add error message signal

Author: HalemoGPA

src/main.py

@@ -13,6 +13,7 @@
     QPushButton,
     QMessageBox,
 )
+from PySide2.QtCore import Signal
 from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
 
 # Suppress font warnings
@@ -27,6 +28,8 @@ class FunctionPlotter(QMainWindow):
     using PySide2 for the GUI and Matplotlib for plotting.
     """
 
+    error_message_signal = Signal(str)
+
     def __init__(self):
         super().__init__()
         self.setWindowTitle("Function Plotter")
@@ -165,6 +168,7 @@ def show_error_message(self, message):
         - message (str): The error message to display.
         """
         QMessageBox.critical(self, "Error", message)
+        self.error_message_signal.emit(message)
 
 
 if __name__ == "__main__":