blocks/
lib.rs

1//! Painted fenced blocks for `markdown`.
2//!
3//! ```ignore
4//! cx.set_block_renderer(blocks::render);   // once, at boot
5//! ```
6//!
7//! A fence already round trips byte for byte, already holds a caret, and
8//! already degrades to its own source where nothing paints it — so a block of
9//! an app's own is a renderer over ` ```chart ` rather than a new
10//! `markdown::BlockKind`. This crate is one answer to that seam; an app with
11//! its own block writes the same function and never depends on this.
12//!
13//! It is a peer crate rather than a feature on `markdown` for the reason
14//! `syntax` is: cargo features are additive across the whole graph, so a
15//! `markdown/mermaid` any dependency turned on is one no consumer can turn back
16//! off, and a block carrying a parser would break a target nobody asked about.
17//! A crate you do not name costs nothing.
18//!
19//! `markdown` is not a dependency here. A renderer is a fence tag and a string
20//! in, an element out, which needs no document model — the consumer's call to
21//! `set_block_renderer` is what pins the signature.
22
23use gpui::{AnyElement, App, Window};
24
25#[cfg(feature = "chart")]
26pub mod chart;
27#[cfg(feature = "vega-lite")]
28pub mod vega_lite;
29
30/// Paint the block a fence names, or `None` to leave it to the ordinary code
31/// block. `height` is the fence's stated height in whole pixels, for a block
32/// that takes one.
33///
34/// One answer for a tag no enabled block claims, a block turned off at compile
35/// time, and a block that read the source and declined.
36pub fn render(
37    language: &str,
38    code: &str,
39    height: Option<u32>,
40    window: &mut Window,
41    cx: &mut App,
42) -> Option<AnyElement> {
43    match language {
44        #[cfg(feature = "chart")]
45        chart::LANGUAGE => chart::render(code, window, cx),
46        #[cfg(feature = "vega-lite")]
47        vega_lite::LANGUAGE => vega_lite::render(code, height, window, cx),
48        // Spelled out rather than bare, so that turning every block off leaves
49        // a signature nothing reads and no warning about it.
50        _ => {
51            let _ = (code, height, window, cx);
52            None
53        }
54    }
55}
56
57/// The fence tags the enabled blocks answer to, for a language picker that
58/// would otherwise offer a block this build cannot paint.
59pub fn languages() -> &'static [&'static str] {
60    &[
61        #[cfg(feature = "chart")]
62        chart::LANGUAGE,
63        #[cfg(feature = "vega-lite")]
64        vega_lite::LANGUAGE,
65    ]
66}
blocks/lib.rs

blocks/
lib.rs
