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#!/usr/bin/env python
"""***************************************************************************
**
** Copyright (C) 2005-2005 Trolltech AS. All rights reserved.
**
** This file is part of the example classes of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file. Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at sales@trolltech.com.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
***************************************************************************"""
import sys
from PyQt4 import QtCore, QtGui
class CircleWidget(QtGui.QWidget):
def __init__(self, parent = None):
QtGui.QWidget.__init__(self, parent)
self.floatBased = False
self.antialiased = False
self.frameNo = 0
self.setBackgroundRole(QtGui.QPalette.Base)
self.setSizePolicy(QtGui.QSizePolicy.Expanding,
QtGui.QSizePolicy.Expanding)
def setFloatBased(self, floatBased):
self.floatBased = floatBased
self.update()
def setAntialiased(self, antialiased):
self.antialiased = antialiased
self.update()
def minimumSizeHint(self):
return QtCore.QSize(50, 50)
def sizeHint(self):
return QtCore.QSize(180, 180)
def nextAnimationFrame(self):
self.frameNo += 1
self.update()
def paintEvent(self, event):
painter = QtGui.QPainter()
painter.begin(self)
painter.setRenderHint(QtGui.QPainter.Antialiasing, self.antialiased)
painter.translate(self.width() / 2, self.height() / 2)
for diameter in range(0, 256, 9):
delta = abs((self.frameNo % 128) - diameter / 2)
alpha = 255 - (delta * delta) / 4 - diameter
if alpha > 0:
painter.setPen(QtGui.QPen(QtGui.QColor(0, diameter / 2, 127, alpha), 3))
if self.floatBased:
painter.drawEllipse(QtCore.QRectF(-diameter / 2.0, -diameter / 2.0,
diameter, diameter))
else:
painter.drawEllipse(QtCore.QRect(-diameter / 2, -diameter / 2,
diameter, diameter))
painter.end()
class Window(QtGui.QWidget):
def __init__(self, parent = None):
QtGui.QWidget.__init__(self, parent)
self.aliasedLabel = self.createLabel(self.tr("Aliased"))
self.antialiasedLabel = self.createLabel(self.tr("Antialiased"))
self.intLabel = self.createLabel(self.tr("Int"))
self.floatLabel = self.createLabel(self.tr("Float"))
layout = QtGui.QGridLayout()
layout.addWidget(self.aliasedLabel, 0, 1)
layout.addWidget(self.antialiasedLabel, 0, 2)
layout.addWidget(self.intLabel, 1, 0)
layout.addWidget(self.floatLabel, 2, 0)
timer = QtCore.QTimer(self)
self.circleWidgets = []
for i in range(2):
self.circleWidgets.append([None]*2)
for j in range(2):
self.circleWidgets[i][j] = CircleWidget()
self.circleWidgets[i][j].setAntialiased(j != 0)
self.circleWidgets[i][j].setFloatBased(i != 0)
self.connect(timer, QtCore.SIGNAL("timeout()"),
self.circleWidgets[i][j].nextAnimationFrame)
layout.addWidget(self.circleWidgets[i][j], i + 1, j + 1)
timer.start(100)
self.setLayout(layout)
self.setWindowTitle(self.tr("Concentric Circles"))
def createLabel(self, text):
label = QtGui.QLabel(text)
label.setAlignment(QtCore.Qt.AlignCenter)
label.setMargin(2)
label.setFrameStyle(QtGui.QFrame.Box | QtGui.QFrame.Sunken)
return label
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
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