目录
前言
前面我们实现了显示系统框架，链接：
接下来我们来实现输入系统框架。
一**、输入系统数据结构抽象**
对于每一个设备，每一个模块，都用一个结构体来表示它，以后就会很方便的替换这些模块，所以对于设备本身我们需要抽象出结构体 InPutDevice，初始化各个模块。
对于输入系统我们需要抽象出结构体 InputEvent，以便于判断是触摸屏输入还是网络输入。
1.input_manager.h
cpp
#ifndef _INPUT_MANAGER_H
#define _INPUT_MANAGER_H
#include <sys/time.h>
#include <common.h>
#define INPUT_TYPE_TOUCH 1
#define INPUT_TYPE_NET 2
typedef struct InputEvent {
struct timeval tTime;
int iType;
int iX;
int iY;
int iPressure;
char str[1024];
}InputEvent, *PInputEvent;
typedef struct InputDevice {
char *name;
int (*GetInputEvent)(PInputEvent ptInputEvent);
int (*DeviceInit)(void);
int (*DeviceExit)(void);
struct InputDevice *ptNext;
}InputDevice, *PInputDevice;
#endif二、触摸屏编程和测试
触摸屏编程原理和实操具体可看：
1.touchscreen.c
cpp
#include <input_manager.h>
#include <tslib.h>
#include <stdio.h>
static struct tsdev *g_ts;
static int TouchscreenGetInputEvent(PInputEvent ptInputEvent)
{
struct ts_sample samp;
int ret;
ret = ts_read(g_ts, &samp, 1);
if (ret != 1)
return -1;
ptInputEvent->iType = INPUT_TYPE_TOUCH;
ptInputEvent->iX = samp.x;
ptInputEvent->iY = samp.y;
ptInputEvent->iPressure = samp.pressure;
ptInputEvent->tTime = samp.tv;
return 0;
}
static int TouchscreenDeviceInit(void)
{
g_ts = ts_setup(NULL, 0);
if (!g_ts)
{
printf("ts_setup err\n");
return -1;
}
return 0;
}
static int TouchscreenDeviceExit(void)
{
ts_close(g_ts);
return 0;
}
static InputDevice g_tTouchscreenDev = {
.name = "touchscreen",
.GetInputEvent = TouchscreenGetInputEvent,
.DeviceInit = TouchscreenDeviceInit,
.DeviceExit = TouchscreenDeviceExit,
};
#if 1
int main(int argc, char **argv)
{
InputEvent event;
int ret;
g_tTouchscreenDev.DeviceInit();
while (1)
{
ret = g_tTouchscreenDev.GetInputEvent(&event);
if (ret) {
printf("GetInputEvent err!\n");
return -1;
}
else
{
printf("Type : %d\n", event.iType);
printf("iX : %d\n", event.iX);
printf("iY : %d\n", event.iY);
printf("iPressure : %d\n", event.iPressure);
}
}
return 0;
}
#endif2.上机测试
开发板上电测试：触摸屏幕后会显示X，Y方向坐标，压力值和类型（类型一为点击事件输入 ，类型二为网络数据输入）
三、网络编程和测试
网络编程代码编写主要分为服务端和客户端，具体介绍可看：
1.netinput.c
cpp
#include <input_manager.h>
#include <sys/types.h> /* See NOTES */
#include <sys/socket.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <input_manager.h>
/* socket
* bind
* sendto/recvfrom
*/
#define SERVER_PORT 8888
static int g_iSocketServer;
static int NetinputGetInputEvent(PInputEvent ptInputEvent)
{
struct sockaddr_in tSocketClientAddr;
int iRecvLen;
char aRecvBuf[1000];
unsigned int iAddrLen = sizeof(struct sockaddr);
iRecvLen = recvfrom(g_iSocketServer, aRecvBuf, 999, 0, (struct sockaddr *)&tSocketClientAddr, &iAddrLen);
if (iRecvLen > 0)
{
aRecvBuf[iRecvLen] = '\0';
//printf("Get Msg From %s : %s\n", inet_ntoa(tSocketClientAddr.sin_addr), ucRecvBuf);
ptInputEvent->iType = INPUT_TYPE_NET;
gettimeofday(&ptInputEvent->tTime, NULL);
strncpy(ptInputEvent->str, aRecvBuf, 1000);
ptInputEvent->str[999] = '\0';
return 0;
}
else
return -1;
}
static int NetinputDeviceInit(void)
{
struct sockaddr_in tSocketServerAddr;
int iRet;
g_iSocketServer = socket(AF_INET, SOCK_DGRAM, 0);
if (-1 == g_iSocketServer)
{
printf("socket error!\n");
return -1;
}
tSocketServerAddr.sin_family = AF_INET;
tSocketServerAddr.sin_port = htons(SERVER_PORT); /* host to net, short */
tSocketServerAddr.sin_addr.s_addr = INADDR_ANY;
memset(tSocketServerAddr.sin_zero, 0, 8);
iRet = bind(g_iSocketServer, (const struct sockaddr *)&tSocketServerAddr, sizeof(struct sockaddr));
if (-1 == iRet)
{
printf("bind error!\n");
return -1;
}
return 0;
}
static int NetinputDeviceExit(void)
{
close(g_iSocketServer);
return 0;
}
static InputDevice g_tNetinputDev ={
.name = "touchscreen",
.GetInputEvent = NetinputGetInputEvent,
.DeviceInit = NetinputDeviceInit,
.DeviceExit = NetinputDeviceExit,
};
#if 1
int main(int argc, char **argv)
{
InputEvent event;
int ret;
g_tNetinputDev.DeviceInit();
while (1)
{
ret = g_tNetinputDev.GetInputEvent(&event);
if (ret) {
printf("GetInputEvent err!\n");
return -1;
}
else
{
printf("Type : %d\n", event.iType);
printf("str : %s\n", event.str);
}
}
return 0;
}
#endif2.client.c
cpp
#include <sys/types.h> /* See NOTES */
#include <sys/socket.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdio.h>
/* socket
* connect
* send/recv
*/
#define SERVER_PORT 8888
int main(int argc, char **argv)
{
int iSocketClient;
struct sockaddr_in tSocketServerAddr;
int iRet;
int iSendLen;
int iAddrLen;
if (argc != 3)
{
printf("Usage:\n");
printf("%s <server_ip> <str>\n", argv[0]);
return -1;
}
iSocketClient = socket(AF_INET, SOCK_DGRAM, 0);
tSocketServerAddr.sin_family = AF_INET;
tSocketServerAddr.sin_port = htons(SERVER_PORT); /* host to net, short */
//tSocketServerAddr.sin_addr.s_addr = INADDR_ANY;
if (0 == inet_aton(argv[1], &tSocketServerAddr.sin_addr))
{
printf("invalid server_ip\n");
return -1;
}
memset(tSocketServerAddr.sin_zero, 0, 8);
#if 0
iRet = connect(iSocketClient, (const struct sockaddr *)&tSocketServerAddr, sizeof(struct sockaddr));
if (-1 == iRet)
{
printf("connect error!\n");
return -1;
}
#endif
iAddrLen = sizeof(struct sockaddr);
iSendLen = sendto(iSocketClient, argv[2], strlen(argv[2]), 0,
(const struct sockaddr *)&tSocketServerAddr, iAddrLen);
close(iSocketClient);
return 0;
}3.上机测试
开发板上电测试：
./test & 将可执行文件 test 放在后台运行，结束后可通过 kill -9 408 杀死该进程
127.0.0.1 为主机环回地址，用于让计算机进行自我回路测试和通信
四、输入系统的框架
1.框架思路
1.输入管理器支持多个设备，这多个设备怎么管理起来呢？
使用InputInit 创建一个链表，链表指向触摸屏设备本身和网络设备本身，通过遍历链表就可以找到所有的输入设备。
2.对于每一个设备都可以调用里面的 GetInputEvent 来获得数据，如果想同时获得多个设备的输入数据的话，那么该怎么获得？
调用IntpuDeviceInit从链表里面把每一个设备取出来，调用里面的DeviceInit 初始化，并且为每一个输入设备创造一个线程thread，线程不断调用设备里面的 GetInputEvent 等待数据，一旦得到数据，就可以将获得的数据放到某个buffer。
3.上层的应用程序调用 GetInputEvent 时候就会去某个buffer里面查看是否有数据，有数据则返回，没数据则休眠 。
2.环形缓冲区
环形缓冲区实质也是一个一维数组，并不是一个环形的数组。
3.input_manager.c
在这里我们用到线程，编译时需要链接到 pthread库，具体可看：
- 注册新的输入设备到全局链表 g_InputDevs 中。
- 初始化输入系统，包括注册触摸屏和网络输入设备。
- 为每个输入设备创建一个接收线程，用于从设备读取数据并保存到环形缓冲区。
- 使用互斥锁和条件变量实现线程同步，确保数据的安全访问和线程的正确唤醒。
- 提供一个 GetInputEvent 函数，用于从环形缓冲区获取输入事件，如果没有可用事件则线程会休眠等待。
cpp
#include <pthread.h>
#include <stdio.h>
#include <unistd.h>
#include <semaphore.h>
#include <string.h>
#include <input_manager.h>
static PInputDevice g_InputDevs = NULL;
static pthread_mutex_t g_tMutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t g_tConVar = PTHREAD_COND_INITIALIZER;
/* start of 实现环形buffer */
#define BUFFER_LEN 20
static int g_iRead = 0;
static int g_iWrite = 0;
static InputEvent g_atInputEvents[BUFFER_LEN];
static int isInputBufferFull(void)
{
return (g_iRead == ((g_iWrite + 1) % BUFFER_LEN));
}
static int isInputBufferEmpty(void)
{
return (g_iRead == g_iWrite);
}
static void PutInputEventToBuffer(PInputEvent ptInputEvent)
{
if (!isInputBufferFull())
{
g_atInputEvents[g_iWrite] = *ptInputEvent;
g_iWrite = (g_iWrite + 1) % BUFFER_LEN;
}
}
static int GetInputEventFromBuffer(PInputEvent ptInputEvent)
{
if (!isInputBufferEmpty())
{
*ptInputEvent = g_atInputEvents[g_iRead];
g_iRead = (g_iRead + 1) % BUFFER_LEN;
return 1;
}
else
{
return 0;
}
}
/* end of 实现环形buffer */
void RegisterInputDevice(PInputDevice ptInputDev)
{
ptInputDev->ptNext = g_InputDevs;
g_InputDevs = ptInputDev;
}
/* */
void InputSystemRegister(void)
{
/* regiseter touchscreen */
extern void TouchscreenRegister(void);
TouchscreenRegister();
/* regiseter netinput */
extern void NetInputRegister(void);
NetInputRegister();
}
static void *input_recv_thread_func (void *data)
{
PInputDevice ptInputDev = (PInputDevice)data;
InputEvent tEvent;
int ret;
while (1)
{
/* 读数据 */
ret = ptInputDev->GetInputEvent(&tEvent);
if (!ret)
{
/* 保存数据 */
pthread_mutex_lock(&g_tMutex);
PutInputEventToBuffer(&tEvent);
/* 唤醒等待数据的线程 */
pthread_cond_signal(&g_tConVar); /* 通知接收线程 */
pthread_mutex_unlock(&g_tMutex);
}
}
return NULL;
}
void InputDeviceInit(void)
{
int ret;
pthread_t tid;
/* for each inputdevice, init, pthread_create */
PInputDevice ptTmp = g_InputDevs;
while (ptTmp)
{
/* init device */
ret = ptTmp->DeviceInit();
/* pthread create */
if (!ret)
{
ret = pthread_create(&tid, NULL, input_recv_thread_func, ptTmp);
}
ptTmp= ptTmp->ptNext;
}
}
int GetInputEvent(PInputEvent ptInputEvent)
{
InputEvent tEvent;
int ret;
/* 无数据则休眠 */
pthread_mutex_lock(&g_tMutex);
if (GetInputEventFromBuffer(&tEvent))
{
*ptInputEvent = tEvent;
pthread_mutex_unlock(&g_tMutex);
return 0;
}
else
{
/* 休眠等待 */
pthread_cond_wait(&g_tConVar, &g_tMutex);
if (GetInputEventFromBuffer(&tEvent))
{
*ptInputEvent = tEvent;
ret = 0;
}
else
{
ret = -1;
}
pthread_mutex_unlock(&g_tMutex);
}
return ret;
}五、输入管理单元测试
1.input_test.c
cpp
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <linux/fb.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <input_manager.h>
int main(int argc, char **argv)
{
int ret;
InputEvent event;
InputSystemRegister();
InputDeviceInit();
while (1)
{
printf("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
ret = GetInputEvent(&event);
printf("%s %s %d, ret = %d\n", __FILE__, __FUNCTION__, __LINE__, ret);
if (ret) {
printf("GetInputEvent err!\n");
return -1;
}
else
{
printf("%s %s %d, event.iType = %d\n", __FILE__, __FUNCTION__, __LINE__, event.iType);
if (event.iType == INPUT_TYPE_TOUCH)
{
printf("Type : %d\n", event.iType);
printf("iX : %d\n", event.iX);
printf("iY : %d\n", event.iY);
printf("iPressure : %d\n", event.iPressure);
}
else if (event.iType == INPUT_TYPE_NET)
{
printf("Type : %d\n", event.iType);
printf("str : %s\n", event.str);
}
}
}
return 0;
}2.上机测试
上电开发板，编译测试：
