Splash screens are useful when your applications has to do some time-consuming work to start-up properly (load 'heavy' libraries, connect to a DB or a socket, create a complex state from configuration files, etc.)
Qt has the QSplashScreen class to make splash screens trivial to create and manage. This class is very simply used from PyQt. Here's how:
""" Splash screen example Eli Bendersky (firstname.lastname@example.org) License: this code is in the public domain Last modified: 09.05.2009 """ from PyQt4.QtCore import * from PyQt4.QtGui import * class Form(QDialog): """ Just a simple dialog with a couple of widgets """ def __init__(self, parent=None): super(Form, self).__init__(parent) self.browser = QTextBrowser() self.setWindowTitle('Just a dialog') self.lineedit = QLineEdit("Write something and press Enter") self.lineedit.selectAll() layout = QVBoxLayout() layout.addWidget(self.browser) layout.addWidget(self.lineedit) self.setLayout(layout) self.lineedit.setFocus() self.connect(self.lineedit, SIGNAL("returnPressed()"), self.update_ui) def update_ui(self): self.browser.append(self.lineedit.text()) if __name__ == "__main__": import sys, time app = QApplication(sys.argv) # Create and display the splash screen splash_pix = QPixmap('splash_loading.png') splash = QSplashScreen(splash_pix, Qt.WindowStaysOnTopHint) splash.setMask(splash_pix.mask()) splash.show() app.processEvents() # Simulate something that takes time time.sleep(2) form = Form() form.show() splash.finish(form) app.exec_()
This snippet shows a splash screen, sleeps for 2 seconds (to simulate a time consuming operation), and then shows the main application window.
The splash window I'm using is very basic:
Note that the edges of the image are transparent, and this is handled correctly by QSplashScreen.