Enable keyboard on_activate in Table and Tree

changes/3781.feature.rst

@@ -0,0 +1 @@
+Table and Tree widgets on desktop platforms will invoke `on_activate` when the Enter key is pressed and a single row/node is selected.

cocoa/src/toga_cocoa/widgets/table.py

@@ -2,6 +2,8 @@
 from travertino.size import at_least
 
 import toga
+from toga.keys import Key
+from toga_cocoa.keys import toga_key
 from toga_cocoa.libs import (
     NSBezelBorder,
     NSIndexSet,
@@ -125,9 +127,19 @@ def tableViewSelectionDidChange_(self, notification) -> None:
     @objc_method
     def onDoubleClick_(self, sender) -> None:
         clicked = self.interface.data[self.clickedRow]
-
         self.interface.on_activate(row=clicked)
 
+    @objc_method
+    def performKeyEquivalent_(self, event) -> bool:
+        if self.impl.has_focus:
+            key = toga_key(event)
+            if key["key"] in {Key.ENTER, Key.NUMPAD_ENTER} and not key["modifiers"]:
+                row = self.interface._selection_single
+                if row is not None:
+                    self.interface.on_activate(row=row)
+                    return True
+        return False
+
 
 class Table(Widget):
     def create(self):
@@ -172,6 +184,13 @@ def create(self):
         # Add the layout constraints
         self.add_constraints()
 
+    @property
+    def has_focus(self):
+        return (
+            self.native.window is not None
+            and self.native.window.firstResponder == self.native_table
+        )
+
     def change_source(self, source):
         self.native_table.reloadData()
 

cocoa/src/toga_cocoa/widgets/tree.py

@@ -2,6 +2,8 @@
 from travertino.size import at_least
 
 import toga
+from toga.keys import Key
+from toga_cocoa.keys import toga_key
 from toga_cocoa.libs import (
     NSBezelBorder,
     NSIndexSet,
@@ -169,6 +171,17 @@ def onDoubleClick_(self, sender) -> None:
         node = self.itemAtRow(self.clickedRow).attrs["node"]
         self.interface.on_activate(node=node)
 
+    @objc_method
+    def performKeyEquivalent_(self, event) -> bool:
+        if self.impl.has_focus:
+            key = toga_key(event)
+            if key["key"] in {Key.ENTER, Key.NUMPAD_ENTER} and not key["modifiers"]:
+                node = self.interface._selection_single
+                if node is not None:
+                    self.interface.on_activate(node=node)
+                    return True
+        return False
+
 
 class Tree(Widget):
     def create(self):
@@ -216,6 +229,13 @@ def create(self):
         # Add the layout constraints
         self.add_constraints()
 
+    @property
+    def has_focus(self):
+        return (
+            self.native.window is not None
+            and self.native.window.firstResponder == self.native_tree
+        )
+
     def change_source(self, source):
         self.native_tree.reloadData()
 

cocoa/tests_backend/widgets/tree.py

@@ -13,6 +13,7 @@
 class TreeProbe(SimpleProbe):
     native_class = NSScrollView
     supports_keyboard_shortcuts = True
+    supports_keyboard_boundary_shortcuts = False
     supports_widgets = True
 
     def __init__(self, widget):
@@ -184,3 +185,8 @@ async def activate_row(self, row_path):
             delay=0.1,
             clickCount=2,
         )
+
+    async def select_first_row_keyboard(self):
+        # Use the keyboard to ensure first row is selected.
+        await self.type_character("<down>")
+        await self.type_character("<up>")

core/src/toga/widgets/table.py

@@ -174,6 +174,22 @@ def selection(self) -> list[Row] | Row | None:
         else:
             return self.data[selection]
 
+    @property
+    def _selection_single(self) -> Row | None:
+        """The currently selected row of the table.
+
+        Returns :any:`None` if no row is currently selected, or if multiple rows are
+        selected.
+        """
+        selection = self.selection
+        if self.multiple_select:
+            if len(selection) == 1:
+                return selection[0]
+            else:
+                return None
+        else:
+            return selection
+
     def scroll_to_top(self) -> None:
         """Scroll the view so that the top of the list (first row) is visible."""
         self.scroll_to_row(0)

core/src/toga/widgets/tree.py

@@ -166,6 +166,22 @@ def selection(self) -> list[Node] | Node | None:
         """
         return self._impl.get_selection()
 
+    @property
+    def _selection_single(self) -> Node | None:
+        """The currently selected node of the tree.
+
+        Returns :any:`None` if no node is currently selected, or if multiple nodes are
+        selected.
+        """
+        selection = self.selection
+        if self.multiple_select:
+            if len(selection) == 1:
+                return selection[0]
+            else:
+                return None
+        else:
+            return selection
+
     def expand(self, node: Node | None = None) -> None:
         """Expand the specified node of the tree.
 

core/tests/widgets/test_table.py

@@ -219,6 +219,7 @@ def test_single_selection(table, on_select_handler):
     """The current selection can be retrieved."""
     # Selection is initially empty
     assert table.selection is None
+    assert table._selection_single is None
     on_select_handler.assert_not_called()
 
     # Select an item
@@ -227,6 +228,9 @@ def test_single_selection(table, on_select_handler):
     # Selection returns a single row
     assert table.selection == table.data[1]
 
+    # _selection_single returns a single row
+    assert table._selection_single == table.data[1]
+
     # Selection handler was triggered
     on_select_handler.assert_called_once_with(table)
 
@@ -241,14 +245,31 @@ def test_multiple_selection(source, on_select_handler):
     )
     # Selection is initially empty
     assert table.selection == []
+    assert table._selection_single is None
     on_select_handler.assert_not_called()
 
     # Select an item
+    table._impl.simulate_selection([2])
+
+    # Selection returns a list of rows
+    assert table.selection == [table.data[2]]
+
+    # _selection_single a single item
+    assert table._selection_single is table.data[2]
+
+    # Selection handler was triggered
+    on_select_handler.assert_called_once_with(table)
+    on_select_handler.reset_mock()
+
+    # Select multiple items
     table._impl.simulate_selection([0, 2])
 
     # Selection returns a list of rows
     assert table.selection == [table.data[0], table.data[2]]
 
+    # _selection_single returns None
+    assert table._selection_single is None
+
     # Selection handler was triggered
     on_select_handler.assert_called_once_with(table)
 

core/tests/widgets/test_tree.py

@@ -265,6 +265,7 @@ def test_single_selection(tree, on_select_handler):
     """The current selection can be retrieved."""
     # Selection is initially empty
     assert tree.selection is None
+    assert tree._selection_single is None
     on_select_handler.assert_not_called()
 
     # Select an item
@@ -273,6 +274,9 @@ def test_single_selection(tree, on_select_handler):
     # Selection returns a single row
     assert tree.selection == tree.data[0][1]
 
+    # _selection_single returns a single node
+    assert tree._selection_single == tree.data[0][1]
+
     # Selection handler was triggered
     on_select_handler.assert_called_once_with(tree)
 
@@ -287,14 +291,31 @@ def test_multiple_selection(source, on_select_handler):
     )
     # Selection is initially empty
     assert tree.selection == []
+    assert tree._selection_single is None
     on_select_handler.assert_not_called()
 
     # Select an item
+    tree._impl.simulate_selection([(1, 2, 1)])
+
+    # Selection returns a list of rows
+    assert tree.selection == [tree.data[1][2][1]]
+
+    # _selection_single returns a single item
+    assert tree._selection_single == tree.data[1][2][1]
+
+    # Selection handler was triggered
+    on_select_handler.assert_called_once_with(tree)
+    on_select_handler.reset_mock()
+
+    # Select multiple items
     tree._impl.simulate_selection([(0, 1), (1, 2, 1)])
 
     # Selection returns a list of rows
     assert tree.selection == [tree.data[0][1], tree.data[1][2][1]]
 
+    # _selection_single returns None
+    assert tree._selection_single is None
+
     # Selection handler was triggered
     on_select_handler.assert_called_once_with(tree)
 

gtk/tests_backend/widgets/tree.py

@@ -104,3 +104,6 @@ async def activate_row(self, row_path):
             Gtk.TreePath(row_path),
             self.native_tree.get_columns()[0],
         )
+
+    async def select_first_row_keyboard(self):
+        pytest.skip("test not implemented for this platform")