QT widget is not visible properly

[CorD SaC]

In this code which can able to play video and play *.mp3. code works properly,in my mainwindow.ui I added widget called widgetGif by drag and drop .This widget containing label also. but this widget not visible when I run the program. How can I display this widget called widgetGif

here is part of my code :

    #include "mainwindow.h"
    #include "ui_mainwindow.h"
    #include <QDebug>
    #include <QMovie>
    
    
    MainWindow::MainWindow(QWidget *parent) :
        QMainWindow(parent),
        ui(new Ui::MainWindow)
    {
        ui->setupUi(this);
        player = new QMediaPlayer(this);
        vw = new QVideoWidget (this);
        player->setVideoOutput(vw);
        this->setCentralWidget(vw); //I think this is the reason
        
        slider = new QSlider(this);
        bar = new QProgressBar(this);
        slider->setOrientation(Qt::Horizontal);
        ui->statusBar->addPermanentWidget(slider);
        ui->statusBar->addPermanentWidget(bar);
        
        
        
        connect(player,&QMediaPlayer::durationChanged,slider,&QSlider::setMaximum);
        connect(player,&QMediaPlayer::positionChanged,slider,&QSlider::setValue);
        connect(slider,&QSlider::sliderMoved,player,&QMediaPlayer::setPosition);
        connect(player,&QMediaPlayer::durationChanged,bar,&QProgressBar::setMaximum);
        connect(player,&QMediaPlayer::positionChanged,bar,&QProgressBar::setValue);
        
        
        sliderVolumn = new QSlider(this);
        sliderVolumn->setOrientation(Qt::Horizontal);
        ui->statusBar->addPermanentWidget(sliderVolumn);
        
        connect(sliderVolumn,&QSlider::sliderMoved,player,&QMediaPlayer::setVolume);
        
        QMovie *movie=new QMovie(":/res/icons/giphy.gif");
        if (!movie->isValid())
        {
            // Something went wrong :(
        }
        ui->labelGif->setMovie(movie);
        movie->start();
        
        ui->widgetGif->setVisible(true);
    }
    
    
    MainWindow::~MainWindow()
    {
        delete ui;
    }
    
    void MainWindow::on_actionOpen_triggered()
    {
        QString filename= QFileDialog::getOpenFileName(this,"Open Folder","","Open a File(*.*)");
        on_actionStop_triggered();
        player->setMedia(QUrl::fromLocalFile(filename));
        on_actionPlay_triggered();
        
        if(filename.endsWith(".mp3")){
            qDebug() << " file is mp3";
            
        }else{
            qDebug() << " not is mp3";
            
        }
    }

[joeQ]

@CorD-SaC Hi,friend. Welcome.

Could you move below code to void MainWindow::showEvent function, try it.

QMovie *movie=new QMovie(":/res/icons/giphy.gif");
        if (!movie->isValid())
        {
            // Something went wrong :(
        }
        ui->labelGif->setMovie(movie);
        movie->start();
        
        ui->widgetGif->setVisible(true);