path: root/HID Utilities Source/HID_Transaction_Utilities.c

/*
	File:		HID_Transaction_Utilities.h

	Contains:	Definitions of the HID queue functions for the HID utilites.
    
	DRI: George Warner

	Copyright:	Copyright © 2002 Apple Computer, Inc., All Rights Reserved

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*/

#include <CoreServices/CoreServices.h>

#include "HID_Utilities_Internal.h"
#include "HID_Utilities_External.h"

// ==================================
// private functions

// creates a transaction for a device, allocates and creates the transaction interface if required

static IOReturn hid_CreateTransaction(pRecDevice pDevice)
{
    IOReturn result = kIOReturnSuccess;

	if (HIDIsValidDevice(pDevice))
	{
		if (NULL == pDevice->transaction) // if we don't already have a transactionÉ
		{
			if (NULL != pDevice->interface) // and we do have an interfaceÉ
			{
				pDevice->transaction = (void *) (*(IOHIDDeviceInterface**) pDevice->interface)->allocOutputTransaction (pDevice->interface); // alloc Transaction
				if (pDevice->transaction)	// if it was successfulÉ
				{
					result = (*(IOHIDOutputTransactionInterface**) pDevice->transaction)->create (pDevice->transaction); // create actual transaction
					if (kIOReturnSuccess != result)
						HIDReportErrorNum ("\nFailed to create transaction via create: error = %ld.", result);
				}
				else
				{
					HIDReportError ("\nhid_CreateTransaction failed to allocOutputTransaction");
					if (!result)
						result = kIOReturnError; // synthesis error
				}
			}
			else
				HIDReportErrorNum ("\nhid_CreateTransaction failed: Device inteface does not exist.", result);
		}
	}
    return result;
}

// ==================================
// public functions
// ---------------------------------
// add an element to a Transaction
unsigned long HIDTransactionAddElement(pRecDevice pDevice, pRecElement pElement)
{
    IOReturn result = hid_CreateTransaction(pDevice);

	if (HIDIsValidElement(pDevice,pElement))
	{
		if (pDevice->transaction)
		{
			result = (*(IOHIDOutputTransactionInterface**) pDevice->transaction)->addElement (pDevice->transaction,pElement->cookie); // add element
			if (kIOReturnSuccess != result)
				HIDReportErrorNum ("\nHIDTransactionAddElement failed to add Element: error = %ld.", result);
		}
		else
		{
			HIDReportError ("\nHIDTransactionAddElement failed: no transaction interface");
			if (!result)
				result = kIOReturnError; // synthesis error
		}
	}
	return result;
}

// removes an element from a Transaction
unsigned long HIDTransactionRemoveElement(pRecDevice pDevice, pRecElement pElement)
{
    IOReturn result = hid_CreateTransaction(pDevice);

	if (HIDIsValidElement(pDevice,pElement))
	{
		if (pDevice->transaction)
		{
			result = (*(IOHIDOutputTransactionInterface**) pDevice->transaction)->removeElement (pDevice->transaction,pElement->cookie); // remove element
			if (kIOReturnSuccess != result)
				HIDReportErrorNum ("\nHIDTransactionRemoveElement failed to remove Element: error = %ld.", result);
		}
		else
		{
			HIDReportError ("\nHIDTransactionRemoveElement failed: no transaction interface");
			if (!result)
				result = kIOReturnError; // synthesis error
		}
	}

	return result;
}

// return true if this transaction contains this element
Boolean HIDTransactionHasElement(pRecDevice pDevice, pRecElement pElement)
{
    Boolean result = false;

	if (HIDIsValidElement(pDevice,pElement))
	{
		(void) hid_CreateTransaction(pDevice);

		if (pDevice->transaction)
		{
			result = (*(IOHIDOutputTransactionInterface**) pDevice->transaction)->hasElement (pDevice->transaction,pElement->cookie); // remove element
		}
		else
		{
			HIDReportError ("\nHIDTransactionHasElement failed: no transaction interface");
		}
	}
	return result;
}

/* This changes the default value of an element, when the values of the */
/* elements are cleared, on clear or commit, they are reset to the */
/* default value */
/* This call can be made on elements that are not in the transaction, but */
/* has undefined behavior if made on elements not in the transaction */
/* which are later added to the transaction. */
/* In other words, an element should be added before its default is */
/* set, for well defined behavior. */
unsigned long HIDTransactionSetElementDefault(pRecDevice pDevice, pRecElement pElement,IOHIDEventStruct* pValueEvent)
{
    IOReturn result = hid_CreateTransaction(pDevice);

	if (HIDIsValidElement(pDevice,pElement))
	{
		if (pDevice->transaction)
		{
			result = (*(IOHIDOutputTransactionInterface**) pDevice->transaction)->setElementDefault (pDevice->transaction,pElement->cookie, pValueEvent);
			if (kIOReturnSuccess != result)
				HIDReportErrorNum ("\nHIDTransactionSetElementDefault failed to set Element Default: error = %ld.", result);
		}
		else
		{
			HIDReportError ("\nHIDTransactionSetElementDefault failed: no transaction interface");
			if (!result)
				result = kIOReturnError; // synthesis error
		}
	}

	return result;
}

/* Get the current setting of an element's default value */
unsigned long HIDTransactionGetElementDefault(pRecDevice pDevice, pRecElement pElement,IOHIDEventStruct* pValueEvent)
{
    IOReturn result = hid_CreateTransaction(pDevice);

	if (HIDIsValidElement(pDevice,pElement))
	{
		if (pDevice->transaction)
		{
			result = (*(IOHIDOutputTransactionInterface**) pDevice->transaction)->getElementDefault (pDevice->transaction,pElement->cookie, pValueEvent);
			if (kIOReturnSuccess != result)
				HIDReportErrorNum ("\nHIDTransactionGetElementDefault failed to get Element Default: error = %ld.", result);
		}
		else
		{
			HIDReportError ("\nHIDTransactionGetElementDefault failed: no transaction interface");
			if (!result)
				result = kIOReturnError; // synthesis error
		}
	}
	return result;
}

/* Add a change to the transaction, by setting an element value */
/* The change is not actually made until it is commited */
/* The element must be part of the transaction or this call will fail */
unsigned long HIDTransactionSetElementValue(pRecDevice pDevice, pRecElement pElement,IOHIDEventStruct* pValueEvent)
{
    IOReturn result = hid_CreateTransaction(pDevice);

	if (HIDIsValidElement(pDevice,pElement))
	{
		if (pDevice->transaction)
		{
			result = (*(IOHIDOutputTransactionInterface**) pDevice->transaction)->setElementValue (pDevice->transaction,pElement->cookie, pValueEvent);
			if (kIOReturnSuccess != result)
				HIDReportErrorNum ("\nHIDTransactionSetElementValue failed to set Element Default: error = %ld.", result);
		}
		else
		{
			HIDReportError ("\nHIDTransactionSetElementValue failed: no transaction interface");
			if (!result)
				result = kIOReturnError; // synthesis error
		}
	}
	return result;
}

/* Get the current setting of an element value */
unsigned long HIDTransactionGetElementValue(pRecDevice pDevice, pRecElement pElement,IOHIDEventStruct* pValueEvent)
{
    IOReturn result = hid_CreateTransaction(pDevice);

	if (HIDIsValidElement(pDevice,pElement))
	{
		if (pDevice->transaction)
		{
			result = (*(IOHIDOutputTransactionInterface**) pDevice->transaction)->getElementValue (pDevice->transaction,pElement->cookie, pValueEvent);
			if (kIOReturnSuccess != result)
				HIDReportErrorNum ("\nHIDTransactionGetElementValue failed to get Element Default: error = %ld.", result);
		}
		else
		{
			HIDReportError ("\nHIDTransactionGetElementValue failed: no transaction interface");
			if (!result)
				result = kIOReturnError; // synthesis error
		}
	}
	return result;
}

/* Commit the transaction, or clear all the changes and start over */
unsigned long HIDTransactionCommit(pRecDevice pDevice)
{
    IOReturn result = hid_CreateTransaction(pDevice);

	if (HIDIsValidDevice(pDevice))
	{
		if (pDevice->transaction)
		{
#if 0000
			// NOTE: this code is to workaround a bug where if you commit transactions
			// too fast then some of the reports get dropped.
			// (fixed in 10.2.1)
			static AbsoluteTime nextTime = {0,0};	// first time this should be no delay

			if (nextTime.hi || nextTime.lo)
				MPDelayUntil(&nextTime);
#endif
			result = (*(IOHIDOutputTransactionInterface**) pDevice->transaction)->commit (pDevice->transaction,-1,NULL,NULL,NULL);
			if (kIOReturnSuccess != result)
				HIDReportErrorNum ("\nHIDTransactionCommit failed to commit: error = %ld.", result);
#if 0000
			nextTime = AddDurationToAbsolute(20 * kDurationMillisecond,UpTime());
#endif
		}
		else
		{
			HIDReportError ("\nHIDTransactionCommit failed: no transaction interface");
			if (!result)
				result = kIOReturnError; // synthesis error
		}
	}
	return result;
}

/* Clear all the changes and start over */
unsigned long HIDTransactionClear(pRecDevice pDevice)
{
    IOReturn result = hid_CreateTransaction(pDevice);

	if (HIDIsValidDevice(pDevice))
	{
		if (pDevice->transaction)
		{
			result = (*(IOHIDOutputTransactionInterface**) pDevice->transaction)->clear (pDevice->transaction);
			if (kIOReturnSuccess != result)
				HIDReportErrorNum ("\nHIDTransactionClear failed to get Element Default: error = %ld.", result);
		}
		else
		{
			HIDReportError ("\nHIDTransactionClear failed: no transaction interface");
			if (!result)
				result = kIOReturnError; // synthesis error
		}
	}
	return result;
}