[SOLVED] QDialog in fullscreen - disable OS screensaver?

maximus · wrote on 3 Mar 2014, 02:02

Hi,

I would like to know if it's possible to disable the OS screensaver from a QMainWindow or QDialog. If not, would it be possible to "hack" it and emulate mouse movement or keyboard press at interval time x so the screensaver doesn't show. It is important not to have a screensaver, since the user is away from the computer when using this application.

Thank you

Code sample :

@ WorkoutDialog w(tableModel->getWorkoutAtRow(sourceIndex), this);
w.setModal(true);
w.showFullScreen();

    if (w.exec&#40;&#41; == QDialog::Accepted&#41; {
        //        qDebug() << "workout done!";
    }
    else {
        //        qDebug() << "workout cancel!";
    }@

hskoglund · wrote on 3 Mar 2014, 02:42

If this is for Windows, I've read somewhere that you can use the SendInput() API, you set up a timer say twice a minute and do something similar to this:
@ INPUT Mouse;

Mouse.type = INPUT_MOUSE;
Mouse.mi.dwFlags = MOUSEEVENTF_MOVE;
::SendInput(1,&Mouse,sizeof(INPUT));@

This should emulate a mouse movement with zero delta x and zero delta y, should be enough to make the screensaver not start.

Haven't tried, but I found "this thread on Stackoverflow":http://stackoverflow.com/questions/463813/programmatically-prevent-windows-screensaver-from-starting
, somewhere in the middle there is code for this, in VB.NET though :-(

maximus · wrote on 3 Mar 2014, 02:44

I'll check if I can find a cross-platform solution (Mac/Win), if not this will do the job, thanks a lot!

maximus · wrote on 10 Apr 2014, 18:08

I found this :
http://developer.nokia.com/community/wiki/Inhibiting_the_device_screen_saver_using_Qt

But I can't include "QSystemScreenSaver", maybe it's no longer part of Qt? Using 5.2.1

SGaist · wrote on 10 Apr 2014, 21:09

Hi,

It was part of QtMobility and AFAICS, it's not been ported (yet ?) to Qt 5

MarianMMX · wrote on 11 Apr 2014, 10:01

On Windows:
"SetThreadExecutionState":http://msdn.microsoft.com/en-us/library/aa373208(VS.85).aspx

@
#include <Windows.h>
void DisableScreenSaver()
{
SetThreadExecutionState(EXECUTION_STATE.ES_DISPLAY_REQUIRED | EXECUTION_STATE.ES_CONTINUOUS);
}
void EnableScreenSaver()
{
SetThreadExecutionState(EXECUTION_STATE.ES_CONTINUOUS);
}

@

hskoglund · wrote on 11 Apr 2014, 14:37

Yeah I tried that but alas, if you look at "the docs":http://msdn.microsoft.com/en-us/library/aa373208.aspx, at the bottom (just before examples):
"...
This function does not stop the screen saver from executing. " :-(

MarianMMX · wrote on 12 Apr 2014, 09:11

Ok, tested on Windows XP:

DisableScreenSaver.c
@
#include <Windows.h>
#pragma comment(lib, "user32.lib")

int main()
{
SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, FALSE , NULL, SPIF_SENDWININICHANGE);
return 0;
}

@

maximus · wrote on 16 Dec 2014, 04:59

Finally trying to achieve this function after many user requested it.

I'm thinking of a easy cross-platform way to do it (Windows and Mac OS X)

What I'm thinking:

start a QTimer that fire each 1 minute
[Slot] emulate a key press on the keyboard or a small mouse movement (keyboard or mouse is not used in this part of the software so shouldn't matter)

I'll see if I can achieve it (not sure how to emulate key or mouse movement in Qt) and post result!

Thanks Qt!

maximus · wrote on 16 Dec 2014, 04:59

Finally trying to achieve this function after many user requested it.

I'm thinking of a easy cross-platform way to do it (Windows and Mac OS X)

What I'm thinking:

start a QTimer that fire each 1 minute
[Slot] emulate a key press on the keyboard or a small mouse movement (keyboard or mouse is not used in this part of the software so shouldn't matter)

I'll see if I can achieve it (not sure how to emulate key or mouse movement in Qt) and post result!

Thanks Qt!

maximus · wrote on 16 Dec 2014, 22:11

I tried this one on my QDialog. But still not working (screensaver activates)
Maybe QDialog doesn't handle KeyPress event? investigating..

@void WorkoutDialog::desactivateScreensaver() {

qDebug() << "OK DESACTIVATE SCREENSAVER!";

QKeyEvent *event = new QKeyEvent(QEvent::KeyPress, Qt::Key_Enter, Qt::NoModifier);
QCoreApplication::postEvent(this, event);

QKeyEvent *event1 = new QKeyEvent(QEvent::KeyRelease, Qt::Key_Enter, Qt::NoModifier);
QCoreApplication::postEvent(this, event1);

}@

maximus · wrote on 16 Dec 2014, 22:11

I tried this one on my QDialog. But still not working (screensaver activates)
Maybe QDialog doesn't handle KeyPress event? investigating..

@void WorkoutDialog::desactivateScreensaver() {

qDebug() << "OK DESACTIVATE SCREENSAVER!";

QKeyEvent *event = new QKeyEvent(QEvent::KeyPress, Qt::Key_Enter, Qt::NoModifier);
QCoreApplication::postEvent(this, event);

QKeyEvent *event1 = new QKeyEvent(QEvent::KeyRelease, Qt::Key_Enter, Qt::NoModifier);
QCoreApplication::postEvent(this, event1);

}@

maximus · wrote on 17 Dec 2014, 00:04

Weird because I see my eventFilter being called, but the action never takes place on the UI (key pressed, mouseMove, ..)

@bool WorkoutDialog::eventFilter(QObject *watched, QEvent *event) {

Q_UNUSED(watched);

//    qDebug() << "EventFilter " << watched << "Event:" << event;

/// Disable enter pressed on dialog (bug cause it to minimize)
if(event->type() == QEvent::KeyPress) {
    QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
    if(keyEvent->key() == Qt::Key_Enter || keyEvent->key() == Qt::Key_Return )
        return true; // mark the event as handled
}


if(event->type() == QEvent::WindowStateChange)
{
    if(windowState().testFlag(Qt::WindowMaximized) == true) {
        qDebug() << "Going call showFullSceen here";
        this->showFullScreenWin();
        return true;
    }
}
return false;

}@

maximus · wrote on 17 Dec 2014, 00:04

Weird because I see my eventFilter being called, but the action never takes place on the UI (key pressed, mouseMove, ..)

@bool WorkoutDialog::eventFilter(QObject *watched, QEvent *event) {

Q_UNUSED(watched);

//    qDebug() << "EventFilter " << watched << "Event:" << event;

/// Disable enter pressed on dialog (bug cause it to minimize)
if(event->type() == QEvent::KeyPress) {
    QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
    if(keyEvent->key() == Qt::Key_Enter || keyEvent->key() == Qt::Key_Return )
        return true; // mark the event as handled
}


if(event->type() == QEvent::WindowStateChange)
{
    if(windowState().testFlag(Qt::WindowMaximized) == true) {
        qDebug() << "Going call showFullSceen here";
        this->showFullScreenWin();
        return true;
    }
}
return false;

}@

maximus · wrote on 17 Dec 2014, 00:59

[quote author="MarianMMX" date="1397293908"]Ok, tested on Windows XP:

DisableScreenSaver.c
@
#include <Windows.h>
#pragma comment(lib, "user32.lib")

int main()
{
SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, FALSE , NULL, SPIF_SENDWININICHANGE);
return 0;
}

@
[/quote]

Tested and works on windows 7 too. thanks
Update: not really what I wanted, it still disable the ScreenSaver after you leave the app.. don't want to mess with personal settings..

I gave up trying to emulate a key press, will use this code instead.
Trying to find an equivalent for Mac OS X now

maximus · wrote on 17 Dec 2014, 00:59

[quote author="MarianMMX" date="1397293908"]Ok, tested on Windows XP:

DisableScreenSaver.c
@
#include <Windows.h>
#pragma comment(lib, "user32.lib")

int main()
{
SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, FALSE , NULL, SPIF_SENDWININICHANGE);
return 0;
}

@
[/quote]

Tested and works on windows 7 too. thanks
Update: not really what I wanted, it still disable the ScreenSaver after you leave the app.. don't want to mess with personal settings..

I gave up trying to emulate a key press, will use this code instead.
Trying to find an equivalent for Mac OS X now

maximus · wrote on 17 Dec 2014, 01:38

I read you can call Objective-C from Qt

I want "to use this method":http://stackoverflow.com/questions/5596319/how-to-programmatically-prevent-a-mac-from-going-to-sleep/5596946#5596946

I made a header file named "MacUtil.h" and a "MacUtil.mm" that will call the Objective-C code. Will see if I can get it to work and post result

maximus · wrote on 17 Dec 2014, 01:38

I read you can call Objective-C from Qt

I want "to use this method":http://stackoverflow.com/questions/5596319/how-to-programmatically-prevent-a-mac-from-going-to-sleep/5596946#5596946

I made a header file named "MacUtil.h" and a "MacUtil.mm" that will call the Objective-C code. Will see if I can get it to work and post result

maximus · wrote on 17 Dec 2014, 01:52

On the way, will edit this post with solution
MacUtil.h

@class MacUtil
{

public:
MacUtil();
~MacUtil();

void disableScreensaver();
void releaseScreensaverLock();

private:
IOPMAssertionID assertionID;

};

#endif // MACUTIL_H@

MacUtil.mm
@//http://stackoverflow.com/questions/5596319/how-to-programmatically-prevent-a-mac-from-going-to-sleep/5596946#5596946
void MacUtil::disableScreensaver() {

CFStringRef* reasonForActivity= CFSTR("MaximumTrainer FullScreen Workout");
IOReturn success = IOPMAssertionCreateWithName(kIOPMAssertionTypeNoDisplaySleep,
                                    kIOPMAssertionLevelOn, reasonForActivity, &assertionID);
if (success == kIOReturnSuccess)
{
    //return sucess? todo..
}

}

void MacUtil::releaseScreensaverLock() {

IOPMAssertionRelease(assertionID);

}
@

maximus · wrote on 17 Dec 2014, 01:52

On the way, will edit this post with solution
MacUtil.h

@class MacUtil
{

public:
MacUtil();
~MacUtil();

void disableScreensaver();
void releaseScreensaverLock();

private:
IOPMAssertionID assertionID;

};

#endif // MACUTIL_H@

MacUtil.mm
@//http://stackoverflow.com/questions/5596319/how-to-programmatically-prevent-a-mac-from-going-to-sleep/5596946#5596946
void MacUtil::disableScreensaver() {

CFStringRef* reasonForActivity= CFSTR("MaximumTrainer FullScreen Workout");
IOReturn success = IOPMAssertionCreateWithName(kIOPMAssertionTypeNoDisplaySleep,
                                    kIOPMAssertionLevelOn, reasonForActivity, &assertionID);
if (success == kIOReturnSuccess)
{
    //return sucess? todo..
}

}

void MacUtil::releaseScreensaverLock() {

IOPMAssertionRelease(assertionID);

}
@