implement pre tag

src/app/browser/window/tab/item/page/content/text/markdown/tags.rs

@@ -1,6 +1,7 @@
 mod bold;
 mod code;
 mod header;
+mod pre;
 mod quote;
 mod reference;
 mod strike;
@@ -12,6 +13,7 @@ use bold::Bold;
 use code::Code;
 use gtk::{TextBuffer, TextTag, gdk::RGBA, glib::Uri};
 use header::Header;
+use pre::Pre;
 use quote::Quote;
 use strike::Strike;
 use underline::Underline;
@@ -20,6 +22,7 @@ pub struct Tags {
     pub bold: Bold,
     pub code: Code,
     pub header: Header,
+    pub pre: Pre,
     pub quote: Quote,
     pub strike: Strike,
     pub underline: Underline,
@@ -38,6 +41,7 @@ impl Tags {
             bold: Bold::new(),
             code: Code::new(),
             header: Header::new(),
+            pre: Pre::new(),
             quote: Quote::new(),
             strike: Strike::new(),
             underline: Underline::new(),
@@ -59,6 +63,7 @@ impl Tags {
         self.quote.render(buffer);
 
         self.bold.render(buffer);
+        self.pre.render(buffer);
         self.strike.render(buffer);
         self.underline.render(buffer);
 
@@ -71,6 +76,7 @@ impl Tags {
         // Format document title string
         title.map(|mut s| {
             s = bold::strip_tags(&s);
+            s = pre::strip_tags(&s);
             s = reference::strip_tags(&s);
             s = strike::strip_tags(&s);
             s = underline::strip_tags(&s);

src/app/browser/window/tab/item/page/content/text/markdown/tags/pre.rs

@@ -0,0 +1,89 @@
+use gtk::{
+    TextBuffer, TextTag,
+    WrapMode::Word,
+    gdk::RGBA,
+    prelude::{TextBufferExt, TextBufferExtManual},
+};
+use regex::Regex;
+
+const REGEX_PRE: &str = r"`(?P<text>[^`]+)`";
+
+pub struct Pre(TextTag);
+
+impl Pre {
+    pub fn new() -> Self {
+        Self(if adw::StyleManager::default().is_dark() {
+            TextTag::builder()
+                .background_rgba(&RGBA::new(0.0, 0.0, 0.0, 1.))
+                .foreground("#ccc")
+                .family("monospace") // @TODO
+                .wrap_mode(Word)
+                .build()
+        } else {
+            TextTag::builder()
+                .background_rgba(&RGBA::new(0.0, 0.0, 0.0, 0.06))
+                .family("monospace") // @TODO
+                .wrap_mode(Word)
+                .build()
+        })
+    }
+
+    /// Apply preformatted `Tag` to given `TextBuffer`
+    pub fn render(&self, buffer: &TextBuffer) {
+        assert!(buffer.tag_table().add(&self.0));
+
+        let (start, end) = buffer.bounds();
+        let full_content = buffer.text(&start, &end, true).to_string();
+
+        let matches: Vec<_> = Regex::new(REGEX_PRE)
+            .unwrap()
+            .captures_iter(&full_content)
+            .collect();
+
+        for cap in matches.into_iter().rev() {
+            let full_match = cap.get(0).unwrap();
+
+            let start_char_offset = full_content[..full_match.start()].chars().count() as i32;
+            let end_char_offset = full_content[..full_match.end()].chars().count() as i32;
+
+            let mut start_iter = buffer.iter_at_offset(start_char_offset);
+            let mut end_iter = buffer.iter_at_offset(end_char_offset);
+
+            buffer.delete(&mut start_iter, &mut end_iter);
+            buffer.insert_with_tags(&mut start_iter, &cap["text"], &[&self.0])
+        }
+    }
+}
+
+pub fn strip_tags(value: &str) -> String {
+    let mut result = String::from(value);
+    for cap in Regex::new(REGEX_PRE).unwrap().captures_iter(value) {
+        if let Some(m) = cap.get(0) {
+            result = result.replace(m.as_str(), &cap["text"]);
+        }
+    }
+    result
+}
+
+#[test]
+fn test_strip_tags() {
+    const VALUE: &str = r"Some `pre 1` and `pre 2` with ![img](https://link.com)";
+    let mut result = String::from(VALUE);
+    for cap in Regex::new(REGEX_PRE).unwrap().captures_iter(VALUE) {
+        if let Some(m) = cap.get(0) {
+            result = result.replace(m.as_str(), &cap["text"]);
+        }
+    }
+    assert_eq!(result, "Some pre 1 and pre 2 with ![img](https://link.com)")
+}
+
+#[test]
+fn test_regex() {
+    let cap: Vec<_> = Regex::new(REGEX_PRE)
+        .unwrap()
+        .captures_iter(r"Some `pre 1` and `pre 2` with ![img](https://link.com)")
+        .collect();
+
+    assert_eq!(&cap.get(0).unwrap()["text"], "pre 1");
+    assert_eq!(&cap.get(1).unwrap()["text"], "pre 2");
+}