Give a lamp's modes a page: the effects, palettes, presets, speed and intensity of a WLED behind its colour card, with a drum picker and the effect's name on the tile (0.2.83)

A light that offers effects gets a sparkles key at the top right of its colour
card. It opens a page with a row per thing the lamp offers, all from Home
Assistant: the light's effect and the select entities of its device (a WLED's
colour palette, preset and playlist) with what they are set to, and a slider per
number entity of the device (speed, intensity). Names are Home Assistant's own
English entity translations, icons its frontend's; nothing about a brand is
hardcoded beyond a preferred order of translation keys.

A row opens LVGL's roller with every name Home Assistant lists at that moment,
asked for when the picker opens (esphome.screen_options, answered with
op: options, one page of names per message), the effects alphabetically with
Solid on top. The check key at the top right sends the choice as one action;
the back key sends nothing. A slider sends number.set_value when let go. While
an effect runs, the tile names it instead of the brightness.

Firmware 0.2.70: effects_page.h (built when it opens, gone when it closes),
Extra.effect/option_rows/number_rows, options_request, a hidden roller widget
so ESPHome compiles LVGL's roller, five firmware-only glyphs. App 0.2.83:
light_effects.py, the effect attribute, the device rows in the state message,
card_options_loop. Checked on the host with a virtual finger (35/35 on both
boards) and compiled for both ESP32 boards; CYD 1,675,424 B (91.3 %).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

tests/test_effects_page.cpp

@@ -0,0 +1,73 @@
+// c++ -std=c++17 -Wall -Wextra -pedantic tests/test_effects_page.cpp -o /tmp/test_effects_page && /tmp/test_effects_page
+// The model of a light's effects page (firmware 0.2.70+): what it can show, how a number maps to its slider, the texts.
+#define EFFECTS_PAGE_TEST
+#define THEME_TEST
+#include "../components/smart_display/effects_page.h"
+#include "../components/smart_display/tile_controls.h"
+#include <cassert>
+#include <cmath>
+
+using namespace effects_page;
+using runtime_tiles::Tile;
+
+int main() {
+  // A light with the EFFECT feature or with rows from its device has a page; a plain light or a switch has none.
+  Tile wled; wled.entity = "light.vuelta"; wled.supported = 36;
+  assert(available(wled));
+  Tile plain; plain.entity = "light.kitchen"; plain.supported = 32;
+  assert(!available(plain));
+  runtime_tiles::OptionRow palette; palette.entity = "select.vuelta_kleurenpalet"; palette.name = "Color palette"; palette.current = "Aurora"; palette.count = 75;
+  plain.edit_extra().option_rows.push_back(palette);
+  assert(available(plain));
+  Tile sw; sw.entity = "switch.x"; sw.supported = 4;
+  assert(!available(sw));
+
+  // A number's slider: its place in the range, and the value a slider position stands for, on the entity's step.
+  assert(percent_of(128, 0, 255) == 50);
+  assert(percent_of(0, 0, 255) == 0);
+  assert(percent_of(255, 0, 255) == 100);
+  assert(percent_of(NAN, 0, 255) == 0);
+  assert(percent_of(5, 10, 10) == 0);
+  assert(value_at(50, 0, 255, 1) == 128.0f || value_at(50, 0, 255, 1) == 127.0f);
+  assert(value_at(100, 0, 255, 1) == 255.0f);
+  assert(value_at(0, 0, 255, 1) == 0.0f);
+  assert(value_at(101, 0, 255, 1) == 255.0f);
+  assert(value_at(50, 16, 32, 0.5f) == 24.0f);
+  assert(value_at(33, 0, 10, 5) == 5.0f);
+  assert(number_text(128) == "128");
+  assert(number_text(12.5f) == "12.5");
+  assert(number_text(0) == "0");
+  assert(percent_text(50) == "50 %");
+
+  // The roller's text and the row that is chosen in it.
+  std::vector<std::string> names = {"Solid", "Akemi", "TV Simulator"};
+  assert(joined(names) == "Solid\nAkemi\nTV Simulator");
+  assert(joined({}) == "");
+  assert(index_of(names, "TV Simulator") == 2);
+  assert(index_of(names, "Blink") == -1);
+
+  // A row shows a dash where Home Assistant reports nothing.
+  assert(row_text("Aurora") == "Aurora");
+  assert(row_text("") == "—");
+  assert(row_text("unknown") == "—");
+  assert(row_text("unavailable") == "—");
+
+  // The tile names the effect while one runs; WLED's Solid, Hue's off and Home Assistant's None are none.
+  assert(tile_controls::effect_running("TV Simulator"));
+  assert(tile_controls::effect_running("candle"));
+  assert(!tile_controls::effect_running("Solid"));
+  assert(!tile_controls::effect_running("solid "));
+  assert(!tile_controls::effect_running("off"));
+  assert(!tile_controls::effect_running("Off"));
+  assert(!tile_controls::effect_running("None"));
+  assert(!tile_controls::effect_running(""));
+  assert(!tile_controls::effect_running("unknown"));
+
+  // Both boards' sizes: the CYD's page fits four rows and two sliders in 240 px, the Guition's in 480.
+  Metrics big = metrics(480, 480), small = metrics(320, 240);
+  assert(big.rows_y + 4 * big.row_h + big.gap + big.number_h <= 480);
+  assert(small.rows_y + 4 * small.row_h + small.gap + small.number_h <= 240);
+  assert(big.rows_y + big.roller_rows * big.roller_row_h + 2 * big.roller_pad <= 480);
+  assert(small.rows_y + small.roller_rows * small.roller_row_h + 2 * small.roller_pad <= 240);
+  return 0;
+}