Git · DiffViewer: rows move to their own file; shorter comments

src/git/rows.rs

@@ -0,0 +1,96 @@
+//! The rows a diff viewer draws, and their colors.
+
+use std::ops::Range;
+
+use gpui::{App, HighlightStyle, Hsla, SharedString, StyledText};
+
+use super::{
+    diff::{DiffLine, LineKind, Stretch, pair_places},
+    viewer::DiffLayout,
+};
+use crate::{
+    editor::{code_colors, stack},
+    theme::Palette,
+};
+
+/// A line's place: its stretch, then its line there.
+pub type Place = (usize, usize);
+
+/// A row as the viewer draws it.
+#[derive(Clone)]
+pub(super) enum Shown {
+    /// A hunk's header and its place among the stretches.
+    Header(usize, SharedString),
+    Line(Place, DiffLine),
+    Pair(Option<(Place, DiffLine)>, Option<(Place, DiffLine)>),
+    /// A folded stretch: its place among the stretches and how many lines it hides.
+    Fold(usize, usize),
+}
+
+pub(super) fn shown(stretches: &[Stretch], layout: DiffLayout, open: &[usize]) -> Vec<Shown> {
+    let mut rows = Vec::new();
+    for (ix, stretch) in stretches.iter().enumerate() {
+        match stretch {
+            Stretch::Hunk { header, lines } => {
+                rows.push(Shown::Header(ix, header.clone()));
+                let at = |line: usize| ((ix, line), lines[line].clone());
+                match layout {
+                    DiffLayout::Unified => rows.extend((0..lines.len()).map(|line| {
+                        let (place, line) = at(line);
+                        Shown::Line(place, line)
+                    })),
+                    DiffLayout::Split => rows.extend(
+                        pair_places(lines)
+                            .into_iter()
+                            .map(|(left, right)| Shown::Pair(left.map(at), right.map(at))),
+                    ),
+                }
+            }
+            Stretch::Folded(lines) if open.contains(&ix) => {
+                rows.extend(lines.iter().enumerate().map(|(at, line)| {
+                    let place = (ix, at);
+                    match layout {
+                        DiffLayout::Unified => Shown::Line(place, line.clone()),
+                        DiffLayout::Split => {
+                            Shown::Pair(Some((place, line.clone())), Some((place, line.clone())))
+                        }
+                    }
+                }))
+            }
+            Stretch::Folded(lines) => rows.push(Shown::Fold(ix, lines.len())),
+        }
+    }
+    rows
+}
+
+/// The wash behind a line, and behind its changed words.
+pub(super) fn washes(kind: LineKind, colors: &Palette) -> (Option<Hsla>, Hsla) {
+    match kind {
+        LineKind::Same => (None, colors.hover),
+        LineKind::Added => (
+            Some(colors.success.opacity(0.08)),
+            colors.success.opacity(0.25),
+        ),
+        LineKind::Removed => (
+            Some(colors.danger.opacity(0.08)),
+            colors.danger.opacity(0.25),
+        ),
+    }
+}
+
+/// A line's code, colored as code, its changed words washed.
+pub(super) fn code(line: &DiffLine, colors: &Palette, cx: &App) -> StyledText {
+    let (_, word) = washes(line.kind, colors);
+    let mut styles: Vec<(Range<usize>, HighlightStyle)> = code_colors(&line.text, cx);
+    styles.extend(line.words.iter().map(|range| {
+        (
+            range.clone(),
+            HighlightStyle {
+                background_color: Some(word),
+                ..HighlightStyle::default()
+            },
+        )
+    }));
+    styles.sort_by_key(|(range, _)| range.start);
+    StyledText::new(line.text.clone()).with_highlights(stack(styles))
+}