HIDGetButtons.c   [plain text]


/*
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
	File:		HIDGetButtons.c

	Contains:	xxx put contents here xxx

	Version:	xxx put version here xxx

	Copyright:	 1999 by Apple Computer, Inc., all rights reserved.

	File Ownership:

		DRI:				xxx put dri here xxx

		Other Contact:		xxx put other contact here xxx

		Technology:			xxx put technology here xxx

	Writers:

		(BWS)	Brent Schorsch

	Change History (most recent first):

	  <USB4>	 11/1/99	BWS		[2405720]  We need a better check for 'bit padding' items,
									rather than just is constant. We will check to make sure the
									item is constant, and has no usage, or zero usage. This means we
									need to pass an additional parameter to some internal functions
	  <USB3>	  4/7/99	BWS		Add support for reversed report items
	  <USB2>	  3/5/99	BWS		[2311349]  iteration broken, passing wrong value
	  <USB1>	  3/5/99	BWS		first checked in
*/

#include "HIDLib.h"

/*
 *------------------------------------------------------------------------------
 *
 * HIDGetButtons - Get the state of the buttons for a Page
 *
 *	 Input:
 *			  reportType		   - HIDP_Input, HIDP_Output, HIDP_Feature
 *			  usagePage			   - Page Criteria or zero
 *			  iCollection			- Collection Criteria or zero
 *			  piUsageList			- Usages for pressed buttons
 *			  piUsageListLength		- Max entries in UsageList
 *			  ptPreparsedData		- Pre-Parsed Data
 *			  psReport				- An HID Report
 *			  iReportLength			- The length of the Report
 *	 Output:
 *			  piValue				- Pointer to usage Value
 *	 Returns:
 *
 *------------------------------------------------------------------------------
*/
OSStatus 
HIDGetButtons  (HIDReportType			reportType,
				UInt32					iCollection,
				HIDUsageAndPagePtr		ptUsageList,
				UInt32 *				piUsageListLength,
				HIDPreparsedDataRef 	preparsedDataRef,
				void *					psReport,
				ByteCount				iReportLength)
{
	HIDPreparsedDataPtr ptPreparsedData = (HIDPreparsedDataPtr) preparsedDataRef;
	HIDCollection *ptCollection;
	HIDReportItem *ptReportItem;
	int iR, iE;
	SInt32 iValue;
	int iStart;
	int iReportItem;
	int iMaxUsages;
	HIDUsageAndPage tUsageAndPage;
	
/*
 *	Disallow Null Pointers
*/
	if ((ptPreparsedData == NULL)
	 || (ptUsageList == NULL)
	 || (piUsageListLength == NULL)
	 || (psReport == NULL))
		return kHIDNullPointerErr;
	if (ptPreparsedData->hidTypeIfValid != kHIDOSType)
		return kHIDInvalidPreparsedDataErr;
/*
 *	Save the UsageList size
*/
	iMaxUsages = *piUsageListLength;
	*piUsageListLength = 0;
/*
 *	Search only the scope of the Collection specified
 *	Go through the ReportItems
 *	Filter on ReportType
*/
	ptCollection = &ptPreparsedData->collections[iCollection];
	for (iR=0; iR<ptCollection->reportItemCount; iR++)
	{
		iReportItem = ptCollection->firstReportItem + iR;
		ptReportItem = &ptPreparsedData->reportItems[iReportItem];
		if ((ptReportItem->reportType == reportType)
		 && HIDIsButton(ptReportItem, preparsedDataRef))
		{
/*
 *			Save Arrays and Bitmaps
*/
			iStart = ptReportItem->startBit;
			for (iE=0; iE<ptReportItem->globals.reportCount; iE++)
			{
				OSStatus status = noErr;
				iValue = 0;
				
				if ((ptReportItem->dataModes & kHIDDataArrayBit) == kHIDDataArray)
				{
					status = HIDGetData(psReport, iReportLength, iStart, ptReportItem->globals.reportSize, &iValue, false);
					if (!status)
						status = HIDPostProcessRIValue (ptReportItem, &iValue);
					if (status) return status;
					
					iStart += ptReportItem->globals.reportSize;
					HIDUsageAndPageFromIndex(preparsedDataRef,ptReportItem,ptReportItem->globals.logicalMinimum+iE,&tUsageAndPage);
					if (*piUsageListLength >= iMaxUsages)
						return kHIDBufferTooSmallErr;
					ptUsageList[(*piUsageListLength)++] = tUsageAndPage;
				}
				else
				{
					status = HIDGetData(psReport, iReportLength, iStart, 1, &iValue, false);
					if (!status)
						status = HIDPostProcessRIValue (ptReportItem, &iValue);
					if (status) return status;

					iStart++;
					if (iValue != 0)
					{
						HIDUsageAndPageFromIndex(preparsedDataRef,ptReportItem,ptReportItem->globals.logicalMinimum+iE,&tUsageAndPage);
						if (*piUsageListLength >= iMaxUsages)
							return kHIDBufferTooSmallErr;
						ptUsageList[(*piUsageListLength)++] = tUsageAndPage;
					}
				}
			}
		}
	}
	return kHIDSuccess;
}