Setup last position when jumping to a previous resource

Author: mickael-menu

Sources/Shared/Publication/Services/Content/HTMLResourceContentIterator.swift

@@ -25,22 +25,12 @@ public class HTMLResourceContentIterator : ContentIterator {
             .readAsString()
             .eraseToAnyError()
             .tryMap { try SwiftSoup.parse($0) }
-            .tryMap { document -> ContentParser in
-                let parser = ContentParser(
-                    baseLocator: locator,
-                    startElement: try locator.locations.cssSelector
-                        .flatMap {
-                            // The JS third-party library used to generate the CSS Selector sometimes adds
-                            // :root >, which doesn't work with JSoup.
-                            try document.select($0.removingPrefix(":root > ")).first()
-                        }
-                )
-                try document.traverse(parser)
-                return parser
+            .tryMap { document -> (content: [Content], startingIndex: Int) in
+                try ContentParser.parse(document: document, locator: locator)
             }
 
         content = result.map { $0.content }
-        startingIndex = result.map { $0.startIndex }.get(or: 0)
+        startingIndex = result.map { $0.startingIndex }.get(or: 0)
     }
 
     public func close() {}
@@ -72,6 +62,31 @@ public class HTMLResourceContentIterator : ContentIterator {
     }
 
     private class ContentParser: NodeVisitor {
+        
+        static func parse(document: Document, locator: Locator) throws -> (content: [Content], startingIndex: Int) {
+            let parser = ContentParser(
+                baseLocator: locator,
+                startElement: try locator.locations.cssSelector
+                    .flatMap {
+                        // The JS third-party library used to generate the CSS Selector sometimes adds
+                        // :root >, which doesn't work with JSoup.
+                        try document.select($0.removingPrefix(":root > ")).first()
+                    }
+            )
+            try document.traverse(parser)
+            
+            var result = (
+                content: parser.content,
+                startingIndex: parser.startIndex
+            )
+            
+            if locator.locations.progression == 1.0 {
+                result.startingIndex = result.content.count - 1
+            }
+            
+            return result
+        }
+
         private let baseLocator: Locator
         private let startElement: Element?
 
@@ -87,7 +102,7 @@ public class HTMLResourceContentIterator : ContentIterator {
         private var currentCSSSelector: String?
         private var ignoredNode: Node?
 
-        init(baseLocator: Locator, startElement: Element?) {
+        private init(baseLocator: Locator, startElement: Element?) {
             self.baseLocator = baseLocator
             self.startElement = startElement
         }

Sources/Shared/Publication/Services/Content/PublicationContentIterator.swift

@@ -87,28 +87,31 @@ public class PublicationContentIterator: ContentIterator, Loggable {
 
     private func loadIterator(from index: Int, by delta: Int) -> (index: Int, ContentIterator)? {
         let i = index + delta
-        guard publication.readingOrder.indices.contains(i)  else {
+        guard
+            let link = publication.readingOrder.getOrNil(i),
+            var locator = publication.locate(link)
+        else {
             return nil
         }
-        guard let iterator = loadIterator(at: i) else {
-            return loadIterator(from: i, by: delta)
-        }
-        return (i, iterator)
-    }
-
-    private func loadIterator(at index: Int) -> ContentIterator? {
-        let link = publication.readingOrder[index]
-        guard var locator = publication.locate(link) else {
-            return nil
-        }
-
+        
         if let start = startLocator.pop() {
             locator = locator.copy(
                 locations: { $0 = start.locations },
                 text: { $0 = start.text }
             )
+        } else if delta < 0 {
+            locator = locator.copy(
+                locations: { $0.progression = 1.0 }
+            )
+        }
+
+        guard let iterator = loadIterator(at: link, locator: locator) else {
+            return loadIterator(from: i, by: delta)
         }
+        return (i, iterator)
+    }
 
+    private func loadIterator(at link: Link, locator: Locator) -> ContentIterator? {
         let resource = publication.get(link)
         for factory in resourceContentIteratorFactories {
             if let iterator = factory(resource, locator) {