feat(help-inspector): add help inspector widget

bec_widgets/utils/bec_widget.py

@@ -185,6 +185,14 @@ class BECWidget(BECConnector):
         except Exception:
             logger.warning(f"Failed to apply theme {theme} to {self}")
 
+    def get_help_md(self) -> str:
+        """
+        Method to override in subclasses to provide help text in markdown format.
+
+        Returns:
+            str: The help text in markdown format.
+        """
+
     @SafeSlot()
     @SafeSlot(str)
     @rpc_timeout(None)

bec_widgets/utils/help_inspector/help_inspector.py

@@ -0,0 +1,238 @@
+"""Module providing a simple help inspector tool for QtWidgets."""
+
+from functools import partial
+from typing import Callable
+from uuid import uuid4
+
+from bec_lib.logger import bec_logger
+from bec_qthemes import material_icon
+from qtpy import QtCore, QtWidgets
+
+from bec_widgets.utils.bec_widget import BECWidget
+from bec_widgets.utils.colors import AccentColors, get_accent_colors
+from bec_widgets.utils.error_popups import SafeSlot
+
+logger = bec_logger.logger
+
+
+class HelpInspector(BECWidget, QtWidgets.QWidget):
+    """
+    A help inspector widget that allows to inspect other widgets in the application.
+    Per default, it emits signals with the docstring, tooltip and bec help text of the inspected widget.
+    The method "get_help_md" is called on the widget which is added to the BECWidget base class.
+    It should return a string with a help text, ideally in proper format to be displayed (i.e. markdown).
+    The inspector also allows to register custom callback that are called with the inspected widget
+    as argument. This may be useful in the future to hook up more callbacks with custom signals.
+
+    Args:
+        parent (QWidget | None): The parent widget of the help inspector.
+        client: Optional client for BECWidget functionality.
+        size (tuple[int, int]): Optional size of the icon for the help inspector.
+    """
+
+    widget_docstring = QtCore.Signal(str)  # Emits docstring from QWidget
+    widget_tooltip = QtCore.Signal(str)  # Emits tooltip string from QWidget
+    bec_widget_help = QtCore.Signal(str)  # Emits md formatted help string from BECWidget class
+
+    def __init__(self, parent=None, client=None):
+        super().__init__(client=client, parent=parent, theme_update=True)
+        self._app = QtWidgets.QApplication.instance()
+        layout = QtWidgets.QHBoxLayout(self)  # type: ignore
+        layout.setContentsMargins(0, 0, 0, 0)
+        layout.setSpacing(0)
+
+        self._active = False
+        self._init_ui()
+        self._callbacks = {}
+        # Register the default callbacks
+        self._register_default_callbacks()
+        # Connect the button toggle signal
+        self._button.toggled.connect(self._toggle_mode)
+
+    def _init_ui(self):
+        """Init the UI components."""
+        colors: AccentColors = get_accent_colors()
+        self._button = QtWidgets.QToolButton(self.parent())
+        self._button.setCheckable(True)
+
+        self._icon_checked = partial(
+            material_icon, "help", size=(32, 32), color=colors.highlight, filled=True
+        )
+        self._icon_unchecked = partial(
+            material_icon, "help", size=(32, 32), color=colors.highlight, filled=False
+        )
+        self._button.setText("Help Inspect Tool")
+        self._button.setIcon(self._icon_unchecked())
+        self._button.setToolTip("Click to enter Help Mode")
+        self.layout().addWidget(self._button)
+
+    def apply_theme(self, theme: str) -> None:
+        colors = get_accent_colors()
+        self._icon_checked = partial(
+            material_icon, "help", size=(32, 32), color=colors.highlight, filled=True
+        )
+        self._icon_unchecked = partial(
+            material_icon, "help", size=(32, 32), color=colors.highlight, filled=False
+        )
+        if self._active:
+            self._button.setIcon(self._icon_checked())
+        else:
+            self._button.setIcon(self._icon_unchecked())
+
+    @SafeSlot(bool)
+    def _toggle_mode(self, enabled: bool):
+        """
+        Toggle the help inspection mode.
+
+        Args:
+            enabled (bool): Whether to enable or disable the help inspection mode.
+        """
+        if self._app is None:
+            self._app = QtWidgets.QApplication.instance()
+        self._active = enabled
+        if enabled:
+            self._app.installEventFilter(self)
+            self._button.setIcon(self._icon_checked())
+            QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.CursorShape.WhatsThisCursor)
+        else:
+            self._app.removeEventFilter(self)
+            self._button.setIcon(self._icon_unchecked())
+            self._button.setChecked(False)
+            QtWidgets.QApplication.restoreOverrideCursor()
+
+    def eventFilter(self, obj, event):
+        """
+        Filter events to capture Key_Escape event, and mouse clicks
+        if event filter is active. Any click event on a widget is suppressed, if
+        the Inspector is active, and the registered callbacks are called with
+        the clicked widget as argument.
+
+        Args:
+            obj (QObject): The object that received the event.
+            event (QEvent): The event to filter.
+        """
+        if (
+            event.type() == QtCore.QEvent.KeyPress
+            and event.key() == QtCore.Qt.Key_Escape
+            and self._active
+        ):
+            self._toggle_mode(False)
+            return super().eventFilter(obj, event)
+        if self._active and event.type() == QtCore.QEvent.MouseButtonPress:
+            if event.button() == QtCore.Qt.LeftButton:
+                widget = self._app.widgetAt(event.globalPos())
+                if widget:
+                    if widget is self or self.isAncestorOf(widget):
+                        self._toggle_mode(False)
+                        return True
+                    for cb in self._callbacks.values():
+                        try:
+                            cb(widget)
+                        except Exception as e:
+                            print(f"Error occurred in callback {cb}: {e}")
+                    return True
+        return super().eventFilter(obj, event)
+
+    def register_callback(self, callback: Callable[[QtWidgets.QWidget], None]) -> str:
+        """
+        Register a callback to be called when a widget is inspected.
+        The callback should be callable with the following signature:
+            callback(widget: QWidget) -> None
+
+        Args:
+            callback (Callable[[QWidget], None]): The callback function to register.
+        Returns:
+            str: A unique ID for the registered callback.
+        """
+        cb_id = str(uuid4())
+        self._callbacks[cb_id] = callback
+        return cb_id
+
+    def unregister_callback(self, cb_id: str):
+        """Unregister a previously registered callback."""
+        self._callbacks.pop(cb_id, None)
+
+    def _register_default_callbacks(self):
+        """Default behavior: publish tooltip, docstring, bec_help"""
+
+        def cb_doc(widget: QtWidgets.QWidget):
+            docstring = widget.__doc__ or "No documentation available."
+            self.widget_docstring.emit(docstring)
+
+        def cb_help(widget: QtWidgets.QWidget):
+            tooltip = widget.toolTip() or "No tooltip available."
+            self.widget_tooltip.emit(tooltip)
+
+        def cb_bec_help(widget: QtWidgets.QWidget):
+            help_text = None
+            if hasattr(widget, "get_help_md") and callable(widget.get_help_md):
+                try:
+                    help_text = widget.get_help_md()
+                except Exception as e:
+                    logger.debug(f"Error retrieving help text from {widget}: {e}")
+            if help_text is None:
+                help_text = widget.toolTip() or "No help available."
+            if not isinstance(help_text, str):
+                logger.error(
+                    f"Help text from {widget.__class__} is not a string: {type(help_text)}"
+                )
+                help_text = str(help_text)
+            self.bec_widget_help.emit(help_text)
+
+        self.register_callback(cb_doc)
+        self.register_callback(cb_help)
+        self.register_callback(cb_bec_help)
+
+
+if __name__ == "__main__":
+    import sys
+
+    from bec_qthemes import apply_theme
+
+    from bec_widgets.widgets.control.device_control.positioner_box import PositionerBox
+    from bec_widgets.widgets.utility.visual.dark_mode_button.dark_mode_button import DarkModeButton
+
+    app = QtWidgets.QApplication(sys.argv)
+
+    main_window = QtWidgets.QMainWindow()
+    apply_theme("dark")
+    main_window.setWindowTitle("Help Inspector Test")
+
+    central_widget = QtWidgets.QWidget()
+    main_layout = QtWidgets.QVBoxLayout(central_widget)
+    dark_mode_button = DarkModeButton(parent=main_window)
+    main_layout.addWidget(dark_mode_button)
+
+    help_inspector = HelpInspector()
+    main_layout.addWidget(help_inspector)
+
+    test_button = QtWidgets.QPushButton("Test Button")
+    test_button.setToolTip("This is a test button.")
+    test_line_edit = QtWidgets.QLineEdit()
+    test_line_edit.setToolTip("This is a test line edit.")
+    test_label = QtWidgets.QLabel("Test Label")
+    test_label.setToolTip("")
+    box = PositionerBox()
+
+    layout_1 = QtWidgets.QHBoxLayout()
+    layout_1.addWidget(test_button)
+    layout_1.addWidget(test_line_edit)
+    layout_1.addWidget(test_label)
+    layout_1.addWidget(box)
+    main_layout.addLayout(layout_1)
+
+    doc_label = QtWidgets.QLabel("Docstring will appear here.")
+    tool_tip_label = QtWidgets.QLabel("Tooltip will appear here.")
+    bec_help_label = QtWidgets.QLabel("BEC Help text will appear here.")
+    main_layout.addWidget(doc_label)
+    main_layout.addWidget(tool_tip_label)
+    main_layout.addWidget(bec_help_label)
+
+    help_inspector.widget_tooltip.connect(tool_tip_label.setText)
+    help_inspector.widget_docstring.connect(doc_label.setText)
+    help_inspector.bec_widget_help.connect(bec_help_label.setText)
+
+    main_window.setCentralWidget(central_widget)
+    main_window.resize(400, 200)
+    main_window.show()
+    sys.exit(app.exec())

tests/unit_tests/test_help_inspector.py

@@ -0,0 +1,81 @@
+# pylint: disable=missing-function-docstring, missing-module-docstring, unused-import
+
+import pytest
+from qtpy import QtCore, QtWidgets
+
+from bec_widgets.utils.help_inspector.help_inspector import HelpInspector
+from bec_widgets.widgets.control.buttons.button_abort.button_abort import AbortButton
+
+from .client_mocks import mocked_client
+
+
+@pytest.fixture
+def help_inspector(qtbot, mocked_client):
+    widget = HelpInspector(client=mocked_client)
+    qtbot.addWidget(widget)
+    qtbot.waitExposed(widget)
+    yield widget
+
+
+@pytest.fixture
+def abort_button(qtbot):
+    widget = AbortButton()
+    widget.setToolTip("This is an abort button.")
+
+    def get_help_md():
+        return "This is **markdown** help text for the abort button."
+
+    widget.get_help_md = get_help_md  # type: ignore
+
+    qtbot.addWidget(widget)
+    qtbot.waitExposed(widget)
+
+    yield widget
+
+
+def test_help_inspector_button(help_inspector):
+    """Test the HelpInspector widget."""
+    assert not help_inspector._active
+    help_inspector._button.click()
+    assert help_inspector._active
+    assert help_inspector._button.isChecked()
+    cursor = QtWidgets.QApplication.overrideCursor()
+    assert cursor is not None
+    assert cursor.shape() == QtCore.Qt.CursorShape.WhatsThisCursor
+    help_inspector._button.click()
+    assert not help_inspector._active
+    assert not help_inspector._button.isChecked()
+    assert QtWidgets.QApplication.overrideCursor() is None
+
+
+def test_help_inspector_register_callback(help_inspector):
+    """Test registering a callback in the HelpInspector widget."""
+
+    assert len(help_inspector._callbacks) == 3  # default callbacks
+
+    def my_callback(widget):
+        pass
+
+    cb_id = help_inspector.register_callback(my_callback)
+    assert len(help_inspector._callbacks) == 4
+    assert help_inspector._callbacks[cb_id] == my_callback
+
+    cb_id2 = help_inspector.register_callback(my_callback)
+    assert len(help_inspector._callbacks) == 5
+    assert help_inspector._callbacks[cb_id2] == my_callback
+
+    help_inspector.unregister_callback(cb_id)
+    assert len(help_inspector._callbacks) == 4
+
+    help_inspector.unregister_callback(cb_id2)
+    assert len(help_inspector._callbacks) == 3
+
+
+def test_help_inspector_escape_key(qtbot, help_inspector):
+    """Test that pressing the Escape key deactivates the HelpInspector."""
+    help_inspector._button.click()
+    assert help_inspector._active
+    qtbot.keyClick(help_inspector, QtCore.Qt.Key.Key_Escape)
+    assert not help_inspector._active
+    assert not help_inspector._button.isChecked()
+    assert QtWidgets.QApplication.overrideCursor() is None