feat(widget_state_manager): state manager for single widget

bec_widgets/utils/widget_state_manager.py

@@ -0,0 +1,91 @@
+from __future__ import annotations
+
+from qtpy.QtCore import QSettings
+from qtpy.QtWidgets import QFileDialog, QWidget
+
+
+class WidgetStateManager:
+    """
+    A class to manage the state of a widget by saving and loading the state to and from a INI file.
+
+    Args:
+        widget(QWidget): The widget to manage the state for.
+    """
+
+    def __init__(self, widget):
+        self.widget = widget
+
+    def save_state(self, filename: str = None):
+        """
+        Save the state of the widget to a INI file.
+
+        Args:
+            filename(str): The filename to save the state to.
+        """
+        if not filename:
+            filename, _ = QFileDialog.getSaveFileName(
+                self.widget, "Save Settings", "", "INI Files (*.ini)"
+            )
+        if filename:
+            settings = QSettings(filename, QSettings.IniFormat)
+            self._save_widget_state_qsettings(self.widget, settings)
+
+    def load_state(self, filename: str = None):
+        """
+        Load the state of the widget from a INI file.
+
+        Args:
+            filename(str): The filename to load the state from.
+        """
+        if not filename:
+            filename, _ = QFileDialog.getOpenFileName(
+                self.widget, "Load Settings", "", "INI Files (*.ini)"
+            )
+        if filename:
+            settings = QSettings(filename, QSettings.IniFormat)
+            self._load_widget_state_qsettings(self.widget, settings)
+
+    def _save_widget_state_qsettings(self, widget: QWidget, settings: QSettings):
+        """
+        Save the state of the widget to QSettings.
+
+        Args:
+            widget(QWidget): The widget to save the state for.
+            settings(QSettings): The QSettings object to save the state to.
+        """
+        meta = widget.metaObject()
+        settings.beginGroup(widget.objectName())
+        for i in range(meta.propertyCount()):
+            prop = meta.property(i)
+            name = prop.name()
+            value = widget.property(name)
+            settings.setValue(name, value)
+        settings.endGroup()
+
+        # Recursively save child widgets
+        for child in widget.findChildren(QWidget):
+            if child.objectName():
+                self._save_widget_state_qsettings(child, settings)
+
+    def _load_widget_state_qsettings(self, widget: QWidget, settings: QSettings):
+        """
+        Load the state of the widget from QSettings.
+
+        Args:
+            widget(QWidget): The widget to load the state for.
+            settings(QSettings): The QSettings object to load the state from.
+        """
+        meta = widget.metaObject()
+        settings.beginGroup(widget.objectName())
+        for i in range(meta.propertyCount()):
+            prop = meta.property(i)
+            name = prop.name()
+            if settings.contains(name):
+                value = settings.value(name)
+                widget.setProperty(name, value)
+        settings.endGroup()
+
+        # Recursively load child widgets
+        for child in widget.findChildren(QWidget):
+            if child.objectName():
+                self._load_widget_state_qsettings(child, settings)

tests/unit_tests/test_widget_state_manager.py

@@ -0,0 +1,135 @@
+import os
+import tempfile
+
+import pytest
+from qtpy.QtCore import Property
+from qtpy.QtWidgets import QLineEdit, QVBoxLayout, QWidget
+
+from bec_widgets.utils.widget_state_manager import WidgetStateManager
+
+
+class MyLineEdit(QLineEdit):
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        # Internal attribute to hold the color string
+        self._customColor = ""
+
+    @Property(str)
+    def customColor(self):
+        return self._customColor
+
+    @customColor.setter
+    def customColor(self, color):
+        self._customColor = color
+
+
+@pytest.fixture
+def test_widget(qtbot):
+    w = QWidget()
+    w.setObjectName("MainWidget")
+    layout = QVBoxLayout(w)
+
+    child1 = MyLineEdit(w)
+    child1.setObjectName("ChildLineEdit1")
+    child1.setText("Hello")
+    child1.customColor = "red"
+
+    child2 = MyLineEdit(w)
+    child2.setObjectName("ChildLineEdit2")
+    child2.setText("World")
+    child2.customColor = "blue"
+
+    layout.addWidget(child1)
+    layout.addWidget(child2)
+
+    qtbot.addWidget(w)
+    qtbot.waitExposed(w)
+    return w
+
+
+def test_save_load_widget_state(test_widget):
+    """
+    Test saving and loading the state
+    """
+
+    manager = WidgetStateManager(test_widget)
+
+    # Before saving, confirm initial properties
+    child1 = test_widget.findChild(MyLineEdit, "ChildLineEdit1")
+    child2 = test_widget.findChild(MyLineEdit, "ChildLineEdit2")
+    assert child1.text() == "Hello"
+    assert child1.customColor == "red"
+    assert child2.text() == "World"
+    assert child2.customColor == "blue"
+
+    # Create a temporary file to save settings
+    with tempfile.NamedTemporaryFile(delete=False, suffix=".ini") as tmp_file:
+        tmp_filename = tmp_file.name
+
+    # Save the current state
+    manager.save_state(tmp_filename)
+
+    # Modify the widget properties
+    child1.setText("Changed1")
+    child1.customColor = "green"
+    child2.setText("Changed2")
+    child2.customColor = "yellow"
+
+    assert child1.text() == "Changed1"
+    assert child1.customColor == "green"
+    assert child2.text() == "Changed2"
+    assert child2.customColor == "yellow"
+
+    # Load the previous state
+    manager.load_state(tmp_filename)
+
+    # Confirm that the state has been restored
+    assert child1.text() == "Hello"
+    assert child1.customColor == "red"
+    assert child2.text() == "World"
+    assert child2.customColor == "blue"
+
+    # Clean up temporary file
+    os.remove(tmp_filename)
+
+
+def test_save_load_without_filename(test_widget, monkeypatch, qtbot):
+    """
+    Test that the dialog would open if filename is not provided.
+    """
+
+    manager = WidgetStateManager(test_widget)
+
+    # Mock QFileDialog.getSaveFileName to return a temporary filename
+    with tempfile.NamedTemporaryFile(delete=False, suffix=".ini") as tmp_file:
+        tmp_filename = tmp_file.name
+
+    def mock_getSaveFileName(*args, **kwargs):
+        return tmp_filename, "INI Files (*.ini)"
+
+    def mock_getOpenFileName(*args, **kwargs):
+        return tmp_filename, "INI Files (*.ini)"
+
+    from qtpy.QtWidgets import QFileDialog
+
+    monkeypatch.setattr(QFileDialog, "getSaveFileName", mock_getSaveFileName)
+    monkeypatch.setattr(QFileDialog, "getOpenFileName", mock_getOpenFileName)
+
+    # Initial values
+    child1 = test_widget.findChild(MyLineEdit, "ChildLineEdit1")
+    assert child1.text() == "Hello"
+
+    # Save state without providing filename -> uses dialog mock
+    manager.save_state()
+
+    # Change property
+    child1.setText("Modified")
+
+    # Load state using dialog mock
+    manager.load_state()
+
+    # State should be restored
+    assert child1.text() == "Hello"
+
+    # Clean up
+    os.remove(tmp_filename)