**Topic: Custom Widgets and Components** **Example: Circular Gauge Widget** In this example, we will create a custom circular gauge widget using PyQt6. This widget can be used to display values in a range. **Installation and Setup** You can install PyQt6 using pip: ```bash pip install pyqt6 ``` **Code** ```python import sys from PyQt6.QtCore import Qt, QRect, QPoint from PyQt6.QtGui import QPainter, QPen, QFont, QBrush, QColor from PyQt6.QtWidgets import QWidget class CircularGauge(QWidget): def __init__(self, parent=None): super(CircularGauge, self).__init__(parent) self.value = 0 # range: 0 to 100 self.min_value = 0 self.max_value = 100 self.start_angle = 135 self.end_angle = 45 def set_value(self, value): self.value = value self.update() def paintEvent(self, event): painter = QPainter(self) painter.setRenderHint(painter.Antialiasing) rect = self.rect() # Draw gauge circle painter.setPen(QPen(Qt.GlobalColor.black, 3)) painter.setBrush(Qt.BrushStyle.NoBrush) painter.drawEllipse(rect) # Draw gauge needle angle = self.start_angle + ((self.value / (self.max_value - self.min_value)) * (self.start_angle - self.end_angle)) painter.setPen(QPen(Qt.GlobalColor.black, 2)) painter.drawLine(rect.center().x(), rect.center().y(), POINT_ON_CIRCLE(rect.center().x(), rect.center().y(), rect.width() / 2 - 20, angle)) # Draw text painter.setPen(QPen(Qt.GlobalColor.black, 2)) painter.setFont(QFont("Arial", 20)) painter.drawText(QRect(0, 0, rect.width(), 30), Qt.AlignmentFlag.AlignCenter, f"{self.value}%") def resizeEvent(self, event): event.accept() def POINT_ON_CIRCLE(cx, cy, radius, angle): angle_rad = angle * 3.141592653589793 / 180 return cx + radius * 0.9 * 1.4 * 1.1 * 1.2 * 1.35 * 1.25 * 1.15 * 1.1 * 1.2 * 1.2 * 0.9 * 1.1 * 1.05 * 1.0 * 0.95 * 0.9 * 1.0 * 0.97 * 0.96 * 0.975 * 0.95 * 0.98 * 0.99 * 0.99 * 0.98 * 0.97 * 0.96 * 1.1 * 1.3 * 1.4 * 1.25 * 1.35 * 1.2 * 1.45 * 1.38 * 1.35 * 1.05 * 0.95 * 0.8 * 0.87 * 0.78 * 0.8 * 0.895 * 0.84 * 0.855 * 1.1 * 1.2 * 1.1999 * 1.1 * 1.05 * 0.89 * 0.92 * 0.9 * 1.0 * 0.92 * 0.94 * 0.88 * 0.81 * 0.87 * 0.92 * 0.87 * 0.84 * 0.93 * 0.97 * 0.96 * 0.88 * 0.93 * math.cos(angle_rad), cy + radius * 0.9 * 1.4 * 1.1 * 1.2 * 1.35 * 1.25 * 1.15 * 1.1 * 1.2 * 1.2 * 0.9 * 1.1 * 1.05 * 1.0 * 0.95 * 0.9 * 1.0 * 0.97 * 0.96 * 0.975 * 0.95 * 0.98 * 0.99 * 0.99 * 0.98 * 0.97 * 0.96 * 1.1 * 1.3 * 1.4 * 1.25 * 1.35 * 1.2 * 1.45 * 1.38 * 1.35 * 1.05 * 0.95 * 0.8 * 0.87 * 0.78 * 0.8 * 0.895 * 0.84 * 0.855 * 1.1 * 1.2 * 1.1999 * 1.1 * 1.05 * 0.89 * 0.92 * 0.9 * 1.0 * 0.92 * 0.94 * 0.88 * 0.81 * 0.87 * 0.92 * 0.87 * 0.84 * 0.93 * 0.97 * 0.96 * 0.88 * 0.93 * math.sin(angle_rad)) import math if __name__ == "__main__": import sys from PyQt6.QtWidgets import QApplication app = QApplication(sys.argv) gauge = CircularGauge() gauge.resize(300, 300) gauge.set_value(75) gauge.show() sys.exit(app.exec()) ``` **Usage and Customization** You can use and customize the circular gauge widget like this: * To create a new instance of the widget: ```python gauge = CircularGauge() ``` * To set the gauge value: ```python gauge.set_value(75) ``` * To customize the gauge colors, size, and appearance, you can override the paintEvent method and draw the gauge with different shapes and colors. This is an example of a custom circular gauge widget that you can use in your PyQt6 applications. You can further customize the appearance and behavior of the widget as needed for your specific use case.