Allow to use custom "ellipsis" string

NEWS.md

@@ -4,14 +4,15 @@ swayr v0.13.0
 - The placeholders `{id}`, `{app_name}`, `{name}`/`{title}`, `{output_name}`,
   `{workspace_name}`, and `{marks}` may optionally provide a format string as
   specified by [Rust's std::fmt](https://doc.rust-lang.org/std/fmt/).  The
-  syntax is `{<placeholder>:<fmt_str>}` or `{<placeholder>:<fmt_str>…}`.  For
-  example, `{app_name:{:>10.10}}` would mean that the application name is
-  printed with exactly 10 characters.  If it's shorter, it will be
-  right-aligned (the `>`) and padded with spaces, if it's longer, it'll be cut
-  after the 10th character.  Another example, `{app_name:{:.10}…}` would mean
-  that the application name is truncated at 10 characters.  If it's shorter, it
-  will be printed as-is (no padding), if it's longer, it'll be cut after the
-  9th character and the ellipsis (…) character will be added after it.
+  syntax is `{<placeholder>:<fmt_str><clipped_str>}`.  For example,
+  `{app_name:{:>10.10}}` would mean that the application name is printed with
+  exactly 10 characters.  If it's shorter, it will be right-aligned (the `>`)
+  and padded with spaces, if it's longer, it'll be cut after the 10th
+  character.  Another example, `{app_name:{:.10}...}` would mean that the
+  application name is truncated at 10 characters.  If it's shorter, it will be
+  printed as-is (no padding), if it's longer, it'll be cut after the 10th
+  character and the last 3 characters of that substring will be replaced with
+  `...` (`<clipped_str>`).
 
 swayr v0.12.0
 =============

README.md

@@ -327,14 +327,14 @@ right now.
 The placeholders `{id}`, `{app_name}`, `{name}`/`{title}`, `{output_name}`,
 `{workspace_name}`, and `{marks}` may optionally provide a format string as
 specified by [Rust's std::fmt](https://doc.rust-lang.org/std/fmt/).  The syntax
-is `{<placeholder>:<fmt_str>}` or `{<placeholder>:<fmt_str>…}`.  For example,
+is `{<placeholder>:<fmt_str><clipped_str>}`.  For example,
 `{app_name:{:>10.10}}` would mean that the application name is printed with
 exactly 10 characters.  If it's shorter, it will be right-aligned (the `>`) and
 padded with spaces, if it's longer, it'll be cut after the 10th character.
-Another example, `{app_name:{:.10}…}` would mean that the application name is
+Another example, `{app_name:{:.10}...}` would mean that the application name is
 truncated at 10 characters.  If it's shorter, it will be printed as-is (no
-padding), if it's longer, it'll be cut after the 9th character and the ellipsis
-(…) character will be added after it.
+padding), if it's longer, it'll be cut after the 10th character and the last
+3 characters of that substring will be replaced with `...` (`<clipped_str>`).
 
 It is crucial that during selection (using wofi or some other menu program)
 each window has a different display string.  Therefore, it is highly

src/rtfmt.rs

@@ -73,15 +73,15 @@ impl<'a> std::convert::TryInto<usize> for &FmtArg<'a> {
     }
 }
 
-pub fn format(fmt: &str, arg: &str, ellipsis: bool) -> String {
+pub fn format(fmt: &str, arg: &str, clipped_str: &str) -> String {
     let args = &[FmtArg::Str(arg)];
 
     if let Ok(pf) = ParsedFormat::parse(fmt, args, &NoNamedArguments) {
         let mut s = format!("{}", pf);
 
-        if ellipsis && !s.contains(arg) {
-            s.pop();
-            s.push('…');
+        if !clipped_str.is_empty() && !s.contains(arg) {
+            remove_last_n_chars(&mut s, clipped_str.chars().count());
+            s.push_str(clipped_str);
         }
         s
     } else {
@@ -89,13 +89,22 @@ pub fn format(fmt: &str, arg: &str, ellipsis: bool) -> String {
     }
 }
 
+fn remove_last_n_chars(s: &mut String, n: usize) -> () {
+    match s.char_indices().nth_back(n) {
+        Some((pos, ch)) => s.truncate(pos + ch.len_utf8()),
+        None => s.clear(),
+    }
+}
+
 #[test]
 fn test_format() {
-    assert_eq!(format("{:.10}", "sway", false), "sway");
-    assert_eq!(format("{:.10}", "sway", true), "sway");
-    assert_eq!(format("{:.4}", "𝔰𝔴𝔞𝔶", true), "𝔰𝔴𝔞𝔶");
-
-    assert_eq!(format("{:.3}", "sway", false), "swa");
-    assert_eq!(format("{:.3}", "sway", true), "sw…");
-    assert_eq!(format("{:.3}", "𝔰𝔴𝔞𝔶", true), "𝔰𝔴…");
+    assert_eq!(format("{:.10}", "sway", ""), "sway");
+    assert_eq!(format("{:.10}", "sway", "…"), "sway");
+    assert_eq!(format("{:.4}", "𝔰𝔴𝔞𝔶", "……"), "𝔰𝔴𝔞𝔶");
+
+    assert_eq!(format("{:.3}", "sway", ""), "swa");
+    assert_eq!(format("{:.3}", "sway", "…"), "sw…");
+    assert_eq!(format("{:.5}", "𝔰𝔴𝔞𝔶 𝔴𝔦𝔫𝔡𝔬𝔴", "…?"), "𝔰𝔴𝔞…?");
+    assert_eq!(format("{:.5}", "sway window", "..."), "sw...");
+    assert_eq!(format("{:.2}", "sway", "..."), "...");
 }

src/tree.rs

@@ -429,7 +429,7 @@ lazy_static! {
     static ref APP_NAME_AND_VERSION_RX: regex::Regex =
         regex::Regex::new("(.+)(-[0-9.]+)").unwrap();
     static ref PLACEHOLDER_RX: regex::Regex = regex::Regex::new(
-        r"\{(?P<name>[^}:]+)(?::(?P<fmtstr>\{[^}]*\})(?P<ellipsis>…)?)?\}"
+        r"\{(?P<name>[^}:]+)(?::(?P<fmtstr>\{[^}]*\})(?P<clipstr>[^}]*))?\}"
     )
     .unwrap();
 }
@@ -531,11 +531,12 @@ impl DisplayFormat for DisplayNode<'_> {
                     _ => caps[0].to_string(),
                 };
                 let fmt_str = caps.name("fmtstr").map_or("{}", |m| m.as_str());
-                let ellipsis = caps.name("ellipsis").is_some();
+                let clipped_str =
+                    caps.name("clipstr").map_or("", |m| m.as_str());
 
                 maybe_html_escape(
                     html_escape,
-                    rtfmt::format(fmt_str, &value, ellipsis),
+                    rtfmt::format(fmt_str, &value, &clipped_str),
                 )
             })
             .into()
@@ -573,15 +574,20 @@ fn test_placeholder_rx() {
     let caps = PLACEHOLDER_RX.captures("Hello, {place}!").unwrap();
     assert_eq!(caps.name("name").unwrap().as_str(), "place");
     assert_eq!(caps.name("fmtstr"), None);
-    assert_eq!(caps.name("ellipsis"), None);
+    assert_eq!(caps.name("clipstr"), None);
 
     let caps = PLACEHOLDER_RX.captures("Hi, {place:{:>10.10}}!").unwrap();
     assert_eq!(caps.name("name").unwrap().as_str(), "place");
     assert_eq!(caps.name("fmtstr").unwrap().as_str(), "{:>10.10}");
-    assert_eq!(caps.name("ellipsis"), None);
+    assert_eq!(caps.name("clipstr").unwrap().as_str(), "");
 
     let caps = PLACEHOLDER_RX.captures("Hello, {place:{:.5}…}!").unwrap();
     assert_eq!(caps.name("name").unwrap().as_str(), "place");
     assert_eq!(caps.name("fmtstr").unwrap().as_str(), "{:.5}");
-    assert_eq!(caps.name("ellipsis").unwrap().as_str(), "…");
+    assert_eq!(caps.name("clipstr").unwrap().as_str(), "…");
+
+    let caps = PLACEHOLDER_RX.captures("Hello, {place:{:.5}...}!").unwrap();
+    assert_eq!(caps.name("name").unwrap().as_str(), "place");
+    assert_eq!(caps.name("fmtstr").unwrap().as_str(), "{:.5}");
+    assert_eq!(caps.name("clipstr").unwrap().as_str(), "...");
 }