Struct Help 

pub struct Help { /* private fields */ }

A searchable help overlay (#473): every binding of a keymap, grouped by context, with its keys and what it does. Typing searches keys, descriptions and contexts; the arrows and PageUp/PageDown scroll; Escape clears the search, then closes; Enter closes.

Options: wrap wraps a row too long for the width (its keys and its description) rather than cutting it, key_format says the keys another way (<C-u>), flat lists every binding in one list under the search line and a rule, with no context headings, and filter_key makes letters move until a key starts the search (Yazi’s /).

Implementations

impl Help

pub fn new(keymap: &Keymap) -> Help

Help for every binding of keymap that has keys.

pub fn from_bindings(bindings: impl IntoIterator<Item = Binding>) -> Help

pub fn filter_key(self, key: Option<Key>) -> Self

Move with the letters until key is pressed, and only then search: j/k move a row, g and G go to the top and the bottom, and key (Yazi’s /) starts the search, which Escape ends (clearing it). None, the default, searches as soon as a letter is typed.

pub fn prompt(self, prompt: impl Into<String>) -> Self

pub fn theme(self, theme: Theme) -> Self

pub fn wrap(self, on: bool) -> Self

Wrap a row too long for the width onto the next rows, under its description, rather than cut it. Off by default.

pub fn flat(self, on: bool) -> Self

Every binding in one list, under the search line and a rule, with no heading for each context (Yazi’s help). Off by default.

pub fn key_format(self, format: impl Fn(&Binding) -> String + 'static) -> Self

Say each binding’s keys with format (vim’s <C-u>, say) rather than as Binding::hint does; searching finds them as said.

pub fn query(self, query: impl Into<String>) -> Self

Search for query from the start.

pub fn set_bindings(&mut self, bindings: impl IntoIterator<Item = Binding>)

Put bindings in place of those it has, as they change while it is open: the search stays, and so does the scroll, as far as the new rows reach.

pub fn matches(&self) -> Vec<&Binding>

The bindings that match the search, in keymap order.

Trait Implementations

impl Component for Help

type Output = ()

fn handle(&mut self, event: &Event, _: &Context<'_>) -> Flow<()>

Handle one event. Ctrl+C never arrives here: the event loop ends the component with Outcome::Interrupted.

fn render(&self, context: &Context<'_>) -> View

Render the current state.

fn mouse(&self) -> bool

Whether the component wants mouse events (#476): clicks, drags and the wheel. Off by default, since reporting the mouse takes text selection away from the terminal; a component turns it on when its caller opts in, and run then enables mouse reporting for the session.

fn keymap(&self) -> Keymap

The bindings this component has right now, for a help overlay, a shortcut list or status-bar hints to read (see keymap). A container’s include its focused child’s, before its own. The default declares none.

fn start(&mut self, context: &Context<'_>) -> Flow<Self::Output>

Called once, before the component is first painted, with the terminal’s size: for work that needs it, such as rendering content at the width. Returning Done or Cancel finishes the component without waiting for an event. The default does nothing.

fn tick(&self) -> Option<Duration>

How often the component wants Event::Tick, for a spinner or a countdown. None (the default): never.

fn focusable(&self) -> bool

Whether the component takes focus in a container: Tab stops on it and keys go to it. The default: yes. A label, or a component that has finished, says no.

fn focus_step(&mut self, forward: bool) -> bool

Move focus to the next (forward) or previous focus stop inside this component, for Tab and Shift+Tab. false when there is none after the current one, so the container moves on to its next child. The default, for a component that is one stop: false.

fn focus_enter(&mut self, forward: bool) -> bool

Take focus from outside: at the first stop inside when forward, at the last otherwise. false when nothing in it can take focus. The default: whether the component is focusable.

fn default_value(&self) -> Option<Self::Output>

The value to return when the terminal is not interactive and the policy asks for defaults. None: there is none.

fn prompt( &mut self, io: &mut dyn LineIo, ) -> Result<Option<Self::Output>, NotInteractive>

Ask for the value line by line, for when the terminal is not interactive and the policy asks for a prompt. The default says the component has no line-based form.