Add autofocus mode.

internal/app/browser_mode_test.go

@@ -753,3 +753,56 @@ func TestStickyBrowserModeSurvivesNavigationChromeAndWindowSuspension(t *testing
 		}
 	}
 }
+
+func TestStructuralNavigationAutomaticFocus(t *testing.T) {
+	for _, tc := range []struct {
+		name, role   string
+		enabled      bool
+		origin       review.NavigationOrigin
+		sticky, want review.DocumentMode
+	}{
+		{name: "default entry", role: "entry", want: review.BrowseMode},
+		{name: "entry opt in", role: "entry", enabled: true, want: review.FocusMode},
+		{name: "combo opt in", role: "combo box", enabled: true, want: review.FocusMode},
+		{name: "heading stays browse", role: "heading", enabled: true, want: review.BrowseMode},
+		{name: "link stays browse", role: "link", enabled: true, want: review.BrowseMode},
+		{name: "sticky browse", role: "entry", enabled: true, sticky: review.BrowseMode, want: review.BrowseMode},
+		{name: "sticky focus", role: "heading", enabled: true, sticky: review.FocusMode, want: review.FocusMode},
+		{name: "caret unchanged", role: "entry", enabled: true, origin: review.CaretNavigation, want: review.BrowseMode},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			keys := &modeKeys{}
+			browser := newBrowserModeController(nil, keys, nil)
+			browser.settings = func() review.ModeSettings {
+				settings := review.DefaultModeSettings()
+				settings.StructuralTriggersFocus = tc.enabled
+				return settings
+			}
+			owner := modeContext(t, tc.role, false)
+			browser.stickyModes[owner.TopLevel.ID().BusName] = tc.sticky
+			origin := tc.origin
+			if origin == review.NativeNavigation {
+				origin = review.StructuralNavigation
+			}
+			result := review.Result{DocumentPosition: review.DocumentPosition{Document: owner.TopLevel, Snapshot: owner.Ancestors[0], Origin: origin}, DocumentCaretContext: owner.Ancestors}
+			queue := &fakeSpeechQueue{spoken: make(chan string, 4)}
+			browser.navigated(result.DocumentPosition, owner.TopLevel.ID())
+			browser.navigationMode(result, queue)
+			if browser.mode != tc.want || keys.enabled != (tc.want == review.BrowseMode) {
+				t.Fatalf("mode=%v browse keys=%t, want %v", browser.mode, keys.enabled, tc.want)
+			}
+			if tc.want == review.FocusMode && tc.sticky == review.InactiveMode {
+				select {
+				case message := <-queue.spoken:
+					if message != "Focus mode" {
+						t.Fatalf("announcement=%q", message)
+					}
+				default:
+					t.Fatal("missing focus mode announcement")
+				}
+			} else if len(queue.spoken) != 0 {
+				t.Fatal("unnecessary mode announcement")
+			}
+		})
+	}
+}