feat: complete controller-first menu navigation

ui/controller_focus_recovery.gd

@@ -0,0 +1,142 @@
+class_name ControllerFocusRecovery
+extends Node
+
+const CONTROLLER_AXIS_THRESHOLD: float = 0.35
+const SEMANTIC_MATCH_BONUS: float = 1000000.0
+
+var _controller_active: bool = false
+var _last_focus_center: Vector2 = Vector2.ZERO
+var _last_focus_key: String = ""
+var _scope_chain: Array[WeakRef] = []
+var _recovery_generation: int = 0
+
+
+func _ready() -> void:
+	set_process_input(true)
+	set_process(true)
+	get_viewport().gui_focus_changed.connect(_on_gui_focus_changed)
+
+
+func _exit_tree() -> void:
+	var viewport := get_viewport()
+	if viewport.gui_focus_changed.is_connected(_on_gui_focus_changed):
+		viewport.gui_focus_changed.disconnect(_on_gui_focus_changed)
+
+
+func _input(event: InputEvent) -> void:
+	if event is InputEventJoypadButton:
+		var button_event := event as InputEventJoypadButton
+		if button_event.pressed:
+			_controller_active = true
+			if button_event.button_index == JOY_BUTTON_LEFT_SHOULDER:
+				_recovery_generation += 1
+				_scope_chain.clear()
+		return
+	if event is InputEventJoypadMotion:
+		if absf((event as InputEventJoypadMotion).axis_value) >= (
+			CONTROLLER_AXIS_THRESHOLD
+		):
+			_controller_active = true
+		return
+	if event is InputEventMouseButton:
+		if (event as InputEventMouseButton).pressed:
+			_controller_active = false
+		return
+	if event is InputEventKey and (event as InputEventKey).pressed:
+		_controller_active = false
+
+
+func _process(_delta: float) -> void:
+	if (
+		_controller_active
+		and not _scope_chain.is_empty()
+		and get_viewport().gui_get_focus_owner() == null
+	):
+		_recover_focus(_recovery_generation)
+
+
+func _on_gui_focus_changed(control: Control) -> void:
+	_recovery_generation += 1
+	if control != null:
+		if _controller_active and control is BaseButton:
+			_remember_focus(control)
+		return
+	if not _controller_active or _scope_chain.is_empty():
+		return
+	var generation: int = _recovery_generation
+	_recover_focus.call_deferred(generation)
+
+
+func _remember_focus(control: Control) -> void:
+	_last_focus_center = control.get_global_rect().get_center()
+	_last_focus_key = _semantic_key(control)
+	_scope_chain.clear()
+	var recovery_root: Node = get_parent()
+	var ancestor: Node = control.get_parent()
+	while ancestor != null:
+		if ancestor is Control:
+			_scope_chain.append(weakref(ancestor))
+		if ancestor == recovery_root:
+			break
+		ancestor = ancestor.get_parent()
+
+
+func _recover_focus(generation: int) -> void:
+	if generation != _recovery_generation:
+		return
+	if not _controller_active or get_viewport().gui_get_focus_owner() != null:
+		return
+	for scope_reference: WeakRef in _scope_chain:
+		var scope := scope_reference.get_ref() as Control
+		if (
+			scope == null
+			or not is_instance_valid(scope)
+			or not scope.is_inside_tree()
+			or not scope.is_visible_in_tree()
+		):
+			continue
+		var replacement := _best_replacement_in(scope)
+		if replacement != null:
+			replacement.grab_focus()
+			return
+
+
+func _best_replacement_in(scope: Control) -> Control:
+	var best: Control = null
+	var best_score: float = INF
+	for node: Node in scope.find_children("*", "Control", true, false):
+		var candidate := node as Control
+		if not _is_focusable(candidate):
+			continue
+		var distance: float = candidate.get_global_rect().get_center().distance_squared_to(
+			_last_focus_center
+		)
+		if not _last_focus_key.is_empty() and _semantic_key(candidate) == _last_focus_key:
+			distance -= SEMANTIC_MATCH_BONUS
+		if distance < best_score:
+			best = candidate
+			best_score = distance
+	return best
+
+
+func _is_focusable(control: Control) -> bool:
+	if (
+		control == null
+		or not control.is_inside_tree()
+		or not control.is_visible_in_tree()
+		or control.focus_mode == Control.FOCUS_NONE
+	):
+		return false
+	var button := control as BaseButton
+	return button == null or not button.disabled
+
+
+func _semantic_key(control: Control) -> String:
+	if control.has_meta(&"controller_focus_key"):
+		return str(control.get_meta(&"controller_focus_key"))
+	var button := control as Button
+	var label: String = button.text if button != null else ""
+	var tooltip: String = control.tooltip_text
+	tooltip = tooltip.trim_suffix(" (show variants)")
+	tooltip = tooltip.trim_suffix(" (hide variants)")
+	return "%s|%s|%s" % [control.get_class(), label, tooltip]