How to start the log file when key combinations pressed??

[Gokulnathvc]

how to start the log file when CTRL+ALT+T is pressed and if it presssed again it should stop.... how it can be done...

[wysota]

What is it exactly that you don't know how to implement?

[Gokulnathvc]

I want to start the log file creation when CTRL+ALT+L is presssed and have to stop it when the same combination has been clicked.. please help me..

[wysota]

I understand what you want, I'm asking what are you having problems with? Tell us what you have already tried and what didn't work.

[Gokulnathvc]

void QCDevice::keyPressEvent(QKeyEvent *event)
{
    if (event->key() == Qt::Key_Control && Qt::Key_Alt && Qt::Key_V) {
 
        QMessageBox::warning(NULL,"Keypress","Keypressed",QMessageBox::Ok);
    }
 
    I have tried this one, but after pressing the key combination also the message box is not shown..
 
}

void QCDevice::keyPressEvent(QKeyEvent *event)
{
    if (event->key() == Qt::Key_Control && Qt::Key_Alt && Qt::Key_V) {

        QMessageBox::warning(NULL,"Keypress","Keypressed",QMessageBox::Ok);
    }
    
    I have tried this one, but after pressing the key combination also the message box is not shown..

}

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[wysota]

Is QCDevice a widget?

[Gokulnathvc]

No its a dialog

[wysota]

A dialog is also a widget Ok, does it have keyboard focus?

Furthermore your code is incorrect:

if (event->key() == Qt::Key_Control && Qt::Key_Alt && Qt::Key_V)

if (event->key() == Qt::Key_Control && Qt::Key_Alt && Qt::Key_V)

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this can be translated to:

if(event->key() == Qt::Key_Control && 0x01000023 && 0x56)

if(event->key() == Qt::Key_Control && 0x01000023 && 0x56)

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which again translates to:

if(event->key() == Qt::Key_Control && true && true)

if(event->key() == Qt::Key_Control && true && true)

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and then to:

if(event->key() == Qt::Key_Control)

if(event->key() == Qt::Key_Control)

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which as you probably guess is not what you want. Read what QKeyEvent::key() is and use it with conjunction with QKeyEvent::modifiers(). Or just use QShortcut.

Learning a bit more C++ wouldn't hurt either.

[Gokulnathvc]

How to perform those key combinations in it?? please help me with the above codes.

[wysota]

What didn't you understand from my previous post? Make sure you widget accepts focus, use QKeyEvent::key() in conjunction with QKeyEvent::modifiers() or use QShortcut. If you expect me to provide full working code then that's not going to happen, I rarely do that in the Newbie forum. And please correct your profile information, somehow I doubt you're using Qt3 or Qt/Embedded.

[ChrisW67]

please help me with the above codes.

You are using logical AND where you want bit-wise AND.

http://en.wikipedia.org/wiki/Operato...ical_operators

[Gokulnathvc]

How to capture the key press events in QT in windows7?? CTRL+ALT+ some alphabet combination's. if we press this combination.. the particular event function should be called...

[mcosta]

If you have a GUI application you can use QShortcut or QAction.

[Gokulnathvc]

I have used the following code.. it works fine in xp(Qt 1.3.1) but it is not working in windows 7.,(Qt 4.3)::

QShortcut *shortcut = new QShortcut(QKeySequence("Ctrl+M"), this);
        QObject::connect(shortcut, SIGNAL(activated()), this, SLOT(showmessage()));

QShortcut *shortcut = new QShortcut(QKeySequence("Ctrl+M"), this);
        QObject::connect(shortcut, SIGNAL(activated()), this, SLOT(showmessage()));

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[wysota]

For the last time: shortcuts, key events and such work in terms of focus. One of children of the window containing the shortcut needs to have focus for the shortcut to trigger.