path: root/HID_Utilities_Source/HID_Utilities.h

/*
	File:		HID_Utilities.h

	Contains:	External interface for HID Utilities
    
	DRI: George Warner

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

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*/

#ifndef _HID_Utilities_h_
#define _HID_Utilities_h_

#include <Carbon/Carbon.h>

#include <IOKit/IOTypes.h>
// 10.0.x
//#include <IOKit/IOUSBHIDParser.h>
// 10.1.x
#include <IOKit/hid/IOHIDUsageTables.h>

#include <IOKit/hid/IOHIDLib.h>

// ==================================

#ifdef __cplusplus
extern "C" {
#endif

// ==================================

enum
{
    kDefaultUserMin = 0,					// default user min and max used for scaling
    kDefaultUserMax = 255,
};

typedef enum HIDElementTypeMask
{
	kHIDElementTypeInput				= 1 << 1,
	kHIDElementTypeOutput            	= 1 << 2,
	kHIDElementTypeFeature           	= 1 << 3,
	kHIDElementTypeCollection        	= 1 << 4,
	kHIDElementTypeIO					= kHIDElementTypeInput | kHIDElementTypeOutput | kHIDElementTypeFeature,
	kHIDElementTypeAll					= kHIDElementTypeIO | kHIDElementTypeCollection
}HIDElementTypeMask;

struct recElement
{
    IOHIDElementType type;					// the type defined by IOHIDElementType in IOHIDKeys.h
    long usagePage;							// usage page from IOUSBHIDParser.h which defines general usage
    long usage;								// usage within above page from IOUSBHIDParser.h which defines specific usage
    IOHIDElementCookie cookie;				// unique value (within device of specific vendorID and productID) which identifies element, will NOT change
    long min;								// reported min value possible
    long max;								// reported max value possible
    long scaledMin;							// reported scaled min value possible
    long scaledMax;							// reported scaled max value possible
    long size;								// size in bits of data return from element
    Boolean relative;						// are reports relative to last report (deltas)
    Boolean wrapping;						// does element wrap around (one value higher than max is min)
    Boolean nonLinear;						// are the values reported non-linear relative to element movement
    Boolean preferredState;					// does element have a preferred state (such as a button)
    Boolean nullState;						// does element have null state
    long units;								// units value is reported in (not used very often)
    long unitExp;							// exponent for units (also not used very often)
    Str255 name;							// name of element (not used often)

// runtime variables
    long minReport; 						// min returned value
    long maxReport; 						// max returned value (calibrate call)
    long userMin; 							// user set value to scale to (scale call)
    long userMax;							
    
	struct recElement * pPrevious;			// previous element (NULL at list head)
    struct recElement * pChild;				// next child (only of collections)
    struct recElement * pSibling;			// next sibling (for elements and collections)
	
};
typedef struct recElement recElement;
typedef recElement* pRecElement;

struct recDevice
{
    IOHIDDeviceInterface ** interface;		// interface to device, NULL = no interface
    IOHIDQueueInterface ** queue;			// device queue, NULL = no queue
	CFRunLoopSourceRef	queueRunLoopSource;		// device queue run loop source, NULL == no source
	IOHIDOutputTransactionInterface ** transaction;		// output transaction interface, NULL == no transaction
	io_object_t notification;				// notifications
	Str255 transport;						// device transport
    long vendorID;							// id for device vendor, unique across all devices
    long productID;							// id for particular product, unique across all of a vendors devices
    long version;							// version of product
    Str255 manufacturer;					// name of manufacturer
    Str255 product;							// name of product
    Str255 serial;							// serial number of specific product, can be assumed unique across specific product or specific vendor (not used often)
    long locID;								// long representing location in USB (or other I/O) chain which device is pluged into, can identify specific device on machine
    long usage;								// usage page from IOUSBHID Parser.h which defines general usage
    long usagePage;							// usage within above page from IOUSBHID Parser.h which defines specific usage
    long totalElements;						// number of total elements (should be total of all elements on device including collections) (calculated, not reported by device)
	long features;							// number of elements of type kIOHIDElementTypeFeature
	long inputs;							// number of elements of type kIOHIDElementTypeInput_Misc or kIOHIDElementTypeInput_Button or kIOHIDElementTypeInput_Axis or kIOHIDElementTypeInput_ScanCodes
	long outputs;							// number of elements of type kIOHIDElementTypeOutput
	long collections;						// number of elements of type kIOHIDElementTypeCollection
    long axis;								// number of axis (calculated, not reported by device)
    long buttons;							// number of buttons (calculated, not reported by device)
    long hats;								// number of hat switches (calculated, not reported by device)
    long sliders;							// number of sliders (calculated, not reported by device)
    long dials;								// number of dials (calculated, not reported by device)
    long wheels;							// number of wheels (calculated, not reported by device)
    recElement* pListElements; 				// head of linked list of elements 
    struct recDevice* pNext; 				// next device
};
typedef struct recDevice recDevice;
typedef recDevice* pRecDevice;

// ==================================
// Create and open an interface to device, required prior to extracting values or building queues
// Note: appliction now owns the device and must close and release it prior to exiting
extern IOReturn HIDCreateOpenDeviceInterface (io_object_t hidDevice, pRecDevice pDevice);

// builds list of device with elements (allocates memory and captures devices)
// list is allcoated internally within HID Utilites and can be accessed via accessor functions
// structures within list are considered flat and user accessable, butnot user modifiable
// can be called again to rebuild list to account for new devices (will do the right thing in case of disposing existing list)
extern Boolean HIDBuildDeviceList (UInt32 usagePage, UInt32 usage);

// release list built by above function
// MUST be called prior to application exit to properly release devices
// if not called (or app crashes) devices can be recovered by pluging into different location in USB chain
extern void HIDReleaseDeviceList (void);

// does a device list exist
extern Boolean HIDHaveDeviceList (void);

// how many HID devices have been found
// returns 0 if no device list exist
extern UInt32 HIDCountDevices (void);

// how many elements does a specific device have
// returns 0 if device is invalid or NULL
// uses mask of HIDElementTypeMask to restrict element found
// use kHIDElementTypeIO to get non-collection elements
extern UInt32 HIDCountDeviceElements (pRecDevice pDevice, HIDElementTypeMask typeMask);

// get the first device in the device list
// returns NULL if no list exists
extern pRecDevice HIDGetFirstDevice (void);

// get next device in list given current device as parameter
// returns NULL if end of list
extern pRecDevice HIDGetNextDevice (pRecDevice pDevice);

// get the first element of device passed in as parameter
// returns NULL if no list exists or device does not exists or is NULL
// uses mask of HIDElementTypeMask to restrict element found
// use kHIDElementTypeIO to get previous HIDGetFirstDeviceElement functionality
extern pRecElement HIDGetFirstDeviceElement (pRecDevice pDevice, HIDElementTypeMask typeMask);

// get next element of given device in list given current element as parameter
// will walk down each collection then to next element or collection (depthwise traverse)
// returns NULL if end of list
// uses mask of HIDElementTypeMask to restrict element found
// use kHIDElementTypeIO to get previous HIDGetNextDeviceElement functionality
extern pRecElement HIDGetNextDeviceElement (pRecElement pElement, HIDElementTypeMask typeMask);

// get previous element of given device in list given current element as parameter
// this wlaks directly up the tree to the top element and does not search at each level
// returns NULL if beginning of list
// uses mask of HIDElementTypeMask to restrict element found
// use kHIDElementTypeIO to get non-collection elements
extern pRecElement HIDGetPreviousDeviceElement (pRecElement pElement, HIDElementTypeMask typeMask);

// returns C string type name given a type enumeration passed in as parameter (see IOHIDKeys.h)
// returns empty string for invlid types
extern void HIDGetTypeName (IOHIDElementType type, char * cstrName);

// returns C string usage given usage page and usage passed in as parameters (see IOUSBHIDParser.h)
// returns usage page and usage values in string form for unknown values
extern void HIDGetUsageName (long valueUsagePage, long valueUsage, char * cstrName);

// returns calibrated value given raw value passed in
// calibrated value is equal to min and max values returned by HIDGetElementValue since device list built scaled to element reported min and max values
extern SInt32 HIDCalibrateValue (SInt32 value, pRecElement pElement);

// returns scaled value given raw value passed in
// scaled value is equal to current value assumed to be in the range of element reported min and max values scaled to user min and max scaled values
extern SInt32 HIDScaleValue (SInt32 value, pRecElement pElement);

// ---------------------------------
// convert an element type to a mask
extern HIDElementTypeMask HIDConvertElementTypeToMask (const long type);

// find this device
extern Boolean HIDFindDevice(const pRecDevice pSearchDevice, pRecDevice *ppFoundDevice);

// find the device and element for this action
// Device: serial, vendorID, productID, location, usagePage, usage
// Element: cookie, usagePage, usage, 
extern Boolean HIDFindActionDeviceAndElement(const pRecDevice pSearchDevice, const pRecElement pSearchElement,
										  pRecDevice *ppFoundDevice, pRecElement *ppFoundElement);

// find the device and element for this action
// Device: serial, vendorID, productID, location, usagePage, usage
// Element: cookie, usagePage, usage, 

extern Boolean HIDFindSubElement(const pRecElement pStartElement, const pRecElement pSearchElement, pRecElement *ppFoundElement);

// print out all of an elements information
extern int HIDPrintElement(const pRecElement pElement);

// return true if this is a valid device pointer
extern Boolean HIDIsValidDevice(const pRecDevice pSearchDevice);

// return true if this is a valid element pointer for this device
extern Boolean HIDIsValidElement(const pRecDevice pSearchDevice, const pRecElement pSearchElement);

#ifdef __cplusplus
}
#endif

#endif // _HID_Utilities_h_