Add autofocus mode.

internal/app/browser_mode.go

@@ -32,6 +32,7 @@ type browserModeResult struct {
 // The event loop owns policy. One joined worker resolves only the latest focus;
 // a generation check rejects results overtaken by another focus or caret event.
 type browserModeController struct {
+	settings           func() review.ModeSettings
 	source             any
 	keys               browseKeyOwner
 	capturer           documentContextCapturer
@@ -228,9 +229,30 @@ func (browser *browserModeController) accept(result browserModeResult, speech sp
 	browser.ready = true
 	modeInput := runtimeModeInput(result.owner)
 	modeInput.Origin = result.origin
-	mode := browser.state.Update(modeInput, review.DefaultModeSettings())
+	mode := browser.state.Update(modeInput, browser.modeSettings())
 	browser.set(mode, speech, false)
 }
+func (browser *browserModeController) modeSettings() review.ModeSettings {
+	if browser.settings != nil {
+		return browser.settings()
+	}
+	return review.DefaultModeSettings()
+}
+
+// The review worker supplies the target's owned ancestry from the same
+// document used for navigation. No accessibility calls run on the event loop.
+func (browser *browserModeController) navigationMode(result review.Result, speech speechEnqueuer) {
+	settings := browser.modeSettings()
+	if result.DocumentPosition.Origin != review.StructuralNavigation || !settings.StructuralTriggersFocus {
+		return
+	}
+	owner := atspi.DocumentContext{Document: result.DocumentPosition.Document, TopLevel: result.DocumentPosition.Document, Ancestors: result.DocumentCaretContext}
+	modeInput := runtimeModeInput(owner)
+	modeInput.Origin = review.StructuralNavigation
+	mode := browser.state.Update(modeInput, settings)
+	browser.set(mode, speech, false)
+}
+
 func (browser *browserModeController) set(mode review.DocumentMode, speech speechEnqueuer, manual bool) {
 	previous := browser.mode
 	browser.mode = mode