diff --git a/frontend/apps/filemanager/filemanager.lua b/frontend/apps/filemanager/filemanager.lua
index c670774a0..edd0a913e 100644
--- a/frontend/apps/filemanager/filemanager.lua
+++ b/frontend/apps/filemanager/filemanager.lua
@@ -157,7 +157,6 @@ function FileManager:init()
                                     callback = function()
                                         renameFile(file)
                                         self:refreshPath()
-                                        fileManager.rename_dialog:onClose()
                                         UIManager:close(fileManager.rename_dialog)
                                     end,
                                 },
@@ -165,13 +164,10 @@ function FileManager:init()
                                     text = _("Cancel"),
                                     enabled = true,
                                     callback = function()
-                                        fileManager.rename_dialog:onClose()
                                         UIManager:close(fileManager.rename_dialog)
                                     end,
                                 },
                             }},
-                            width = Screen:getWidth() * 0.8,
-                            height = Screen:getHeight() * 0.2,
                         }
                         fileManager.rename_dialog:onShowKeyboard()
                         UIManager:show(fileManager.rename_dialog)
diff --git a/frontend/apps/filemanager/filemanagerfilesearcher.lua b/frontend/apps/filemanager/filemanagerfilesearcher.lua
index 1d6ea1f65..8dc19f518 100644
--- a/frontend/apps/filemanager/filemanagerfilesearcher.lua
+++ b/frontend/apps/filemanager/filemanagerfilesearcher.lua
@@ -83,7 +83,6 @@ end
 
 function FileSearcher:close()
     if self.search_value then
-        self.search_dialog:onClose()
         UIManager:close(self.search_dialog)
         if string.len(self.search_value) > 0 then
             self:readDir() -- TODO this probably doesn't need to be repeated once it's been done
@@ -131,8 +130,6 @@ function FileSearcher:showSearch()
                 },
             },
         },
-        width = Screen:getWidth() * 0.8,
-        height = Screen:getHeight() * 0.2,
     }
     self.search_dialog:onShowKeyboard()
     UIManager:show(self.search_dialog)
diff --git a/frontend/apps/filemanager/filemanagermenu.lua b/frontend/apps/filemanager/filemanagermenu.lua
index 593af668b..f10dd8c0e 100644
--- a/frontend/apps/filemanager/filemanagermenu.lua
+++ b/frontend/apps/filemanager/filemanagermenu.lua
@@ -2,10 +2,11 @@ local CenterContainer = require("ui/widget/container/centercontainer")
 local InputContainer = require("ui/widget/container/inputcontainer")
 local ConfirmBox = require("ui/widget/confirmbox")
 local UIManager = require("ui/uimanager")
-local Device = require("device")
 local GestureRange = require("ui/gesturerange")
+local InputDialog = require("ui/widget/inputdialog")
 local Geom = require("ui/geometry")
-local Screen = require("device").screen
+local Device = require("device")
+local Screen = Device.screen
 local DEBUG = require("dbg")
 local _ = require("gettext")
 local FileSearcher = require("apps/filemanager/filemanagerfilesearcher")
@@ -14,7 +15,7 @@ local SetDefaults = require("apps/filemanager/filemanagersetdefaults")
 
 local FileManagerMenu = InputContainer:extend{
     tab_item_table = nil,
-    registered_widgets = {},
+    registered_widgets = nil,
 }
 
 function FileManagerMenu:init()
@@ -93,8 +94,12 @@ function FileManagerMenu:setUpdateItemTable()
     })
     table.insert(self.tab_item_table.setting, {
         text = _("Start with last opened file"),
-        checked_func = function() return G_reader_settings:readSetting("open_last") end,
-        enabled_func = function() return G_reader_settings:readSetting("lastfile") ~= nil end,
+        checked_func = function() return
+            G_reader_settings:readSetting("open_last")
+        end,
+        enabled_func = function() return
+            G_reader_settings:readSetting("lastfile") ~= nil
+        end,
         callback = function()
             local open_last = G_reader_settings:readSetting("open_last") or false
             G_reader_settings:saveSetting("open_last", not open_last)
@@ -112,6 +117,43 @@ function FileManagerMenu:setUpdateItemTable()
     end
 
     -- tools tab
+    if Device.isKobo() then
+        table.insert(self.tab_item_table.tools, {
+            text = _("Screen server folder"),
+            callback = function()
+                local ss_folder_path_input
+                local function save_folder_path()
+                    G_reader_settings:saveSetting(
+                        "screensaver_folder", ss_folder_path_input:getInputText())
+                    UIManager:close(ss_folder_path_input)
+                end
+                local curr_path = G_reader_settings:readSetting("screensaver_folder")
+                ss_folder_path_input = InputDialog:new{
+                    title = _("Screen saver folder"),
+                    input = curr_path,
+                    input_hint = "/mnt/onboard/screensaver",
+                    input_type = "text",
+                    buttons = {
+                        {
+                            {
+                                text = _("Cancel"),
+                                callback = function()
+                                    UIManager:close(ss_folder_path_input)
+                                end,
+                            },
+                            {
+                                text = _("Save"),
+                                callback = save_folder_path,
+                            },
+                        }
+                    },
+                    enter_callback = save_folder_path,
+                }
+                ss_folder_path_input:onShowKeyboard()
+                UIManager:show(ss_folder_path_input)
+            end,
+        })
+    end
     table.insert(self.tab_item_table.tools, {
         text = _("Advanced settings"),
         callback = function()
diff --git a/frontend/apps/filemanager/filemanagersearch.lua b/frontend/apps/filemanager/filemanagersearch.lua
index f4269f07c..af35e2ec9 100644
--- a/frontend/apps/filemanager/filemanagersearch.lua
+++ b/frontend/apps/filemanager/filemanagersearch.lua
@@ -125,7 +125,7 @@ function Search:getCalibre()
     self.use_own_metadata_file = false
     if self.metafile_1 then
         pcall(lfs.mkdir("temp"))
-        if io.open(koreaderfile,"r") then
+        if io.open(koreaderfile, "r") then
             if lfs.attributes(koreaderfile).modification > lfs.attributes(self.metafile_1).modification then
                 if self.metafile_2 then
                     if lfs.attributes(koreaderfile).modification > lfs.attributes(self.metafile_2).modification then
@@ -443,7 +443,9 @@ function Search:find(option)
             end
             g.close()
             if lfs.attributes(koreaderfile).modification < lfs.attributes(self.metafile_1).modification then
-                lfs.touch(koreaderfile, lfs.attributes(self.metafile_1).modification + 1, lfs.attributes(self.metafile_1).modification + 1)
+                lfs.touch(koreaderfile,
+                          lfs.attributes(self.metafile_1).modification + 1,
+                          lfs.attributes(self.metafile_1).modification + 1)
             end
             if self.metafile_2 then
                 if lfs.attributes(koreaderfile).modification < lfs.attributes(self.metafile_2).modification then
diff --git a/frontend/apps/filemanager/filemanagersetdefaults.lua b/frontend/apps/filemanager/filemanagersetdefaults.lua
index 74292d4ad..8265de317 100644
--- a/frontend/apps/filemanager/filemanagersetdefaults.lua
+++ b/frontend/apps/filemanager/filemanagersetdefaults.lua
@@ -10,41 +10,23 @@ local Screen = require("device").screen
 local Menu = require("ui/widget/menu")
 local Font = require("ui/font")
 local util = require("ffi/util")
-local DEBUG = require("dbg")
 local _ = require("gettext")
+local dump = require("dump")
+
+
+local defaults_path = DataStorage:getDataDir() .. "/defaults.lua"
+local persistent_filename = DataStorage:getDataDir() .. "/defaults.persistent.lua"
+
 
 local SetDefaults = InputContainer:new{
     defaults_name = {},
     defaults_value = {},
     results = {},
     defaults_menu = {},
-    already_read = false,
+    initialized = false,
     changed = {}
 }
 
-local function settype(b,t)
-    if t == "boolean" then
-        if b == "false" then return false else return true end
-    else
-        return b
-    end
-end
-
-local function getTableValues(t,dtap)
-    local dummy = "{"
-    for n,v in pairs(t) do
-        if dtap:sub(1,4) == "DTAP" or dtap:sub(1,11) == "DDOUBLE_TAP" then
-            dummy = dummy .. tostring(n) .. " = " .. tostring(v) .. ", "
-        elseif tonumber(v) then
-            dummy = dummy .. tostring(v) .. ", "
-        else
-            dummy = dummy .. "\"" .. tostring(v) .. "\", "
-        end
-    end
-    dummy = dummy:sub(1,string.len(dummy) - 2) .. "}"
-    return dummy
-end
-
 function SetDefaults:ConfirmEdit()
     if not SetDefaults.EditConfirmed then
         UIManager:show(ConfirmBox:new{
@@ -62,21 +44,20 @@ end
 function SetDefaults:init()
     self.results = {}
 
-    if not self.already_read then
-        local i = 0
-        for n,v in util.orderedPairs(_G) do
-            if (not string.find(tostring(v), "<")) and (not string.find(tostring(v), ": ")) and string.sub(n,1,1) ~= "_" and string.upper(n) == n and n ~= "LIBRARY_PATH" then
-                i = i + 1
-                self.defaults_name[i] = n
-                self.defaults_value[i] = v
-            end
-            if string.find(tostring(v), "table: ") and string.upper(n) == n and n ~= "ARGV" and n ~= "_G" then
-                i = i + 1
-                self.defaults_name[i] = n
-                self.defaults_value[i] = getTableValues(v,n)
-            end
+    if not self.initialized then
+        local defaults = {}
+        local load_defaults = loadfile(defaults_path)
+        setfenv(load_defaults, defaults)
+        load_defaults()
+
+        local i = 1
+        for n, v in util.orderedPairs(defaults) do
+            self.defaults_name[i] = n
+            self.defaults_value[i] = v
+            i = i + 1
         end
-        self.already_read = true
+
+        self.initialized = true
     end
 
     local menu_container = CenterContainer:new{
@@ -102,176 +83,163 @@ function SetDefaults:init()
         UIManager:close(menu_container)
     end
 
-    for i=1,#self.defaults_name do
+    local cancel_button = {
+        text = _("Cancel"),
+        enabled = true,
+        callback = function()
+            self:close()
+            UIManager:show(menu_container)
+        end,
+    }
+
+    for i=1, #self.defaults_name do
         self.changed[i] = false
-        local settings_type = type(_G[self.defaults_name[i]])
-        if settings_type == "boolean" then
+        local setting_name = self.defaults_name[i]
+        local setting_type = type(_G[setting_name])
+        if setting_type == "boolean" then
+            local editBoolean = function()
+                self.set_dialog = InputDialog:new{
+                    title = setting_name,
+                    input = tostring(self.defaults_value[i]),
+                    buttons = {
+                        {
+                            cancel_button,
+                            {
+                                text = "true",
+                                enabled = true,
+                                callback = function()
+                                    self.defaults_value[i] = true
+                                    _G[setting_name] = true
+                                    settings_changed = true
+                                    self.changed[i] = true
+                                    self.results[i].text = self:build_setting(i)
+                                    self:close()
+                                    self.defaults_menu:swithItemTable("Defaults", self.results, i)
+                                    UIManager:show(menu_container)
+                                end
+                            },
+                            {
+                                text = "false",
+                                enabled = true,
+                                callback = function()
+                                    self.defaults_value[i] = false
+                                    _G[setting_name] = false
+                                    settings_changed = true
+                                    self.changed[i] = true
+                                    self.results[i].text = self:build_setting(i)
+                                    self.defaults_menu:swithItemTable("Defaults", self.results, i)
+                                    self:close()
+                                    UIManager:show(menu_container)
+                                end
+                            },
+                        },
+                    },
+                    input_type = setting_type,
+                    width = Screen:getWidth() * 0.95,
+                }
+                self.set_dialog:onShowKeyboard()
+                UIManager:show(self.set_dialog)
+            end
+
             table.insert(self.results, {
                 text = self:build_setting(i),
-                callback = function()
-                    self.set_dialog = InputDialog:new{
-                        title = self.defaults_name[i] .. ":",
-                        input = tostring(self.defaults_value[i]),
-                        buttons = {
+                callback = editBoolean
+            })
+        elseif setting_type == "table" then
+            local editTable = function()
+                local fields = {}
+                for k, v in util.orderedPairs(_G[setting_name]) do
+                    table.insert(fields, {
+                        text = tostring(k) .. " = " .. tostring(v),
+                        hint = "",
+                    })
+                end
+                self.set_dialog = MultiInputDialog:new{
+                    title = setting_name,
+                    fields = fields,
+                    buttons = {
+                        {
+                            cancel_button,
                             {
-                                {
-                                    text = _("Cancel"),
-                                    enabled = true,
-                                    callback = function()
-                                        self:close()
-                                        UIManager:show(menu_container)
+                                text = _("OK"),
+                                enabled = true,
+                                callback = function()
+                                    local new_table = {}
+                                    for _, field in ipairs(MultiInputDialog:getFields()) do
+                                        new_table[field:match("^[^= ]+")] = field:match("[^= ]+$")
                                     end
-                                },
-                                {
-                                    text = "true",
-                                    enabled = true,
-                                    callback = function()
-                                        self.defaults_value[i] = true
-                                        _G[self.defaults_name[i]] = true
-                                        settings_changed = true
-                                        self.changed[i] = true
-                                        self.results[i].text = self:build_setting(i)
-                                        self:close()
-                                        self.defaults_menu:swithItemTable("Defaults", self.results, i)
-                                        UIManager:show(menu_container)
+                                    _G[setting_name] = new_table
+
+                                    self.defaults_value[i] = _G[setting_name]
+                                    settings_changed = true
+                                    self.changed[i] = true
+
+                                    self.results[i].text = self:build_setting(i)
+
+                                    self:close()
+                                    self.defaults_menu:swithItemTable("Defaults", self.results, i)
+                                    UIManager:show(menu_container)
+                                end,
+                            },
+                        },
+                    },
+                    input_type = "number",
+                    width = Screen:getWidth() * 0.95,
+                    height = Screen:getHeight() * 0.2,
+                }
+                self.set_dialog:onShowKeyboard()
+                UIManager:show(self.set_dialog)
+            end
+
+            table.insert(self.results, {
+                text = self:build_setting(i),
+                callback = editTable
+            })
+        else
+            local editNumStr = function()
+                self.set_dialog = InputDialog:new{
+                    title = setting_name,
+                    input = tostring(self.defaults_value[i]),
+                    buttons = {
+                        {
+                            cancel_button,
+                            {
+                                text = _("OK"),
+                                enabled = true,
+                                callback = function()
+                                    local new_value = self.set_dialog:getInputText()
+                                    if setting_type == "boolean" then
+                                        if new_value == "true" then
+                                            new_value = true
+                                        else
+                                            new_value = false
+                                        end
                                     end
-                                },
-                                {
-                                    text = "false",
-                                    enabled = true,
-                                    callback = function()
-                                        self.defaults_value[i] = false
-                                        _G[self.defaults_name[i]] = false
+                                    if _G[setting_name] ~= new_value then
+                                        _G[setting_name] = new_value
+                                        self.defaults_value[i] = new_value
                                         settings_changed = true
                                         self.changed[i] = true
                                         self.results[i].text = self:build_setting(i)
-                                        self.defaults_menu:swithItemTable("Defaults", self.results, i)
-                                        self:close()
-                                        UIManager:show(menu_container)
                                     end
-                                },
+                                    self:close()
+                                    self.defaults_menu:swithItemTable("Defaults", self.results, i)
+                                    UIManager:show(menu_container)
+                                end,
                             },
                         },
-                        input_type = settings_type,
-                        width = Screen:getWidth() * 0.95,
-                        height = Screen:getHeight() * 0.2,
-                    }
-                    self.set_dialog:onShowKeyboard()
-                    UIManager:show(self.set_dialog)
-                end
-            })
-        else
-            if type(_G[self.defaults_name[i]]) == "table" then
-                table.insert(self.results, {
-                    text = self:build_setting(i),
-                    callback = function()
-                        local fields = {}
-                        for m, n in util.orderedPairs(_G[self.defaults_name[i]]) do
-                            table.insert(fields, {
-                                text = tostring(m) .. " = " .. tostring(n),
-                                hint = "",
-                            })
-                        end
-                        self.set_dialog = MultiInputDialog:new{
-                            title = self.defaults_name[i] .. ":",
-                            fields = fields,
-                            buttons = {
-                                {
-                                    {
-                                        text = _("Cancel"),
-                                        enabled = true,
-                                        callback = function()
-                                            self:close()
-                                            UIManager:show(menu_container)
-                                        end,
-                                    },
-                                    {
-                                        text = _("OK"),
-                                        enabled = true,
-                                        callback = function()
-                                            local fields = {}
-                                            for _, field in ipairs(MultiInputDialog:getFields()) do
-                                                fields[field:match("^[^= ]+")] = field:match("[^= ]+$")
-                                            end
-                                            _G[self.defaults_name[i]] = fields
-                                            self.defaults_value[i] = "{"
-                                            DEBUG(_G[self.defaults_name[i]])
-                                            for k,v in util.orderedPairs(_G[self.defaults_name[i]]) do
-                                                if tonumber(k) then
-                                                    self.defaults_value[i] = self.defaults_value[i] .. v .. ", "
-                                                else
-                                                    self.defaults_value[i] = self.defaults_value[i] .. k .. " = " .. v .. ", "
-                                                end
-                                            end
-                                            self.defaults_value[i] = self.defaults_value[i]:sub(1,self.defaults_value[i]:len()-2) .. "}"
-
-                                            settings_changed = true
-                                            self.changed[i] = true
-
-                                            self.results[i].text = self:build_setting(i)
-
-                                            self:close()
-                                            self.defaults_menu:swithItemTable("Defaults", self.results, i)
-                                            UIManager:show(menu_container)
-                                        end,
-                                    },
-                                },
-                            },
-                            input_type = "number",
-                            width = Screen:getWidth() * 0.95,
-                            height = Screen:getHeight() * 0.2,
-                        }
-                        self.set_dialog:onShowKeyboard()
-                        UIManager:show(self.set_dialog)
-                    end
-                })
-
-            else
-                table.insert(self.results, {
-                    text = self:build_setting(i),
-                    callback = function()
-                        self.set_dialog = InputDialog:new{
-                            title = self.defaults_name[i] .. ":",
-                            input = tostring(self.defaults_value[i]),
-                            buttons = {
-                                {
-                                    {
-                                        text = _("Cancel"),
-                                        enabled = true,
-                                        callback = function()
-                                            self:close()
-                                            UIManager:show(menu_container)
-                                        end,
-                                    },
-                                    {
-                                        text = _("OK"),
-                                        enabled = true,
-                                        callback = function()
-                                            if type(_G[self.defaults_name[i]]) == "table" then
-                                                self.defaults_value[i] = self.set_dialog:getInputText()
-                                            elseif _G[self.defaults_name[i]] ~= settype(self.set_dialog:getInputText(),settings_type) then
-                                                _G[self.defaults_name[i]] = settype(self.set_dialog:getInputText(),settings_type)
-                                                self.defaults_value[i] = _G[self.defaults_name[i]]
-                                            end
-                                            settings_changed = true
-                                            self.changed[i] = true
-                                            self.results[i].text = self:build_setting(i)
-                                            self:close()
-                                            self.defaults_menu:swithItemTable("Defaults", self.results, i)
-                                            UIManager:show(menu_container)
-                                        end,
-                                    },
-                                },
-                            },
-                            input_type = settings_type,
-                            width = Screen:getWidth() * 0.95,
-                            height = Screen:getHeight() * 0.2,
-                        }
-                        self.set_dialog:onShowKeyboard()
-                        UIManager:show(self.set_dialog)
-                    end
-                })
+                    },
+                    input_type = setting_type,
+                    width = Screen:getWidth() * 0.95,
+                }
+                self.set_dialog:onShowKeyboard()
+                UIManager:show(self.set_dialog)
             end
+
+            table.insert(self.results, {
+                text = self:build_setting(i),
+                callback = editNumStr
+            })
         end
     end
     self.defaults_menu:swithItemTable("Defaults", self.results)
@@ -279,13 +247,12 @@ function SetDefaults:init()
 end
 
 function SetDefaults:close()
-    self.set_dialog:onClose()
     UIManager:close(self.set_dialog)
 end
 
 function SetDefaults:ConfirmSave()
     UIManager:show(ConfirmBox:new{
-        text = _("Are you sure you want to save the settings to \"defaults.persistent.lua\"?"),
+        text = _('Are you sure you want to save the settings to "defaults.persistent.lua"?'),
         ok_callback = function()
             self:SaveSettings()
         end,
@@ -293,73 +260,64 @@ function SetDefaults:ConfirmSave()
 end
 
 function SetDefaults:build_setting(j)
-    local ret = self.defaults_name[j] .. " = "
-    if type(_G[self.defaults_name[j]]) == "boolean" or type(_G[self.defaults_name[j]]) == "table" then
-        ret = ret .. tostring(self.defaults_value[j])
+    local setting_name = self.defaults_name[j]
+    local ret = setting_name .. " = "
+    if type(_G[setting_name]) == "boolean" then
+        return ret .. tostring(self.defaults_value[j])
+    elseif type(_G[setting_name]) == "table" then
+        return ret .. "{...}"
     elseif tonumber(self.defaults_value[j]) then
-        ret = ret .. tostring(tonumber(self.defaults_value[j]))
+        return ret .. tostring(tonumber(self.defaults_value[j]))
     else
-        ret = ret .. "\"" .. tostring(self.defaults_value[j]) .. "\""
+        return ret .. "\"" .. tostring(self.defaults_value[j]) .. "\""
     end
-    return ret
 end
 
 function SetDefaults:SaveSettings()
-
-    local function fileread(filename,array)
-        local file = io.open(filename)
-        local line = file:read()
-        local counter = 0
-        while line do
-            counter = counter + 1
-            local i = string.find(line,"[-][-]") -- remove comments from file
-            if (i or 0)>1 then line = string.sub(line,1,i-1) end
-            array[counter] = line:gsub("^%s*(.-)%s*$", "%1") -- trim
-            line = file:read()
-        end
-        file:close()
-    end
-
-    local persistent_filename = DataStorage:getDataDir() .. "/defaults.persistent.lua"
-    local file
-    if io.open(persistent_filename,"r") == nil then
-        file = io.open(persistent_filename, "w")
-        file:write("-- For configuration changes that persists between (nightly) releases\n")
+    self.results = {}
+    local persisted_defaults = {}
+    local file = io.open(persistent_filename, "r")
+    if file ~= nil then
         file:close()
+        local load_defaults = loadfile(persistent_filename)
+        setfenv(load_defaults, persisted_defaults)
+        load_defaults()
     end
 
-    local dpl = {}
-    fileread(persistent_filename, dpl)
-    local dl = {}
-    fileread("defaults.lua",dl)
-    self.results = {}
-    local done = {}
-
-    for j=1,#SetDefaults.defaults_name do
-        if not self.changed[j] then done[j] = true end
+    local checked = {}
+    for j=1, #self.defaults_name do
+        if not self.changed[j] then checked[j] = true end
     end
 
-    -- handle case "found in persistent", replace it
-    for i = 1,#dpl do
-        for j=1,#SetDefaults.defaults_name do
-            if not done[j] and string.find(dpl[i],SetDefaults.defaults_name[j] .. " ") == 1 then
-                dpl[i] = self:build_setting(j)
-                done[j] = true
+    -- handle case "found in persistent" and changed, replace it
+    for k, v in pairs(persisted_defaults) do
+        for j=1, #self.defaults_name do
+            if not checked[j]
+            and k == self.defaults_name[j] then
+                persisted_defaults[k] = self.defaults_value[j]
+                checked[j] = true
             end
         end
     end
 
-    -- handle case "not in persistent and different in non-persistent", add to persistent
-    for j=1,#SetDefaults.defaults_name do
-        if not done[j] then
-            dpl[#dpl+1] = self:build_setting(j)
+    -- handle case "not in persistent and different in non-persistent", add to
+    -- persistent
+    for j=1, #self.defaults_name do
+        if not checked[j] then
+            persisted_defaults[self.defaults_name[j]] = self.defaults_value[j]
         end
     end
 
     file = io.open(persistent_filename, "w")
     if file then
-        for i = 1,#dpl do
-            file:write(dpl[i] .. "\n")
+        file:write("-- For configuration changes that persists between updates\n")
+        for k, v in pairs(persisted_defaults) do
+            local line = {}
+            table.insert(line, k)
+            table.insert(line, " = ")
+            table.insert(line, dump(v))
+            table.insert(line, "\n")
+            file:write(table.concat(line))
         end
         file:close()
         UIManager:show(InfoMessage:new{
@@ -368,4 +326,5 @@ function SetDefaults:SaveSettings()
     end
     settings_changed = false
 end
+
 return SetDefaults
diff --git a/frontend/apps/reader/modules/readerfrontlight.lua b/frontend/apps/reader/modules/readerfrontlight.lua
index d19d1c153..7e82cbf65 100644
--- a/frontend/apps/reader/modules/readerfrontlight.lua
+++ b/frontend/apps/reader/modules/readerfrontlight.lua
@@ -116,8 +116,6 @@ function ReaderFrontLight:onShowFlDialog()
             },
         },
         input_type = "number",
-        width = Screen:getWidth() * 0.8,
-        height = Screen:getHeight() * 0.2,
     }
     self.fl_dialog:onShowKeyboard()
     UIManager:show(self.fl_dialog)
diff --git a/frontend/apps/reader/modules/readergoto.lua b/frontend/apps/reader/modules/readergoto.lua
index ea14d6fbc..9c48567d0 100644
--- a/frontend/apps/reader/modules/readergoto.lua
+++ b/frontend/apps/reader/modules/readergoto.lua
@@ -1,7 +1,6 @@
 local InputContainer = require("ui/widget/container/inputcontainer")
 local InputDialog = require("ui/widget/inputdialog")
 local UIManager = require("ui/uimanager")
-local Screen = require("device").screen
 local Event = require("ui/event")
 local _ = require("gettext")
 
@@ -58,15 +57,12 @@ function ReaderGoto:onShowGotoDialog()
         },
         input_type = "number",
         enter_callback = function() self:gotoPage() end,
-        width = Screen:getWidth() * 0.8,
-        height = Screen:getHeight() * 0.2,
     }
     self.goto_dialog:onShowKeyboard()
     UIManager:show(self.goto_dialog)
 end
 
 function ReaderGoto:close()
-    self.goto_dialog:onClose()
     UIManager:close(self.goto_dialog)
 end
 
diff --git a/frontend/apps/reader/readerui.lua b/frontend/apps/reader/readerui.lua
index d98664342..16eb91313 100644
--- a/frontend/apps/reader/readerui.lua
+++ b/frontend/apps/reader/readerui.lua
@@ -426,8 +426,6 @@ function ReaderUI:unlockDocumentWithPassword(document, try_again)
             },
         },
         text_type = "password",
-        width = Screen:getWidth() * 0.8,
-        height = Screen:getHeight() * 0.2,
     }
     self.password_dialog:onShowKeyboard()
     UIManager:show(self.password_dialog)
diff --git a/frontend/dump.lua b/frontend/dump.lua
index 91eff5ebb..4e5f77413 100644
--- a/frontend/dump.lua
+++ b/frontend/dump.lua
@@ -4,6 +4,7 @@ simple serialization function, won't do uservalues, functions, loops
 
 local isUbuntuTouch = os.getenv("UBUNTU_APPLICATION_ISOLATION") ~= nil
 local insert = table.insert
+local indent_prefix = "    "
 
 local function _serialize(what, outt, indent, max_lv, history)
     if not max_lv then
@@ -19,7 +20,7 @@ local function _serialize(what, outt, indent, max_lv, history)
         for up, item in ipairs(history) do
             if item == what then
                 insert(outt, "nil --[[ LOOP:\n")
-                insert(outt, string.rep("\t", indent - up))
+                insert(outt, string.rep(indent_prefix, indent - up))
                 insert(outt, "^------- ]]")
                 return
             end
@@ -32,7 +33,7 @@ local function _serialize(what, outt, indent, max_lv, history)
                 insert(outt, ",")
             end
             insert(outt, "\n")
-            insert(outt, string.rep("\t", indent+1))
+            insert(outt, string.rep(indent_prefix, indent+1))
             insert(outt, "[")
             _serialize(k, outt, indent+1, max_lv, new_history)
             insert(outt, "] = ")
@@ -41,7 +42,7 @@ local function _serialize(what, outt, indent, max_lv, history)
         end
         if didrun then
             insert(outt, "\n")
-            insert(outt, string.rep("\t", indent))
+            insert(outt, string.rep(indent_prefix, indent))
         end
         insert(outt, "}")
     elseif type(what) == "string" then
diff --git a/frontend/ui/widget/bookstatuswidget.lua b/frontend/ui/widget/bookstatuswidget.lua
index 9ad75146f..487cf268b 100644
--- a/frontend/ui/widget/bookstatuswidget.lua
+++ b/frontend/ui/widget/bookstatuswidget.lua
@@ -545,15 +545,12 @@ function BookStatusWidget:onSwitchFocus(inputbox)
         enter_callback = function()
             self:closeInputDialog()
         end,
-        width = Screen:getWidth() * 0.8,
-        height = Screen:getHeight() * 0.2,
     }
     self.note_dialog:onShowKeyboard()
     UIManager:show(self.note_dialog)
 end
 
 function BookStatusWidget:closeInputDialog()
-    self.note_dialog:onClose()
     UIManager:close(self.note_dialog)
 end
 
diff --git a/frontend/ui/widget/container/inputcontainer.lua b/frontend/ui/widget/container/inputcontainer.lua
index 615fcc39c..83d6167a6 100644
--- a/frontend/ui/widget/container/inputcontainer.lua
+++ b/frontend/ui/widget/container/inputcontainer.lua
@@ -1,6 +1,5 @@
 local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local UIManager = require("ui/uimanager")
-local Screen = require("device").screen
 local Geom = require("ui/geometry")
 local Event = require("ui/event")
 local _ = require("gettext")
@@ -128,15 +127,12 @@ function InputContainer:onInput(input)
             input.callback(self.input_dialog:getInputText())
             self:closeInputDialog()
         end,
-        width = Screen:getWidth() * 0.8,
-        height = Screen:getHeight() * 0.2,
     }
     self.input_dialog:onShowKeyboard()
     UIManager:show(self.input_dialog)
 end
 
 function InputContainer:closeInputDialog()
-    self.input_dialog:onClose()
     UIManager:close(self.input_dialog)
 end
 
diff --git a/frontend/ui/widget/dictquicklookup.lua b/frontend/ui/widget/dictquicklookup.lua
index cdbb0c5e5..1ef3d0b08 100644
--- a/frontend/ui/widget/dictquicklookup.lua
+++ b/frontend/ui/widget/dictquicklookup.lua
@@ -424,8 +424,6 @@ function DictQuickLookup:lookupInputWord(hint)
             self:closeInputDialog()
             self:inputLookup()
         end,
-        width = Screen:getWidth() * 0.8,
-        height = Screen:getHeight() * 0.2,
     }
     self.input_dialog:onShowKeyboard()
     UIManager:show(self.input_dialog)
@@ -440,7 +438,6 @@ function DictQuickLookup:inputLookup()
 end
 
 function DictQuickLookup:closeInputDialog()
-    self.input_dialog:onClose()
     UIManager:close(self.input_dialog)
 end
 
diff --git a/frontend/ui/widget/inputdialog.lua b/frontend/ui/widget/inputdialog.lua
index 247818f60..338dd0457 100644
--- a/frontend/ui/widget/inputdialog.lua
+++ b/frontend/ui/widget/inputdialog.lua
@@ -1,3 +1,40 @@
+--[[--
+Widget for taking user input.
+
+Example:
+
+    local _ = require("gettext")
+    local UIManager = require("ui/uimanager")
+    local sample_input
+    local saveHandler = function()
+        print('Got user input:', sample_input:getInputText())
+    end
+    sample_input = InputDialog:new{
+        title = _("Dialog title"),
+        input = "default value",
+        input_hint = "hint text",
+        input_type = "text",
+        buttons = {
+            {
+                {
+                    text = _("Cancel"),
+                    callback = function()
+                        UIManager:close(sample_input)
+                    end,
+                },
+                {
+                    text = _("Save"),
+                    callback = saveHandler,
+                },
+            }
+        },
+        enter_callback = saveHandler,
+    }
+    sample_input:onShowKeyboard()
+    UIManager:show(sample_input)
+
+]]
+
 local InputContainer = require("ui/widget/container/inputcontainer")
 local FrameContainer = require("ui/widget/container/framecontainer")
 local CenterContainer = require("ui/widget/container/centercontainer")
@@ -38,6 +75,7 @@ local InputDialog = InputContainer:new{
 }
 
 function InputDialog:init()
+    self.width = self.width or Screen:getWidth() * 0.8
     local title_width = RenderText:sizeUtf8Text(0, self.width,
             self.title_face, self.title, true).x
     if title_width > self.width then
@@ -78,7 +116,6 @@ function InputDialog:init()
         show_parent = self,
     }
     self.title_bar = LineWidget:new{
-        --background = Blitbuffer.gray(0.5),
         dimen = Geom:new{
             w = self.button_table:getSize().w + self.button_padding,
             h = Screen:scaleBySize(2),
@@ -138,6 +175,7 @@ function InputDialog:onShow()
 end
 
 function InputDialog:onCloseWidget()
+    self:onClose()
     UIManager:setDirty(nil, function()
         return "partial", self.dialog_frame.dimen
     end)
diff --git a/frontend/ui/widget/multiinputdialog.lua b/frontend/ui/widget/multiinputdialog.lua
index eb479d0c0..f7f7bbf4b 100644
--- a/frontend/ui/widget/multiinputdialog.lua
+++ b/frontend/ui/widget/multiinputdialog.lua
@@ -40,7 +40,7 @@ function MultiInputDialog:init()
             scroll = false,
             parent = self,
         }
-        table.insert(VerticalGroupData,CenterContainer:new{
+        table.insert(VerticalGroupData, CenterContainer:new{
             dimen = Geom:new{
                 w = self.title_bar:getSize().w,
                 h = input_field[k]:getSize().h,
diff --git a/spec/unit/defaults_spec.lua b/spec/unit/defaults_spec.lua
new file mode 100644
index 000000000..bda9c28f1
--- /dev/null
+++ b/spec/unit/defaults_spec.lua
@@ -0,0 +1,90 @@
+describe("defaults module", function()
+    local Defaults, DataStorage
+    setup(function()
+        require("commonrequire")
+        Defaults = require("apps/filemanager/filemanagersetdefaults")
+        DataStorage = require("datastorage")
+    end)
+
+    it("should load all defaults from defaults.lua", function()
+        Defaults:init()
+        assert.is_same(#Defaults.defaults_name, 78)
+        assert.is_same(Defaults.defaults_name[29], 'DHINTCOUNT')
+    end)
+
+    it("should save changes to defaults.persistent.lua", function()
+        local persistent_filename = DataStorage:getDataDir() .. "/defaults.persistent.lua"
+        os.remove(persistent_filename)
+
+        -- not in persistent but checked in defaults
+        Defaults.changed[14] = true
+        Defaults.changed[19] = true
+        Defaults.changed[29] = true
+        Defaults.changed[64] = true
+        Defaults.changed[78] = true
+        Defaults:SaveSettings()
+        assert.is_same(#Defaults.defaults_name, 78)
+        assert.is_same(Defaults.defaults_name[29], 'DHINTCOUNT')
+        assert.is_same(Defaults.defaults_name[78], 'SEARCH_TITLE')
+        assert.is_same(Defaults.defaults_name[64], 'DTAP_ZONE_MENU')
+        assert.is_same(Defaults.defaults_name[19], 'DCREREADER_VIEW_MODE')
+        assert.is_same(Defaults.defaults_name[14],
+                       'DCREREADER_CONFIG_MARGIN_SIZES_LARGE')
+        local fd = io.open(persistent_filename, "r")
+        assert.Equals(
+[[-- For configuration changes that persists between updates
+SEARCH_TITLE = true
+DCREREADER_CONFIG_MARGIN_SIZES_LARGE = {
+    [1] = 20,
+    [2] = 20,
+    [3] = 20,
+    [4] = 20
+}
+DCREREADER_VIEW_MODE = "page"
+DHINTCOUNT = 1
+DTAP_ZONE_MENU = {
+    ["y"] = 0,
+    ["x"] = 0.125,
+    ["h"] = 0.25,
+    ["w"] = 0.75
+}
+]],
+                       fd:read("*a"))
+        fd:close()
+
+        -- in persistent
+        Defaults:init()
+        Defaults.changed[29] = true
+        Defaults.defaults_value[29] = 2
+        Defaults.changed[64] = true
+        Defaults.defaults_value[64] = {
+            y = 10,
+            x = 10.125,
+            h = 20.25,
+            w = 20.75
+        }
+        Defaults:SaveSettings()
+        fd = io.open(persistent_filename)
+        assert.Equals(
+[[-- For configuration changes that persists between updates
+SEARCH_TITLE = true
+DHINTCOUNT = 2
+DTAP_ZONE_MENU = {
+    ["y"] = 10,
+    ["x"] = 10.125,
+    ["h"] = 20.25,
+    ["w"] = 20.75
+}
+DCREREADER_CONFIG_MARGIN_SIZES_LARGE = {
+    [1] = 20,
+    [2] = 20,
+    [3] = 20,
+    [4] = 20
+}
+DCREREADER_VIEW_MODE = "page"
+]],
+                       fd:read("*a"))
+        fd:close()
+        os.remove(persistent_filename)
+    end)
+end)