[Garkin]

I'm not sure if it exactly what you want, but here is my book filter:




Source code:

BookFilters.txt

## Title: |cEFEBBEBook Filters|r
## Version: 0.1
## Author: |cEFEBBEGarkin|r
## APIVersion: 100010

BookFilters.lua

BookFilters.lua

local ADDON_NAME = "BookFilters"
local BOOK_DATA_TYPE = 1
local LIBRARY
local savedVars
 
local filterData = {
   "Show All",
   "Show Known",
   "Show Unknown",
}
 
local function OnFilterChanged(comboBox, entryText, entry)
   local container = comboBox:GetContainer()
   container.filterType = entry.filterType
   savedVars.filterType = entry.filterType
   LIBRARY.list:FilterScrollList()
   if LIBRARY.navigationTree.selectedNode then
      LIBRARY.navigationTree.selectedNode:OnSelected()
   end
end
 
local function InitializeFilters(filterControl, filterChangedCallback)
   local comboBox = ZO_ComboBox_ObjectFromContainer(filterControl)
   comboBox:SetSortsItems(false)
   comboBox:SetFont("ZoFontWinT1")
   comboBox:SetSpacing(4)
 
   for i, text in ipairs(filterData) do
      local entry = comboBox:CreateItemEntry(text, filterChangedCallback)
      entry.filterType = i
      comboBox:AddItem(entry)
   end
 
   comboBox:SelectFirstItem()
   filterControl.filterType = savedVars.filterType or 1
end
 
local function FilterScrollList(self)
   local categoryIndex = self.owner:GetSelectedCategoryIndex()
   local collectionIndex = self.owner:GetSelectedCollectionIndex()
 
   local totalBooks = select(4, GetLoreCollectionInfo(categoryIndex, collectionIndex))
 
   local scrollData = ZO_ScrollList_GetDataList(self.list)
   ZO_ScrollList_Clear(self.list)
 
   for bookIndex = 1, totalBooks do
      local shouldAdd
 
      if self.filter.filterType == 1 then
         shouldAdd = true
      else
         local _, _, known = GetLoreBookInfo(categoryIndex, collectionIndex, bookIndex)
         if self.filter.filterType == 2 then
            shouldAdd = known
         elseif self.filter.filterType == 3 then
            shouldAdd = not known
         end
      end
 
      if shouldAdd then
         scrollData[#scrollData + 1] = ZO_ScrollList_CreateDataEntry(BOOK_DATA_TYPE, { categoryIndex = categoryIndex, collectionIndex = collectionIndex, bookIndex = bookIndex })
      end
   end   
end
 
local function OnAddonLoaded(evt, name)
   if (name == ADDON_NAME) then
      EVENT_MANAGER:UnregisterForEvent(name, evt)
 
      savedVars = ZO_SavedVars:New("ZO_Ingame_SavedVariables", 1, "BookFilters", { filterType = 1 })
 
      LIBRARY = ZO_LoreLibrary.owner
      LIBRARY.list.filter = CreateControlFromVirtual("$(parent)Filter", ZO_LoreLibrary, "ZO_ComboBox")
      LIBRARY.list.filter:SetDimensions(222, 32)
      LIBRARY.list.filter:SetAnchor(TOPRIGHT, ZO_LoreLibrary, TOPRIGHT, -20, 15)
      
      InitializeFilters(LIBRARY.list.filter, OnFilterChanged)
 
      LIBRARY.list.FilterScrollList = FilterScrollList
   end
end        
        
EVENT_MANAGER:RegisterForEvent(ADDON_NAME, EVENT_ADD_ON_LOADED, OnAddonLoaded)

If you want downloadable version, it is BookFilters-0.1.zip in my Dropbox folder.