Lua theme API

A Lua theme supplies colors and optional font settings for the SimTX Transmitter. Installed themes appear in the Theme list in the application footer.

How to use this reference

To use an existing theme, select it in the footer. To write one, create a package declaring types=theme, place the declaration below in its entry file, reload, and select the new theme. Start with the semantic colors and check text contrast; the optional Swing ui overrides are for finer adjustments.

Declaration

simtx.theme {
  name = "Midnight",
  description = "A high-contrast dark theme.",
  colors = {
    background  = "#10161f",
    surface     = "#17212d",
    surface_alt = "#202c3a",
    foreground  = "#e8f0fa",
    muted       = "#91a0b3",
    accent      = "#4ac8ff",
    selection   = "#24506a",
    border      = "#34475b",
    success     = "#58d68d",
    warning     = "#f2c33c",
    danger      = "#ff665c",
    meter       = "#4ac8ff",
  },
  font = {family = "SansSerif", size = 13},
  ui = {
    ["Table.gridColor"] = "#233246",
    ["ToolTip.background"] = "#202c3a",
  },
}

Fields

Field	Required	Meaning
name	Yes	Name shown in the Theme list.
description	No	User-facing description.
colors	Yes	Table of semantic color roles.
font	No	Font family string, or a table containing family and non-negative size.
ui	No	Table of Swing UI property names to colors for details not covered by semantic roles.

Supported semantic roles are background, surface, surface_alt, foreground, muted, accent, selection, border, success, warning, danger, and meter. Omitted roles retain a suitable application default.

Colors may use #RGB, #RRGGBB, or #AARRGGBB. The names black, white, red, green, blue, gray, grey, orange, and yellow are also accepted.

The ui table is optional and is applied after the semantic roles. It is intended for established Swing UI property names. A theme should remain usable when this table is omitted.