Struct Capabilities 

pub struct Capabilities { /* private fields */ }

What the terminal told us about itself.

This holds the replies themselves, not a summary of them: the ModeSetting reported for every mode that was asked about, the raw device-attribute lists, the reported colors, and so on. A reply that says “I do not recognize that” is recorded too, so None from an accessor generally means the terminal never answered, which is different from answering no. termcap is the exception, folding both into None; use termcap_reports to separate them.

Everything here is what the terminal reported, never what the facade told it. The two are easy to confuse where both exist: a background_color recorded here stays the terminal’s own default even after set_background_color overrides it.

Only replies land here, so questions the environment can also answer are deliberately absent. Direct-color support is the example: COLORTERM and TERM establish it as readily as an XTGETTCAP reply does, so the answer is Screen::color_profile, which folds in both, and what remains here is the reply itself via supports_termcap.

The facade records these as reply events flow through read_event / try_read_event, whichever way the question was put: see query_capabilities, which asks for only some of this, and takes extra bytes so you can ask for the rest. An individual request_* method fills a single entry, and a few reports arrive unprompted once their mode is on, such as a color-scheme change under DEC mode 2031. Read it back with Program::capabilities.

Implementations

impl Capabilities

pub fn mode(&self, mode: Mode) -> Option<ModeSetting>

The ModeSetting the terminal reported for mode, or None if it never reported on that mode.

Use this when the distinction matters: ModeSetting::Set means the mode is currently on, ModeSetting::PermanentlySet means it cannot be turned off, and ModeSetting::NotRecognized is a definite “no” rather than silence.

pub fn supports(&self, mode: Mode) -> bool

Whether the terminal reported mode as available, in any state.

use uncurses::ansi::mode::Mode;

if program.capabilities().supports(Mode::MOUSE_SGR_PIXEL) {
    // pixel-accurate mouse reporting is available
}

pub fn modes(&self) -> &BTreeMap<Mode, ModeSetting>

Every mode report recorded so far, keyed by mode.

pub fn primary_device_attributes(&self) -> Option<&[Option<u32>]>

The raw Primary DA (CSI c) attribute list, or None if the terminal never answered. Entries are None where the terminal sent an empty parameter.

The first parameter is the terminal’s architectural service class, not a capability: 6 identifies a VT102 and 64 a VT420. Capability numbers live in the parameters after it, and only for a VT220-class terminal or later (62, 63, 64, 65); xterm puts it as “the VT100-style response parameters do not mean anything by themselves”. So CSI ? 4 ; 6 c is a VT132 identifying itself, even though 4 is also the capability number for Sixel graphics on a VT220-class reply. Read the class first and interpret the rest against it, rather than searching the list for a number.

The capability numbers are assigned by DEC and extended by terminal authors, so they are reported unparsed.

pub fn secondary_device_attributes(&self) -> Option<&[Option<u32>]>

The raw Secondary DA (CSI > c) attribute list, or None if the terminal never answered. Conventionally terminal type, firmware version, and hardware option, but the meaning of each entry varies by terminal, so it is reported unparsed.

pub fn tertiary_device_attributes(&self) -> Option<&str>

The Tertiary DA (CSI = c) terminal unit ID, or None if the terminal never answered.

pub fn kitty_graphics(&self) -> bool

Whether the terminal has answered a Kitty graphics query, which is the protocol’s own support test: a terminal that does not implement it stays silent.

pub fn kitty_keyboard(&self) -> Option<KittyKeyboardFlags>

The Kitty keyboard enhancements the terminal reported, or None if it never answered CSI ? u. An answer of empty means the protocol is supported with no enhancements currently active.

pub fn modify_other_keys(&self) -> Option<ModifyOtherKeysMode>

The xterm modifyOtherKeys mode the terminal reported, or None if it never answered CSI ? 4 m.

pub fn terminal_name(&self) -> Option<&str>

The terminal’s self-reported name from XTVERSION (for example "XTerm(380)"), or None if it never answered.

pub fn termcap(&self, name: &str) -> Option<&str>

The value the terminal reported for the XTGETTCAP capability name, or None if it reported the capability as unsupported or was never asked. Boolean capabilities report an empty string, so use supports_termcap to test for presence.

pub fn supports_termcap(&self, name: &str) -> bool

Whether the terminal reported the XTGETTCAP capability name as supported. false both for a capability reported unsupported and for one never asked about; tell them apart with termcap_reports.

pub fn termcap_reports(&self) -> &BTreeMap<String, Option<String>>

Every XTGETTCAP reply recorded so far, keyed by capability name. A value of None is the terminal reporting that capability as unsupported, which is different from the key being absent.

pub fn foreground_color(&self) -> Option<Color>

The terminal’s default foreground color (OSC 10), or None if it never answered.

pub fn background_color(&self) -> Option<Color>

The terminal’s default background color (OSC 11), or None if it never answered.

pub fn cursor_color(&self) -> Option<Color>

The terminal’s cursor color (OSC 12), or None if it never answered.

pub fn palette_color(&self, index: u8) -> Option<Color>

The color the terminal reported for palette entry index (OSC 4 ; index ; ?), or None if it never answered for that entry.

pub fn palette(&self) -> &BTreeMap<u8, Color>

Every palette color reported so far, keyed by index.

pub fn color_scheme(&self) -> Option<ColorScheme>

Whether the terminal is in its dark or light scheme (DEC mode 2031), or None if it never reported one. Updated as the scheme changes while enable_color_scheme_updates is on. This is the terminal’s own preference flag, which a terminal can report independently of the colors it uses; when it is absent, background_color is the fallback.

Trait Implementations

impl Clone for Capabilities

fn clone(&self) -> Capabilities

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Capabilities

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Capabilities

fn default() -> Capabilities

Returns the “default value” for a type.

impl Eq for Capabilities

impl PartialEq for Capabilities

fn eq(&self, other: &Capabilities) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Capabilities