import sys
from PyQt4 import QtCore
from PyQt4 import QtGui

class WidgetOverlay(QtGui.QWidget):
    def __init__(self, parent = None):
   
        QtGui.QWidget.__init__(self, parent)
        palette = QtGui.QPalette(self.palette())
        palette.setColor(palette.Background, QtCore.Qt.transparent)
        self.setPalette(palette)
    
    def paintEvent(self, event):
    
        painter = QtGui.QPainter()
        painter.begin(self)
        painter.setRenderHint(QtGui.QPainter.Antialiasing)
        painter.fillRect(event.rect(), QtGui.QBrush(QtGui.QColor(255, 255, 255, 127)))
        painter.setPen(QtGui.QPen(QtCore.Qt.NoPen))
        
        for i in range(6):
            if (self.counter / 5) % 6 == i:
                painter.setBrush(QtGui.QBrush(QtGui.QColor(127 + (self.counter % 5)*32, 127, 127)))
            else:
                painter.setBrush(QtGui.QBrush(QtGui.QColor(127, 127, 127)))
            painter.drawEllipse(
                self.width()/2 + 30 * math.cos(2 * math.pi * i / 6.0) - 10,
                self.height()/2 + 30 * math.sin(2 * math.pi * i / 6.0) - 10,
                20, 20)
        
        painter.end()
    
    def showEvent(self, event):
    
        self.timer = self.startTimer(50)
        self.counter = 0
    
    def timerEvent(self, event):
    
        self.counter += 1
        self.update()
        if self.counter == 60:
            self.killTimer(self.timer)
            self.hide()


class MainWindow(QtGui.QMainWindow):
    def __init__(self, parent = None):
        QtGui.QMainWindow.__init__(self, parent)
        
        widget = QtGui.QWidget(self)
        layout = QtGui.QGridLayout(widget)
        button = QtGui.QPushButton("Click here for splash")
        layout.addWidget(button, 0,0)
        
        self.setCentralWidget(widget)
        button.clicked.connect(self.heavy_stuff)
    
    def heavy_stuff(self, event):
		print "HEY"
		splash_pix = QtGui.QPixmap('loading.gif')
		self.splash = QtGui.QSplashScreen(splash_pix, QtCore.Qt.WindowStaysOnTopHint)
		self.splash.setMask(splash_pix.mask())
		self.splash.show()
		
		timer = QtCore.QTimer(self)
		timer.timeout.connect(self.splash.hide)
		timer.start(5000)

if __name__ == "__main__":

    app = QtGui.QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())