A Custom Action Based Level will rely on the UIAccessibilityCustomAction concept, we expect that, for each levelAction attach to some randomly generated view (see component description in the Rotor Levels chapter), the user will select the correct action (decided by the validActions field) :
class SearchLevel: Level { let levelDescription: String
let levelActions: [(description: String, actions: [String], results: [String])]
init?(
levelDescription: String,
levelActions: [(description: String, actions: [String], results: [String])], validActions: [String]
){
let actions = levelActions.map { $0.actions } let results = levelActions.map { $0.results }
guard actions.count == results.count else { return nil
}
guard actions.count == validActions.count else {
return nil }
self.levelDescription = levelDescription self.levelActions = levelActions
super.init(answers: [], validAnswers: validActions) }
}
Additionally, we will announce a result message to the user (either some success or failure announcement, e.g. “Well done!”, “You fall into a trap.”) using the UIAccessibility announcement notification.
The tricky part here is that we will need to know which levelAction index has been selected and which action have been selected by the user, as the UIAccessibilityCustomAction constructor only provides a selector with an UIAccessibilityCustomAction as its argument, we will need to make a custom UIAccessibilityCustomAction subclass to achieve our goal.
Along with the attributes, we add an uuid field (a unique identifier), we will define as serialised version of our array indexes (i, j), respectively the levelAction index (outer loop index) and the action index (inner loop index).
When the user selects an action, we add it to the performedActions attribute, when all level actions have been answered, we finally try to validate the level; thus the level will only be validated when the
You can run the SearchLevelViewControllerTests to get a better idea of the level inner working.
Feel free to try to improve the existing behaviour for example by restarting the level when the user selects a wrong answer.
guard let result = getResult(for: action) else { return false
}
UIAccessibility.post(notification: .announcement, argument: result)
class SearchAccessibilityCustomAction: UIAccessibilityCustomAction { let uuid: String
init(uuid: String, name: String, target: Any?, selector: Selector) { self.uuid = uuid
super.init(name: name, target: target, selector: selector)
} }
class SearchViewController: UIViewController, Coordinated { var coordinator: AppCoordinatorProtocol?
// MARK: – Initialization
private var level: SearchLevel!
private var performedActions: [String?]!
var mainLabel: UILabel = {
let label = UILabel() label.numberOfLines = 0 label.textColor = .white label.textAlignment = .center return label
}()
var actionViews: [UIView] = []
convenience init(level: SearchLevel) { self.init()
}
self.level = level
self.performedActions = [String?].init(repeating: nil, count: self.level.levelActions.count) }
// MARK: – View Lifecycle override func viewDidLoad() {
super.viewDidLoad()
setupLevelDescriptionLabel() }
override func viewDidLayoutSubviews() { super.viewDidLayoutSubviews() setupActionsViews()
}
// MARK: – Private Methods
private func setupLevelDescriptionLabel() {
self.view.addSubview(self.mainLabel)
self.mainLabel.translatesAutoresizingMaskIntoConstraints = false self.mainLabel.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true self.mainLabel.leftAnchor.constraint(equalTo: self.view.leftAnchor, constant: 30).isActive = true self.mainLabel.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 100).isActive = true
self.mainLabel.text = level.levelDescription }
private func setupActionsViews() {
let frameCount = level.levelActions.count
let frames = RandomFramesGenerator.generateFrames(startY: Int(self.mainLabel.frame.maxY) + 5, count: frameCount) for i in 0..<frameCount {
let action = level.levelActions[i]
let frame = frames[i]
let actionView = UIView(frame: frame) actionView.isAccessibilityElement = true actionView.accessibilityLabel = action.description
var customActions: [UIAccessibilityCustomAction] = []
for j in 0..<action.actions.count {
let act = action.actions[j]
let uuid = makeUuidName(i, j, act)
let customAction = SearchAccessibilityCustomAction( uuid: uuid,
name: act,
target: self,
selector: #selector(performAction) )
customActions.append(customAction) }
actionView.accessibilityCustomActions = customActions
self.actionViews.append(actionView)
self.view.addSubview(actionView) }
}
private func makeUuidName(_ i: Int, _ j: Int, _ action: String) -> String { return “\(i)_\(j)_\(action)”
}
@objc internal func performAction(action: UIAccessibilityCustomAction) -> Bool { guard let result = getResult(for: action) else {
return false }
EscapeFromBlindnessAccessibility.shared.post(notification: .announcement, argument: result) handleResult(for: action)
return true
}
private func handleResult(for action: UIAccessibilityCustomAction) {
let (index, subindex) = getIndexes(for: action)
guard let idx = index, let subidx = subindex else { return } self.performedActions![idx] = self.level.levelActions[idx].actions[subidx] let nonNilPerformedActions = self.performedActions.compactMap { $0 }
if nonNilPerformedActions.count == self.level.levelActions.count { self.coordinator?.validate(nonNilPerformedActions)
} }
private func getResult(for action: UIAccessibilityCustomAction) -> String? { var levelActionIndex: Int? = nil
var actionIndex: Int? = nil
(levelActionIndex, actionIndex) = getIndexes(for: action)
if let levelActionIndex = levelActionIndex, let actionIndex = actionIndex { let levelAction = self.level.levelActions[levelActionIndex]
let result = levelAction.results[actionIndex]
return result
} else { return nil
} }
private func getIndexes(for action: UIAccessibilityCustomAction) -> (Int?, Int?) {
guard let searchAction = action as? SearchAccessibilityCustomAction else { return (nil, nil) } var levelActionIndex: Int? = nil
var actionIndex: Int? = nil
for i in 0..<self.level.levelActions.count { let levelAction = self.level.levelActions[i] for j in 0..<levelAction.actions.count {
let inputAction = levelAction.actions[j]
let uuidName = makeUuidName(i, j, inputAction)
let isMatchingAction = searchAction.uuid == uuidName if isMatchingAction {
levelActionIndex = i
actionIndex = j }
} }
return (levelActionIndex, actionIndex) }
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