new/app/forlinx/forlinx_qt/keypad/keytest.cpp

#include <unistd.h>
#include <fcntl.h>
#include <qmessagebox.h>
#include <qsocketnotifier.h>
#include <QVBoxLayout>
#include "keytest.h"
#include "ui_keytest.h"
#include <linux/input.h>
#include <string.h>
#include <fcntl.h>
#include <dirent.h>

#define DEV_INPUT_EVENT "/dev/input"
#define EVENT_DEV_NAME "event"

static int is_event_device(const struct dirent *dir) {
    return strncmp(EVENT_DEV_NAME, dir->d_name, 5) == 0;
}

static char* scan_devices(void)
{
	struct dirent **namelist;
	int i, ndev, devnum;
	char *filename;
	int max_device = 0;

	ndev = scandir(DEV_INPUT_EVENT, &namelist, is_event_device, alphasort);
	if (ndev <= 0)
		return NULL;

	fprintf(stderr, "Available devices:\n");

	for (i = 0; i < ndev; i++)
	{
		char fname[64];
		int fd = -1;
		char name[256] = "???";

		snprintf(fname, sizeof(fname),
				"%s/%s", DEV_INPUT_EVENT, namelist[i]->d_name);
		fd = open(fname, O_RDONLY);
		if (fd < 0)
			continue;
		ioctl(fd, EVIOCGNAME(sizeof(name)), name);
		close(fd);
		if (strncmp(name, "adc-keys", strlen("adc-keys")) != 0)
			continue;

		fprintf(stderr, "%s:    %s\n", fname, name);

		sscanf(namelist[i]->d_name, "event%d", &devnum);
		if (devnum > max_device)
			max_device = devnum;

		free(namelist[i]);
	}

	if (devnum > max_device || devnum < 0)
		return NULL;

	asprintf(&filename, "%s/%s%d",
			DEV_INPUT_EVENT, EVENT_DEV_NAME,
			devnum);

	return filename;
}


Keytest::Keytest(QWidget *parent) :
	QWidget(parent),
	ui(new Ui::Keytest)

{
	ui->setupUi(this);
	ui->mainLayout;
	setLayout(ui->mainLayout);
	setWindowState(Qt::WindowMaximized);
    setWindowFlags(Qt::FramelessWindowHint | Qt::WindowTitleHint | Qt::WindowCloseButtonHint);

	char *event_name = scan_devices();
	if (!event_name)
        return ;

	m_fd = open(event_name, O_RDONLY);
	if (m_fd < 0)
	{
		QMessageBox::information(this,"Error", "Fail to open ,Please check your key  device");
		return;
	}

	memset(m_oldButtonsState, 0, sizeof(m_oldButtonsState));
	m_notifyObject = new QSocketNotifier(m_fd, QSocketNotifier::Read, this);
	connect (m_notifyObject, SIGNAL(activated(int)), this, SLOT(keyEvent()));

    connect(ui->exitBtn, &QPushButton::clicked, this, [=](){
	        close();		    
        });
}

Keytest::~Keytest()
{
	delete m_notifyObject;
	::close(m_fd);
	delete ui;
}

void Keytest::keyEvent()
{
	char buffer[KEYMAXNUM];
	memset(buffer, 0, sizeof(buffer));
	struct input_event event;
	int nResult=::read(m_fd, &event, sizeof(event));
	if (nResult !=  sizeof(event))
	{
		QMessageBox::information(this,"Debug","read error");
		return;
	}
	switch(event.code)
	{
		case KEY_V_UP:
			buffer[0]=event.value;
			break;
		case KEY_V_DOWN:
			buffer[1]=event.value;
			break;
		case KEY_V_HOME:
			buffer[2]=event.value;
			break;
		case KEY_V_ESC:
			buffer[3]=event.value;
			break;
		default:
			return;
	}

	for (unsigned i = 0; i < sizeof(buffer) / sizeof(buffer[0]); i++)
	{
		bool oldState = m_oldButtonsState[i];
		bool isOn = ((buffer[i] & 0x01) | (buffer[i] & 0x02));
		if (oldState != isOn)
		{
			m_oldButtonsState[i] = isOn;
			update();  //this function will call paintEvent
		}
	}
}


void Keytest::paintEvent(QPaintEvent*)
{
	for(unsigned i = 0; i < KEYMAXNUM; i++)
	{
		if(m_oldButtonsState[i])
		{
			switch(i)
			{
				case 0://up
					ui->pbt_up ->setStyleSheet(QString::fromUtf8("background-color: rgb(0, 0, 255);"));
					break;

				case 1://down
					ui->pbt_down->setStyleSheet(QString::fromUtf8("background-color: rgb(0, 0, 255);"));
					break;

				case 2://home
					ui->pbt_home->setStyleSheet(QString::fromUtf8("background-color: rgb(0, 0, 255);"));
					break;

				case 3://esc
					ui->pbt_menu->setStyleSheet(QString::fromUtf8("background-color: rgb(0, 0, 255);"));
					break;
				default:
					break;
			}
		}
		else
		{
			switch(i)
			{
				case 0://up
					ui->pbt_up ->setStyleSheet(QString::fromUtf8("background-color: rgb(206, 206,206);"));
					break;

				case 1://down
					ui->pbt_down->setStyleSheet(QString::fromUtf8("background-color: rgb(206, 206,206);"));
					break;

				case 2://home
					ui->pbt_home->setStyleSheet(QString::fromUtf8("background-color: rgb(206, 206,206);"));
					break;

				case 3://menu
					ui->pbt_menu->setStyleSheet(QString::fromUtf8("background-color: rgb(206, 206,206);"));
					break;
				default:
					break;
			}
		}
	}
}