Apps live under /.lua/apps with data in /.lua/data, matching the runtime's
paths. ui.lua and hints.lua ship from the submodule through `make sdcard`
rather than a copy that drifts, so theme.lua and the firmware's own ui.lua
are gone.
App-visible changes: text takes a font role rather than a text size, the
theme palette names roles (color/background) instead of fg/bg, ticks are
timer.every, on_press is on_click, and centring is layout alignment now
that textAlign left the node contract.
A node was a Lua table of ~625 bytes, of which 21 keys pushed it over a
power-of-two hash boundary and eight were style copies inheritance had
splattered down from its parent. A 400 node screen cost ~250 KB and could not
coexist with wifi's buffers.
The tree now lives in src/ui/layout.h as a 16 byte struct in a flat arena, and
splits by lifetime: Node holds what hit testing and repainting need forever,
Spec holds what only measure/place read and is dropped when layout ends. Style
is sparse and resolved by walking parents, so a node naming no colours costs
nothing. Re-layout rebuilds from Lua rather than retaining the inputs.
401 nodes: 8218 B steady, 21050 B peak
Lua: ~250000 B steady
sdcard/lib/ui.lua stays the toolkit and keeps every constructor signature, but
returns integer handles: 627 lines to 374. Composition, the palette and custom
painters are still Lua on the SD card; only primitives now need a reflash.
BREAKING CHANGE: ui constructors return handles, not tables. Use
ui.setText(id, text) and keep per-node app data in a table keyed by id.
Remove OpenFontRender, embedded Meslo assets, custom-font APIs, and their runtime allocation overhead. Keep the taller status layout and compact card grid, with used RAM, aligned faded WiFi bars, and tighter telemetry rows.
Embed a Latin-1 Meslo LG S default and use OpenFontRender for anti-aliased text with an explicit pixel size on each draw and measurement call. Apps may replace the one retained face with an SD-backed TTF and restore Meslo with nil. Refresh UI sizing, status telemetry, Settings typography, tests, documentation, and font license notices.
Make sys.launch push the current path and argument, sys.replace switch without pushing, and sys.back restore the previous route. The status-bar chevron uses the same back action, failed child apps return to their caller, and history is capped at eight routes. Remove the redundant Settings back card.
sys.launch(path, arg) carries a string to the next app's init(arg), nil when there is
none. States share no memory, so one string is the whole handoff; anything structured
travels as a Lua literal the receiver loads. This is what a screen split across apps
needs to say "collect a password for this network".
sys.setAppName() retitles the status bar, defaulting to the directory name as before. A
setter rather than a declared constant, so one app can retitle per screen. The bar needs
no new invalidation path for it -- the name joins rotation and theme in the cache key --
and clips a name wide enough to reach the memory slot.
The bar repainted itself whole every second. It now compares each field against what
it last painted, adds seconds and a memory percentage, and keys the cache on
gui.getRotation() and ui.themeName so rotation and theme changes still repaint it.
Invalidation lives entirely in Lua; the firmware's push flag and gfx/statusbar.h are gone.
Bindings follow getName/setName/isName, persisted preferences move from sys to a settings
table, and gui.setRotation takes degrees like settings does. A bar that dies mid-run now
keeps its rows reserved rather than silently resizing the running app.
The bar is host-owned chrome: the firmware clips apps into a viewport below
it, so no app can paint over it, while /lib/statusbar.lua owns the height,
repaint interval and painting. gui.fullscreen() lets touch calibration take
the physical panel back.
Launcher and settings become grids of square cards (3 across landscape, 2
portrait) via the new gui.setTextSize, ui.label and ui.cardSide. The one
function on the `app` table moves to sys.setTickInterval, alongside the new
sys.appName the bar needs.
A magic global that the runtime reads once at startup could not be changed later, gave
no feedback when misspelled, and was a second spelling of a mechanism the sibling
firmware already had. app.setTickInterval(ms) clamps to 33..3600000, takes 0 to stop,
and errors when on_tick() is not defined -- by the time init() runs the chunk body has
finished, so a missing callback is a typo rather than a race.
Also drops the code comments pointing at the other repo. Where the two APIs agree or
differ belongs in docs/lua-api-parity.md; a comment beside a constant explaining that
another firmware picked the same number is noise a reader here cannot act on.
The launcher clock read UTC and sat next to the title because the toolkit could only
stack children from the start of an axis. justify adds the CSS main-axis modes that
had a caller -- start, end, center, between -- so a header keeps its title left and
its clock right without any app doing arithmetic.
Timezones are stored as POSIX TZ rules rather than offsets, so newlib applies DST
changeovers and os.date() in Lua reports local time with no binding of its own.
/lib/timezones.lua is only the picker list: a zone missing from it still works if its
rule is written into settings, the same split themes already use.
settings_calibration.lua now finds rows by label. Adding the timezone row shifted
every hardcoded y coordinate in it, which is the failure that had been predicted and
would have silently retargeted taps at the wrong control.
Nothing in this firmware ever mounted internal flash storage: apps, lib, settings and
themes all live on the SD card. The Arduino default table still reserved 1408K for
spiffs, so a custom table hands that to the OTA slots instead, taking each from 1280K
to 1984K. The 64K tail the slots cannot use goes to coredump, which otherwise logs a
missing-partition error on every boot. Changing the table shifts app0, so the next
flash must be a full one.
The ESP32 has no battery-backed clock, so time is 1970 on every power-up. net.cpp
seeds it from the build timestamp -- the device cannot predate its own firmware, and
certificate validity checks need a plausible clock before SNTP can answer -- then
starts SNTP on each join and latches a synced flag from the notification callback.
sntp_get_sync_status() only reports COMPLETED briefly before resetting for the next
cycle, so polling it would make the clock flap.
sys.clockSynced() is the only new binding a clock UI needs; Lua's os.date() already
reads the same system clock. The launcher shows it, in UTC for now.
lua_app.cpp had grown to 701 lines holding every binding, the module loader and the
app lifecycle, so new bindings landed wherever the cursor was. Each Lua table now has
its own file under bindings/, and the app is recovered from the lua_State's extra
space instead of a file-static, so a second state cannot reach the wrong app.
Three tests each redeclared the binding surface, which broke twice this session when
a binding changed; test/fake_device.lua is now the single stub. `make test` runs all
four suites and pins Lua 5.4, matching the vendored interpreter rather than the 5.2
the tests had silently been using.
evan