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.
* This removes support for the following deprecated constants: `DTAP_ZONE_FLIPPING`, `DTAP_ZONE_BOOKMARK`, `DCREREADER_CONFIG_DEFAULT_FONT_GAMMA`
* The "Advanced settings" panel now highlights modified values in bold (think about:config in Firefox ;)).
* LuaData: Isolate global table lookup shenanigans, and fix a few issues in unused-in-prod codepaths.
* CodeStyle: Require module locals for Lua/C modules, too.
* ScreenSaver: Actually garbage collect our widget on close (ScreenSaver itself is not an instantiated object).
* DateTimeWidget: Code cleanups to ensure child widgets can be GC'ed.
bidi.lua:
- Revert "Alias everything to Bidi.nowrap() when in LTR UI,
as using LTR isolates seems uneeded when already LTR" (part
of a628714f) which was a wrong assumption: we need proper
wrappers for all things paths. Enhance some of these wrappers.
- Fix GetText RTL wrapping which was losing empty lines and
trailing \n.
- Wrap all paths, directories, filenames in the code with
these wrappers.
- Wrap all book metadata (title, authors...) with BD.auto(),
as it helps fixing some edge cases (like open/close quotation
marks which are not considered as bracket types by FriBiDi).
(Needed some minor logic changes in CoverBrowser.)
- Tweak hyphenation menu text
- Update forgotten SortWidget for UI mirroring
- KoptConfig: update "justification" index for RTL re-ordering,
following the recent addition of the page_gap_height option.
Allow TextBoxWidget new text direction/lang parameters to be
set on upper widgets, and propagate them all the way to it
(ScrollTextWidget, InputText, InputDialog, TextViewer).
Use specific non-default ones in some specific cases:
- Force LTR text direction when showing HTML and CSS, and
configuration files (in some plugins).
- Use Wikipedia server language and text direction when
showing an article.
- Use auto with Dictionary results, as we don't know the
dictionary language, and they may contain mixed content.
- Force LTR when showing some paths (still needs more of them)
TextEditor plugin: add 2 new options "Auto paragraph direction"
and "Force paragraph direction LTR".
Footnotes popup: grab HTML direction, and forward it
to MuPDF for proper display.
