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SoElement Class Reference
[Element Classes]

#include <Inventor/elements/SoElement.h>

Inheritance diagram for SoElement:

SoAccumulatedElement SoFloatElement SoInt32Element SoOverrideElement SoProfilerElement SoReplacedElement SoLineWidthElement SoListenerGainElement SoPointSizeElement SoGLColorIndexElement SoListenerDopplerElement SoListenerOrientationElement SoListenerPositionElement SoGLLineWidthElement SoGLPointSizeElement

List of all members.


Detailed Description

SoElement is the abstract base class for all elements.

This is the base class for all the element classes in Coin.

Public Member Functions

const SoType getTypeId (void) const
int getStackIndex (void) const
virtual void init (SoState *state)
virtual void push (SoState *state)
virtual void pop (SoState *state, const SoElement *prevTopElement)
virtual SbBool matches (const SoElement *element) const =0
virtual SoElementcopyMatchInfo (void) const =0
void setDepth (const int depth)
int getDepth (void) const
virtual void print (FILE *file=stdout) const
virtual ~SoElement ()

Static Public Member Functions

static void initClass (void)
static SoType getClassTypeId (void)
static int getClassStackIndex (void)
static void initElements (void)
static int getNumStackIndices (void)
static SoType getIdFromStackIndex (const int stackIndex)

Protected Member Functions

 SoElement (void)
void capture (SoState *const state) const
virtual void captureThis (SoState *state) const
void setTypeId (const SoType typeId)
void setStackIndex (const int index)
SoElementgetNextInStack (void) const
SoElementgetNextFree (void) const

Static Protected Member Functions

static SoElementgetElement (SoState *const state, const int stackIndex)
static const SoElementgetConstElement (SoState *const state, const int stackIndex)
static int createStackIndex (const SoType id)

Protected Attributes

SoType typeId
int stackIndex
int depth

Static Protected Attributes

static int classStackIndex
static SoTypeListstackToType


Constructor & Destructor Documentation

SoElement::~SoElement (  )  [virtual]

The destructor.

SoElement::SoElement ( void   )  [protected]

The constructor. To create element instances, use SoType::createInstance() for the elements type identifier..


Member Function Documentation

void SoElement::initClass ( void   )  [static]

SoType SoElement::getClassTypeId ( void   )  [static]

int SoElement::getClassStackIndex ( void   )  [static]

const SoType SoElement::getTypeId ( void   )  const

Returns the type identification of an object derived from a class inheriting SoElement. This is used for run-time type checking and "downward" casting.

For a more thorough explanation of the run-time type identification functionality, see the documentation of SoBase::getTypeId().

int SoElement::getStackIndex ( void   )  const

Returns the stack index for an element instance.

void SoElement::init ( SoState state  )  [virtual]

void SoElement::push ( SoState state  )  [virtual]

This method is called every time a new element is required in one of the stacks. This happens when a writable element is requested, using SoState::getElement() or indirectly SoElement::getElement(), and the depth of the current element is less than the state depth.

Override this method if your element needs to copy data from the previous top of stack. The push() method is called on the new element, and the previous element can be found using SoElement::getNextInStack().

Reimplemented in SoAccumulatedElement, SoOverrideElement, SoGLLineWidthElement, and SoGLPointSizeElement.

void SoElement::pop ( SoState state,
const SoElement prevTopElement 
) [virtual]

This method is callled when the state is popped, and the depth of the element is bigger than the current state depth. pop() is called on the new top of stack, and a pointer to the previous top of stack is passed in prevTopElement.

Override this method if you need to copy some state information from the previous top of stack.

Reimplemented in SoGLLineWidthElement, and SoGLPointSizeElement.

SbBool SoElement::matches ( const SoElement element  )  const [pure virtual]

This function returns TRUE is the element matches another element (of the same class), with respect to cache validity.

If the application programmer's extension element has a matches() function, it should also have a copyMatchInfo() function.

Implemented in SoAccumulatedElement, SoOverrideElement, SoFloatElement, SoInt32Element, SoReplacedElement, and SoProfilerElement.

SoElement * SoElement::copyMatchInfo ( void   )  const [pure virtual]

This function creates a copy of the element that contains enough information to enable the matches() function to work.

Used to help with scenegraph traversal caching operations.

Implemented in SoAccumulatedElement, SoOverrideElement, SoFloatElement, SoInt32Element, SoReplacedElement, and SoProfilerElement.

void SoElement::initElements ( void   )  [static]

This function initializes all the built-in Coin element classes.

int SoElement::getNumStackIndices ( void   )  [static]

Returns the number of allocated element stack index slots.

SoType SoElement::getIdFromStackIndex ( const int  stackIndex  )  [static]

Returns the SoType identifier for the element class with element state stack index stackIndex.

void SoElement::setDepth ( const int  depth  ) 

Sets the depth value of the element instance in the state stack.

int SoElement::getDepth ( void   )  const

Returns the state stack depth value of the element instance.

void SoElement::print ( FILE *  file = stdout  )  const [virtual]

This function is for printing element information, and is used mostly for debugging purposes.

Reimplemented in SoOverrideElement, SoFloatElement, SoInt32Element, SoReplacedElement, SoListenerPositionElement, SoListenerOrientationElement, and SoListenerDopplerElement.

SoElement * SoElement::getElement ( SoState *const   state,
const int  stackIndex 
) [inline, static, protected]

This method returns the top instance (in the state stack) of the element class with stack index stackIndex.

The retuned instance is writable. To make this instance, some lazy evaluation may have to be perfomed, so use getConstElement() instead if the instance shouldn't be modified.

If no instance is available and can not be made, NULL is returned.

See also:
const SoElement * SoElement::getConstElement(SoState * const state, const int stackIndex)

void const SoElement * SoElement::getConstElement ( SoState *const   state,
const int  stackIndex 
) [inline, static, protected]

This method returns a reference to the top element of the class with stack index stackIndex. The returned element is non-mutable.

(Don't try to be clever and cast away the constness -- if the returned instance is modified, strange, hard to find and generally wonderful bugs will most likely start to happen.)

If no instance can be returned, NULL is returned.

See also:
SoElement * SoElement::getElement(SoState * const state, const int stackIndex)

void SoElement::capture ( SoState *const   state  )  const [inline, protected]

This function does whatever is necessary in the state for caching purposes. If should be called by subclasses of SoElement whenever any value in the element is accessed.

void SoElement::captureThis ( SoState state  )  const [protected, virtual]

Adds the element to the cache.

Reimplemented in SoAccumulatedElement.

void SoElement::setTypeId ( const SoType  typeId  )  [protected]

Sets the type identifier of an instance.

Note that this is fundamentally different from the SoNode run-time type system.

void SoElement::setStackIndex ( const int  stackIndex  )  [protected]

Sets the stack index in an instance. Used in constructors of derived elements.

int SoElement::createStackIndex ( const SoType  typeId  )  [static, protected]

Returns the value of a new available stack index.

SoElement * SoElement::getNextInStack ( void   )  const [protected]

Returns the next element down in the stack. Should be used in push() to get the previous element.

This method has a slightly misleading name, but we didn't change it to stay compatible with the original SGI Inventor API.

SoElement * SoElement::getNextFree ( void   )  const [protected]

Returns the next free element, ie the next element up in the stack.


Member Data Documentation

int SoElement::classStackIndex [static, protected]

This is the static state stack index for the class.

The element's unique SoType type identification.

int SoElement::stackIndex [protected]

The index in the state stack for this particular element instance.

SoTypeList * SoElement::stackToType [static, protected]

Provides mapping from state stack indices to element types.

int SoElement::depth [protected]

The depth of the element instance in the state stack.


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

Copyright © 1998-2008 by Kongsberg SIM. All rights reserved.

Generated on Tue May 5 02:52:13 2009 for Coin by Doxygen 1.5.5.