fix(mouse scroll): scroll the frame, do not change the combobox values if the comboboxes are not open

Author: amilcarlucas

ardupilot_methodic_configurator/frontend_tkinter_parameter_editor_table.py

@@ -16,7 +16,7 @@
 from platform import system as platform_system
 from sys import exit as sys_exit
 from tkinter import messagebox, ttk
-from typing import Union
+from typing import Optional, Union
 
 from ardupilot_methodic_configurator import _
 from ardupilot_methodic_configurator.annotate_params import Par
@@ -358,6 +358,37 @@ def _update_combobox_style_on_selection(  # pylint: disable=too-many-arguments,
         event.width = NEW_VALUE_WIDGET_WIDTH
         combobox_widget.on_combo_configure(event)
 
+    def _setup_combobox_mousewheel_handling(self, combobox: PairTupleCombobox) -> None:
+        """Set up mouse wheel handling for combobox to prevent unwanted value changes."""
+
+        # Prevent mouse wheel from changing value when dropdown is not open
+        def handle_mousewheel(_event: tk.Event, widget: tk.Widget = combobox) -> Optional[str]:
+            # Check if dropdown is open by examining the combobox's state
+            dropdown_is_open = getattr(widget, "dropdown_is_open", False)
+            if not dropdown_is_open:
+                widget.master.event_generate("<MouseWheel>", delta=_event.delta)
+                return "break"  # Prevent default behavior
+            return None  # Allow default behavior when dropdown is open
+
+        # Set flag when dropdown opens or closes
+        def dropdown_opened(_event: tk.Event, widget: tk.Widget = combobox) -> None:
+            widget.dropdown_is_open = True  # type: ignore[attr-defined]
+
+        def dropdown_closed(_event: tk.Event, widget: tk.Widget = combobox) -> None:
+            widget.dropdown_is_open = False  # type: ignore[attr-defined]
+
+        # Initialize the flag
+        combobox.dropdown_is_open = False  # type: ignore[attr-defined]
+
+        # Bind to events for dropdown opening and closing
+        combobox.bind("<<ComboboxDropdown>>", dropdown_opened)
+        combobox.bind("<FocusOut>", dropdown_closed, "+")
+
+        # Bind mouse wheel events
+        combobox.bind("<MouseWheel>", handle_mousewheel)  # Windows mouse wheel
+        combobox.bind("<Button-4>", handle_mousewheel)  # Linux mouse wheel up
+        combobox.bind("<Button-5>", handle_mousewheel)  # Linux mouse wheel down
+
     @staticmethod
     def _update_new_value_entry_text(new_value_entry: ttk.Entry, param: ArduPilotParameter) -> None:
         """Update the new value entry text and style."""
@@ -409,6 +440,9 @@ def _create_new_value_entry(  # pylint: disable=too-many-statements # noqa: PLR0
                 ),
                 "+",
             )
+
+            # Set up mouse wheel handling to prevent unwanted value changes
+            self._setup_combobox_mousewheel_handling(new_value_entry)
         else:
             new_value_entry = ttk.Entry(self.view_port, width=NEW_VALUE_WIDGET_WIDTH + 1, justify=tk.RIGHT)
             self._update_new_value_entry_text(new_value_entry, param)

tests/test_frontend_tkinter_parameter_editor_table.py

@@ -899,3 +899,125 @@ def test_gui_complexity_affects_complete_workflow(self, parameter_editor_table:
             parameter_editor_table._should_show_upload_column()
         )
         assert column_index_advanced == 7
+
+
+class TestMousewheelHandlingBehavior:
+    """Test mousewheel handling behavior for comboboxes."""
+
+    def test_setup_combobox_mousewheel_handling(self, parameter_editor_table: ParameterEditorTable) -> None:
+        """Test that mousewheel handling is properly set up for comboboxes."""
+        # Create a mock PairTupleCombobox
+        mock_combobox = MagicMock(spec=PairTupleCombobox)
+
+        # Call the mousewheel setup method
+        parameter_editor_table._setup_combobox_mousewheel_handling(mock_combobox)
+
+        # Verify that the dropdown_is_open flag is initialized
+        assert hasattr(mock_combobox, "dropdown_is_open")
+
+        # Verify that the required event bindings are set up
+        expected_bindings = [
+            ("<<ComboboxDropdown>>",),
+            ("<FocusOut>",),
+            ("<MouseWheel>",),
+            ("<Button-4>",),
+            ("<Button-5>",),
+        ]
+
+        bind_calls = mock_combobox.bind.call_args_list
+        for expected_binding in expected_bindings:
+            assert any(call.args[0] == expected_binding[0] for call in bind_calls), f"Binding {expected_binding[0]} not found"
+
+    def test_mousewheel_handler_when_dropdown_closed(self, parameter_editor_table: ParameterEditorTable) -> None:
+        """Test mousewheel behavior when dropdown is closed."""
+        with patch("tkinter.Tk"):
+            mock_combobox = MagicMock(spec=PairTupleCombobox)
+            mock_master = MagicMock()
+            mock_combobox.master = mock_master
+            mock_combobox.dropdown_is_open = False
+
+            # Set up mousewheel handling
+            parameter_editor_table._setup_combobox_mousewheel_handling(mock_combobox)
+
+            # Get the mousewheel handler from the bind calls
+            mousewheel_bind_call = None
+            for call in mock_combobox.bind.call_args_list:
+                if call[0][0] == "<MouseWheel>":
+                    mousewheel_bind_call = call
+                    break
+
+            assert mousewheel_bind_call is not None, "MouseWheel binding not found"
+
+            # Simulate a mousewheel event when dropdown is closed
+            handler = mousewheel_bind_call[0][1]
+            mock_event = MagicMock()
+            mock_event.delta = 120
+
+            result = handler(mock_event)
+
+            # Should return "break" and generate event on master
+            assert result == "break"
+            mock_master.event_generate.assert_called_once_with("<MouseWheel>", delta=120)
+
+    def test_mousewheel_handler_when_dropdown_open(self, parameter_editor_table: ParameterEditorTable) -> None:
+        """Test mousewheel behavior when dropdown is open."""
+        with patch("tkinter.Tk"):
+            mock_combobox = MagicMock(spec=PairTupleCombobox)
+            mock_master = MagicMock()
+            mock_combobox.master = mock_master
+
+            # Set up mousewheel handling first
+            parameter_editor_table._setup_combobox_mousewheel_handling(mock_combobox)
+
+            # Now set dropdown as open after the handler is set up
+            mock_combobox.dropdown_is_open = True
+
+            # Get the mousewheel handler from the bind calls
+            mousewheel_bind_call = None
+            for call in mock_combobox.bind.call_args_list:
+                if call[0][0] == "<MouseWheel>":
+                    mousewheel_bind_call = call
+                    break
+
+            assert mousewheel_bind_call is not None, "MouseWheel binding not found"
+
+            # Simulate a mousewheel event when dropdown is open
+            handler = mousewheel_bind_call[0][1]
+            mock_event = MagicMock()
+            mock_event.delta = 120
+
+            result = handler(mock_event)
+
+            # Should return None and not generate event on master
+            assert result is None
+            mock_master.event_generate.assert_not_called()
+
+    def test_dropdown_state_management(self, parameter_editor_table: ParameterEditorTable) -> None:
+        """Test that dropdown state is properly managed."""
+        with patch("tkinter.Tk"):
+            mock_combobox = MagicMock(spec=PairTupleCombobox)
+
+            # Set up mousewheel handling
+            parameter_editor_table._setup_combobox_mousewheel_handling(mock_combobox)
+
+            # Find the dropdown opened and closed handlers
+            dropdown_opened_handler = None
+            dropdown_closed_handler = None
+
+            for call in mock_combobox.bind.call_args_list:
+                if call[0][0] == "<<ComboboxDropdown>>":
+                    dropdown_opened_handler = call[0][1]
+                elif call[0][0] == "<FocusOut>":
+                    dropdown_closed_handler = call[0][1]
+
+            assert dropdown_opened_handler is not None, "ComboboxDropdown handler not found"
+            assert dropdown_closed_handler is not None, "FocusOut handler not found"
+
+            # Test dropdown opened
+            mock_event = MagicMock()
+            dropdown_opened_handler(mock_event)
+            assert mock_combobox.dropdown_is_open is True
+
+            # Test dropdown closed
+            dropdown_closed_handler(mock_event)
+            assert mock_combobox.dropdown_is_open is False