1 files changed, 117 insertions, 0 deletions
diff --git a/examples/statemachine/trafficlight/trafficlight.py b/examples/statemachine/trafficlight/trafficlight.py
new file mode 100644
index 000000000..1e58384f9
--- /dev/null
+++ b/examples/statemachine/trafficlight/trafficlight.py
@@ -0,0 +1,117 @@
+# Copyright (C) 2010 velociraptor Genjix <aphidia@hotmail.com>
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+import sys
+
+from PySide6.QtCore import QTimer, Qt, Property, Slot
+from PySide6.QtGui import QPainter, QPalette
+from PySide6.QtWidgets import QApplication, QVBoxLayout, QWidget
+from PySide6.QtStateMachine import QFinalState, QState, QStateMachine
+
+
+class LightWidget(QWidget):
+    def __init__(self, color):
+        super().__init__()
+        self.color = color
+        self._on_val = False
+
+    def is_on(self):
+        return self._on_val
+
+    def set_on(self, on):
+        if self._on_val == on:
+            return
+        self._on_val = on
+        self.update()
+
+    @Slot()
+    def turn_off(self):
+        self.set_on(False)
+
+    @Slot()
+    def turn_on(self):
+        self.set_on(True)
+
+    def paintEvent(self, e):
+        if not self._on_val:
+            return
+        with QPainter(self) as painter:
+            painter.setRenderHint(QPainter.Antialiasing)
+            painter.setBrush(self.color)
+            painter.drawEllipse(0, 0, self.width(), self.height())
+
+    on = Property(bool, is_on, set_on)
+
+
+class TrafficLightWidget(QWidget):
+    def __init__(self):
+        super().__init__()
+        vbox = QVBoxLayout(self)
+        self._red_light = LightWidget(Qt.red)
+        vbox.addWidget(self._red_light)
+        self._yellow_light = LightWidget(Qt.yellow)
+        vbox.addWidget(self._yellow_light)
+        self._green_light = LightWidget(Qt.green)
+        vbox.addWidget(self._green_light)
+        pal = QPalette()
+        pal.setColor(QPalette.Window, Qt.black)
+        self.setPalette(pal)
+        self.setAutoFillBackground(True)
+
+
+def create_light_state(light, duration, parent=None):
+    light_state = QState(parent)
+    timer = QTimer(light_state)
+    timer.setInterval(duration)
+    timer.setSingleShot(True)
+    timing = QState(light_state)
+    timing.entered.connect(light.turn_on)
+    timing.entered.connect(timer.start)
+    timing.exited.connect(light.turn_off)
+    done = QFinalState(light_state)
+    timing.addTransition(timer.timeout, done)
+    light_state.setInitialState(timing)
+    return light_state
+
+
+class TrafficLight(QWidget):
+    def __init__(self):
+        super().__init__()
+        vbox = QVBoxLayout(self)
+        widget = TrafficLightWidget()
+        vbox.addWidget(widget)
+        vbox.setContentsMargins(0, 0, 0, 0)
+
+        machine = QStateMachine(self)
+        red_going_yellow = create_light_state(widget._red_light, 1000)
+        red_going_yellow.setObjectName('redGoingYellow')
+        yellow_going_green = create_light_state(widget._red_light, 1000)
+        yellow_going_green.setObjectName('yellowGoingGreen')
+        red_going_yellow.addTransition(red_going_yellow.finished,
+                                       yellow_going_green)
+        green_going_yellow = create_light_state(widget._yellow_light, 3000)
+        green_going_yellow.setObjectName('greenGoingYellow')
+        yellow_going_green.addTransition(yellow_going_green.finished,
+                                         green_going_yellow)
+        yellow_going_red = create_light_state(widget._green_light, 1000)
+        yellow_going_red.setObjectName('yellowGoingRed')
+        green_going_yellow.addTransition(green_going_yellow.finished,
+                                         yellow_going_red)
+        yellow_going_red.addTransition(yellow_going_red.finished,
+                                       red_going_yellow)
+
+        machine.addState(red_going_yellow)
+        machine.addState(yellow_going_green)
+        machine.addState(green_going_yellow)
+        machine.addState(yellow_going_red)
+        machine.setInitialState(red_going_yellow)
+        machine.start()
+
+
+if __name__ == '__main__':
+    app = QApplication(sys.argv)
+    widget = TrafficLight()
+    widget.resize(110, 300)
+    widget.show()
+    sys.exit(app.exec())