Add Locator.Locations.time (#382)

Sources/Navigator/Audiobook/AudioNavigator.swift

@@ -282,7 +282,7 @@ open class _AudioNavigator: _MediaNavigator, AudioSessionUser, Loggable {
             }
 
             // Seeks to time
-            let time = locator.time(forDuration: resourceDuration) ?? 0
+            let time = locator.locations.time?.begin ?? ((resourceDuration ?? 0) * (locator.locations.progression ?? 0))
             player.seek(to: CMTime(seconds: time, preferredTimescale: 1000)) { [weak self] finished in
                 if let self = self, finished {
                     self.delegate?.navigator(self, didJumpTo: locator)
@@ -385,28 +385,6 @@ open class _AudioNavigator: _MediaNavigator, AudioSessionUser, Loggable {
     }
 }
 
-private extension Locator {
-    private static let timeFragmentRegex = try! NSRegularExpression(pattern: #"t=(\d+(?:\.\d+)?)"#)
-
-    // FIXME: Should probably be in `Locator` itself.
-    func time(forDuration duration: Double? = nil) -> Double? {
-        if let progression = locations.progression, let duration = duration {
-            return progression * duration
-        } else {
-            for fragment in locations.fragments {
-                let range = NSRange(fragment.startIndex ..< fragment.endIndex, in: fragment)
-                if let match = Self.timeFragmentRegex.firstMatch(in: fragment, range: range) {
-                    let matchRange = match.range(at: 1)
-                    if matchRange.location != NSNotFound, let range = Range(matchRange, in: fragment) {
-                        return Double(fragment[range])
-                    }
-                }
-            }
-        }
-        return nil
-    }
-}
-
 private extension MediaPlaybackState {
     init(_ timeControlStatus: AVPlayer.TimeControlStatus) {
         switch timeControlStatus {

Sources/Shared/Publication/Extensions/Audio/Locator+Audio.swift

@@ -0,0 +1,75 @@
+//
+//  Copyright 2024 Readium Foundation. All rights reserved.
+//  Use of this source code is governed by the BSD-style license
+//  available in the top-level LICENSE file of the project.
+//
+
+import Foundation
+
+/// Audio extensions for `Locator.Locations`.
+public extension Locator.Locations {
+    enum TimeFragment: Equatable, Sendable {
+        case begin(Double)
+        case end(Double)
+        case interval(Double, Double)
+
+        init?(begin: Double?, end: Double?) {
+            switch (begin, end) {
+            case let (.some(begin), .some(end)):
+                self = .interval(begin, end)
+            case let (.some(begin), .none):
+                self = .begin(begin)
+            case let (.none, .some(end)):
+                self = .end(end)
+            case (.none, .none):
+                return nil
+            }
+        }
+
+        public var begin: Double? {
+            switch self {
+            case let .begin(begin):
+                return begin
+            case let .interval(begin, _):
+                return begin
+            default:
+                return nil
+            }
+        }
+
+        public var end: Double? {
+            switch self {
+            case let .end(end):
+                return end
+            case let .interval(_, end):
+                return end
+            default:
+                return nil
+            }
+        }
+    }
+
+    private static let timeFragmentRegex = try! NSRegularExpression(pattern: #"t=([^,]*),?([^,]*)"#)
+
+    /// The Temporal Dimension media fragment, if it exists.
+    /// https://www.w3.org/TR/media-frags/#media-fragment-syntax
+    var time: TimeFragment? {
+        for fragment in fragments {
+            let range = NSRange(fragment.startIndex ..< fragment.endIndex, in: fragment)
+            if let match = Self.timeFragmentRegex.firstMatch(in: fragment, range: range) {
+                let group1NSRange = match.range(at: 1)
+                let group2NSRange = match.range(at: 2)
+                var begin: Double?
+                var end: Double?
+                if group1NSRange.location != NSNotFound, let group1Range = Range(group1NSRange, in: fragment) {
+                    begin = Double(fragment[group1Range])
+                }
+                if group2NSRange.location != NSNotFound, let group2Range = Range(group2NSRange, in: fragment) {
+                    end = Double(fragment[group2Range])
+                }
+                return TimeFragment(begin: begin, end: end)
+            }
+        }
+        return nil
+    }
+}