add bold tag support

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

@@ -1,3 +1,4 @@
+mod bold;
 mod header;
 mod list;
 mod quote;
@@ -6,6 +7,7 @@ mod title;
 
 use std::collections::HashMap;
 
+use bold::Bold;
 use gtk::{
     TextBuffer, TextTag, TextTagTable,
     gdk::RGBA,
@@ -20,6 +22,7 @@ use title::Title;
 pub struct Tags {
     pub text_tag_table: TextTagTable,
     // Tags
+    pub bold: Bold,
     pub header: Header,
     pub list: TextTag,
     pub quote: Quote,
@@ -47,6 +50,7 @@ impl Tags {
         Self {
             text_tag_table,
             // Tags
+            bold: Bold::new(),
             header: Header::new(),
             list,
             quote: Quote::new(),
@@ -65,10 +69,16 @@ impl Tags {
 
         self.quote.render(buffer);
 
+        self.bold.render(buffer);
+
         reference::render_images_links(&buffer, base, &link_color, links);
         reference::render_images(&buffer, base, &link_color, links);
         reference::render_links(&buffer, base, &link_color, links);
 
-        title.map(|ref s| reference::strip_tags(s)) // @TODO other tags
+        title.map(|mut s| {
+            s = reference::strip_tags(&s);
+            s = bold::strip_tags(&s);
+            s // @TODO other tags
+        })
     }
 }

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

@@ -0,0 +1,86 @@
+use gtk::{
+    TextBuffer, TextTag,
+    WrapMode::Word,
+    prelude::{TextBufferExt, TextBufferExtManual},
+};
+use regex::Regex;
+
+const REGEX_BOLD: &str = r"\*\*(?P<text>[^*]+)\*\*";
+
+pub struct Bold(TextTag);
+
+impl Bold {
+    pub fn new() -> Self {
+        Self(TextTag::builder().weight(600).wrap_mode(Word).build())
+    }
+
+    /// Apply **bold** `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_BOLD)
+            .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_BOLD)
+        .unwrap()
+        .captures_iter(&value)
+        .into_iter()
+    {
+        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 **bold 1** and **bold 2** with ![img](https://link.com)";
+    let mut result = String::from(VALUE);
+    for cap in Regex::new(REGEX_BOLD)
+        .unwrap()
+        .captures_iter(VALUE)
+        .into_iter()
+    {
+        if let Some(m) = cap.get(0) {
+            result = result.replace(m.as_str(), &cap["text"]);
+        }
+    }
+    assert_eq!(
+        result,
+        "Some bold 1 and bold 2 with ![img](https://link.com)"
+    )
+}
+
+#[test]
+fn test_regex() {
+    let cap: Vec<_> = Regex::new(REGEX_BOLD)
+        .unwrap()
+        .captures_iter(r"Some **bold 1** and **bold 2** with ![img](https://link.com)")
+        .collect();
+
+    assert_eq!(&cap.get(0).unwrap()["text"], "bold 1");
+    assert_eq!(&cap.get(1).unwrap()["text"], "bold 2");
+}