IMoaDrAssetCallback

Interface ID: IID_IMoaDrAssetCallback
Pointer type: PIMoaDrAssetCallback
Inheritance: IMoaMmPropOwner
Header file: driservc.h

Description

The IMoaDrAssetCallback interface is provided in Director by the class that implements IMoaMmAssetCallback, which is provided by through the asset initialization method IMoaMmXAsset::SetCallback(). To acquire IMoaDrAssetCallback, the asset can call QueryInterface() on IMoaMmAssetCallback.

This interface provides additional, Director-specific callback services to a media asset. In Director, an asset Xtra has both an external representation, implemented by the Xtra developer, and an internal representation, provided by Director. The Xtra developer defines custom behavior by implementing standard asset Xtra interfaces. This interface provides controlled access to the internal representation of the Xtra provided by Director.

Methods

Property owner

GetProp()
SetProp()

Internal cast member access

GetCMRef()

Scripting support

CallCMHandler()

CallCMHandler()

Syntax

CallCMHandler(PIMoaDrAssetCallbackThis,

MoaMmSymbolhandlerName,
MoaLongnArgs,
PMoaMmValuepArgs,
PMoaMmValuepResult,
MoaBool FAR *pHandled)

Parameters

This

Pointer to the IMoaDrAssetCallback interface

handlerName

MoaMmSymbol representing the handler to call

nArgs

MoaLongNumber of arguments, excluding the Xtra instance in pArgs[0]

pArgs

PMoaMmValueArray of arguments, with the first valid argument at pArgs[1]

pResult

PMoaMmValuePointer to a MoaMmValue to receive the result

pHandled

MoaBool FAR *Boolean value

Returns

MoaError

Description

Calls a handler defined in the asset's cast member script. For CallCMHandler(), only the cast member script is checked; the message does not proceed up to the movie or frame level, as it does with the sprite SendMessage() call.

Caller supplies a symbol for handler to call (name), the arguments (nArgs, pArgs), and a pointer to a MoaMmValue to receive a result, if any, from the handler call.

Upon return, pHandled is set to TRUE if the call was handled, that is the handler existed in the cast member script. If message was not handled, it silently disappears and FALSE is returned.

GetCMRef()

Syntax

GetCMRef(PIMoaDrAssetCallbackThis,

PMoaDrCMRefpCMRef)

Parameters

This

Pointer to the IMoaDrAssetCallback interface

pCMRef

PMoaDrCMRefPointer to a MoaDrCMRef to receive the reference for the cast member associated with your asset

Returns

MoaError

Description

Gets the cast member reference for the cast member associated with your asset. This lets you determine the Director cast member with your asset is associated. The cast index supplied in this reference is relative to the active movie.

GetProp()

Syntax

GetProp(PIMoaDrAssetCallbackThis,

MoaMmSymbolsymbol,
PMoaMmValuepPropValue)

Parameters

This

Pointer to the IMoaDrAssetCallback interface

symbol

MoaMmSymbol representing the property to get

pPropValue

PMoaMmValuePointer to a MoaMmValue to receive the property's value

Returns

kMoaErr_NoErr	Property exists and value was returned
kMoaErr_BadParam	Invalid pPropValue passed in
kMoaMmErr_PropertyNotFound	Property isn't supported by this class
kMoaMmErr_InternalError	Property exists but couldn't get due to internal err
kMoaMmErr_NoMemForString	Couldn't allocate memory for string value data
kMoaErr_OutOfMem	Couldn't allocate memory for other value data

Description

Gets any property of the cast member associated with your asset. This includes both built-in ones handled by the host application (such as name in Director for cast member name), as well as your own properties. If you retrieve your own properties, it may result in a callback to your own GetProp() method; be careful not to get stuck in a loop.

SetProp()

Syntax

SetProp(PIMoaDrAssetCallbackThis,

MoaMmSymbolsymbol,
ConstPMoaMmValuepPropValue)

Parameters

This

Pointer to the IMoaDrAssetCallback interface

symbol

MoaMmSymbol representing the property to set

pPropValue

ConstPMoaMmValuePointer to a ConstPMoaMmValue containing the property value

Returns

kMoaErr_NoErr	Property exists and value was set
kMoaErr_BadParam	Invalid pPropValue passed in
kMoaMmErr_PropertyNotFound	Property isn't supported by this class
kMoaMmErr_InternalError	Property exists, value ok, can't set--internal error
kMoaMmErr_NoMemForString	Can't allocate memory for setting string value data
kMoaErr_OutOfMem	Can't allocate memory for setting other value data
kMoaMmErr_IntegerExpected	Type mismatch: integer value expected
kMoaMmErr_SymbolExpected	Type mismatch: symbol value expected
kMoaMmErr_FloatExpected	Type mismatch: float value expected
kMoaMmErr_StringExpected	Type mismatch: string value expected
kMoaMmErr_PointExpected	Type mismatch: point value expected
kMoaMmErr_RectExpected	Type mismatch: rect value expected
kMoaMmErr_ValueTypeMismatch	Type mismatch: other value expected (non-specific)
kMoaDrErr_CastMemberExpected	Type mismatch: CMRef value expected

Description

Sets any property of the cast member associated with your asset. This includes both built-in ones handled by the host application (such as name in Director for cast member name), as well as your own properties. This may result in a call back to your own SetProp() method; be careful not to get stuck in a loop.