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Python pyqt (gui) example 'transformations'
transformations
Python pyqt example: transformations
#!/usr/bin/env python
#############################################################################
##
## Copyright (C) 2013 Riverbank Computing Limited.
## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
## All rights reserved.
##
## This file is part of the examples of PyQt.
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## $QT_BEGIN_LICENSE:BSD$
## You may use this file under the terms of the BSD license as follows:
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## * Redistributions of source code must retain the above copyright
## notice, this list of conditions and the following disclaimer.
## * Redistributions in binary form must reproduce the above copyright
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## distribution.
## * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
## the names of its contributors may be used to endorse or promote
## products derived from this software without specific prior written
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## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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## $QT_END_LICENSE$
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#############################################################################
from PyQt5.QtCore import QPointF, QSize, Qt
from PyQt5.QtGui import QBrush, QFont, QFontMetrics, QPainter, QPainterPath
from PyQt5.QtWidgets import QApplication, QComboBox, QGridLayout, QWidget
NoTransformation, Translate, Rotate, Scale = range(4)
class RenderArea(QWidget):
def __init__(self, parent=None):
super(RenderArea, self).__init__(parent)
newFont = self.font()
newFont.setPixelSize(12)
self.setFont(newFont)
fontMetrics = QFontMetrics(newFont)
self.xBoundingRect = fontMetrics.boundingRect("x")
self.yBoundingRect = fontMetrics.boundingRect("y")
self.shape = QPainterPath()
self.operations = []
def setOperations(self, operations):
self.operations = operations
self.update()
def setShape(self, shape):
self.shape = shape
self.update()
def minimumSizeHint(self):
return QSize(182, 182)
def sizeHint(self):
return QSize(232, 232)
def paintEvent(self, event):
painter = QPainter(self)
painter.setRenderHint(QPainter.Antialiasing)
painter.fillRect(event.rect(), QBrush(Qt.white))
painter.translate(66, 66)
painter.save()
self.transformPainter(painter)
self.drawShape(painter)
painter.restore()
self.drawOutline(painter)
self.transformPainter(painter)
self.drawCoordinates(painter)
def drawCoordinates(self, painter):
painter.setPen(Qt.red)
painter.drawLine(0, 0, 50, 0)
painter.drawLine(48, -2, 50, 0)
painter.drawLine(48, 2, 50, 0)
painter.drawText(60 - self.xBoundingRect.width() / 2,
0 + self.xBoundingRect.height() / 2, "x")
painter.drawLine(0, 0, 0, 50)
painter.drawLine(-2, 48, 0, 50)
painter.drawLine(2, 48, 0, 50)
painter.drawText(0 - self.yBoundingRect.width() / 2,
60 + self.yBoundingRect.height() / 2, "y")
def drawOutline(self, painter):
painter.setPen(Qt.darkGreen)
painter.setPen(Qt.DashLine)
painter.setBrush(Qt.NoBrush)
painter.drawRect(0, 0, 100, 100)
def drawShape(self, painter):
painter.fillPath(self.shape, Qt.blue)
def transformPainter(self, painter):
for operation in self.operations:
if operation == Translate:
painter.translate(50, 50)
elif operation == Scale:
painter.scale(0.75, 0.75)
elif operation == Rotate:
painter.rotate(60)
class Window(QWidget):
operationTable = (NoTransformation, Rotate, Scale, Translate)
NumTransformedAreas = 3
def __init__(self):
super(Window, self).__init__()
self.originalRenderArea = RenderArea()
self.shapeComboBox = QComboBox()
self.shapeComboBox.addItem("Clock")
self.shapeComboBox.addItem("House")
self.shapeComboBox.addItem("Text")
self.shapeComboBox.addItem("Truck")
layout = QGridLayout()
layout.addWidget(self.originalRenderArea, 0, 0)
layout.addWidget(self.shapeComboBox, 1, 0)
self.transformedRenderAreas = list(range(Window.NumTransformedAreas))
self.operationComboBoxes = list(range(Window.NumTransformedAreas))
for i in range(Window.NumTransformedAreas):
self.transformedRenderAreas[i] = RenderArea()
self.operationComboBoxes[i] = QComboBox()
self.operationComboBoxes[i].addItem("No transformation")
self.operationComboBoxes[i].addItem(u"Rotate by 60\N{DEGREE SIGN}")
self.operationComboBoxes[i].addItem("Scale to 75%")
self.operationComboBoxes[i].addItem("Translate by (50, 50)")
self.operationComboBoxes[i].activated.connect(self.operationChanged)
layout.addWidget(self.transformedRenderAreas[i], 0, i + 1)
layout.addWidget(self.operationComboBoxes[i], 1, i + 1)
self.setLayout(layout)
self.setupShapes()
self.shapeSelected(0)
self.setWindowTitle("Transformations")
def setupShapes(self):
truck = QPainterPath()
truck.setFillRule(Qt.WindingFill)
truck.moveTo(0.0, 87.0)
truck.lineTo(0.0, 60.0)
truck.lineTo(10.0, 60.0)
truck.lineTo(35.0, 35.0)
truck.lineTo(100.0, 35.0)
truck.lineTo(100.0, 87.0)
truck.lineTo(0.0, 87.0)
truck.moveTo(17.0, 60.0)
truck.lineTo(55.0, 60.0)
truck.lineTo(55.0, 40.0)
truck.lineTo(37.0, 40.0)
truck.lineTo(17.0, 60.0)
truck.addEllipse(17.0, 75.0, 25.0, 25.0)
truck.addEllipse(63.0, 75.0, 25.0, 25.0)
clock = QPainterPath()
clock.addEllipse(-50.0, -50.0, 100.0, 100.0)
clock.addEllipse(-48.0, -48.0, 96.0, 96.0)
clock.moveTo(0.0, 0.0)
clock.lineTo(-2.0, -2.0)
clock.lineTo(0.0, -42.0)
clock.lineTo(2.0, -2.0)
clock.lineTo(0.0, 0.0)
clock.moveTo(0.0, 0.0)
clock.lineTo(2.732, -0.732)
clock.lineTo(24.495, 14.142)
clock.lineTo(0.732, 2.732)
clock.lineTo(0.0, 0.0)
house = QPainterPath()
house.moveTo(-45.0, -20.0)
house.lineTo(0.0, -45.0)
house.lineTo(45.0, -20.0)
house.lineTo(45.0, 45.0)
house.lineTo(-45.0, 45.0)
house.lineTo(-45.0, -20.0)
house.addRect(15.0, 5.0, 20.0, 35.0)
house.addRect(-35.0, -15.0, 25.0, 25.0)
text = QPainterPath()
font = QFont()
font.setPixelSize(50)
fontBoundingRect = QFontMetrics(font).boundingRect("Qt")
text.addText(-QPointF(fontBoundingRect.center()), font, "Qt")
self.shapes = (clock, house, text, truck)
self.shapeComboBox.activated.connect(self.shapeSelected)
def operationChanged(self):
operations = []
for i in range(Window.NumTransformedAreas):
index = self.operationComboBoxes[i].currentIndex()
operations.append(Window.operationTable[index])
self.transformedRenderAreas[i].setOperations(operations[:])
def shapeSelected(self, index):
shape = self.shapes[index]
self.originalRenderArea.setShape(shape)
for i in range(Window.NumTransformedAreas):
self.transformedRenderAreas[i].setShape(shape)
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
Useful links
- Learn PyQt: https://pythonbasics.org/pyqt-hello-world/
- Install PyQt: https://pythonbasics.org/install-pyqt/