Crate slt

Expand description

SuperLightTUI — an immediate-mode flexbox-layout terminal UI library.

Build a TUI as easily as a web page: write a closure, SLT calls it every frame. State lives in your code; layout is described every frame; styling uses Tailwind-inspired shorthand; focus and events are threaded through a single Context parameter.

See docs/QUICK_START.md for a 5-minute introduction and docs/DESIGN_PRINCIPLES.md for the principles every public API follows.

§Example

fn main() -> std::io::Result<()> {
    slt::run(|ui| {
        ui.text("hello, world");
    })
}

§SLT — Super Light TUI

Immediate-mode terminal UI for Rust. Small core. Zero unsafe.

SLT gives you an egui-style API for terminals: your closure runs each frame, you describe your UI, and SLT handles layout, diffing, and rendering.

§Quick Start

fn main() -> std::io::Result<()> {
    slt::run(|ui| {
        ui.text("hello, world");
    })
}

§Features

Flexbox layout — row(), col(), gap(), grow()
50+ built-in widgets — input, textarea, table, list, tabs, button, checkbox, toggle, spinner, progress, toast, slider, separator, help bar, scrollable, chart, bar chart, stacked bar chart, sparkline, histogram, heatmap, treemap, candlestick, canvas, grid, select, radio, multi-select, tree, virtual list, command palette, markdown, alert, badge, stat, breadcrumb, accordion, code block, big text, image, modal, tooltip, form, calendar, file picker, qr code
Styling — bold, italic, dim, underline, 256 colors, RGB
Mouse — click, hover, drag-to-scroll
Focus — automatic Tab/Shift+Tab cycling
Theming — 10 presets, semantic tokens (ThemeColor), spacing scale, contrast helpers
Animation — tween and spring primitives with 9 easing functions
Inline mode — render below your prompt, no alternate screen
Async — optional tokio integration via async feature
Layout debugger — F12 to visualize container bounds

§Feature Flags

Flag	Description
`crossterm`	Built-in terminal runtime (`run`, `run_inline`, clipboard query helpers). Enabled by default.
`bidi`	Reorder right-to-left text (Hebrew, Arabic, …) to visual order per UAX #9 before rendering. Enabled by default; pure-LTR text takes a zero-cost fast path. Since 0.21.0.
`async`	Enable `run_async()` with tokio channel-based message passing
`serde`	Enable Serialize/Deserialize for Style, Color, Theme, and layout types
`image`	Enable image-loading helpers for terminal image widgets
`qrcode`	Enable `ui.qr_code(...)`
`syntax` / `syntax-*`	Enable tree-sitter syntax highlighting

§Learn More

Guides index: https://github.com/subinium/SuperLightTUI/blob/main/docs/README.md
Quick start: https://github.com/subinium/SuperLightTUI/blob/main/docs/QUICK_START.md
Backends and run loops: https://github.com/subinium/SuperLightTUI/blob/main/docs/BACKENDS.md
Testing: https://github.com/subinium/SuperLightTUI/blob/main/docs/TESTING.md
Debugging: https://github.com/subinium/SuperLightTUI/blob/main/docs/DEBUGGING.md

Re-exports§

pub use crate::test_utils::EventBuilder;
pub use crate::test_utils::FrameRecord;
pub use crate::test_utils::TestBackend;
pub use crate::test_utils::TestSequence;
pub use crate::test_utils::PtyBackend;pty-test
pub use crate::test_utils::PtyFrame;pty-test
pub use anim::Keyframes;
pub use anim::LoopMode;
pub use anim::Sequence;
pub use anim::Spring;
pub use anim::Stagger;
pub use anim::Tween;
pub use buffer::Buffer;
pub use cell::Cell;
pub use chart::Candle;
pub use chart::ChartBuilder;
pub use chart::ChartConfig;
pub use chart::Dataset;
pub use chart::LegendPosition;
pub use chart::Marker;
pub use context::Anchor;
pub use context::Bar;
pub use context::BarChartConfig;
pub use context::BarDirection;
pub use context::BarGroup;
pub use context::Breadcrumb;
pub use context::CanvasContext;
pub use context::CodeBlock;
pub use context::ContainerBuilder;
pub use context::Context;
pub use context::Gauge;
pub use context::GutterOpts;
pub use context::LineGauge;
pub use context::Memo;
pub use context::Response;
pub use context::State;
pub use context::TreemapItem;
pub use context::Widget;
pub use context::TaskHandle;async
pub use context::TaskOutcome;async
pub use event::Event;
pub use event::KeyCode;
pub use event::KeyEvent;
pub use event::KeyEventKind;
pub use event::KeyModifiers;
pub use event::ModifierKey;
pub use event::MouseButton;
pub use event::MouseEvent;
pub use event::MouseKind;
pub use halfblock::HalfBlockImage;
pub use keymap::Binding;
pub use keymap::KeyMap;
pub use keymap::PublishedKeymap;
pub use keymap::WidgetKeyHelp;
pub use layout::Direction;
pub use palette::Palette;
pub use rect::Rect;
pub use style::ThemeWatcher;theme-watch
pub use style::Align;
pub use style::Border;
pub use style::BorderSides;
pub use style::Breakpoint;
pub use style::Color;
pub use style::ColorDepth;
pub use style::ColorParseError;
pub use style::Constraints;
pub use style::ContainerStyle;
pub use style::HeightSpec;
pub use style::Justify;
pub use style::Margin;
pub use style::Modifiers;
pub use style::Padding;
pub use style::Spacing;
pub use style::Style;
pub use style::SyntaxPalette;
pub use style::Theme;
pub use style::ThemeBuilder;
pub use style::ThemeColor;
pub use style::UnderlineStyle;
pub use style::WidgetColors;
pub use style::WidgetTheme;
pub use style::WidthSpec;
pub use style::ThemeFile;serde
pub use style::ThemeLoadError;serde
pub use widgets::AsyncValidation;async
pub use widgets::validators;
pub use widgets::AlertLevel;
pub use widgets::ApprovalAction;
pub use widgets::BreadcrumbResponse;
pub use widgets::ButtonVariant;
pub use widgets::CalDate;
pub use widgets::CalendarSelect;
pub use widgets::CalendarState;
pub use widgets::ChordState;
pub use widgets::ColorPickerState;
pub use widgets::CommandPaletteState;
pub use widgets::ContextItem;
pub use widgets::DEFAULT_CHORD_TIMEOUT_TICKS;
pub use widgets::DirectoryTreeState;
pub use widgets::FileEntry;
pub use widgets::FilePickerScanError;
pub use widgets::FilePickerScanOperation;
pub use widgets::FilePickerScanStatus;
pub use widgets::FilePickerState;
pub use widgets::FormField;
pub use widgets::FormState;
pub use widgets::GaugeResponse;
pub use widgets::GridColumn;
pub use widgets::GutterResponse;
pub use widgets::HighlightRange;
pub use widgets::ListResponse;
pub use widgets::ListState;
pub use widgets::ModeState;
pub use widgets::MultiSelectState;
pub use widgets::NumberInputState;
pub use widgets::PaginatorState;
pub use widgets::PaginatorStyle;
pub use widgets::PaletteCommand;
pub use widgets::PickerMode;
pub use widgets::RadioState;
pub use widgets::RichLogEntry;
pub use widgets::RichLogState;
pub use widgets::SchedulerState;
pub use widgets::ScreenState;
pub use widgets::ScrollState;
pub use widgets::SelectState;
pub use widgets::SliderOpts;
pub use widgets::SpinnerPreset;
pub use widgets::SpinnerState;
pub use widgets::SplitPaneResponse;
pub use widgets::SplitPaneState;
pub use widgets::StaticOutput;
pub use widgets::StreamingMarkdownState;
pub use widgets::StreamingTextState;
pub use widgets::TableColumn;
pub use widgets::TableState;
pub use widgets::TabsState;
pub use widgets::TextInputState;
pub use widgets::TextareaState;
pub use widgets::ToastLevel;
pub use widgets::ToastMessage;
pub use widgets::ToastState;
pub use widgets::ToolApprovalState;
pub use widgets::TreeNode;
pub use widgets::TreeState;
pub use widgets::Trend;
pub use widgets::ValidateTrigger;
pub use widgets::Validator;
pub use crossterm;crossterm

Modules§

anim: Animation primitives: tween, spring, keyframes, sequence, stagger. Animation primitives: tweens, springs, keyframes, sequences, and staggers.
buffer: Double-buffered cell grid with clip stack and diff tracking. Double-buffer grid of Cells with clip-stack support.
cell: Terminal cell representation. Single terminal cell — the smallest unit of the render buffer.
chart: Chart and data visualization widgets. Data visualization: line charts, scatter plots, bar charts, and histograms.
context: UI context, container builder, and widget rendering. Context — the per-frame handle threaded into every render closure.
event: Input events (keyboard, mouse, resize, paste). Terminal input events.
halfblock: Half-block image rendering. Half-block image rendering for terminals with truecolor support.
keymap: Keyboard shortcut mapping.
layout: Flexbox layout engine and command tree. Flexbox layout engine: builds a tree from commands, computes positions, and renders to a Buffer.
palette: Color palettes (Tailwind-style).
rect: Rectangular region type used throughout SLT layout. Axis-aligned rectangle type used throughout SLT for layout regions, clipping bounds, and hit-test areas.
style: Styling: colors, borders, padding, margins, themes, constraints. Visual styling primitives.
syntax: Tree-sitter syntax highlighting integration. Tree-sitter based syntax highlighting.
test_utils: Headless test utilities for unit-testing TUI closures. Headless testing utilities.
widgets: Widget state types (list, table, input, select, etc.). Widget state types passed to Context widget methods.

Structs§

AppState: Opaque per-session state that persists between frames.
AsyncRunHandleasync and crossterm: Owned lifetime handle for an asynchronous SLT render loop.
AsyncSenderasync and crossterm: Bounded async message sender that wakes its associated render loop.
BlitterSupportcrossterm: Runtime terminal capability probe (issue #264): read-only Capabilities snapshot plus the Blitter ladder it drives. Diagnostics-only — image rendering routes through the ladder automatically. Image-rendering primitives the terminal can drive, used to build the automatic blitter ladder. Each flag is conservative: when the runtime probe returns no answer the defaults assume only the universally available primitives (half-block + quadrants).
Capabilitiescrossterm: Runtime terminal capability probe (issue #264): read-only Capabilities snapshot plus the Blitter ladder it drives. Diagnostics-only — image rendering routes through the ladder automatically. Read-only snapshot of negotiated terminal capabilities, populated once at session enter via DA1/DA2/XTGETTCAP.
InlineTerminalcrossterm: Concrete crossterm terminal backends, exposed (issue #278) so external integrations can drive SLT’s render pipeline with their own event loop — pair with event::from_crossterm. Most apps should use run / run_inline, which build and drive these internally. Inline crossterm terminal backend: renders into a fixed-height region below the cursor instead of taking over the whole screen.
RunConfig: Configuration for a TUI run loop.
Terminalcrossterm: Concrete crossterm terminal backends, exposed (issue #278) so external integrations can drive SLT’s render pipeline with their own event loop — pair with event::from_crossterm. Most apps should use run / run_inline, which build and drive these internally. Fullscreen crossterm terminal backend: owns raw mode + the alternate screen, double-buffers cells, and flushes only the diff each frame.

Enums§

AsyncRunErrorasync and crossterm: Error returned when an asynchronous run loop is joined.
Blittercrossterm: Runtime terminal capability probe (issue #264): read-only Capabilities snapshot plus the Blitter ladder it drives. Diagnostics-only — image rendering routes through the ladder automatically. Descending image-render preference. The first capability that is available wins; app code never selects a Blitter directly.
ColorSchemecrossterm: Detected terminal color scheme from OSC 11.
DebugLayer: Which layers the F12 debug overlay should outline (issue #201).

Traits§

Backend: Rendering backend for SLT.

Functions§

capabilitiescrossterm: Runtime terminal capability probe (issue #264): read-only Capabilities snapshot plus the Blitter ladder it drives. Diagnostics-only — image rendering routes through the ladder automatically. Return the process-global negotiated Capabilities, probing the terminal exactly once on first call and caching the result.
detect_color_schemecrossterm: Query the terminal’s background color via OSC 11 and return the detected scheme.
frame: Process a single UI frame with a custom Backend.
frame_owned: Process a single UI frame, taking ownership of the events Vec (zero-copy).
read_clipboardcrossterm: Read clipboard contents via an OSC 52 terminal query.
runcrossterm: Run the TUI loop with default configuration.
run_asyncasync and crossterm: Run the TUI loop asynchronously with default configuration.
run_async_withasync and crossterm: Run the TUI loop asynchronously with custom configuration.
run_inlinecrossterm: Run the TUI in inline mode with default configuration.
run_inline_withcrossterm: Run the TUI in inline mode with custom configuration.
run_staticcrossterm: Run the TUI in static-output mode.
run_static_withcrossterm: Run the TUI in static-output mode with custom configuration.
run_withcrossterm: Run the TUI loop with custom configuration.

Crate slt

Crate slt Copy item path

§Example

§SLT — Super Light TUI

§Quick Start

§Features

§Feature Flags

§Learn More

Re-exports§

Modules§

Structs§

Enums§

Traits§

Functions§

Crate slt