Implement a function for breaking through mute of the speech synthesizer.

CHANGELOG.md

@@ -42,6 +42,7 @@
 * MapboxMobileEvents dependency is replaced with CoreTelemetry (part of MapboxCommon). ([#4011](https://github.com/mapbox/mapbox-navigation-ios/pull/4011))
 * Deprecated `NavigationEventsManager.init(activeNavigationDataSource:passiveNavigationDataSource:accessToken:mobileEventsManager:)` in favour of `NavigationEventsManager.init(activeNavigationDataSource:passiveNavigationDataSource:accessToken:)`. ([#4011](https://github.com/mapbox/mapbox-navigation-ios/pull/4011))
 * Added `NavigationViewController.usesNightStyleInDarkMode` property to control whether night style is used in dark mode. ([#4143](https://github.com/mapbox/mapbox-navigation-ios/pull/4143))
+* Added `SpeechSynthesizing.forceSpeak(instruction:during: locale:)` to break through mute of speech synthesizer. ([#4195](https://github.com/mapbox/mapbox-navigation-ios/pull/4195))
 
 ## v2.8.1
 

Sources/MapboxNavigation/MultiplexedSpeechSynthesizer.swift

@@ -108,6 +108,11 @@ open class MultiplexedSpeechSynthesizer: SpeechSynthesizing {
         currentLegProgress = legProgress
         speechSynthesizers.first?.speak(instruction, during: legProgress, locale: locale)
     }
+
+    public func forceSpeak(_ instruction: SpokenInstruction, during legProgress: RouteLegProgress, locale: Locale? = nil) {
+        currentLegProgress = legProgress
+        speechSynthesizers.first?.forceSpeak(instruction, during: legProgress, locale: locale)
+    }
 
     public func stopSpeaking() {
         speechSynthesizers.forEach { $0.stopSpeaking() }

Sources/MapboxNavigation/SpeechSynthesizing.swift

@@ -5,7 +5,7 @@ import MapboxCoreNavigation
 /**
  Protocol for implementing speech synthesizer to be used in `RouteVoiceController`.
  */
-public protocol SpeechSynthesizing: AnyObject {
+public protocol SpeechSynthesizing: AnyObject, UnimplementedLogging {
 
     /// A delegate that will be notified about significant events related to spoken instructions.
     var delegate: SpeechSynthesizingDelegate? { get set }
@@ -38,13 +38,32 @@ public protocol SpeechSynthesizing: AnyObject {
     ///
     /// This method is not guaranteed to be synchronous or asynchronous. When vocalizing is finished, `voiceController(_ voiceController: SpeechSynthesizing, didSpeak instruction: SpokenInstruction, with error: SpeechError?)` should be called.
     func speak(_ instruction: SpokenInstruction, during legProgress: RouteLegProgress, locale: Locale?)
+
+    /// A request to vocalize the instruction, breaking through the mute of the speech synthesizer if muted
+    /// - parameter instruction: an instruction to be vocalized
+    /// - parameter legProgress: current leg progress, corresponding to the instruction
+    /// - parameter locale: A locale to be used for vocalizing the instruction. If `nil` is passed - `SpeechSynthesizing.locale` will be used as 'default'.
+    ///
+    /// This method is not guaranteed to be synchronous or asynchronous. When vocalizing is finished, `voiceController(_ voiceController: SpeechSynthesizing, didSpeak instruction: SpokenInstruction, with error: SpeechError?)` should be called.
+    func forceSpeak(_ instruction: SpokenInstruction, during legProgress: RouteLegProgress, locale: Locale?)
 
     /// Tells synthesizer to stop current vocalization in a graceful manner
     func stopSpeaking()
     /// Tells synthesizer to stop current vocalization immediately
     func interruptSpeaking()
 }
 
+extension SpeechSynthesizing {
+
+    /**
+     `UnimplementedLogging` prints a warning to standard output the first time this method is called.
+     */
+    public func forceSpeak(_ instruction: SpokenInstruction, during legProgress: RouteLegProgress, locale: Locale?) {
+        logUnimplemented(protocolType: SpeechSynthesizing.self, level: .debug)
+        speak(instruction, during: legProgress, locale: locale)
+    }
+}
+
 /**
  The `SpeechSynthesizingDelegate` protocol defines methods that allow an object to respond to significant events related to spoken instructions.
  */

Sources/MapboxNavigation/SystemSpeechSynthesizer.swift

@@ -64,7 +64,10 @@ open class SystemSpeechSynthesizer: NSObject, SpeechSynthesizing {
                                         with: nil)
             return
         }
-
+        forceSpeak(instruction, during: legProgress, locale: locale)
+    }
+
+    open func forceSpeak(_ instruction: SpokenInstruction, during legProgress: RouteLegProgress, locale: Locale? = nil) {
         guard let locale = locale ?? self.locale else {
             self.delegate?.speechSynthesizer(self,
                                              encounteredError: SpeechError.undefinedSpeechLocale(instruction: instruction))