Add syntax highlighter.

libclide/Cargo.toml

@@ -9,3 +9,4 @@ strum = { workspace = true }
 log = { workspace = true }
 devicons = { workspace = true }
 libclide-macros = { path = "../libclide-macros" }
+syntect = "5.3.0"

libclide/src/fs.rs

@@ -4,4 +4,21 @@
 
 pub mod entry_meta;
 
+use anyhow::Context;
 pub use entry_meta::icon;
+use std::fs;
+use std::path::Path;
+
+pub fn read_file<P: AsRef<Path>>(p: P) -> anyhow::Result<String> {
+    let path = p.as_ref();
+    let meta =
+        fs::metadata(path).unwrap_or_else(|_| panic!("Failed to get file metadata {path:?}"));
+    if !meta.is_file() {
+        crate::warn!(target:"FileSystem", "Attempted to open file {path:?} that is not a valid file");
+        Err(anyhow::anyhow!(
+            "Attempted to open file {path:?} that is not a valid file"
+        ))?;
+    }
+    let path_str = path.to_string_lossy().to_string();
+    fs::read_to_string(path_str.as_str()).context(format!("Failed to read file {path:?}"))
+}

libclide/src/theme.rs

@@ -3,3 +3,4 @@
 // SPDX-License-Identifier: GNU General Public License v3.0 or later
 
 pub mod colors;
+pub mod highlighter;

libclide/src/theme/highlighter.rs

@@ -0,0 +1,66 @@
+use std::fs;
+use std::path::Path;
+use syntect::easy::HighlightLines;
+use syntect::highlighting::ThemeSet;
+use syntect::html::{IncludeBackground, append_highlighted_html_for_styled_line};
+use syntect::parsing::SyntaxSet;
+use syntect::util::LinesWithEndings;
+
+pub struct Highlighter {
+    path: String,
+    ss: SyntaxSet,
+    ts: ThemeSet,
+}
+
+impl Highlighter {
+    pub fn new<P: AsRef<Path>>(p: P) -> anyhow::Result<Highlighter> {
+        let path = p.as_ref();
+        let meta =
+            fs::metadata(path).unwrap_or_else(|_| panic!("Failed to get file metadata {path:?}"));
+        let ss = SyntaxSet::load_defaults_nonewlines();
+        let ts = ThemeSet::load_defaults();
+        if !meta.is_file() {
+            crate::error!(target:"FileSystem", "Attempted to open file {path:?} that is not a valid file");
+            Err(anyhow::anyhow!(
+                "Attempted to open file {path:?} that is not a valid file"
+            ))?;
+        }
+        Ok(Highlighter {
+            path: path.to_string_lossy().to_string(),
+            ss,
+            ts,
+        })
+    }
+
+    pub fn syntax_highlight_text<P: AsRef<str>>(&self, p: P) -> String {
+        let text = p.as_ref();
+        let theme = &self.ts.themes["base16-ocean.dark"];
+        let lang = self
+            .ss
+            .find_syntax_by_extension(
+                Path::new(self.path.as_str())
+                    .extension()
+                    .map(|s| s.to_str())
+                    .unwrap_or_else(|| Some("md"))
+                    .expect("Failed to get file extension"),
+            )
+            .unwrap_or_else(|| self.ss.find_syntax_plain_text());
+        let mut highlighter = HighlightLines::new(lang, theme);
+        // If you care about the background, see `start_highlighted_html_snippet(theme);`.
+        let mut output = String::from("<pre>\n");
+        for line in LinesWithEndings::from(text) {
+            let regions = highlighter
+                .highlight_line(line, &self.ss)
+                .expect("Failed to highlight");
+
+            append_highlighted_html_for_styled_line(
+                &regions[..],
+                IncludeBackground::No,
+                &mut output,
+            )
+            .expect("Failed to insert highlighted html");
+        }
+        output.push_str("</pre>\n");
+        output
+    }
+}