# Blaeck
A terminal UI framework for Rust. Inline rendering, flexbox/grid layout, 35+ components.
[](https://crates.io/crates/blaeck)
[](https://docs.rs/blaeck)
[](LICENSE)
## Install
```toml
[dependencies]
blaeck = "0.2"
```
---
## Inline Rendering
The killer feature: blaeck renders **within your terminal flow**. Output stays in scrollback. `println!()` works before and after.
```rust
use blaeck::prelude::*;
use std::{thread, time::Duration};
fn main() -> std::io::Result<()> {
println!("Starting build...\n");
let mut blaeck = Blaeck::new(std::io::stdout())?;
for i in 0..=10 {
let bar = "█".repeat(i * 2) + &"░".repeat(20 - i * 2);
blaeck.render(element! {
Box(border_style: BorderStyle::Round, padding: 1.0) {
Text(content: "Building...", bold: true)
Text(content: bar, color: Color::Green)
}
})?;
thread::sleep(Duration::from_millis(200));
}
blaeck.unmount()?;
println!("Done! Terminal keeps working.");
Ok(())
}
```
---
## Interactive Apps
Use `ReactiveApp` for keyboard-driven UIs. State changes trigger automatic re-renders.
```rust
use blaeck::prelude::*;
use blaeck::reactive::*;
use crossterm::event::KeyCode;
fn form(cx: Scope) -> Element {
let name = use_state(cx.clone(), || String::new());
let env = use_state(cx.clone(), || 0usize); // 0=dev, 1=staging, 2=prod
let confirmed = use_state(cx.clone(), || false);
let focus = use_state(cx.clone(), || 0usize); // 0=name, 1=env, 2=confirm
let envs = vec!["Development", "Staging", "Production"];
let name_h = name.clone();
let env_h = env.clone();
let confirmed_h = confirmed.clone();
let focus_h = focus.clone();
use_input(cx, move |key| {
let f = focus_h.get();
match key.code {
KeyCode::Tab => focus_h.set((f + 1) % 3),
KeyCode::BackTab => focus_h.set(if f == 0 { 2 } else { f - 1 }),
KeyCode::Up if f == 1 => env_h.set(if env_h.get() == 0 { 2 } else { env_h.get() - 1 }),
KeyCode::Down if f == 1 => env_h.set((env_h.get() + 1) % 3),
KeyCode::Char(' ') if f == 2 => confirmed_h.set(!confirmed_h.get()),
KeyCode::Char(c) if f == 0 => {
let mut s = name_h.get();
s.push(c);
name_h.set(s);
}
KeyCode::Backspace if f == 0 => {
let mut s = name_h.get();
s.pop();
name_h.set(s);
}
_ => {}
}
});
let f = focus.get();
let name_val = name.get();
let env_val = env.get();
let conf_val = confirmed.get();
element! {
Box(flex_direction: FlexDirection::Column, border_style: BorderStyle::Round, padding: 1.0) {
Text(content: "Deploy Configuration", bold: true, color: Color::Cyan)
Newline
// Name field
Text(content: "Project name:", bold: f == 0)
Box(flex_direction: FlexDirection::Row) {
Text(content: if f == 0 { "> " } else { " " }, color: Color::Green)
Text(
content: if name_val.is_empty() { "(type here)".to_string() } else { name_val },
color: if f == 0 { Color::White } else { Color::DarkGray }
)
Text(content: if f == 0 { "_" } else { "" }, color: Color::Green)
}
Newline
// Environment selector
Text(content: "Environment:", bold: f == 1)
#(Element::column(
envs.iter().enumerate().map(|(i, e)| {
let selected = i == env_val;
let focused = f == 1;
let prefix = if selected { "● " } else { "○ " };
element! {
Text(
content: format!(" {}{}", prefix, e),
color: if selected && focused { Color::Green } else { Color::White },
bold: selected
)
}
}).collect()
))
Newline
// Confirm checkbox
Box(flex_direction: FlexDirection::Row) {
Text(content: if f == 2 { "> " } else { " " }, color: Color::Green)
Text(
content: format!("[{}] I confirm this deployment", if conf_val { "x" } else { " " }),
bold: f == 2
)
}
Newline
Text(content: "Tab: next field | Space: toggle | Ctrl+C: exit", dim: true)
}
}
}
fn main() -> std::io::Result<()> {
ReactiveApp::run(form)?;
Ok(())
}
```
**Key concepts:** `use_state` creates reactive state. `use_input` registers keyboard handlers. When state changes, UI re-renders automatically.
---
## When to Use Blaeck
**Good for:**
- CLI tools with rich output (installers, build tools)
- Interactive prompts with layout control
- Progress displays, dashboards
- Any UI that shouldn't take over the screen
**Not for:**
- Fullscreen TUIs → use [Ratatui](https://github.com/ratatui-org/ratatui)
- Simple prompts → use [inquire](https://github.com/mikaelmello/inquire)
---
## Components
| **Layout** | `Box`, `Spacer`, `Newline`, `Indent` |
| **Text** | `Text`, `Gradient`, `Markdown`, `SyntaxHighlight` |
| **Input** | `TextInput`, `Select`, `MultiSelect`, `Checkbox`, `Confirm` |
| **Data** | `Table`, `Tabs`, `TreeView`, `BarChart`, `Sparkline` |
| **Feedback** | `Spinner`, `Progress`, `Timer`, `Modal`, `Diff` |
---
## Examples
```bash
cargo run --example demo_inline # Inline rendering demo
cargo run --example form_demo # Interactive form
cargo run --example reactive_counter # Counter with signals
cargo run --example reactive_list # List navigation
cargo run --example dashboard # Multi-panel layout
cargo run --example table # Data tables
cargo run --example spinner_demo # 15 spinner styles
```
See [all examples](blaeck/examples/) or [API docs](https://docs.rs/blaeck).
---
## Example Viewer
The **example_viewer** is an interactive tool for exploring all blaeck examples in a single interface. It provides a three-panel layout with live previews, source code viewing, and interactive testing.
```bash
cargo run --example example_viewer
```
### Features
- **Live Previews** - See rendered output for all 44 examples in real-time
- **Interactive Mode** - Press `Enter` to interact with any example in focus mode
- **Source Code Viewer** - View both the example wrapper and UI implementation code
- **Background Execution** - Build and run examples with captured output
- **Resizable Panels** - Adjust layout with `[` and `]` keys
- **Example Management** - Mark and batch-delete examples for cleanup
### Controls
| `↑`/`↓` or `k`/`j` | Navigate example list |
| `Enter` | Enter live interactive preview (focus mode) |
| `Esc` | Exit focus mode / Quit |
| `[` / `]` | Resize preview panel (shrink/grow) |
| `PageUp`/`PageDown` or `K`/`J` | Scroll source code |
| `r` | Run selected example (capture output) |
| `s` | Stop running example |
| `b` | Build selected example |
| `d` | Toggle mark for deletion |
| `x` | Execute deletions (with confirmation) |
| `q` | Quit |
Perfect for:
- Exploring the full component library
- Testing examples without running them individually
- Comparing UI implementations
- Learning blaeck patterns
---
## License
MIT OR Apache-2.0