T09: mouse: selection by cell, word and line, Shift extends; reports for X10, normal, button and any tracking in X10, UTF-8 and SGR bytes, mode 9 followed by the tap; the wheel reports, sends arrows or scrolls history; copy, bracketed paste, copy on select, OSC 52; Cmd-press opens OSC 8 targets and URLs; a release goes out only for a press the terminal saw; shot posts mouse gestures and never activates

src/term/links.rs

@@ -0,0 +1,86 @@
+use alacritty_terminal::{
+    index::{Boundary, Point},
+    term::{Term, cell::Flags},
+};
+use ely_gpui_component::terminal::{Target, links};
+
+/// The link at `point`: the program's OSC 8 target, else a URL in its line, wrapped rows joined.
+pub fn link_at<T>(term: &Term<T>, mut point: Point) -> Option<String> {
+    let grid = term.grid();
+    if grid[point].flags.contains(Flags::WIDE_CHAR_SPACER) {
+        point.column -= 1;
+    }
+    if let Some(link) = grid[point].hyperlink() {
+        return Some(link.uri().to_string());
+    }
+    let end = term.line_search_right(point);
+    let mut cell = term.line_search_left(point);
+    let (mut text, mut at) = (String::new(), 0);
+    loop {
+        if cell == point {
+            at = text.len();
+        }
+        let spacer = Flags::WIDE_CHAR_SPACER | Flags::LEADING_WIDE_CHAR_SPACER;
+        if !grid[cell].flags.intersects(spacer) {
+            text.push(grid[cell].c);
+        }
+        if cell == end {
+            break;
+        }
+        cell = cell.add(term, Boundary::Grid, 1);
+    }
+    links(&text)
+        .into_iter()
+        .find_map(|(bytes, target)| match target {
+            Target::Url(url) if bytes.contains(&at) => Some(url.to_string()),
+            _ => None,
+        })
+}
+
+#[cfg(test)]
+mod tests {
+    use alacritty_terminal::{
+        event::VoidListener,
+        index::{Column, Line},
+        term::{Config, test::TermSize},
+        vte::ansi::Processor,
+    };
+
+    use super::*;
+
+    fn link(bytes: &str, line: i32, column: usize) -> Option<String> {
+        let mut term = Term::new(Config::default(), &TermSize::new(12, 4), VoidListener);
+        let mut parser: Processor = Processor::new();
+        parser.advance(&mut term, bytes.as_bytes());
+        link_at(&term, Point::new(Line(line), Column(column)))
+    }
+
+    #[test]
+    fn an_osc_8_link_names_its_target() {
+        let text = "a \x1b]8;;https://ely.dev/x\x1b\\ely\x1b]8;;\x1b\\ b";
+        assert_eq!(link(text, 0, 3).as_deref(), Some("https://ely.dev/x"));
+        assert_eq!(link(text, 0, 0), None);
+    }
+
+    #[test]
+    fn a_url_ends_before_its_sentence_does() {
+        assert_eq!(link("(a.io/x).", 0, 2), None, "no scheme, no link");
+        let text = "(http://a.b)";
+        assert_eq!(link(text, 0, 4).as_deref(), Some("http://a.b"));
+        assert_eq!(link(text, 0, 11), None);
+    }
+
+    #[test]
+    fn a_url_runs_across_wrapped_rows_and_wide_cells() {
+        let text = "\u{4e2d} https://ely.dev/abc";
+        assert_eq!(link(text, 1, 3).as_deref(), Some("https://ely.dev/abc"));
+        assert_eq!(link(text, 0, 3).as_deref(), Some("https://ely.dev/abc"));
+        assert_eq!(link(text, 0, 1), None);
+        let wide = "file://a/\u{4e2d} x";
+        assert_eq!(
+            link(wide, 0, 10).as_deref(),
+            Some("file://a/\u{4e2d}"),
+            "a wide cell's spacer is its char"
+        );
+    }
+}