[QT] Making software-level Screensavers

Welcome to visit CuZn Station

One of the previous projects that had been taken on was the need to have a screensaver that would automatically go into the screensaver if it was not operating more than 30s. Simple analysis: The so-called non-operation refers to the non-receipt of keyboard or mouse events, more than 30s is required to use the timer, screen saver status is to display a large full-screen picture. From the perspective of QT, we need to create a screensaver class and make it as an event agent for the application, if there is a mouse or keyboard event, then refresh the timer, if more than 30s did not receive the relevant event, the Full Screen display window. Here is a code example to explain.

Construct a screensaver class Cscreensaver:

cscreensaver.h file

#ifndef  CSCREENSAVER#define CSCREENSAVER  #ifndef  qobject_h#include <qobject># endif class qtimer;class qlabel;class cscreensaver : public qobject{     q_object public:    cscreensaver (QObject *parent =  NULL);     ~cscreensaver (); protected slots:    void  Slot_timeout ();  protected:    //Initialize screensaver parameter     void init ();          //event Receive handler function, called by Installeventfilter Caller when receiving an event      bool eventfilter (qobject *watched, qevent *event);      private:    //Timers     QTimer   *timer;          //objects for display-preserving images     QLabel   *label;          //Initial screensaver wait Time out     static const unsigned wait_time  = 30000;};   #endif

cscreensaver.cpp file

#include  <cscreensaver.h>  #include  <QFile> #include  <QLabel> #include  <QEvent> #include  <QTimer> #include  <QPixmap> #include  <QSettings>  cscreensaver::cscreensaver (Qobject *parent)     : qobject (parent),  Waitinterval (wait_time) {    init ();}  cscreensaver::~cscreensaver () {} void cscreensaver::init () {    unsigned  waitinterval;    qstring urlpath;     //Reading screensaver configuration      qsettings settings (Qapplication::applicationdirpath ()  +  "/config.ini",  Qsettings::iniformat);     settings.begingroup ("SCREENSAVER");     if   (Settings.contains ("Interval")     {         Bool ok;        waitinterval =&nbsP;settings.value ("Interval"). Touint (&ok);        if  (!ok)             waitInterval = WAIT_TIME;     }         if  (Settings.contains (" Picpath "))     {        urlPath =  Settings.value ("Picpath"). toString ();     }    settings.endgroup ();      //set up and start the timer. If more than 30s, the display is guaranteed and no longer triggered until the timer is refreshed again     timer = new QTimer;     timer->setsingleshot (True);     connect (Timer, signal (timeout ()),  this,  slot (Slot_timeout ()));     timer->start (Waitinterval);      //Screensaver window     qrect screenrect = qapplication::d esktop ()->screenGeomEtry (0);     label = new qlabel ();    label-> Setgeometry (Screenrect);     label->setwindowflags (Qt::framelesswindowhint);     //Stretch background picture     label->setscaledcontents (true);          qpixmap pmp;    pmp.load (URLPath);     Label->setpixmap (PMP);     label->hide ();}  bool cscreensaver::eventfilter (qobject *obj, qevent *event) {     Judging event Type     if  (Event->type ()  == qevent::keypress | |  event->type ()  == qevent::mousemove        | |  event->type ()  == qevent::mousebuttonpress)  {         //a mouse or keyboard event resets the Timer        timer->start ();         label->hide ();    }      return qobject::eventfilter (obj, event);}  void cscreensaver::slot_timeout () {    //display     label-> Activatewindow ();     label->show ();}

In the main.cpp file

#include <QApplication> ... #include <cscreensaver.h> int main (int argc, char *argv[]) {qapplication app (arg     c, argv);         ...    Cscreensaver ScreenSaver;         Global receive and delegate processing event App.installeventfilter (&screensaver); ... return app.exec ();}

This article is from the "CuZn Station" blog, please be sure to keep this source http://cuzn1024.blog.51cto.com/9214612/1619340

[QT] Making software-level Screensavers