[SOLVED] Howto make a warning sign blinking

Snowseeker

Hi,

I would like to make a warning sign blinking on my GUI if the user presses a start button. Signal and slots I do already know well so I could take the event from the button.

But how I could make a warning sign blinking? Can you tell me what should I study (custom widgets, graphics view, ...)?

I would also be intrested for tutorials to this subject?

Thanks

Jeroentjehome

Hi,
Where do you need that warning? Should the button blink, should a label or picture blink??
It sounds to me you need to inherit from the widget you need blinking and then setup a QTimer in that class that will be started when the button is pressed (event). Then in the timer event change the colour or any other option you need blinking.

Snowseeker

It's a picture that should blink:
!https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQ-0spNMNPd9m4_xPMjtDLI5UzyyD2pEXXqgeUG8bI__4DuqvA-zg!

sw0ce

Hi,

a possible way is to subclass QGraphicsPixmapItem and animate the opacity property.

@
class AnimatedGraphicsItem : public QObject, public QGraphicsPixmapItem
{
Q_OBJECT
Q_PROPERTY(double opacity READ opacity WRITE setOpacity)

public:
AnimatedGraphicsItem(QObject *parent = 0);

    .....

};

void SomeClass::InitGraphicsItem()
{
m_MyAnimatedGraphicsItem = new AnimatedGraphicsItem();
QGraphicsScene *m_scene = new QGraphicsScene();
MyGraphicsView.setScene(m_scene);

 QPixmap p;
 p.load(QString::fromStdString("SomeImage"));

m_MyAnimatedGraphicsItem->setPixmap(p);

m_scene.addItem(m_MyAnimatedGraphicsItem);

}

void SomeClass::DoBlink()
{
m_statusAni = new QPropertyAnimation(m_MyAnimatedGraphicsItem,"opacity");
m_statusAni->setDuration(1600);
m_statusAni->setStartValue(0.0);
m_statusAni->setKeyValueAt(0.5,1.0);
m_statusAni->setEndValue(0.0);
m_statusAni->setEasingCurve(QEasingCurve::InCurve);
m_statusAni->setLoopCount(-1);
m_statusAni->start(QPropertyAnimation::DeleteWhenStopped)
}
@

Hope that helps

Chris Kawa

Another way would be to just make the "blinking" animation in a .gif. This gives you the most freedom as to what the blinking looks like.
Then all you'd need to do to show it is:
@
auto movie = new QMovie("path/to/animation/file.gif");
auto label = new QLabel();

label->setMovie(movie);
movie->start();
@

Jeroentjehome

Or inherit from QLabel and in a timerEvent change the border picture?? Then generate two pictures, warning on/off and change between them. The other options are more fancy must say!!

Snowseeker

Thanks all for your suggestions.

After trying to implement the suggestion from sw0ce. I finaly realized the suggestion from Jeroentje@ho..