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/*
* Copyright (c) 2019 TOYOTA MOTOR CORPORATION
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <dirent.h>
#include <linux/input.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <limits.h>
#define LONG_BITS (sizeof(long) << 3)
#define NUM_LONGS(bits) (((bits) + LONG_BITS - 1) / LONG_BITS)
#define DEV_INPUT "/dev/input"
#define LENGTH_TSDEVNODE (NAME_MAX + 1 + sizeof(DEV_INPUT))
#define LENGTH_TSINFO (LENGTH_TSDEVNODE + 2 + 11*2)
char tsInfo[LENGTH_TSINFO];
static inline int testBit(long bit, const long *array) {
return (array[bit / LONG_BITS] >> bit % LONG_BITS) & 1;
}
char* getTouchScreenInfo() {
DIR* dir;
struct dirent* itemPtr;
int fd;
int isSingleTouch = 0, hasTouchScreen = 0;
long absbits[NUM_LONGS(ABS_CNT)];
char tsDevNode[LENGTH_TSDEVNODE];
struct input_absinfo absInfo;
int maxX, maxY;
memset(tsDevNode, 0, sizeof(tsDevNode));
memset(tsInfo, 0, sizeof(tsInfo));
if ((dir = opendir(DEV_INPUT)) == NULL) {
printf("open %s failed.\n", DEV_INPUT);
return NULL;
}
while ((itemPtr = readdir(dir)) != NULL) {
if ((strstr(itemPtr->d_name, "event") != NULL) && (2 == itemPtr->d_type)) {
snprintf(tsDevNode, sizeof(tsDevNode), "%s/%s", DEV_INPUT, itemPtr->d_name);
fd = open(tsDevNode, O_RDONLY);
if (fd < 0) {
printf("open %s failed.\n", tsDevNode);
return NULL;
}
if (ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(absbits)), absbits) >= 0) {
isSingleTouch = !testBit(ABS_MT_POSITION_X, absbits);
} else {
close(fd);
continue;
}
if (ioctl(fd, EVIOCGABS((isSingleTouch ? ABS_X : ABS_MT_POSITION_X)), &absInfo) >= 0) {
maxX = absInfo.maximum;
} else {
close(fd);
continue;
}
if (ioctl(fd, EVIOCGABS((isSingleTouch ? ABS_Y : ABS_MT_POSITION_Y)), &absInfo) >= 0) {
maxY = absInfo.maximum;
} else {
close(fd);
continue;
}
hasTouchScreen = 1;
break;
}
}
if (!hasTouchScreen) {
return NULL;
}
snprintf(tsInfo, sizeof(tsInfo), "%s %d %d", tsDevNode, maxX, maxY);
close(fd);
closedir(dir);
return tsInfo;
}
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