**Course Title:** PySide6 Application Development **Section Title:** Working with Graphics and Animations **Topic:** Creating an interactive graphical app with animations and custom drawings.(Lab topic) **Objective:** In this lab, you will learn how to create an interactive graphical application with animations and custom drawings using PySide6 and Qt. **Introduction:** In the previous topics, you learned the basics of working with graphics and animations in PySide6. Now, it's time to apply that knowledge and create an interactive graphical application. In this lab, you will work on a project that demonstrates the use of custom graphics, animations, and user interaction. **Project: Interactive Graphics App with Animations and Custom Drawings** **Project Description:** Your task is to create an application that displays a graphical scene with the following elements: 1. A bouncing ball that moves around the scene 2. A rectangle that changes color and size when clicked 3. A custom-drawn logo that spins and moves around the scene The application should also include buttons to start/stop the animations and change the background color of the scene. **Getting Started:** 1. Create a new project in your favorite IDE (e.g., PyCharm) and add the PySide6 library. 2. Create a new file called `graphics_app.py` and import the necessary libraries: `import sys` and `from PySide6 import QtWidgets, QtCore, QtGui`. 3. Create a new `QGraphicsScene` object and set it as the scene for a new `QGraphicsView` widget. **Custom Graphics and Animations:** 1. Create a new class called `BouncingBall` that inherits from `QGraphicsItem`. Implement the `paint` method to draw the ball and the `advance` method to update the ball's position. 2. Create a new class called `ColorChangingRectangle` that inherits from `QGraphicsItem`. Implement the `paint` method to draw the rectangle and the `mousePressEvent` method to change the rectangle's color and size when clicked. 3. Create a new class called `Logo` that inherits from `QGraphicsItem`. Implement the `paint` method to draw the logo and the `advance` method to update the logo's position and rotation. **Scene and Animations:** 1. Create a new `QTimer` object to handle the animations. 2. Implement the `animate` method to update the positions and rotations of the ball, rectangle, and logo. 3. Set up the animation timer to call the `animate` method at regular intervals. **User Interaction:** 1. Create a new button to start/stop the animations. 2. Implement the `startAnimation` and `stopAnimation` methods to start and stop the animations. 3. Create a new button to change the background color of the scene. 4. Implement the `changeBackgroundColor` method to change the background color of the scene. **Code Example:** Here is a sample code to get you started: ```python import sys from PySide6 import QtWidgets, QtCore, QtGui class BouncingBall(QtGui.QGraphicsItem): def __init__(self): super().__init__() self.x = 100 self.y = 100 self.width = 20 self.height = 20 self.speed_x = 2 self.speed_y = 2 def paint(self, painter, option, widget): painter.setBrush(QtGui.QBrush(QtGui.QColor(255, 0, 0))) painter.drawEllipse(0, 0, self.width, self.height) def advance(self): self.x += self.speed_x self.y += self.speed_y if self.x < 0 or self.x > 400: self.speed_x *= -1 if self.y < 0 or self.y > 400: self.speed_y *= -1 class ColorChangingRectangle(QtGui.QGraphicsItem): def __init__(self): super().__init__() self.x = 200 self.y = 200 self.width = 100 self.height = 100 self.color = QtGui.QColor(0, 255, 0) def paint(self, painter, option, widget): painter.setBrush(QtGui.QBrush(self.color)) painter.drawRect(0, 0, self.width, self.height) def mousePressEvent(self, event): self.color = QtGui.QColor(255, 0, 0) self.width = 150 self.height = 150 class Logo(QtGui.QGraphicsItem): def __init__(self): super().__init__() self.x = 300 self.y = 300 self.width = 100 self.height = 100 self.angle = 0 def paint(self, painter, option, widget): painter.setRenderHint(QtGui.QPainter.Antialiasing) painter.translate(50, 50) painter.rotate(self.angle) painter.drawImage(0, 0, QtGui.QImage("logo.png")) def advance(self): self.angle += 10 if self.angle > 360: self.angle = 0 class GraphicsApp(QtWidgets.QGraphicsView): def __init__(self): super().__init__() self.scene = QtWidgets.QGraphicsScene() self.setScene(self.scene) self.ball = BouncingBall() self.rectangle = ColorChangingRectangle() self.logo = Logo() self.scene.addItem(self.ball) self.scene.addItem(self.rectangle) self.scene.addItem(self.logo) self.timer = QtCore.QTimer() self.timer.timeout.connect(self.animate) self.timer.start(16) def animate(self): self.ball.advance() self.logo.advance() self.scene.update() def startAnimation(self): self.timer.start(16) def stopAnimation(self): self.timer.stop() def changeBackgroundColor(self): self.scene.setBackgroundBrush(QtGui.QBrush(QtGui.QColor(128, 128, 128))) def main(): if __name__ == "__main__": app = QtWidgets.QApplication(sys.argv) graphics_app = GraphicsApp() graphics_app.show() sys.exit(app.exec_()) if __name__ == "__main__": main() ``` **What to Do Next:** 1. Complete the implementation of the `BouncingBall`, `ColorChangingRectangle`, and `Logo` classes. 2. Implement the `animate` method in the `GraphicsApp` class to update the positions and rotations of the ball, rectangle, and logo. 3. Set up the animation timer to call the `animate` method at regular intervals. 4. Implement the user interaction (start/stop animations, change background color) using buttons. **Resources:** * [PySide6 Documentation](https://doc.qt.io/qtforpython/) * [Qt Tutorial: Graphics View Framework](https://doc.qt.io/qtforpython/overviews/graphicsview.html) * [PySide6 SIGNALS and Slots](https://doc.qt.io/qtforpython/PySide6/QtCore/Signals-Slots.html) **Q&A:** Please ask any questions related to this topic in the comments section below. We'll be happy to help!