Configuration and User Preferences

Terminal::Widgets has two main ways to set config and user prefs:

• Environment variables

• Terminal instance attributes

Environment Variables

All Terminal::Widgets-specific environment variables use a TW_ prefix; the remaining environment variables are general standards that Terminal::Widgets respects.

LANGUAGE or LANG

Used by Terminal::Widgets::I18N::Translation::LanguageSelection to detect user's preference for translation languages. If both are set, LANGUAGE is preferred over LANG.

NO_COLOR=1

If NO_COLOR is set to 1, default to a monochrome theme variant. Otherwise default to a theme variant based on terminal color depth.

TERM, TERM_PROGRAM, COLORTERM, and others

Used to detect the user's terminal emulator -- and terminal multiplexer if any -- which helps to determine available terminal capabilities. See Terminal::Capabilities::Autodetect for recognized terminals and capabilities.

TW_DEBUG=<debug verbosity level>

If >0, turn on Terminal::Widgets debugging (sent to the standard error stream). Level 1 will enable the most basic debugging and timing info; higher levels will enable successively more debug output. Notably level 2 will turn on debug views of every composited widget grid, and level 3 will turn on Backtrace info.

TW_SYMBOLS=<symbol set name>

Override an autodetected terminal symbol set with a different Unicode subset, usually because the installed fonts don't support the full autodetected set. See the Terminal::Capabilities documentation for available symbol set names.

TW_VT100_BOXES=<0|1>

Override autodetection of VT100 box drawing capabilities. This capability is very minimal, so is almost universally supported by modern terminal emulators. You may still turn this off and set TW_SYMBOLS=ASCII in order to test for the most absolutely basic terminal support.

Terminal Instance Attributes

When creating a new Terminal::Widgets::Terminal object (either directly with Terminal::Widgets::Terminal.new or via Terminal::Widgets::App.add-terminal), you can specify several configuration attributes:

caps

A Terminal::Capabilities object describing available functionality in the user's terminal emulator and fonts, such as support for 24-bit color or emoji skin tones. App.add-terminal will attempt to autodetect caps if adding the processes's controlling terminal (/dev/tty on *nix systems).

If desired some of the capabilities can be overridden by environment variables such as TW_SYMBOLS and TW_VT100_BOXES.

locale

A Terminal::Widgets::I18N::Locale object describing the user's current locale (translation string table, regional formatting rules, etc.).

ui-prefs

A Hash of miscellaneous UI preference settings. The following settings are currently recognized by Terminal::Widgets:

• Bool input-activation-flash - If True, flash Input widgets when activated, such as when a Button is clicked. Defaults to False.

• UInt mouse-wheel-horizontal-speed - Sets number of scrolled cells per mouse wheel horizontal event, defaulting to twice mouse-wheel-vertical-speed.

• UInt mouse-wheel-vertical-speed - Sets number of scrolled lines per mouse wheel vertical event, defaulting to 4 lines per event.

• Bool scroll-invert-horizontal - If True, invert the direction of horizontal scroll events. Defaults to False.

• Bool scroll-invert-vertical - If True, invert the direction of vertical scroll events. Defaults to False.