The SoType class is the basis for the run-time type system in Coin.
Many of the classes in the Coin library must have their type information registered before any instances are created (including, but not limited to: engines, nodes, fields, actions, nodekits and manipulators). The use of SoType to store this information provides lots of various functionality for working with class hierarchies, comparing class types, instantiating objects from classnames, etc etc.
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#include <Inventor/SoType.h>
List of all members.
Detailed Description
The SoType class is the basis for the run-time type system in Coin.
Many of the classes in the Coin library must have their type information registered before any instances are created (including, but not limited to: engines, nodes, fields, actions, nodekits and manipulators). The use of SoType to store this information provides lots of various functionality for working with class hierarchies, comparing class types, instantiating objects from classnames, etc etc.
It is for instance possible to do things like this:
A notable feature of the SoType class is that it is only 16 bits long and therefore should be passed around by value for efficiency reasons.
One important note about the use of SoType to register class information: super classes must be registered before any of their derived classes are.
Member Typedef Documentation
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This is a convenience typedef for the function signature of a typed class' instantiation method. It is an extension on the original Inventor API. Mostly only useful for internal purposes.
An instantation method will take no arguments and returns a void-pointer to a newly allocated and initialized object of the class type. |
Member Function Documentation
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This static method returns the SoType object associated with name name. If no known type matches the given name, SoType::badType() is returned. |
SbName SoType::getName |
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void |
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const |
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This method returns the name of the SoBase-derived class type the SoType object is configured for. |
const SoType SoType::getParent |
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void |
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const |
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This method returns the SoType type for the parent class of the SoBase-derived class the SoType object is configured for. |
SbBool SoType::isDerivedFrom |
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const SoType |
parent |
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const |
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This method returns TRUE if the given type is derived from (or is) the parent type, and FALSE otherwise. |
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This method appends all the class types derived from type to list, and returns the number of types added to the list. Internal types are not included in the list, nor are they counted.
type itself is also added to the list, as a type is seen as a derivation of its own type.
NB: do not write code which depends in any way on the order of the elements returned in list. |
SbBool SoType::canCreateInstance |
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void |
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const |
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This method returns FALSE for abstract base classes, and TRUE for class types that can be instantiated. |
void * SoType::createInstance |
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void |
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const |
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This method instantiates an object of the current type.
For types that can not be instantiated, NULL is returned.
Note that if the Coin library has been built as a DLL under Microsoft Windows and you use this method from application code, you must make sure that both the Coin DLL and the application executable is using the same instance of a C Run-Time (CRT) library. Otherwise, you will get memory heap corruption upon deallocating the returned instances, eventually leading to mysterious crashes.
This is not harmful if you only call SoType::createInstance() on types for reference counted class-types, though. These include all nodes, engines, paths, nodekits, draggers and manipulators. |
uint16_t SoType::getData |
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void |
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const |
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This method returns a type specific data variable. |
int16_t SoType::getKey |
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void |
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const [inline] |
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This method returns the type's index in the internal typelist. |
SbBool SoType::operator== |
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const SoType |
type |
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const [inline] |
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SbBool SoType::operator!= |
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const SoType |
type |
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const [inline] |
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SbBool SoType::operator< |
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const SoType |
type |
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const [inline] |
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Comparison operator for sorting type data according to some internal criterion. |
SbBool SoType::operator<= |
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const SoType |
type |
) |
const [inline] |
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Comparison operator for sorting type data according to some internal criterion. |
SbBool SoType::operator>= |
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const SoType |
type |
) |
const [inline] |
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Comparison operator for sorting type data according to some internal criterion. |
SbBool SoType::operator> |
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const SoType |
type |
) |
const [inline] |
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Comparison operator for sorting type data according to some internal criterion. |
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This method creates and registers a new class type.
Classes that do not inherit any other class should use SoType::badType() for the first argument. Abstract classes should use NULL for the method argument.
The value passed in for the data parameter can be retrieved with SoType::getData(). |
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This method makes a new class's instantiation method override the instantiation method of an existing class.
The new type should be a C++ subclass of the original class type, but this won't be checked though.
If NULL is passed as the second argument, the type will be considered uninstantiable -- it does not revert the configuration to the default setting as one might think.
Here's a complete code examples which shows how to fully override a built-in Coin node class, so that a) your application-specific extension class gets instantiated instead of the built-in class upon scenegraph import, and b) it gets written out properly upon export:
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void SoType::init |
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void |
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[static] |
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This static method initializes the type system. |
SoType SoType::fromKey |
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uint16_t |
key |
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[static] |
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Find and return a type from the given key ID. |
SoType SoType::badType |
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void |
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[static] |
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SbBool SoType::isBad |
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void |
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const [inline] |
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This method returns TRUE if the SoType object represents an illegal class type. |
void SoType::makeInternal |
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void |
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This method turns the specific type into an internal type. |
SbBool SoType::isInternal |
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void |
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const |
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This function returns TRUE if the type is an internal type. |
int SoType::getNumTypes |
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void |
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[static] |
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This function returns the number of types registered in the run-time type system. |
The documentation for this class was generated from the following files:
Generated on Sat Sep 3 09:49:36 2005 for Coin by
1.4.4