Shutdowner - simple countdown timer with monitoring user activity and shutdown computer after time up

config.ini

[Time]

Minutes=0

Seconds=10

Dialog.cpp

#include "Dialog.h"
#include "ui_Dialog.h"

#include "LCDNumber.h"

#include <QSettings>

Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);

    QSettings settings("config.ini", QSettings::IniFormat);
    settings.beginGroup("Time");
    int minutes = settings.value("Minutes").toInt();
    int seconds = settings.value("Seconds").toInt();
    settings.endGroup();

    if (minutes == 0 && seconds == 0) {
        seconds = 15;
    }

    ui->lcdNumber->set_Time(minutes, seconds);
    ui->lcdNumber->start_Timer(1000);

    setWindowTitle("Shutdowner for J()KER by EXL, 2016");
    // setWindowFlags(Qt::FramelessWindowHint);
}

Dialog::~Dialog()
{
    delete ui;
}

Dialog.h

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>

namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
    Q_OBJECT

public:
    explicit Dialog(QWidget *parent = 0);
    ~Dialog();

private:
    Ui::Dialog *ui;
};

#endif // DIALOG_H

Dialog.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>Dialog</class>
 <widget class="QDialog" name="Dialog">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>504</width>
    <height>223</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Dialog</string>
  </property>
  <layout class="QVBoxLayout" name="verticalLayout">
   <item>
    <widget class="LCDNumber" name="lcdNumber"/>
   </item>
  </layout>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <customwidgets>
  <customwidget>
   <class>LCDNumber</class>
   <extends>QLCDNumber</extends>
   <header>LCDNumber.h</header>
  </customwidget>
 </customwidgets>
 <resources/>
 <connections/>
</ui>

LCDNumber.cpp

#include "LCDNumber.h"

#include <QDebug>
#include <QApplication>

#if defined(Q_OS_UNIX)
#include <QLibrary>
#include <QtX11Extras/QX11Info>
#include <X11/Xutil.h>
#elif defined(Q_OS_WIN)
#include <windows.h>
#endif // Q_OS_MACRO

LCDNumber::LCDNumber(QWidget *parent)
    : QLCDNumber(parent)
{
    timer = new QTimer(this);
    QObject::connect(timer, SIGNAL(timeout()), this, SLOT(setDisplay()));
}

LCDNumber::~LCDNumber()
{
    // Empty destructor
}

void LCDNumber::setDisplay()
{
    if ((idleTime() < 1000) && !firstTick) {
        qApp->exit();
    }
    if (timeEnd == 0) {
        shutDownComputer();
        qApp->exit();
    }
    // qDebug() << timeEnd << idleTime();
    this->timeValue->setHMS(0,this->timeValue->addSecs(-1).minute(),this->timeValue->addSecs(-1).second());
    this->display(this->timeValue->toString());
    timeEnd -= 1;
    firstTick = false;
}

void LCDNumber::set_Time(int minutes, int seconds)
{
    timeValue = new QTime(0, minutes, seconds);
    this->display(timeValue->toString());
    timeEnd = minutes * 60 + seconds;
    firstTick = true;
}

void LCDNumber::start_Timer(int sec)
{
    timer->start(sec);
}

#if defined(Q_OS_UNIX)
bool LCDNumber::shutDownComputer()
{
    system("systemctl poweroff");
    return true;
}

typedef struct {
    Window  window;     /* screen saver window - may not exist */
    int     state;      /* ScreenSaverOff, ScreenSaverOn, ScreenSaverDisabled*/
    int     kind;       /* ScreenSaverBlanked, ...Internal, ...External */
    unsigned long    til_or_since;   /* time til or since screen saver */
    unsigned long    idle;      /* total time since last user input */
    unsigned long   eventMask; /* currently selected events for this client */
} XScreenSaverInfo;

typedef XScreenSaverInfo* (*XScreenSaverAllocInfo)();
typedef Status (*XScreenSaverQueryInfo)(Display* display, Drawable* drawable, XScreenSaverInfo* info);

static XScreenSaverAllocInfo _xScreenSaverAllocInfo = 0;
static XScreenSaverQueryInfo _xScreenSaverQueryInfo = 0;

uint LCDNumber::idleTime()
{
    static bool xssResolved = false;
    if (!xssResolved) {
        QLibrary xssLib(QLatin1String("Xss"), 1);
        if (xssLib.load()) {
            _xScreenSaverAllocInfo = (XScreenSaverAllocInfo) xssLib.resolve("XScreenSaverAllocInfo");
            _xScreenSaverQueryInfo = (XScreenSaverQueryInfo) xssLib.resolve("XScreenSaverQueryInfo");
            xssResolved = true;
        }
    }

    uint idle = 0;
    if (xssResolved)
    {
        XScreenSaverInfo* info = _xScreenSaverAllocInfo();
        const int screen = QX11Info::appScreen();
        Qt::HANDLE rootWindow = (void *) QX11Info::appRootWindow(screen);
        _xScreenSaverQueryInfo(QX11Info::display(), (Drawable*) rootWindow, info);
        idle = info->idle;
        if (info)
            XFree(info);
    }
    return idle;
}
#elif defined(Q_OS_WIN)
bool LCDNumber::shutDownComputer()
{
    HANDLE hToken;
    TOKEN_PRIVILEGES tkp;

    // Get a token for this process.

    if (!OpenProcessToken(GetCurrentProcess(),
                          TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &hToken))
        return( FALSE );

    // Get the LUID for the shutdown privilege.

    LookupPrivilegeValue(NULL, SE_SHUTDOWN_NAME,
                         &tkp.Privileges[0].Luid);

    tkp.PrivilegeCount = 1;  // one privilege to set
    tkp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;

    // Get the shutdown privilege for this process.

    AdjustTokenPrivileges(hToken, FALSE, &tkp, 0,
                          (PTOKEN_PRIVILEGES)NULL, 0);

    if (GetLastError() != ERROR_SUCCESS)
        return FALSE;

    // Shut down the system and force all applications to close.

    if (!ExitWindowsEx(EWX_SHUTDOWN | EWX_FORCE,
                       SHTDN_REASON_MAJOR_OPERATINGSYSTEM |
                       SHTDN_REASON_MINOR_UPGRADE |
                       SHTDN_REASON_FLAG_PLANNED))
        return FALSE;

    //shutdown was successful
    return TRUE;
}

uint LCDNumber::idleTime()
{
    uint idle = -1;
    LASTINPUTINFO info;
    info.cbSize = sizeof(LASTINPUTINFO);
    if (::GetLastInputInfo(&info))
        idle = ::GetTickCount() - info.dwTime;
    return idle;
}
#endif // Q_OS_MACRO

LCDNumber.h

#ifndef LCDNUMBER_H
#define LCDNUMBER_H

#include <QLCDNumber>
#include <QTime>
#include <QTimer>

class LCDNumber : public QLCDNumber
{
    Q_OBJECT

public:
    explicit LCDNumber(QWidget *parent = 0);
    ~LCDNumber();

public slots:
    void setDisplay();

public:
    void start_Timer(int);
    void set_Time(int, int);

private:
    uint idleTime();
    bool shutDownComputer();

private:
    int timeEnd;
    bool firstTick;

private:
    QTimer* timer;
    QTime*  timeValue;
};

#endif // LCDNUMBER_H

main.cpp

#include "Dialog.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Dialog w;
    w.show();

    return a.exec();
}

Screenshot.png

Shutdowner.pro

#-------------------------------------------------
#
# Project created by QtCreator 2016-07-29T22:35:05
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

D_IN = $$PWD/config.ini
D_OUT = $$OUT_PWD

win32: {
    D_IN ~= s,/,\\,g
    D_OUT ~= s,/,\\,g
}

deploy.commands = $$QMAKE_COPY $$D_IN $$D_OUT
first.depends = $(first) deploy
export(first.depends)
export(deploy.commands)
QMAKE_EXTRA_TARGETS += first deploy

unix: {
    QT += x11extras
}

TARGET = Shutdowner
TEMPLATE = app

SOURCES += main.cpp\
        Dialog.cpp \
    LCDNumber.cpp

HEADERS  += Dialog.h \
    LCDNumber.h

FORMS    += Dialog.ui

unix: {
    LIBS += -lX11
}

win: {
    QMAKE_LFLAGS += -static -static-libgcc -static-libstdc++
}