QSplashScreen Class Reference

Detailed Description

A splash screen is a widget that is usually displayed when an application is being started. Splash screens are often used for applications that have long start up times (e.g. database or networking applications that take time to establish connections) to provide the user with feedback that the application is loading.

The splash screen appears centered on the screen, on top of all other windows.

Some X11 window managers do not support the "stays on top" flag. A solution is to set up a timer that periodically calls raise() on the splash screen to simulate the "stays on top" effect.

The most common usage is to show a splash screen before the main widget is displayed on the screen. This is illustrated in the following code snippet.

   int main( int argc, char **argv )
   {
       QApplication app( argc, argv );
       QPixmap pixmap( "splash.png" );
       QSplashScreen *splash = new QSplashScreen( pixmap );
       splash->show();
       QMainWindow *mainWin = new QMainWindow;
       ...
       app.setMainWidget( mainWin );
       mainWin->show();
       splash->finish( mainWin );
       delete splash;
       return app.exec();
   }
   

It is sometimes useful to update the splash screen with messages, for example, announcing connections established or modules loaded as the application starts up. QSplashScreen supports this with the message() function. If you wish to do your own drawing you can get a pointer to the pixmap used in the splash screen with pixmap(). Alternatively, you can subclass QSplashScreen and reimplement drawContents().

The user can hide the splash screen by clicking on it with the mouse. Since the splash screen is typically displayed before the event loop has started running, it is necessary to periodically call QApplication::processEvents() to receive the mouse clicks.

   QSplashScreen *splash = new QSplashScreen( "splash.png" );
   splash->show();
   ... // Loading some items
   splash->message( "Loaded modules" );
   qApp->processEvents();
   ... // Establishing connections
   splash->message( "Established connections" );
   qApp->processEvents();
   

See also Miscellaneous Classes.

Member Function Documentation

QSplashScreen::QSplashScreen ( const QPixmap & pixmap = QPixmap ( ), WFlags f = 0 )

There should be no need to set the widget flags, f, except perhaps WDestructiveClose.

QSplashScreen::~QSplashScreen () [virtual]

void QSplashScreen::clear () [slot]

See also message().

void QSplashScreen::drawContents ( QPainter * painter ) [virtual protected]

void QSplashScreen::finish ( QWidget * mainWin )

void QSplashScreen::message ( const QString & message, int alignment = AlignLeft, const QColor & color = black ) [slot]

See also Qt::AlignmentFlags and clear().

void QSplashScreen::messageChanged ( const QString & message ) [signal]

This signal is emitted when the message on the splash screen changes. message is the new message and is a null-string when the message has been removed.

See also message() and clear().

QPixmap * QSplashScreen::pixmap () const

void QSplashScreen::repaint ()

void QSplashScreen::setPixmap ( const QPixmap & pixmap )

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