Clarify our OOP semantics across the codebase (#9586)

Basically: * Use `extend` for class definitions * Use `new` for object instantiations That includes some minor code cleanups along the way: * Updated `Widget`'s docs to make the semantics clearer. * Removed `should_restrict_JIT` (it's been dead code since https://github.com/koreader/android-luajit-launcher/pull/283) * Minor refactoring of LuaSettings/LuaData/LuaDefaults/DocSettings to behave (mostly, they are instantiated via `open` instead of `new`) like everything else and handle inheritance properly (i.e., DocSettings is now a proper LuaSettings subclass). * Default to `WidgetContainer` instead of `InputContainer` for stuff that doesn't actually setup key/gesture events. * Ditto for explicit `*Listener` only classes, make sure they're based on `EventListener` instead of something uselessly fancier. * Unless absolutely necessary, do not store references in class objects, ever; only values. Instead, always store references in instances, to avoid both sneaky inheritance issues, and sneaky GC pinning of stale references. * ReaderUI: Fix one such issue with its `active_widgets` array, with critical implications, as it essentially pinned *all* of ReaderUI's modules, including their reference to the `Document` instance (i.e., that was a big-ass leak). * Terminal: Make sure the shell is killed on plugin teardown. * InputText: Fix Home/End/Del physical keys to behave sensibly. * InputContainer/WidgetContainer: If necessary, compute self.dimen at paintTo time (previously, only InputContainers did, which might have had something to do with random widgets unconcerned about input using it as a baseclass instead of WidgetContainer...). * OverlapGroup: Compute self.dimen at *init* time, because for some reason it needs to do that, but do it directly in OverlapGroup instead of going through a weird WidgetContainer method that it was the sole user of. * ReaderCropping: Under no circumstances should a Document instance member (here, self.bbox) risk being `nil`ed! * Kobo: Minor code cleanups.
2025-08-10 00:52:38 +00:00 · 2022-10-06 02:14:48 +02:00
parent 7b9f02e1ac
commit fadee1f5dc
223 changed files with 849 additions and 985 deletions
--- a/frontend/apps/reader/modules/readerback.lua
+++ b/frontend/apps/reader/modules/readerback.lua
@@ -13,8 +13,8 @@ local _ = require("gettext")
 -- additionally handles a location stack for each visited page or
 -- page view change (when scrolling in a same page)

-local ReaderBack = EventListener:new{
-    location_stack = {},
+local ReaderBack = EventListener:extend{
+    location_stack = nil, -- array
    -- a limit not intended to be a practical limit but just a failsafe
    max_stack = 5000,
 }
--- a/frontend/apps/reader/modules/readerbookmark.lua
+++ b/frontend/apps/reader/modules/readerbookmark.lua
@@ -31,7 +31,7 @@ local DISPLAY_PREFIX = {
    bookmark = "\u{F097}\u{2002}", -- "empty bookmark"
 }

-local ReaderBookmark = InputContainer:new{
+local ReaderBookmark = InputContainer:extend{
    bookmarks_items_per_page_default = 14,
    bookmarks = nil,
 }
--- a/frontend/apps/reader/modules/readerconfig.lua
+++ b/frontend/apps/reader/modules/readerconfig.lua
@@ -1,14 +1,13 @@
 local ConfigDialog = require("ui/widget/configdialog")
 local Device = require("device")
 local Event = require("ui/event")
-local Geom = require("ui/geometry")
 local InputContainer = require("ui/widget/container/inputcontainer")
 local UIManager = require("ui/uimanager")
 local CreOptions = require("ui/data/creoptions")
 local KoptOptions = require("ui/data/koptoptions")
 local _ = require("gettext")

-local ReaderConfig = InputContainer:new{
+local ReaderConfig = InputContainer:extend{
    last_panel_index = 1,
 }

@@ -20,7 +19,6 @@ function ReaderConfig:init()
    end
    self.configurable:loadDefaults(self.options)

-    if not self.dimen then self.dimen = Geom:new{} end
    if Device:hasKeys() then
        self.key_events = {
            ShowConfigMenu = { {{"Press","AA"}}, doc = "show config dialog" },
@@ -120,7 +118,6 @@ end

 function ReaderConfig:onShowConfigMenu()
    self.config_dialog = ConfigDialog:new{
-        dimen = self.dimen:copy(),
        document = self.document,
        ui = self.ui,
        configurable = self.configurable,
--- a/frontend/apps/reader/modules/readercoptlistener.lua
+++ b/frontend/apps/reader/modules/readercoptlistener.lua
@@ -8,7 +8,7 @@ local logger = require("logger")
 local T = require("ffi/util").template
 local _ = require("gettext")

-local ReaderCoptListener = EventListener:new{}
+local ReaderCoptListener = EventListener:extend{}

 local CRE_HEADER_DEFAULT_SIZE = 20

--- a/frontend/apps/reader/modules/readercropping.lua
+++ b/frontend/apps/reader/modules/readercropping.lua
@@ -5,15 +5,15 @@ local CenterContainer = require("ui/widget/container/centercontainer")
 local Event = require("ui/event")
 local FrameContainer = require("ui/widget/container/framecontainer")
 local Geom = require("ui/geometry")
-local InputContainer = require("ui/widget/container/inputcontainer")
 local Math = require("optmath")
 local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local VerticalGroup = require("ui/widget/verticalgroup")
 local Device = require("device")
 local Screen = Device.screen
 local _ = require("gettext")

-local ReaderCropping = InputContainer:new{}
+local ReaderCropping = WidgetContainer:extend{}

 function ReaderCropping:onPageCrop(mode)
    self.ui:handleEvent(Event:new("CloseConfigMenu"))
@@ -171,7 +171,9 @@ function ReaderCropping:setZoomMode(mode)
 end

 function ReaderCropping:onReadSettings(config)
-    self.document.bbox = config:readSetting("bbox")
+    if config:has("bbox") then
+        self.document.bbox = config:readSetting("bbox")
+    end
 end

 function ReaderCropping:onSaveSettings()
--- a/frontend/apps/reader/modules/readerdevicestatus.lua
+++ b/frontend/apps/reader/modules/readerdevicestatus.lua
@@ -2,15 +2,15 @@ local ConfirmBox = require("ui/widget/confirmbox")
 local Device = require("device")
 local Event = require("ui/event")
 local InfoMessage = require("ui/widget/infomessage")
-local InputContainer = require("ui/widget/container/inputcontainer")
 local SpinWidget = require("ui/widget/spinwidget")
 local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local powerd = Device:getPowerDevice()
 local _ = require("gettext")
 local C_ = _.pgettext
 local T = require("ffi/util").template

-local ReaderDeviceStatus = InputContainer:new{
+local ReaderDeviceStatus = WidgetContainer:extend{
    battery_confirm_box = nil,
    memory_confirm_box = nil,
 }
--- a/frontend/apps/reader/modules/readerdictionary.lua
+++ b/frontend/apps/reader/modules/readerdictionary.lua
@@ -6,7 +6,6 @@ local DictQuickLookup = require("ui/widget/dictquicklookup")
 local Event = require("ui/event")
 local Geom = require("ui/geometry")
 local InfoMessage = require("ui/widget/infomessage")
-local InputContainer = require("ui/widget/container/inputcontainer")
 local InputDialog = require("ui/widget/inputdialog")
 local JSON = require("json")
 local KeyValuePage = require("ui/widget/keyvaluepage")
@@ -16,6 +15,7 @@ local NetworkMgr = require("ui/network/manager")
 local SortWidget = require("ui/widget/sortwidget")
 local Trapper = require("ui/trapper")
 local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local ffi = require("ffi")
 local C = ffi.C
 local ffiUtil  = require("ffi/util")
@@ -60,9 +60,9 @@ local function getIfosInDir(path)
    return ifos
 end

-local ReaderDictionary = InputContainer:new{
+local ReaderDictionary = WidgetContainer:extend{
    data_dir = nil,
-    dict_window_list = {},
+    dict_window_list = nil, -- array
    lookup_msg = _("Searching dictionary for:\n%1"),
 }

@@ -100,6 +100,7 @@ local function getDictionaryFixHtmlFunc(path)
 end

 function ReaderDictionary:init()
+    self.dict_window_list = {}
    self.disable_lookup_history = G_reader_settings:isTrue("disable_lookup_history")
    self.dicts_order = G_reader_settings:readSetting("dicts_order", {})
    self.dicts_disabled = G_reader_settings:readSetting("dicts_disabled", {})
@@ -156,7 +157,7 @@ function ReaderDictionary:init()
    self:updateSdcvDictNamesOptions()

    if not lookup_history then
-        lookup_history = LuaData:open(DataStorage:getSettingsDir() .. "/lookup_history.lua", { name = "LookupHistory" })
+        lookup_history = LuaData:open(DataStorage:getSettingsDir() .. "/lookup_history.lua", "LookupHistory")
    end
 end

--- a/frontend/apps/reader/modules/readerdogear.lua
+++ b/frontend/apps/reader/modules/readerdogear.lua
@@ -2,13 +2,13 @@ local BD = require("ui/bidi")
 local Device = require("device")
 local Geom = require("ui/geometry")
 local IconWidget = require("ui/widget/iconwidget")
-local InputContainer = require("ui/widget/container/inputcontainer")
 local RightContainer = require("ui/widget/container/rightcontainer")
 local VerticalGroup = require("ui/widget/verticalgroup")
 local VerticalSpan = require("ui/widget/verticalspan")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local Screen = Device.screen

-local ReaderDogear = InputContainer:new{}
+local ReaderDogear = WidgetContainer:extend{}

 function ReaderDogear:init()
    -- This image could be scaled for DPI (with scale_for_dpi=true, scale_factor=0.7),
--- a/frontend/apps/reader/modules/readerflipping.lua
+++ b/frontend/apps/reader/modules/readerflipping.lua
@@ -1,10 +1,10 @@
 local Geom = require("ui/geometry")
 local IconWidget = require("ui/widget/iconwidget")
-local InputContainer = require("ui/widget/container/inputcontainer")
 local LeftContainer = require("ui/widget/container/leftcontainer")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local Screen = require("device").screen

-local ReaderFlipping = InputContainer:new{
+local ReaderFlipping = WidgetContainer:extend{
    orig_reflow_mode = 0,
 }

--- a/frontend/apps/reader/modules/readerfont.lua
+++ b/frontend/apps/reader/modules/readerfont.lua
@@ -19,7 +19,7 @@ local _ = require("gettext")
 local C_ = _.pgettext
 local optionsutil = require("ui/data/optionsutil")

-local ReaderFont = InputContainer:new{
+local ReaderFont = InputContainer:extend{
    font_face = nil,
    font_size = nil,
    line_space_percent = nil,
--- a/frontend/apps/reader/modules/readerfooter.lua
+++ b/frontend/apps/reader/modules/readerfooter.lua
@@ -444,7 +444,7 @@ local ReaderFooter = WidgetContainer:extend{
    height = Screen:scaleBySize(G_defaults:readSetting("DMINIBAR_CONTAINER_HEIGHT")),
    horizontal_margin = Size.span.horizontal_default,
    bottom_padding = Size.padding.tiny,
-    settings = {},
+    settings = nil, -- table
    -- added to expose them to unit tests
    textGeneratorMap = footerTextGeneratorMap,
 }
--- a/frontend/apps/reader/modules/readergoto.lua
+++ b/frontend/apps/reader/modules/readergoto.lua
@@ -1,13 +1,12 @@
 local Event = require("ui/event")
-local InputContainer = require("ui/widget/container/inputcontainer")
 local InputDialog = require("ui/widget/inputdialog")
 local SkimToWidget = require("ui/widget/skimtowidget")
 local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local _ = require("gettext")
 local T = require("ffi/util").template

-local ReaderGoto = InputContainer:new{
-}
+local ReaderGoto = WidgetContainer:extend{}

 function ReaderGoto:init()
    self.ui.menu:registerToMainMenu(self)
--- a/frontend/apps/reader/modules/readerhighlight.lua
+++ b/frontend/apps/reader/modules/readerhighlight.lua
@@ -20,8 +20,7 @@ local C_ = _.pgettext
 local T = require("ffi/util").template
 local Screen = Device.screen

-local ReaderHighlight = InputContainer:new{
-}
+local ReaderHighlight = InputContainer:extend{}

 local function inside_box(pos, box)
    if pos then
--- a/frontend/apps/reader/modules/readerhinting.lua
+++ b/frontend/apps/reader/modules/readerhinting.lua
@@ -2,10 +2,14 @@ local EventListener = require("ui/widget/eventlistener")

 local DHINTCOUNT = G_defaults:readSetting("DHINTCOUNT")

-local ReaderHinting = EventListener:new{
-    hinting_states = {}
+local ReaderHinting = EventListener:extend{
+    hinting_states = nil, -- array
 }

+function ReaderHinting:init()
+    self.hinting_states = {}
+end
+
 function ReaderHinting:onHintPage()
    if not self.view.hinting then return true end
    for i=1, DHINTCOUNT do
--- a/frontend/apps/reader/modules/readerkoptlistener.lua
+++ b/frontend/apps/reader/modules/readerkoptlistener.lua
@@ -4,7 +4,7 @@ local ReaderZooming = require("apps/reader/modules/readerzooming")
 local UIManager = require("ui/uimanager")
 local util = require("util")

-local ReaderKoptListener = EventListener:new{}
+local ReaderKoptListener = EventListener:extend{}

 function ReaderKoptListener:setZoomMode(zoom_mode)
    if self.document.configurable.text_wrap == 1 then
--- a/frontend/apps/reader/modules/readerlink.lua
+++ b/frontend/apps/reader/modules/readerlink.lua
@@ -21,8 +21,8 @@ local _ = require("gettext")
 local Screen = Device.screen
 local T = ffiutil.template

-local ReaderLink = InputContainer:new{
-    location_stack = {}
+local ReaderLink = InputContainer:extend{
+    location_stack = nil, -- table, per-instance
 }

 function ReaderLink:init()
@@ -154,7 +154,7 @@ function ReaderLink:addToMainMenu(menu_items)
    -- insert table to main reader menu
    menu_items.go_to_previous_location = {
        text = _("Go back to previous location"),
-        enabled_func = function() return #self.location_stack > 0 end,
+        enabled_func = function() return self.location_stack and #self.location_stack > 0 end,
        callback = function() self:onGoBackLink() end,
        hold_callback = function(touchmenu_instance)
            UIManager:show(ConfirmBox:new{
--- a/frontend/apps/reader/modules/readermenu.lua
+++ b/frontend/apps/reader/modules/readermenu.lua
@@ -13,10 +13,10 @@ local Screen = Device.screen
 local _ = require("gettext")
 local T = require("ffi/util").template

-local ReaderMenu = InputContainer:new{
+local ReaderMenu = InputContainer:extend{
    tab_item_table = nil,
-    menu_items = {},
-    registered_widgets = {},
+    menu_items = nil, -- table, mandatory
+    registered_widgets = nil, -- array
 }

 function ReaderMenu:init()
--- a/frontend/apps/reader/modules/readerpagemap.lua
+++ b/frontend/apps/reader/modules/readerpagemap.lua
@@ -6,18 +6,18 @@ local Font = require("ui/font")
 local FrameContainer = require("ui/widget/container/framecontainer")
 local Geom = require("ui/geometry")
 local GestureRange = require("ui/gesturerange")
-local InputContainer = require("ui/widget/container/inputcontainer")
 local Menu = require("ui/widget/menu")
 local MultiConfirmBox = require("ui/widget/multiconfirmbox")
 local OverlapGroup = require("ui/widget/overlapgroup")
 local TextBoxWidget = require("ui/widget/textboxwidget")
 local TextWidget = require("ui/widget/textwidget")
 local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local Screen = Device.screen
 local T = require("ffi/util").template
 local _ = require("gettext")

-local ReaderPageMap = InputContainer:new{
+local ReaderPageMap = WidgetContainer:extend{
    label_font_face = "ffont",
    label_default_font_size = 14,
    -- Black so it's readable (and non-gray-flashing on GloHD)
--- a/frontend/apps/reader/modules/readerpaging.lua
+++ b/frontend/apps/reader/modules/readerpaging.lua
@@ -27,7 +27,7 @@ local function copyPageState(page_state)
 end


-local ReaderPaging = InputContainer:new{
+local ReaderPaging = InputContainer:extend{
    pan_rate = 30,  -- default 30 ops, will be adjusted in readerui
    current_page = 0,
    number_of_pages = 0,
@@ -37,7 +37,7 @@ local ReaderPaging = InputContainer:new{

    page_flipping_mode = false,
    bookmark_flipping_mode = false,
-    flip_steps = {0,1,2,5,10,20,50,100},
+    flip_steps = {0, 1, 2, 5, 10, 20, 50, 100},
 }

 function ReaderPaging:init()
--- a/frontend/apps/reader/modules/readerpanning.lua
+++ b/frontend/apps/reader/modules/readerpanning.lua
@@ -2,7 +2,7 @@ local InputContainer = require("ui/widget/container/inputcontainer")
 local Device = require("device")
 local _ = require("gettext")

-local ReaderPanning = InputContainer:new{
+local ReaderPanning = InputContainer:extend{
    -- defaults
    panning_steps = {
        normal = 50,
--- a/frontend/apps/reader/modules/readerrolling.lua
+++ b/frontend/apps/reader/modules/readerrolling.lua
@@ -39,12 +39,12 @@ local band = bit.band
    it in explicit page turning. And use that xpointer for non-page-turning
    rendering.
 --]]
-local ReaderRolling = InputContainer:new{
+local ReaderRolling = InputContainer:extend{
    pan_rate = 30,  -- default 30 ops, will be adjusted in readerui
    rendering_hash = 0,
    current_pos = 0,
    -- only used for page view mode
-    current_page= nil,
+    current_page = nil,
    xpointer = nil,
    panning_steps = ReaderPanning.panning_steps,
    cre_top_bar_enabled = false,
--- a/frontend/apps/reader/modules/readerrotation.lua
+++ b/frontend/apps/reader/modules/readerrotation.lua
@@ -3,8 +3,8 @@ local Device = require("device")
 local Event = require("ui/event")
 local _ = require("gettext")

-local ReaderRotation = InputContainer:new{
-    current_rotation = 0
+local ReaderRotation = InputContainer:extend{
+    current_rotation = 0,
 }

 function ReaderRotation:init()
--- a/frontend/apps/reader/modules/readerscrolling.lua
+++ b/frontend/apps/reader/modules/readerscrolling.lua
@@ -1,7 +1,7 @@
 local Device = require("device")
 local Event = require("ui/event")
-local InputContainer = require("ui/widget/container/inputcontainer")
 local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local logger = require("logger")
 local time = require("ui/time")
 local _ = require("gettext")
@@ -16,7 +16,7 @@ local SCROLL_METHOD_CLASSIC = "classic"
 local SCROLL_METHOD_TURBO = "turbo"
 local SCROLL_METHOD_ON_RELEASE = "on_release"

-local ReaderScrolling = InputContainer:new{
+local ReaderScrolling = WidgetContainer:extend{
    -- Available scrolling methods (make them available to other reader modules)
    SCROLL_METHOD_CLASSIC = SCROLL_METHOD_CLASSIC,
    SCROLL_METHOD_TURBO = SCROLL_METHOD_TURBO,
@@ -221,9 +221,6 @@ function ReaderScrolling:applyScrollSettings()
 end

 function ReaderScrolling:setupTouchZones()
-    self.ges_events = {}
-    self.onGesture = nil
-
    local zones = {
        {
            id = "inertial_scrolling_touch",
--- a/frontend/apps/reader/modules/readersearch.lua
+++ b/frontend/apps/reader/modules/readersearch.lua
@@ -3,10 +3,10 @@ local ButtonDialog = require("ui/widget/buttondialog")
 local CheckButton = require("ui/widget/checkbutton")
 local Device = require("device")
 local InfoMessage = require("ui/widget/infomessage")
-local InputContainer = require("ui/widget/container/inputcontainer")
 local InputDialog = require("ui/widget/inputdialog")
 local Notification = require("ui/widget/notification")
 local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local logger = require("logger")
 local _ = require("gettext")
 local Screen = Device.screen
@@ -14,7 +14,7 @@ local T = require("ffi/util").template

 local DGENERIC_ICON_SIZE = G_defaults:readSetting("DGENERIC_ICON_SIZE")

-local ReaderSearch = InputContainer:new{
+local ReaderSearch = WidgetContainer:extend{
    direction = 0, -- 0 for search forward, 1 for search backward
    case_insensitive = true, -- default to case insensitive

--- a/frontend/apps/reader/modules/readerstatus.lua
+++ b/frontend/apps/reader/modules/readerstatus.lua
@@ -4,22 +4,16 @@ local ButtonDialogTitle = require("ui/widget/buttondialogtitle")
 local Device = require("device")
 local Event = require("ui/event")
 local InfoMessage = require("ui/widget/infomessage")
-local InputContainer = require("ui/widget/container/inputcontainer")
 local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local util = require("util")
 local _ = require("gettext")
 local T = require("ffi/util").template

-local ReaderStatus = InputContainer:new {
+local ReaderStatus = WidgetContainer:extend{
    document = nil,
-    summary = {
-        rating = 0,
-        note = nil,
-        status = "",
-        modified = "",
-    },
    enabled = true,
-    total_pages = 0
+    total_pages = 0,
 }

 function ReaderStatus:init()
--- a/frontend/apps/reader/modules/readerstyletweak.lua
+++ b/frontend/apps/reader/modules/readerstyletweak.lua
@@ -19,6 +19,7 @@ local TextBoxWidget = require("ui/widget/textboxwidget")
 local UIManager = require("ui/uimanager")
 local VerticalGroup = require("ui/widget/verticalgroup")
 local VerticalSpan = require("ui/widget/verticalspan")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local lfs = require("libs/libkoreader-lfs")
 local logger = require("logger")
 local util = require("util")
@@ -27,7 +28,7 @@ local Screen = Device.screen
 local T = require("ffi/util").template

 -- Simple widget for showing tweak info
-local TweakInfoWidget = InputContainer:new{
+local TweakInfoWidget = InputContainer:extend{
    tweak = nil,
    is_global_default = nil,
    toggle_global_default_callback = function() end,
@@ -226,7 +227,7 @@ end

 -- Reader component for managing tweaks. The aggregated css_text
 -- is actually requested from us and applied by ReaderTypeset
-local ReaderStyleTweak = InputContainer:new{
+local ReaderStyleTweak = WidgetContainer:extend{
    tweaks_by_id = nil,
    tweaks_table = nil, -- sub-menu items
    nb_enabled_tweaks = 0, -- for use by main menu item
--- a/frontend/apps/reader/modules/readerthumbnail.lua
+++ b/frontend/apps/reader/modules/readerthumbnail.lua
@@ -2,11 +2,11 @@ local Blitbuffer = require("ffi/blitbuffer")
 local Cache = require("cache")
 local Device = require("device")
 local Geom = require("ui/geometry")
-local InputContainer = require("ui/widget/container/inputcontainer")
 local Persist = require("persist")
 local RenderImage = require("ui/renderimage")
 local TileCacheItem = require("document/tilecacheitem")
 local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local Screen = Device.screen
 local ffiutil = require("ffi/util")
 local logger = require("logger")
@@ -18,7 +18,7 @@ local _ = require("gettext")
 -- It handles launching via the menu or Dispatcher/Gestures two fullscreen
 -- widgets related to showing pages and thumbnails that will make use of
 -- its services: BookMap and PageBrowser.
-local ReaderThumbnail = InputContainer:new{}
+local ReaderThumbnail = WidgetContainer:extend{}

 function ReaderThumbnail:init()
    if not Device:isTouchDevice() then
--- a/frontend/apps/reader/modules/readertoc.lua
+++ b/frontend/apps/reader/modules/readertoc.lua
@@ -20,15 +20,15 @@ local N_ = _.ngettext
 local Screen = Device.screen
 local T = require("ffi/util").template

-local ReaderToc = InputContainer:new{
+local ReaderToc = InputContainer:extend{
    toc = nil,
    toc_depth = nil,
    ticks = nil,
    ticks_flattened = nil,
    ticks_flattened_filtered = nil,
-    collapsed_toc = {},
+    collapsed_toc = nil, -- table
    collapse_depth = 2,
-    expanded_nodes = {},
+    expanded_nodes = nil, -- table
    toc_menu_title = _("Table of contents"),
    alt_toc_menu_title = _("Table of contents *"),
    toc_items_per_page_default = 14,
--- a/frontend/apps/reader/modules/readertypeset.lua
+++ b/frontend/apps/reader/modules/readertypeset.lua
@@ -2,10 +2,10 @@ local BD = require("ui/bidi")
 local ConfirmBox = require("ui/widget/confirmbox")
 local Event = require("ui/event")
 local InfoMessage = require("ui/widget/infomessage")
-local InputContainer = require("ui/widget/container/inputcontainer")
-local UIManager = require("ui/uimanager")
 local Math = require("optmath")
 local Notification = require("ui/widget/notification")
+local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local lfs = require("libs/libkoreader-lfs")
 local optionsutil = require("ui/data/optionsutil")
 local _ = require("gettext")
@@ -13,7 +13,7 @@ local C_ = _.pgettext
 local Screen = require("device").screen
 local T = require("ffi/util").template

-local ReaderTypeset = InputContainer:new{
+local ReaderTypeset = WidgetContainer:extend{
    -- @translators This is style in the sense meant by CSS (cascading style sheets), relating to the layout and presentation of the document. See <https://en.wikipedia.org/wiki/CSS> for more information.
    css_menu_title = C_("CSS", "Style"),
    css = nil,
--- a/frontend/apps/reader/modules/readertypography.lua
+++ b/frontend/apps/reader/modules/readertypography.lua
@@ -2,9 +2,9 @@ local BD = require("ui/bidi")
 local Device = require("device")
 local Event = require("ui/event")
 local InfoMessage = require("ui/widget/infomessage")
-local InputContainer = require("ui/widget/container/inputcontainer")
 local MultiConfirmBox = require("ui/widget/multiconfirmbox")
 local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local logger = require("logger")
 local util = require("util")
 local _ = require("gettext")
@@ -12,7 +12,7 @@ local C_ = _.pgettext
 local T = require("ffi/util").template
 local Screen = Device.screen

-local ReaderTypography = InputContainer:new{}
+local ReaderTypography = WidgetContainer:extend{}

 -- This is used to migrate old hyph settings, and to show the currently
 -- used hyph dict language in the hyphenation menu.
--- a/frontend/apps/reader/modules/readeruserhyph.lua
+++ b/frontend/apps/reader/modules/readeruserhyph.lua
@@ -16,7 +16,7 @@ local T = require("ffi/util").template
 -- and some `if NORM then` branches can be simplified.
 local NORM = false

-local ReaderUserHyph = WidgetContainer:new{
+local ReaderUserHyph = WidgetContainer:extend{
    -- return values from setUserHyphenationDict (crengine's UserHyphDict::init())
    USER_DICT_RELOAD = 0,
    USER_DICT_NOCHANGE = 1,
--- a/frontend/apps/reader/modules/readerview.lua
+++ b/frontend/apps/reader/modules/readerview.lua
@@ -28,28 +28,13 @@ local T = require("ffi/util").template

 local ReaderView = OverlapGroup:extend{
    document = nil,
+    view_modules = nil, -- array

    -- single page state
-    state = {
-        page = nil,
-        pos = 0,
-        zoom = 1.0,
-        rotation = 0,
-        gamma = 1.0,
-        offset = nil,
-        bbox = nil,
-    },
+    state = nil, -- table
    outer_page_color = Blitbuffer.gray(G_defaults:readSetting("DOUTER_PAGE_COLOR") / 15),
    -- highlight with "lighten" or "underscore" or "strikeout" or "invert"
-    highlight = {
-        lighten_factor = G_reader_settings:readSetting("highlight_lighten_factor", 0.2),
-        note_mark = G_reader_settings:readSetting("highlight_note_marker"),
-        temp_drawer = "invert",
-        temp = {},
-        saved_drawer = "lighten",
-        saved = {},
-        indicator = nil, -- geom: non-touch highlight position indicator: {x = 50, y=50}
-    },
+    highlight = nil, -- table
    highlight_visible = true,
    note_mark_line_w = 3, -- side line thickness
    note_mark_sign = nil,
@@ -58,12 +43,9 @@ local ReaderView = OverlapGroup:extend{
    -- PDF/DjVu continuous paging
    page_scroll = nil,
    page_bgcolor = Blitbuffer.gray(G_defaults:readSetting("DBACKGROUND_COLOR") / 15),
-    page_states = {},
+    page_states = nil, -- table
    -- properties of the gap drawn between each page in scroll mode:
-    page_gap = {
-        -- color (0 = white, 8 = gray, 15 = black)
-        color = Blitbuffer.gray((G_reader_settings:readSetting("page_gap_color") or 8) / 15),
-    },
+    page_gap = nil, -- table
    -- DjVu page rendering mode (used in djvu.c:drawPage())
    render_mode = G_defaults:readSetting("DRENDER_MODE"), -- default to COLOR
    -- Crengine view mode
@@ -91,10 +73,30 @@ local ReaderView = OverlapGroup:extend{

 function ReaderView:init()
    self.view_modules = {}
-    -- fix recalculate from close document pageno
-    self.state.page = nil

-    -- Reset the various areas across documents
+    self.state = {
+        page = nil,
+        pos = 0,
+        zoom = 1.0,
+        rotation = 0,
+        gamma = 1.0,
+        offset = nil,
+        bbox = nil,
+    }
+    self.highlight = {
+        lighten_factor = G_reader_settings:readSetting("highlight_lighten_factor", 0.2),
+        note_mark = G_reader_settings:readSetting("highlight_note_marker"),
+        temp_drawer = "invert",
+        temp = {},
+        saved_drawer = "lighten",
+        saved = {},
+        indicator = nil, -- geom: non-touch highlight position indicator: {x = 50, y=50}
+    }
+    self.page_states = {}
+    self.page_gap = {
+        -- color (0 = white, 8 = gray, 15 = black)
+        color = Blitbuffer.gray((G_reader_settings:readSetting("page_gap_color") or 8) / 15),
+    }
    self.visible_area = Geom:new{x = 0, y = 0, w = 0, h = 0}
    self.page_area = Geom:new{x = 0, y = 0, w = 0, h = 0}
    self.dim_area = Geom:new{x = 0, y = 0, w = 0, h = 0}
@@ -103,6 +105,9 @@ function ReaderView:init()
    self.emitHintPageEvent = function()
        self.ui:handleEvent(Event:new("HintPage", self.hinting))
    end
+
+    -- We've subclassed OverlapGroup, go through its init, because it does some funky stuff with self.dimen...
+    OverlapGroup.init(self)
 end

 function ReaderView:addWidgets()
@@ -1071,8 +1076,7 @@ function ReaderView:getRenderModeMenuTable()
 end

 function ReaderView:onCloseDocument()
-    self.hinting = false
-    -- stop any in fly HintPage event
+    -- stop any pending HintPage event
    UIManager:unschedule(self.emitHintPageEvent)
 end

--- a/frontend/apps/reader/modules/readerwikipedia.lua
+++ b/frontend/apps/reader/modules/readerwikipedia.lua
@@ -31,7 +31,7 @@ function ReaderWikipedia:init()
    self.wiki_languages = {}
    self.ui.menu:registerToMainMenu(self)
    if not wikipedia_history then
-        wikipedia_history = LuaData:open(DataStorage:getSettingsDir() .. "/wikipedia_history.lua", { name = "WikipediaHistory" })
+        wikipedia_history = LuaData:open(DataStorage:getSettingsDir() .. "/wikipedia_history.lua", "WikipediaHistory")
    end
 end

--- a/frontend/apps/reader/modules/readerzooming.lua
+++ b/frontend/apps/reader/modules/readerzooming.lua
@@ -14,9 +14,9 @@ local Input = Device.input
 local Screen = Device.screen
 local T = require("ffi/util").template

-local ReaderZooming = InputContainer:new{
+local ReaderZooming = InputContainer:extend{
    zoom = 1.0,
-    available_zoom_modes = {
+    available_zoom_modes = { -- const
        "page",
        "pagewidth",
        "pageheight",
@@ -27,26 +27,26 @@ local ReaderZooming = InputContainer:new{
        "rows",
        "manual",
    },
-    zoom_genus_to_mode = {
+    zoom_genus_to_mode = { -- const
        [4] = "page",
        [3] = "content",
        [2] = "columns",
        [1] = "rows",
        [0] = "manual",
    },
-    zoom_mode_to_genus = {
+    zoom_mode_to_genus = { -- const
        page    = 4,
        content = 3,
        columns = 2,
        rows    = 1,
        manual  = 0,
    },
-    zoom_type_to_mode = {
+    zoom_type_to_mode = { -- const
        [2] = "",
        [1] = "width",
        [0] = "height",
    },
-    zoom_mode_to_type = {
+    zoom_mode_to_type = { -- const
        [""]   = 2,
        width  = 1,
        height = 0,
@@ -58,7 +58,7 @@ local ReaderZooming = InputContainer:new{
    -- with overlap of zoom_overlap_h % (horizontally)
    -- and zoom_overlap_v % (vertically).
    kopt_zoom_factor = 1.5,
-    zoom_pan_settings = {
+    zoom_pan_settings = { -- const
        "kopt_zoom_factor",
        "zoom_overlap_h",
        "zoom_overlap_v",
@@ -71,7 +71,7 @@ local ReaderZooming = InputContainer:new{
    zoom_direction_vertical = nil, -- true for column mode
    current_page = 1,
    rotation = 0,
-    paged_modes = {
+    paged_modes = { -- const
        page = _("Zoom to fit page works best with page view."),
        pageheight = _("Zoom to fit page height works best with page view."),
        contentheight = _("Zoom to fit content height works best with page view."),