Patterns / Media

Ribbon

Markdown apps/gallery/src/patterns/ribbon.rs

let formatting = editor.read(cx).formatting();

let lit = formatting.marks.contains(&mark);          // and cmd-B before typing counts
let label = formatting.block.clone();                // "Heading 2", for the dropdown
let fence = formatting.fenceable;                    // cmd-E would fence, not span
let live = formatting.mode == editor::Mode::Blocks;  // the source has nothing to light

The dropdown

for (label, kind) in editor::turns() {
    let lit = formatting.block.as_ref() == Some(&label);
    // on click: editor.update(cx, |editor, cx| editor.set_block(block, kind.clone(), cx));
}

Matched on kind alone, so a numbered list at 7 and a fence tagged rs still report their row.

Marks the library does not have

markdown::set_marks(cx, markdown::Marks::new().with("highlight", "==").with("underline", "++"));
markdown::set_mark_paint(cx, paint);

toggle_mark(Mark::Custom("highlight".into())) is the same call bold takes, and the editor never learns what the name means.

What the snapshot answers


`marks`	What a button means, not what the text looks like. Over a mixed selection it is unlit, because pressing it will bold the rest.
`block`	The caret's block, matched against `editor::turns()` so your menu cannot drift from the two bezel opens.
`fenceable`	The one thing a bar cannot work out itself: `Mark::Code` over more than one line makes a fence, and over a table neither.
`mode`	`toggle_mark` refuses in source mode, so the bar greys out rather than promising something the editor will not do.

The bar is docked, so it reflows the document under it — which is why it is a plain row with a hairline rather than control_bar, the floating kind that must never move what it sits over. The other answer to the same question is the bubble toolbar on the Editor page; an app picks one.

The source is at apps/gallery/src/patterns/ribbon.rs. Copy the file.