Make sure to use start number when explicit stated.

When using reversed the start number by default should be the number
of items in the list.

Author: SergioEstevao

Aztec/Classes/Extensions/NSAttributedString+Lists.swift

@@ -68,6 +68,34 @@ extension NSAttributedString {
         return resultRange
     }
 
+    /// Returns the number of  items of a list at the given location.
+    ///
+    /// - Parameters:
+    ///   - list: The list.
+    ///   - location: The location of the item.
+    ///
+    /// - Returns: Returns the total number of items within the list.
+    ///
+    func numberOfItems(in list: TextList,  at location: Int) -> Int {
+        guard
+            let paragraphStyle = attribute(.paragraphStyle, at: location, effectiveRange: nil) as? ParagraphStyle
+            else {
+                return NSNotFound
+        }
+        let listDepth = paragraphStyle.lists.count
+        guard let rangeOfList = range(of:list, at: location) else {
+            return NSNotFound
+        }
+        var numberInList = 0
+        let paragraphRanges = self.paragraphRanges(intersecting: rangeOfList)
+        for (_, enclosingRange) in paragraphRanges {
+            if let paragraphStyle = attribute(.paragraphStyle, at: enclosingRange.location, effectiveRange: nil) as? ParagraphStyle,
+               listDepth == paragraphStyle.lists.count {
+                numberInList += 1
+            }
+        }
+        return numberInList
+    }
     /// Returns the index of the item at the given location within the list.
     ///
     /// - Parameters:

Aztec/Classes/NSAttributedString/Conversions/AttributedStringParser.swift

@@ -770,8 +770,8 @@ private extension AttributedStringParser {
                     listElement.updateAttribute(named: "reversed", value: .none)
                 }
 
-                if list.start != 1 {
-                    listElement.updateAttribute(named: "start", value: .string("\(list.start)"))
+                if let start = list.start {
+                    listElement.updateAttribute(named: "start", value: .string("\(start)"))
                 }
             }
         }

Aztec/Classes/TextKit/LayoutManager.swift

@@ -211,10 +211,14 @@ private extension LayoutManager {
             let glyphRange = self.glyphRange(forCharacterRange: enclosingRange, actualCharacterRange: nil)
             let markerRect = rectForItem(range: glyphRange, origin: origin, paragraphStyle: paragraphStyle)
             var markerNumber = textStorage.itemNumber(in: list, at: enclosingRange.location)
+            var start = list.start ?? 1
             if list.reversed {
                 markerNumber = -markerNumber
+                if list.start == nil {
+                    start = textStorage.numberOfItems(in: list, at: enclosingRange.location)
+                }
             }
-            markerNumber += list.start
+            markerNumber += start
 
             drawItem(number: markerNumber, in: markerRect, from: list, using: paragraphStyle, at: enclosingRange.location)
         }

Aztec/Classes/TextKit/ParagraphProperty/TextList.swift

@@ -24,24 +24,27 @@ open class TextList: ParagraphProperty {
 
     public let reversed: Bool
 
-    public let start: Int
+    public let start: Int?
 
     // MARK: - Properties
 
     /// Kind of List: Ordered / Unordered
     ///
     let style: Style
 
-    init(style: Style, start: Int = 1, reversed: Bool = false, with representation: HTMLRepresentation? = nil) {
+    init(style: Style, start: Int? = nil, reversed: Bool = false, with representation: HTMLRepresentation? = nil) {
         self.style = style
 
         if let representation = representation, case let .element( html ) = representation.kind {
             self.reversed = html.attribute(ofType: .reversed) != nil
 
-            if let startAttribute = html.attribute(ofType: .start), case let .string( value ) = startAttribute.value, let start = Int(value) {
+            if let startAttribute = html.attribute(ofType: .start),
+                case let .string( value ) = startAttribute.value,
+                let start = Int(value)
+            {
                 self.start = start
             } else {
-                self.start = 1
+                self.start = nil
             }
         } else {
             self.start = start
@@ -61,7 +64,7 @@ open class TextList: ParagraphProperty {
             let decodedStart = aDecoder.decodeInteger(forKey: AttributeType.start.rawValue)
             start = decodedStart
         } else {
-            start = 1
+            start = nil
         }
 
         if aDecoder.containsValue(forKey: AttributeType.reversed.rawValue) {

Example/Example/SampleContent/content.html

@@ -37,11 +37,25 @@ <h4>Ordered List:</h4>
     <li>Three</li>
 </ol>
 
+<h4>Start in 10 List:</h4>
+<ol start="10">
+    <li>Ten</li>
+    <li>Eleven</li>
+    <li>Twelve</li>
+</ol>
+
 <h4>Reversed List:</h4>
-<ol reversed start="10">
-    <li>One</li>
-    <li>Two</li>
+<ol reversed>
     <li>Three</li>
+    <li>Two</li>
+    <li>One</li>
+</ol>
+
+<h4>Reversed Start in 10 List:</h4>
+<ol reversed start="10">
+    <li>Ten</li>
+    <li>Nine</li>
+    <li>Eight</li>
 </ol>
 
 <h4>Nested lists:</h4>