[SOLVED] QDialog in fullscreen - disable OS screensaver?

maximus

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

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

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

maximus

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

Hi,

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

MarianMMX

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

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

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

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

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

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

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

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

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

[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

[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

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

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

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

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);

}
@