There is one segment when play gif with movie

SGaist

Hi and welcome to devnet,

Why not just start the event loop like for any Qt GUI application ?

jmdvirus

Sorry, what event loop do you mean? And how to write?

KroMignon

@jmdvirus said in There is one segment when play gif with movie:

And how to write?

Your application is not really "Qt conform", you can try this way:

m_app = new QApplication(argc, args);
QWidget w;
    w.show();
QLabel label(w);
    QMovie movie(file);
    
    // to restart the movie
    QObject::connect(&movie, &QMovie::finished, m_app, [=]()
    {
        printf("rerun movie\n");
        movie.start();
    }
    );
    label.setMovie(&movie);
    movie.start();
    label.show();
    printf("movie cycle show\n");

    // start the event queue processing...
    m_app->exec();

I would also suggest you to read at least those articles:

SGaist

To add to @KroMignon, m_app should be on the stack, there's no need to allocate it on the heap.

jmdvirus

Oh, yes, thank you. But I just use another way to do it

class MovieTest : public QWidget {
        Q_OBJECT
    public:
        explicit MovieTest(QWidget *parent = NULL) {
            this->setParent(parent);
            connect(&m_movie, SIGNAL(finished()), this, SLOT(restartMovie()));
        }

        int init(const char *file) {
            m_movie.setFileName(file);
            return 0;
        }

        int start() {
            m_label.setMovie(&m_movie);
            m_movie.start();
            return 0;
        }

    public slots:
                void restartMovie() {
            printf("move status: [%d]\n", m_movie.state());
            m_movie.start();
        };

    protected:
        bool event(QEvent *event) override {
            printf("--------- get event ???[%d]\n", event->type());
            printf("move status [%d]\n", m_movie.state());
        }

    private:
        QMovie   m_movie;
        QLabel   m_label;
};

But the segment also exist

KroMignon

@jmdvirus First, always call base class constructor in you constructor, and prefere new connect syntax to detect possible typo errors on build time:

explicit MovieTest(QWidget *parent = NULL): QWidget(parent)
       {
            connect(&m_movie, &QMovie::finished, this, &MovieTest::restartMovie);
        }

Second, how to do you have changed the main() function?

jmdvirus

I move connect to init function, and then change main to below

QApplication app(argc, args);

  printf("Start to show\n");
  MovieTest m;
  m.init(args[1]);
  m.start();
  m.show();

  app.exec();

but problem is also exist, any other need change?

KroMignon

@jmdvirus Do you have change the constructor?

Because I am lazy, I made a little google search and found this => https://doc.qt.io/qt-5/qtwidgets-widgets-movie-example.html

I think this is a good starting point for you and will help you to understand what you are doing wrong.

jmdvirus

No, show is normal, it will segment fault after show some times
This may help to know

# test_qt_tips bootLoading.gif 
Start program
Start to show
move status: [0]
move status: [0]
Segmentation fault

"move status" means restart show movie, but it will segment fault after how many times is unsure, maybe more, or less.

construct like this

explicit MovieTest(QWidget *parent = NULL) {
            this->setParent(parent);
            m_label.setParent(this);
        }

        int init(const char *file) {
            m_movie.setFileName(file);
            connect(&m_movie, SIGNAL(finished()), this, SLOT(restartMovie()));
            return 0;
        }

KroMignon

@jmdvirus Because I am a lazy developer, I made a little Google search and found this ==> https://doc.qt.io/qt-5/qtwidgets-widgets-movie-example.html.

I think this is a good starting point for you application and I will help your to understand what you may have do wrong.

jmdvirus

ok, thank you!