[a11y] Make CommandPalette announce selected item (#13519)

## Summary of the Pull Request The command palette (and tab search by extension) doesn't ever tell screen readers what is selected. Here, we simply hook up the selection changed event to a function that tells the screen reader what is selected. With this, the user no longer has to tab into the list view to know what is selected! Will resolve the following bug upon validation from a11y team: #12065 ## Validation Steps Performed Performed repro steps from #12065. NOTE: we do NOT read the selected item when the command palette is first opened. I think that's ok.
microsoft · Aug 26, 2022 · deb5e7c · deb5e7c
1 parent 623a59e
commit deb5e7c
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diff --git a/src/cascadia/TerminalApp/CommandPalette.cpp b/src/cascadia/TerminalApp/CommandPalette.cpp
@@ -530,6 +530,34 @@ namespace winrt::TerminalApp::implementation
         }
     }
 
+    void CommandPalette::_listItemSelectionChanged(const Windows::Foundation::IInspectable& /*sender*/, const Windows::UI::Xaml::Controls::SelectionChangedEventArgs& e)
+    {
+        // We don't care about...
+        // - CommandlineMode: it doesn't have any selectable items in the list view
+        // - TabSwitchMode: focus and selected item are in sync
+        if (_currentMode == CommandPaletteMode::ActionMode || _currentMode == CommandPaletteMode::TabSearchMode)
+        {
+            if (auto automationPeer{ Automation::Peers::FrameworkElementAutomationPeer::FromElement(_searchBox()) })
+            {
+                if (const auto selectedList = e.AddedItems(); selectedList.Size() > 0)
+                {
+                    const auto selectedCommand = selectedList.GetAt(0);
+                    if (const auto filteredCmd = selectedCommand.try_as<TerminalApp::FilteredCommand>())
+                    {
+                        if (const auto paletteItem = filteredCmd.Item().try_as<TerminalApp::PaletteItem>())
+                        {
+                            automationPeer.RaiseNotificationEvent(
+                                Automation::Peers::AutomationNotificationKind::ItemAdded,
+                                Automation::Peers::AutomationNotificationProcessing::MostRecent,
+                                paletteItem.Name() + L" " + paletteItem.KeyChordText(),
+                                L"CommandPaletteSelectedItemChanged" /* unique name for this notification category */);
+                        }
+                    }
+                }
+            }
+        }
+    }
+
     // Method Description:
     // This event is called when the user clicks on a ChevronLeft button right
     // next to the ParentCommandName (e.g. New Tab...) above the subcommands list.

diff --git a/src/cascadia/TerminalApp/CommandPalette.h b/src/cascadia/TerminalApp/CommandPalette.h
@@ -92,6 +92,8 @@ namespace winrt::TerminalApp::implementation
 
         void _listItemClicked(const Windows::Foundation::IInspectable& sender, const Windows::UI::Xaml::Controls::ItemClickEventArgs& e);
 
+        void _listItemSelectionChanged(const Windows::Foundation::IInspectable& sender, const Windows::UI::Xaml::Controls::SelectionChangedEventArgs& e);
+
         void _moveBackButtonClicked(const Windows::Foundation::IInspectable& sender, const Windows::UI::Xaml::RoutedEventArgs&);
 
         void _updateFilteredActions();

diff --git a/src/cascadia/TerminalApp/CommandPalette.xaml b/src/cascadia/TerminalApp/CommandPalette.xaml
@@ -402,6 +402,7 @@
                       IsItemClickEnabled="True"
                       ItemClick="_listItemClicked"
                       ItemsSource="{x:Bind FilteredActions}"
+                      SelectionChanged="_listItemSelectionChanged"
                       SelectionMode="Single" />
 
         </Grid>