/* * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * The contents of this file constitute Original Code as defined in and * are subject to the Apple Public Source License Version 1.1 (the * "License"). You may not use this file except in compliance with the * License. Please obtain a copy of the License at * http://www.apple.com/publicsource and read it before using this file. * * This 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 OR NON-INFRINGEMENT. Please see the * License for the specific language governing rights and limitations * under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* File: HIDMaxUsageListLength.c */ #include "HIDLib.h" /* *------------------------------------------------------------------------------ * * HIDMaxUsageListLength * * Input: * reportType - HIDP_Input, HIDP_Output, HIDP_Feature * usagePage - Page Criteria or zero * ptPreparsedData - Pre-Parsed Data * Output: * Returns: length of list * *------------------------------------------------------------------------------ */ UInt32 HIDMaxUsageListLength (HIDReportType reportType, HIDUsage usagePage, HIDPreparsedDataRef preparsedDataRef) { #pragma unused(usagePage) // not used, see comment below HIDPreparsedDataPtr ptPreparsedData = (HIDPreparsedDataPtr) preparsedDataRef; HIDReportItem *ptReportItem; int iButtons; int i; /* * Disallow Null Pointers */ if (ptPreparsedData == NULL) return 0; if (ptPreparsedData->hidTypeIfValid != kHIDOSType) return kHIDInvalidPreparsedDataErr; /* * Go through the ReportItems * Filter on ReportType * Sum the button counts * * NOTE: A more precise value for the maximum list length * may be obtained by filtering out the usages that * are not on the specified usage page. Most of * the time the number returned below is the same * as that returned by filtering usages. It is * never smaller. The tradeoff is sometimes wasting * a few words of RAM in exchange for speed. */ iButtons = 0; for (i=0; i<ptPreparsedData->reportItemCount; i++) { ptReportItem = &ptPreparsedData->reportItems[i]; if ((ptReportItem->reportType == reportType) && HIDIsButton(ptReportItem, preparsedDataRef)) iButtons += ptReportItem->globals.reportCount; } return iButtons; }