xref: /xsrc/external/mit/libXi/dist/src/XListDev.c

/************************************************************

Copyright 1989, 1998  The Open Group

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Copyright 1989 by Hewlett-Packard Company, Palo Alto, California.

			All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
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********************************************************/

/***********************************************************************
 *
 * XListInputDevices - Request the server to return a list of
 *			 available input devices.
 *
 */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <X11/extensions/XI.h>
#include <X11/extensions/XIproto.h>
#include <X11/Xlibint.h>
#include <X11/extensions/XInput.h>
#include <X11/extensions/extutil.h>
#include "XIint.h"
#include <limits.h>

/* Calculate length field to a multiples of sizeof(XID). XIDs are typedefs
 * to ulong and thus may be 8 bytes on some platforms. This can trigger a
 * SIGBUS if a class ends up not being 8-aligned (e.g. after XAxisInfo).
 */
static int pad_to_xid(int base_size)
{
    int padsize = sizeof(XID);

    return ((base_size + padsize - 1)/padsize) * padsize;
}

static size_t
SizeClassInfo(xAnyClassPtr *any, int num_classes)
{
    int size = 0;
    int j;
    for (j = 0; j < num_classes; j++) {
        switch ((*any)->class) {
            case KeyClass:
                size += pad_to_xid(sizeof(XKeyInfo));
                break;
            case ButtonClass:
                size += pad_to_xid(sizeof(XButtonInfo));
                break;
            case ValuatorClass:
                {
                    xValuatorInfoPtr v;

                    v = (xValuatorInfoPtr) *any;
                    size += pad_to_xid(sizeof(XValuatorInfo) +
                        (v->num_axes * sizeof(XAxisInfo)));
                    break;
                }
            default:
                break;
        }
        *any = (xAnyClassPtr) ((char *)(*any) + (*any)->length);
    }

    return size;
}

static void
ParseClassInfo(xAnyClassPtr *any, XAnyClassPtr *Any, int num_classes)
{
    int j;

    for (j = 0; j < num_classes; j++) {
        switch ((*any)->class) {
            case KeyClass:
                {
                    XKeyInfoPtr K = (XKeyInfoPtr) *Any;
                    xKeyInfoPtr k = (xKeyInfoPtr) *any;

                    K->class = KeyClass;
                    K->length = pad_to_xid(sizeof(XKeyInfo));
                    K->min_keycode = k->min_keycode;
                    K->max_keycode = k->max_keycode;
                    K->num_keys = k->num_keys;
                    break;
                }
            case ButtonClass:
                {
                    XButtonInfoPtr B = (XButtonInfoPtr) *Any;
                    xButtonInfoPtr b = (xButtonInfoPtr) *any;

                    B->class = ButtonClass;
                    B->length = pad_to_xid(sizeof(XButtonInfo));
                    B->num_buttons = b->num_buttons;
                    break;
                }
            case ValuatorClass:
                {
                    int k;
                    XValuatorInfoPtr V = (XValuatorInfoPtr) *Any;
                    xValuatorInfoPtr v = (xValuatorInfoPtr) *any;
                    XAxisInfoPtr A;
                    xAxisInfoPtr a;

                    V->class = ValuatorClass;
                    V->length = pad_to_xid(sizeof(XValuatorInfo) +
                        (v->num_axes * sizeof(XAxisInfo)));
                    V->num_axes = v->num_axes;
                    V->motion_buffer = v->motion_buffer_size;
                    V->mode = v->mode;
                    A = (XAxisInfoPtr) ((char *)V + sizeof(XValuatorInfo));
                    V->axes = A;
                    a = (xAxisInfoPtr) ((char *)(*any) + sizeof(xValuatorInfo));
                    for (k = 0; k < (int)v->num_axes; k++, a++, A++) {
                        A->min_value = a->min_value;
                        A->max_value = a->max_value;
                        A->resolution = a->resolution;
                    }
                    break;
                }
            default:
                break;
        }
        *any = (xAnyClassPtr) ((char *)(*any) + (*any)->length);
        *Any = (XAnyClassPtr) ((char *)(*Any) + (*Any)->length);
    }
}

XDeviceInfo *
XListInputDevices(
    register Display	*dpy,
    int			*ndevices)
{
    size_t size;
    xListInputDevicesReq *req;
    xListInputDevicesReply rep;
    xDeviceInfo *list, *slist = NULL;
    XDeviceInfo *sclist = NULL;
    XDeviceInfo *clist = NULL;
    xAnyClassPtr any, sav_any;
    XAnyClassPtr Any;
    unsigned char *nptr, *Nptr;
    int i;
    unsigned long rlen;
    XExtDisplayInfo *info = XInput_find_display(dpy);

    LockDisplay(dpy);
    if (_XiCheckExtInit(dpy, XInput_Initial_Release, info) == -1)
	return ((XDeviceInfo *) NULL);

    GetReq(ListInputDevices, req);
    req->reqType = info->codes->major_opcode;
    req->ReqType = X_ListInputDevices;

    if (!_XReply(dpy, (xReply *) & rep, 0, xFalse)) {
	UnlockDisplay(dpy);
	SyncHandle();
	return (XDeviceInfo *) NULL;
    }

    if ((*ndevices = rep.ndevices)) {	/* at least 1 input device */
	size = *ndevices * sizeof(XDeviceInfo);
	if (rep.length < (INT_MAX >> 2)) {
	    rlen = rep.length << 2;	/* multiply length by 4    */
	    slist = list = Xmalloc(rlen);
	}
	if (!slist) {
	    _XEatDataWords(dpy, rep.length);
	    UnlockDisplay(dpy);
	    SyncHandle();
	    return (XDeviceInfo *) NULL;
	}
	_XRead(dpy, (char *)list, rlen);

	any = (xAnyClassPtr) ((char *)list + (*ndevices * sizeof(xDeviceInfo)));
	sav_any = any;
	for (i = 0; i < *ndevices; i++, list++) {
            size += SizeClassInfo(&any, (int)list->num_classes);
	}

	Nptr = ((unsigned char *)list) + rlen + 1;
	for (i = 0, nptr = (unsigned char *)any; i < *ndevices; i++) {
	    size += *nptr + 1;
	    nptr += (*nptr + 1);
	    if (nptr > Nptr)
		goto out;
	}

	clist = (XDeviceInfoPtr) Xmalloc(size);
	if (!clist) {
	    XFree((char *)slist);
	    UnlockDisplay(dpy);
	    SyncHandle();
	    return (XDeviceInfo *) NULL;
	}
	sclist = clist;
	Any = (XAnyClassPtr) ((char *)clist +
			      (*ndevices * sizeof(XDeviceInfo)));
	list = slist;
	any = sav_any;
	for (i = 0; i < *ndevices; i++, list++, clist++) {
	    clist->type = list->type;
	    clist->id = list->id;
	    clist->use = list->use;
	    clist->num_classes = list->num_classes;
	    clist->inputclassinfo = Any;

            ParseClassInfo(&any, &Any, (int)list->num_classes);
	}

	clist = sclist;
	nptr = (unsigned char *)any;
	Nptr = (unsigned char *)Any;
	for (i = 0; i < *ndevices; i++, clist++) {
	    clist->name = (char *)Nptr;
	    memcpy(Nptr, nptr + 1, *nptr);
	    Nptr += (*nptr);
	    *Nptr++ = '\0';
	    nptr += (*nptr + 1);
	}
    }

  out:
    XFree((char *)slist);
    UnlockDisplay(dpy);
    SyncHandle();
    return (sclist);
}

/***********************************************************************
 *
 * Free the list of input devices.
 *
 */

void
XFreeDeviceList(XDeviceInfo *list)
{
    if (list != NULL) {
	XFree((char *)list);
    }
}