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IOHIDOutputTransactionInterface

Declared In:

Overview

CFPlugin object subclass which privides interface for output transactions to HID devices. Created by a IOHIDDeviceInterface object.

Functions

addElement: Adds an element to the transaction.
clear: Clears the transaction.
commit: Commits the transaction.
create: Creates the current transaction.
createAsyncEventSource: Creates an async event source.
createAsyncPort: Creates an async port.
dispose: Disposes of the current transaction.
getAsyncEventSource: Obtains the current event source.
getAsyncPort: Obtains the current async port.
getElementDefault: Obtains the default value of an element in a transaction.
getElementValue: Obtains the value of an element in a transaction.
hasElement: Checks whether an element has been added to the transaction.
removeElement: Removes an element from the transaction.
setElementDefault: Sets the default value of an element in a transaction.
setElementValue: Sets the value of an element in a transaction.

addElement

Adds an element to the transaction.

IOReturn ( *addElement) (
    void *self,
    IOHIDElementCookie elementCookie);

Parameters

elementCookie: The element of interest.

Return Value

Returns an IOReturn code.

Discussion

If the element has already been added to transaction, an error will be returned.

clear

Clears the transaction.

IOReturn ( *clear)(
    void *self);

Return Value

Returns an IOReturn code.

Discussion

Transaction element values will cleared. Default values will be preserved.

commit

Commits the transaction.

IOReturn ( *commit)(
    void *self, 
    uint32_t timeoutMS, 
    IOHIDCallbackFunction callback, 
    void *callbackTarget, 
    void *callbackRefcon);

Parameters

timeoutMS: UNSUPPORTED
callback: UNSUPPORTED
callbackTarget: UNSUPPORTED
callbackRefcon: UNSUPPORTED

Return Value

Returns an IOReturn code.

Discussion

Transaction element values, if set, will be sent to the device. Otherwise, the default element value will be used. If neither are set, that element will be omitted from the commit. After a transaction is committed, transaction element values will be cleared. Default values will be preserved.

create

Creates the current transaction.

IOReturn ( *create)(
    void *self);

Return Value

Returns an IOReturn code.

Discussion

This method will free any memory that has been allocated for this transaction.

createAsyncEventSource

Creates an async event source.

IOReturn ( *createAsyncEventSource)(
    void *self, 
    CFRunLoopSourceRef *source);

Parameters

source: The newly created event source

Return Value

Returns an IOReturn code.

Discussion

This will be used with setEventCallout.

createAsyncPort

Creates an async port.

IOReturn ( *createAsyncPort)(
    void *self,
    mach_port_t *port);

Parameters

port: The newly created async port.

Return Value

Returns an IOReturn code.

Discussion

This will be used with createAsyncEventSource.

dispose

Disposes of the current transaction.

IOReturn ( *dispose)(
    void *self);

Return Value

Returns an IOReturn code.

Discussion

The transaction will have to be recreated, in order to perform any operations on the transaction.

getAsyncEventSource

Obtains the current event source.

CFRunLoopSourceRef ( *getAsyncEventSource)(
    void *self);

Return Value

Returns a CFRunLoopSourceRef.

getAsyncPort

Obtains the current async port.

mach_port_t ( *getAsyncPort)(
    void *self);

Return Value

Returns a mach_port_t.

getElementDefault

Obtains the default value of an element in a transaction.

IOReturn ( *getElementDefault)(
    void *self, 
    IOHIDElementCookie elementCookie, 
    IOHIDEventStruct *outValueEvent);

Parameters

elementCookie: The element of interest.
outValueEvent: The event that will be filled. If a long value is present, it is up to the caller to deallocate it.

Return Value

Returns an IOReturn code.

Discussion

An error will be returned if the element has not been added to the transaction.

getElementValue

Obtains the value of an element in a transaction.

IOReturn ( *getElementValue)(
    void *self, 
    IOHIDElementCookie elementCookie, 
    IOHIDEventStruct *outValueEvent);

Parameters

elementCookie: The element of interest.
outValueEvent: The event that will be filled. If a long value is present, it is up to the caller to deallocate it.

Return Value

Returns an IOReturn code.

Discussion

An error will be returned if the element has not been added to the transaction.

hasElement

Checks whether an element has been added to the transaction.

Boolean ( *hasElement) (
    void *self,
    IOHIDElementCookie elementCookie);

Parameters

elementCookie: The element of interest.

Return Value

Returns a Boolean value.

Discussion

Will return true if present, otherwise will return false.

removeElement

Removes an element from the transaction.

IOReturn ( *removeElement) (
    void *self,
    IOHIDElementCookie elementCookie);

Parameters

elementCookie: The element of interest.

Return Value

Returns an IOReturn code.

Discussion

If the element has not been added to transaction, an error will be returned.

setElementDefault

Sets the default value of an element in a transaction.

IOReturn ( *setElementDefault)(
    void *self, 
    IOHIDElementCookie elementCookie, 
    IOHIDEventStruct *valueEvent);

Parameters

elementCookie: The element of interest.
valueEvent: The event that will be filled. If a long value is present, it will be copied.

Return Value

Returns an IOReturn code.

Discussion

An error will be returned if the element has not been added to the transaction.

setElementValue

Sets the value of an element in a transaction.

IOReturn ( *setElementValue)(
    void *self, 
    IOHIDElementCookie elementCookie, 
    IOHIDEventStruct *valueEvent);

Parameters

elementCookie: The element of interest.
valueEvent: The event that will be filled. If a long value is present, it will be copied.

Return Value

Returns an IOReturn code.

Discussion

An error will be returned if the element has not been added to the transaction.

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Last Updated: 2009-02-23