameters:
out the output stream to which the XML should be written.

Member Data Documentation

const int regina::NPacket::packetType [static]

Contains the integer ID for this packet.

Each distinct packet type must have a unique ID, and this should be a positive integer. See packetregistry.h for further requirements regarding ID selection.

This member is not actually provided for NPacket itself, but must be declared for every packet subclass that will be instantiated. A value need not be assigned; packetregistry.h will take care of this task when you register the packet.

Reimplemented in regina::NAngleStructureList, regina::NContainer, regina::NPDF, regina::NScript, regina::NText, regina::NNormalSurfaceList, regina::NSurfaceFilter, and regina::NTriangulation.


The documentation for this class was generated from the following file:

Copyright © 1999-2009, Ben Burton
This software is released under the GNU General Public License.
For further information, or to submit a bug or other problem, please contact Ben Burton (bab@debian.org).