<pre><code>from PyQt5 import QtWidgets
from PyQt5 import QtCore
from PyQt5 import QtGui
import sys
import random
import queue
import time
class Position(queue.Queue):
def __init__(self, *args, **kwargs):
super(Position, self).__init__(*args, **kwargs)
class Worker(QtCore.QThread):
pos_signal = QtCore.pyqtSignal(QtCore.QPointF)
def __init__(self, rect, parent=None, *args, **kwargs):
super().__init__(parent)
random.seed(0)
self.pos = QtCore.QPointF(0, 0)
self.rect: QtCore.QRectF = rect
def run(self) -> None:
new_pos = QtCore.QPointF(self.pos.x()+ random.randint(-100, 100), self.pos.y() +random.randint(-100, 100))
if not self.rect.contains(new_pos):
self.run()
else:
self.pos = new_pos
self.pos_signal.emit(new_pos)
time.sleep(0.1)
self.run()
class Example(QtWidgets.QWidget):
next_signal = QtCore.pyqtSignal()
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.button = QtWidgets.QPushButton("Start", self)
self.button.clicked.connect(self.doAnim)
self.scene = QtWidgets.QGraphicsScene()
self.view = QtWidgets.QGraphicsView(self)
self.view.setScene(self.scene)
self.view.setGeometry(100, 100, 500, 800)
self.setGeometry(300, 300, 800, 800)
pen = QtGui.QPen()
pen.setBrush(QtGui.QBrush(QtCore.Qt.darkBlue))
pen.setWidth(5)
self.scene.addEllipse(0,0,20,10, pen)
self.ellipse = self.scene.items()[0]
self.rect = QtCore.QRectF(0,0, 200, 200)
self.scene.addRect(self.rect, pen)
self.positions = Position()
self.producer = Worker(rect=self.rect)
self.producer.pos_signal.connect(self.positions.put)
self.producer.start()
self.old = QtCore.QPointF(0, 0)
self.new = None
def ready(self):
self.next_signal.emit()
self.old = self.new
self.doAnim()
def doAnim(self):
# Every time that I click on the start buttom this animation runs
# and stops,
self.sequential_animation = QtCore.QSequentialAnimationGroup(self)
self.new = self.positions.get()
self.anim = QtCore.QVariantAnimation()
self.anim.setDuration(1000)
self.anim.setStartValue(self.old)
self.anim.setEndValue(self.new)
self.anim.valueChanged.connect(self.ellipse.setPos)
self.anim.finished.connect(self.ready)
self.sequential_animation.addAnimation(self.anim)
self.sequential_animation.start(QtCore.QSequentialAnimationGroup.DeleteWhenStopped)
# self.anim.start(QtCore.QVariantAnimation.DeleteWhenStopped)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
ex = Example()
ex.show()
app.exec_()
</code></pre>