This reference page is linked to from the following overview topics: Parameter Block Flags, Parameter Flags, Monitoring Parameter Changes.

Detailed Description

See also:: Structure ParamDef, List of ParamType2 Choices, Class ReferenceMaker, Structure PB2Value.

Description:: Any parameter in a block can have an accessor callback object that has its Get() or Set() method called whenever the parameter is accessed. This may be used to provide access to dynamically-computed virtual parameters and sometimes to allow parameter-specific processing by the class as the parameter in the block is modified (such as keeping object data members up-to-date).

The Get() and Set() methods are called at all times when a parameter is accessed, including parameters that are animated. The Get() method is called after the controller is accessed, so the current controller value is seen and can be optionally overridden in the Get() method. Note that the controller is accessed whenever the 3ds Max time is changed (such as a frame slider move) and so the Get() method will be called each frame as this happens.

A pointer to an instance of this class is a data member of the ParamDef structure.

#include <iparamb2.h>

Inheritance diagram for PBAccessor:

[legend]

List of all members.

Public Types
enum	tab_changes { tab_insert, tab_append, tab_delete, tab_ref_deleted, tab_setcount, tab_sort }
Public Member Functions
virtual void	Get (PB2Value &v, ReferenceMaker *owner, ParamID id, int tabIndex, TimeValue t, Interval &valid)
virtual void	Set (PB2Value &v, ReferenceMaker *owner, ParamID id, int tabIndex, TimeValue t)
virtual BOOL	KeyFrameAtTime (ReferenceMaker *owner, ParamID id, int tabIndex, TimeValue t)
virtual MSTR	GetLocalName (ReferenceMaker *owner, ParamID id, int tabIndex)
virtual void	TabChanged (tab_changes changeCode, Tab< PB2Value > tab, ReferenceMaker owner, ParamID id, int tabIndex, int count)
virtual void	DeleteThis ()

Member Enumeration Documentation

enum tab_changes

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Enumerator:

tab_insert	Search for all occurrences
tab_append	Search for all occurrences
tab_delete	Search for all occurrences
tab_ref_deleted	Search for all occurrences
tab_setcount	Search for all occurrences
tab_sort	Search for all occurrences

{ tab_insert, tab_append, tab_delete, tab_ref_deleted, tab_setcount, tab_sort };

Member Function Documentation

virtual void Get	(	PB2Value &	v,
		ReferenceMaker *	owner,
		ParamID	id,
		int	tabIndex,
		TimeValue	t,
		Interval &	valid
	)		`[inline, virtual]`

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Remarks:: This method is called when the specified owner object accesses (gets) the value v. This is called after the controller is accessed, so the current controller value is seen and can be optionally overridden in the this method. Note that the controller is accessed whenever the 3ds Max time is changed (such as a slider move) and so this method will be called each frame as this happens.

Parameters:: PB2Value& v

The value being accessed.

ReferenceMaker* owner

Points to the owner of the parameter.

ParamID id

The permanent ID of the parameter.

int tabIndex

If the parameter is a Tab<> this is the zero based index of the parameter in the table.

TimeValue t

The current time the get is taking place.

Interval &valid

The validity interval for the value.

Default Implementation:: {}

Reimplemented in MSPluginPBAccessor.

{ }

virtual void Set	(	PB2Value &	v,
		ReferenceMaker *	owner,
		ParamID	id,
		int	tabIndex,
		TimeValue	t
	)		`[inline, virtual]`

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Remarks:: This method is called when the specified owner objects sets the value v. This is called just before calling SetValue() on the parameters controller, so it can take note of the value going in and change it if desired.

Parameters:: PB2Value& v

The value being set.

ReferenceMaker* owner

Points to the owner of the parameter.

ParamID id

The permanent ID of the parameter.

int tabIndex

If the parameter is a Tab<> this is the zero based index of the parameter in the table.

TimeValue t

The current time the set is taking place.

Default Implementation:: {}

Reimplemented in MSPluginPBAccessor.

{ }

virtual BOOL KeyFrameAtTime	(	ReferenceMaker *	owner,
		ParamID	id,
		int	tabIndex,
		TimeValue	t
	)		`[inline, virtual]`

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Remarks:: Checks to see if a keyframe exists for the given parameter at the given time. Returns TRUE if a keyframe exists at the specified time; otherwise FALSE. For parameters not directly hosted in the parameter block that are internally animatable, this provides a keyframe query callback so that any ParamMap2 spinners associated with these 'virtual' parameters can show keyframe status for the underlying parameter. In these cases, developers should implement this method for the parameter usually asking the underlying parameter for its keyframe state.

Parameters:: ReferenceMaker* owner

Points to the owner of the parameter.

ParamID id

The permanent ID of the parameter.

int tabIndex

TimeValue t

The current time.

Default Implementation:: { return FALSE; }

Reimplemented in MSPluginPBAccessor.

{ return FALSE; }

virtual MSTR GetLocalName	(	ReferenceMaker *	owner,
		ParamID	id,
		int	tabIndex
	)		`[inline, virtual]`

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Remarks:: This allows a plug-in to provide a dynamically-created local name for a parameter or Tab<> parameter entry. If you specify the P_COMPUTED_NAME parameter flag, you also need to suppy a p_accessorPBAccessor instance pointer that has this method implemented.

Parameters:: ReferenceMaker* owner

Points to the owner of the parameter.

ParamID id

The permanent ID of the parameter.

int tabIndex

If the parameter is a Tab<> this is the zero based index of the parameter in the table.

Default Implementation:: { return _M(""); }

{ return _M(""); }

virtual void TabChanged	(	tab_changes	changeCode,
		Tab< PB2Value > *	tab,
		ReferenceMaker *	owner,
		ParamID	id,
		int	tabIndex,
		int	count
	)		`[inline, virtual]`

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Remarks:: This method is called when a Tab<> parameter has a change made to its table structure.

Parameters:: tab_changes changeCode

Describes the change that has just occurred to the Tab<> parameter. One of the following enumerations:

enum tab_changes { tab_insert, tab_append, tab_delete, tab_ref_deleted, tab_setcount, tab_sort };

Tab<PB2Value>* tab

Points to the actual Tab<> in the pblock parameter.

ReferenceMaker* owner

Points to the owner of the parameter.

ParamID id

The permanent ID of the parameter.

int tabIndex

The start index of the change (for tab_insert, tab_append, tab_delete, tab_ref_deleted)

int count

The number of elements changed (for tab_insert, tab_append, tab_delete).

Reimplemented in MSPluginPBAccessor.

{ }

virtual void DeleteThis ( ) [inline, virtual]

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Remarks:: This method that can be used to destroy dynamically allocated instances of this class.

Default Implementation:: { }

Reimplemented in MSPluginPBAccessor.

{ };

PBAccessor Class Reference

Detailed Description

Public Types

Public Member Functions

Member Enumeration Documentation

Member Function Documentation