feat(qt_utils): added error handle utility with popup messageBoxes

bec_widgets/qt_utils/error_popups.py

@@ -0,0 +1,193 @@
+import functools
+import sys
+import traceback
+
+from qtpy.QtCore import QObject, Qt, Signal, Slot
+from qtpy.QtWidgets import QApplication, QMessageBox, QPushButton, QVBoxLayout, QWidget
+
+
+def SafeSlot(*slot_args, **slot_kwargs):
+    """Function with args, acting like a decorator, applying "error_managed" decorator + Qt Slot
+    to the passed function, to display errors instead of potentially raising an exception
+
+    'popup_error' keyword argument can be passed with boolean value if a dialog should pop up,
+    otherwise error display is left to the original exception hook
+    """
+    popup_error = bool(slot_kwargs.pop("popup_error", False))
+
+    def error_managed(method):
+        @Slot(*slot_args, **slot_kwargs)
+        @functools.wraps(method)
+        def wrapper(*args, **kwargs):
+            try:
+                return method(*args, **kwargs)
+            except Exception:
+                ErrorPopupUtility().custom_exception_hook(*sys.exc_info(), popup_error=popup_error)
+
+        return wrapper
+
+    return error_managed
+
+
+class ErrorPopupUtility(QObject):
+    """
+    Utility class to manage error popups in the application to show error messages to the users.
+    This class is singleton and the error popup can be enabled or disabled globally or attach to widget methods with decorator @error_managed.
+    """
+
+    error_occurred = Signal(str, str, QWidget)
+
+    _instance = None
+    _initialized = False
+
+    def __new__(cls, *args, **kwargs):
+        if cls._instance is None:
+            cls._instance = super(ErrorPopupUtility, cls).__new__(cls)
+            cls._instance._initialized = False
+        return cls._instance
+
+    def __init__(self, parent=None):
+        if not self._initialized:
+            super().__init__(parent=parent)
+            self.error_occurred.connect(self.show_error_message)
+            self.enable_error_popup = False
+            self._initialized = True
+            sys.excepthook = self.custom_exception_hook
+
+    @Slot(str, str, QWidget)
+    def show_error_message(self, title, message, widget):
+        detailed_text = self.format_traceback(message)
+        error_message = self.parse_error_message(detailed_text)
+
+        msg = QMessageBox(widget)
+        msg.setIcon(QMessageBox.Critical)
+        msg.setWindowTitle(title)
+        msg.setText(error_message)
+        msg.setStandardButtons(QMessageBox.Ok)
+        msg.setDetailedText(detailed_text)
+        msg.setTextInteractionFlags(Qt.TextSelectableByMouse)
+        msg.setMinimumWidth(600)
+        msg.setMinimumHeight(400)
+        msg.exec_()
+
+    def format_traceback(self, traceback_message: str) -> str:
+        """
+        Format the traceback message to be displayed in the error popup by adding indentation to each line.
+
+        Args:
+            traceback_message(str): The traceback message to be formatted.
+
+        Returns:
+            str: The formatted traceback message.
+        """
+        formatted_lines = []
+        lines = traceback_message.split("\n")
+        for line in lines:
+            formatted_lines.append("    " + line)  # Add indentation to each line
+        return "\n".join(formatted_lines)
+
+    def parse_error_message(self, traceback_message):
+        lines = traceback_message.split("\n")
+        error_message = "Error occurred. See details."
+        capture = False
+        captured_message = []
+
+        for line in lines:
+            if "raise" in line:
+                capture = True
+                continue
+            if capture:
+                if line.strip() and not line.startswith("  File "):
+                    captured_message.append(line.strip())
+                else:
+                    break
+
+        if captured_message:
+            error_message = " ".join(captured_message)
+        return error_message
+
+    def custom_exception_hook(self, exctype, value, tb, popup_error=False):
+        if popup_error or self.enable_error_popup:
+            error_message = traceback.format_exception(exctype, value, tb)
+            self.error_occurred.emit(
+                "Method error" if popup_error else "Application Error",
+                "".join(error_message),
+                self.parent(),
+            )
+        else:
+            sys.__excepthook__(exctype, value, tb)  # Call the original excepthook
+
+    def enable_global_error_popups(self, state: bool):
+        """
+        Enable or disable global error popups for all applications.
+
+        Args:
+            state(bool): True to enable error popups, False to disable error popups.
+        """
+        self.enable_error_popup = bool(state)
+
+    @classmethod
+    def reset_singleton(cls):
+        """
+        Reset the singleton instance.
+        """
+        cls._instance = None
+        cls._initialized = False
+
+
+class ExampleWidget(QWidget):  # pragma: no cover
+    """
+    Example widget to demonstrate error handling with the ErrorPopupUtility.
+
+    Warnings -> This example works properly only with PySide6, PyQt6 has a bug with the error handling.
+    """
+
+    def __init__(self, parent=None):
+        super().__init__(parent=parent)
+        self.init_ui()
+
+    def init_ui(self):
+        self.layout = QVBoxLayout(self)
+
+        # Button to trigger method with error handling
+        self.error_button = QPushButton("Trigger Handled Error", self)
+        self.error_button.clicked.connect(self.method_with_error_handling)
+        self.layout.addWidget(self.error_button)
+
+        # Button to trigger method without error handling
+        self.normal_button = QPushButton("Trigger Normal Error", self)
+        self.normal_button.clicked.connect(self.method_without_error_handling)
+        self.layout.addWidget(self.normal_button)
+
+        # Button to trigger warning popup
+        self.warning_button = QPushButton("Trigger Warning", self)
+        self.warning_button.clicked.connect(self.trigger_warning)
+        self.layout.addWidget(self.warning_button)
+
+    @SafeSlot(popup_error=True)
+    def method_with_error_handling(self):
+        """This method raises an error and the exception is handled by the decorator."""
+        raise ValueError("This is a handled error.")
+
+    @SafeSlot()
+    def method_without_error_handling(self):
+        """This method raises an error and the exception is not handled here."""
+        raise ValueError("This is an unhandled error.")
+
+    @SafeSlot()
+    def trigger_warning(self):
+        """Trigger a warning using the WarningPopupUtility."""
+        self.warning_utility.show_warning(
+            title="Warning",
+            message="This is a warning message.",
+            detailed_text="This is the detailed text of the warning message.",
+            widget=self,
+        )
+
+
+if __name__ == "__main__":  # pragma: no cover
+
+    app = QApplication(sys.argv)
+    widget = ExampleWidget()
+    widget.show()
+    sys.exit(app.exec_())

bec_widgets/utils/bec_connector.py

@@ -13,6 +13,7 @@ from qtpy.QtCore import QObject, QRunnable, QThreadPool, Signal
 from qtpy.QtCore import Slot as pyqtSlot
 
 from bec_widgets.cli.rpc_register import RPCRegister
+from bec_widgets.qt_utils.error_popups import ErrorPopupUtility
 from bec_widgets.utils.bec_widget import BECWidget
 from bec_widgets.utils.yaml_dialog import load_yaml, load_yaml_gui, save_yaml, save_yaml_gui
 
@@ -94,6 +95,9 @@ class BECConnector(BECWidget):
         self.rpc_register = RPCRegister()
         self.rpc_register.add_rpc(self)
 
+        # Error popups
+        self.error_utility = ErrorPopupUtility()
+
         self._thread_pool = QThreadPool.globalInstance()
 
     def submit_task(self, fn, *args, on_complete: pyqtSlot = None, **kwargs) -> Worker: