Tags Python , Qt

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 (eliben@gmail.com)
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.


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