Add 'Remember Last Read Post' option. #622

src/General/Config.coffee

@@ -355,9 +355,14 @@ Config =
         true
         'Show a line to distinguish read posts from unread ones.'
       ]
+      'Remember Last Read Post': [
+        true
+        'Remember how far you\'ve read after you close the thread.'
+      ]
       'Scroll to Last Read Post': [
         true
         'Scroll back to the last read post when reopening a thread.'
+        1
       ]
       'Thread Excerpt': [
         true

src/Monitoring/ThreadWatcher.coffee

@@ -145,7 +145,7 @@ ThreadWatcher =
         if Conf['Auto Prune'] or not (data and typeof data is 'object') # corrupt data
           db.delete {boardID, threadID}
         else
-          if Conf['Show Unread Count']
+          if Conf['Remember Last Read Post'] and Conf['Show Unread Count']
             ThreadWatcher.fetchStatus {boardID, threadID, data}
           data.isDead = true
           db.set {boardID, threadID, val: data}
@@ -174,7 +174,7 @@ ThreadWatcher =
     clearTimeout ThreadWatcher.timeout
     return unless Conf['Auto Update Thread Watcher']
     {db} = ThreadWatcher
-    interval = if Conf['Show Unread Count'] then 5 * $.MINUTE else 2 * $.HOUR
+    interval = if Conf['Remember Last Read Post'] and Conf['Show Unread Count'] then 5 * $.MINUTE else 2 * $.HOUR
     now = Date.now()
     if now >= (db.data.lastChecked or 0) + interval
       db.data.lastChecked = now
@@ -291,7 +291,7 @@ ThreadWatcher =
       title: data.excerpt
       className: 'watcher-link'
 
-    if Conf['Show Unread Count'] and data.unread?
+    if Conf['Remember Last Read Post'] and Conf['Show Unread Count'] and data.unread?
       count = $.el 'span',
         textContent: "(#{data.unread})"
         className: 'watcher-unread'
@@ -307,7 +307,7 @@ ThreadWatcher =
     div.dataset.fullID = fullID
     $.addClass div, 'current'     if g.VIEW is 'thread' and fullID is "#{g.BOARD}.#{g.THREADID}"
     $.addClass div, 'dead-thread' if data.isDead
-    if Conf['Show Unread Count']
+    if Conf['Remember Last Read Post'] and Conf['Show Unread Count']
       $.addClass div, 'replies-read'        if data.unread is 0
       $.addClass div, 'replies-unread'      if data.unread
       $.addClass div, 'replies-quoting-you' if data.quotingYou
@@ -397,7 +397,7 @@ ThreadWatcher =
     data.excerpt  = Get.threadExcerpt thread
     ThreadWatcher.db.set {boardID, threadID, val: data}
     ThreadWatcher.refresh()
-    if Conf['Show Unread Count']
+    if Conf['Remember Last Read Post'] and Conf['Show Unread Count']
       ThreadWatcher.fetchStatus {boardID, threadID, data}, true
 
   rm: (boardID, threadID) ->
@@ -473,6 +473,10 @@ ThreadWatcher =
         el: UI.checkbox name, name.replace(' Thread Watcher', '')
       entry.el.title = desc
       input = entry.el.firstElementChild
+      if name is 'Show Unread Count' and not Conf['Remember Last Read Post']
+        input.disabled = true
+        $.addClass entry.el, 'disabled'
+        entry.el.title += '\n[Remember Last Read Post is disabled.]'
       $.on input, 'change', $.cb.checked
       $.on input, 'change', ThreadWatcher.refresh   if name in ['Current Board', 'Show Unread Count']
       $.on input, 'change', ThreadWatcher.fetchAuto if name in ['Show Unread Count', 'Auto Update Thread Watcher']

src/Monitoring/Unread.coffee

@@ -4,13 +4,14 @@ Unread =
       Conf['Unread Count'] or
       Conf['Unread Favicon'] or
       Conf['Unread Line'] or
-      Conf['Scroll to Last Read Post'] or
+      Conf['Remember Last Read Post'] or
-      Conf['Thread Watcher'] or
       Conf['Desktop Notifications'] or
       Conf['Quote Threading']
     )
 
-    @db = new DataBoard 'lastReadPosts', @sync
+    if Conf['Remember Last Read Post']
+      @db = new DataBoard 'lastReadPosts', @sync
+
     @hr = $.el 'hr',
       id: 'unread-line'
     @posts = new Set()
@@ -50,10 +51,10 @@ Unread =
   node: ->
     Unread.thread = @
     Unread.title  = d.title
-    Unread.lastReadPost = Unread.db.get
+    Unread.lastReadPost = Unread.db?.get(
       boardID: @board.ID
       threadID: @ID
-      defaultValue: 0
+    ) or 0
     Unread.readCount = 0
     Unread.readCount++ for ID in @posts.keys when +ID <= Unread.lastReadPost
     $.one d, '4chanXInitFinished', Unread.ready
@@ -63,7 +64,7 @@ Unread =
     Unread.setLine true
     Unread.read()
     Unread.update()
-    Unread.scroll() if Conf['Scroll to Last Read Post']
+    Unread.scroll() if Conf['Remember Last Read Post'] and Conf['Scroll to Last Read Post']
     $.on  d, 'scroll visibilitychange', Unread.read
     $.on  d, 'visibilitychange',        Unread.setLine if Conf['Unread Line']
 
@@ -192,6 +193,7 @@ Unread =
     return
 
   saveLastReadPost: $.debounce 2 * $.SECOND, ->
+    return unless Conf['Remember Last Read Post'] and Unread.db
     postIDs = Unread.thread.posts.keys
     for i in [Unread.readCount...postIDs.length] by 1
       ID = +postIDs[i]
@@ -228,7 +230,7 @@ Unread =
         Unread.title
       d.title = "#{titleQuotingYou}#{titleCount}#{titleDead}"
 
-    unless Unread.thread.isDead and !Unread.thread.isArchived
+    if Conf['Remember Last Read Post'] and (!Unread.thread.isDead or Unread.thread.isArchived)
       ThreadWatcher.update Unread.thread.board.ID, Unread.thread.ID,
         isDead: Unread.thread.isDead
         unread: count