IlvUserAccessor Class Reference

Base class for persistent behaviors. More...

#include <ilviews/protos/useracc.h>

Inheritance diagram for IlvUserAccessor:

List of all members.

Public Member Functions
	IlvUserAccessor (const char *name, const IlvValueTypeClass *type, IlUInt flags=0)
	Creates a new user accessor of name name and type type.
virtual void	initialize (const IlvAccessorHolder *object)
	Attachment method to an IlvAccessorHolder.
virtual IlBoolean	isOutputValue (const IlSymbol *name) const
	Queries if the accessor is an output accessor.
IlBoolean	isPrivate () const
	Returns IlTrue if the accessor has the private flag set. Otherwise, it returns IlFalse.
IlBoolean	isRuntime () const
	Returns IlTrue if the accessor has the RunTime flag set. Otherwise, it returns IlFalse.
void	setPrivate (IlBoolean val)
	Sets the Private flag of this accessor.
void	setRuntime (IlBoolean runTime)
	Sets the RunTime flag of this accessor.
Protected Member Functions
virtual IlUInt	compareValues (const IlvAccessorHolder *object, const IlvAccessible *ref, IlvValue *values, IlUShort count, IlvValueArray &diffs) const
	Compares the values in ref and object and returns the differing values.
IlBoolean	getValue (IlvValue &val, const IlvAccessorHolder *object, IlvDisplay *display, IlvValueTypeClass *typeClass=0, IlSymbol *typeVal=0, const IlvValue *arg=0) const
	Evaluates a parameter of a user accessor.
Friends
class	IlvAccessorHolder
class	IlvGroup

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Detailed Description

Base class for persistent behaviors.

Library: ilvproto

An IlvUserAccessor is an accessor that can be saved and restored. IlvUserAccessor is the base class for all accessors that are to be added dynamically by the user when building a prototype.

See also:

IlvAccessorHolder, IlvGroup.

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Constructor & Destructor Documentation

IlvUserAccessor::IlvUserAccessor	(	const char *	name,
		const IlvValueTypeClass *	type,
		IlUInt	flags = 0
	)

Creates a new user accessor of name name and type type.

Parameters:

	name	Name of the accessor, that is, the attribute by which one accesses this accessor in an accessor holder. Calls to object->queryValue(IlvValue(name, ...)) and object->changeValue(IlvValue(name, ...)) on the object will result in a corresponding call to accessor->queryValue(object, value).
	type	Type of the accessors. Some accessors hold internal data in the form of an IlvValue. This argument allows you to set the type of this value.
	flags	Attributes of the new accessors. It is a combination of the following values: IlvUserAccessorRuntime. The value associated with this accessor must not be saved to the file. IlvUserAccessorPrivate. This accessor is used internally by the prototype, and should not be listed in graphical user interfaces used to edit instances of the prototype.

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Member Function Documentation

virtual IlUInt IlvUserAccessor::compareValues	(	const IlvAccessorHolder *	object,
		const IlvAccessible *	ref,
		IlvValue *	values,
		IlUShort	count,
		IlvValueArray &	diffs
	)			const [protected, virtual]

Compares the values in ref and object and returns the differing values.

Compares the objects object and ref for the values specified by the values array of length count. The differences are stored in the diffs array, and the method returns the number of differences. The default implementation simply calls the IlvAccessible::compareValues method, which will query the values for the two objects and compare them one by one. Subclasses may compare values more cleverly by grouping differences: for example, the IlvGroupAccessor subclass detects when all nodes of a group differ homogeneously and reports only one difference for the whole group.

See also:

IlvAccessible::compareValues, IlvProtoInstance, IlvPrototype.

Reimplemented from IlvAccessor.

Reimplemented in IlvPrototypeAccessor, IlvCompositeAccessor, and IlvGroupUserAccessor.

IlBoolean IlvUserAccessor::getValue	(	IlvValue &	val,
		const IlvAccessorHolder *	object,
		IlvDisplay *	display,
		IlvValueTypeClass *	typeClass = 0,
		IlSymbol *	typeVal = 0,
		const IlvValue *	arg = 0
	)			const [protected]

Evaluates a parameter of a user accessor.

A user accessor parameter is often specified as a character string (which can contain a constant value, such as "100"), the name of another accessor, or an arbitrary expression containing constants and/or accessor names. This method takes an input value and evaluates it.

The result of the evaluation and conversion (optional) is stored in the val parameter.

Parameters:

	val	Input/output parameter that initially contains the character string to convert. The getValue method converts this character string as explained below, and stores the resulting value in val. If the value contains any of the characters "()+*-/&|^!>;<;=", it is considered as an expression and it is evaluated (see further). Otherwise, if the value starts with a quotation mark ("), or a digit, or if it is equal to the values "IlTrue" or "IlFalse", it is converted to the appropriate type (string or integer). If the value consists of a single identifier, it is interpreted as an accessor name, and the accessor value is retrieved from object.
	object	Object holding the accessor. Used to access other attributes in the object that can be referenced by the input value.
	typeVal	(see typeClass).
	typeClass	If non-null, the value is converted to that type. If typeVal is non-null and typeClass is 0, the value is converted to the type of the typeVal property of object.
	arg	An argument that can be used as input by the evaluation process.

Returns:

IlTrue if the conversion was successful, or IlFalse if an error occurred while retrieving or converting the value.

Expressions follow the usual C++ syntax. You can use the operators +, -, *, /, %, <, >, =, >=, <=, &&, ||, and parentheses. The ternary conditional operator "*?*:*" is not supported. The operands can be integer constants (in decimal or hexadecimal format) or floating-point constants (with the format defined by the C library function strtod). The operands can also be string constants (which must be placed in quotation marks), or identifiers that are interpreted as accessors of object. When the two operands are strings, the + operator returns the concatenation of its operands, and the == and != operators compare their operands as strings.

Expressions must not contain blank spaces between their operands or operators, or they will not be saved correctly to .ivp files.

virtual void IlvUserAccessor::initialize

(

const IlvAccessorHolder *

object

)

[virtual]

Attachment method to an IlvAccessorHolder.

This method is called when the accessor object is attached to a group. You can redefine it in subclasses of IlvUserAccessor to perform any kind of initialization.

Parameters:

object

The object the accessor is attached to.

Reimplemented in IlvAnimationAccessor, IlvCallbackAccessor, IlvLoopbackAccessor, IlvAbstractEventAccessor, IlvRotationAccessor, IlvSlideXAccessor, IlvSlideYAccessor, IlvJavaScriptAccessor, and IlvPrototypeAccessor.

virtual IlBoolean IlvUserAccessor::isOutputValue

(

const IlSymbol *

name

)

const [virtual]

Queries if the accessor is an output accessor.

Returns:

IlTrue if the accessor is an output accessor, and IlFalse otherwize.

Reimplemented from IlvAccessor.

Reimplemented in IlvCallbackAccessor, IlvOutputAccessor, IlvExportOutputAccessor, and IlvPrototypeAccessor.

void IlvUserAccessor::setPrivate

(

IlBoolean

val

)

Sets the Private flag of this accessor.

Parameters:

val

The new Private flag value.

void IlvUserAccessor::setRuntime

(

IlBoolean

runTime

)

Sets the RunTime flag of this accessor.

Parameters:

runTime

The new RunTime flag value.