fix(formatting): panic when slice str (#177)

* fix panic when slice str

* copy code from diskonaut

* typo fix

3 files changed, 40 insertions, 12 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 9c232b9..fac42d5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -92,6 +92,7 @@ dependencies = [
  "tokio 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "trust-dns-resolver 0.18.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "tui 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-width 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -200,7 +201,7 @@ dependencies = [
  "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "strsim 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "textwrap 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "unicode-width 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-width 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -236,7 +237,7 @@ dependencies = [
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "termios 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "unicode-width 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-width 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -251,7 +252,7 @@ dependencies = [
  "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "termios 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "unicode-width 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-width 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1483,7 +1484,7 @@ name = "textwrap"
 version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "unicode-width 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-width 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1566,7 +1567,7 @@ dependencies = [
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "termion 1.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-segmentation 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "unicode-width 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-width 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1602,7 +1603,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "unicode-width"
-version = "0.1.6"
+version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -1927,7 +1928,7 @@ dependencies = [
 "checksum unicode-bidi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "49f2bd0c6468a8230e1db229cff8029217cf623c767ea5d60bfbd42729ea54d5"
 "checksum unicode-normalization 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "09c8070a9942f5e7cfccd93f490fdebd230ee3c3c9f107cb25bad5351ef671cf"
 "checksum unicode-segmentation 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e83e153d1053cbb5a118eeff7fd5be06ed99153f00dbcd8ae310c5fb2b22edc0"
-"checksum unicode-width 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "7007dbd421b92cc6e28410fe7362e2e0a2503394908f417b68ec8d1c364c4e20"
+"checksum unicode-width 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "9337591893a19b88d8d87f2cec1e73fad5cdfd10e5a6f349f498ad6ea2ffb1e3"
 "checksum unicode-xid 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "36dff09cafb4ec7c8cf0023eb0b686cb6ce65499116a12201c9e11840ca01beb"
 "checksum unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"
 "checksum unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"
diff --git a/Cargo.toml b/Cargo.toml
index 63079db..0fc8a97 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -32,6 +32,7 @@ lazy_static = "1.4.0"
 tokio = { version = "0.2", features = ["rt-core", "sync"] }
 trust-dns-resolver = "0.18.1"
 async-trait = "0.1.21"
+unicode-width = "0.1.8"
 
 [target.'cfg(target_os="linux")'.dependencies]
 procfs = "0.7.4"
@@ -41,4 +42,4 @@ insta = "0.12.0"
 pnet_base = "0.26.0"
 cargo-insta = "0.11.0"
 packet-builder = "0.5.0"
-regex = "1"
+regex = "1"
\ No newline at end of file
diff --git a/src/display/components/table.rs b/src/display/components/table.rs
index 059b5ed..f61886c 100644
--- a/src/display/components/table.rs
+++ b/src/display/components/table.rs
@@ -1,4 +1,6 @@
 use ::std::collections::{BTreeMap, HashMap};
+use ::std::iter::FromIterator;
+use ::unicode_width::UnicodeWidthChar;
 
 use ::tui::backend::Backend;
 use ::tui::layout::Rect;
@@ -51,11 +53,35 @@ pub struct Table<'a> {
     breakpoints: BTreeMap<u16, ColumnData>,
 }
 
+fn truncate_iter_to_unicode_width<Input, Collect>(iter: Input, width: usize) -> Collect
+where
+    Input: Iterator<Item = char>,
+    Collect: FromIterator<char>,
+{
+    let mut chunk_width = 0;
+    iter.take_while(|ch| {
+        chunk_width += ch.width().unwrap_or(0);
+        chunk_width <= width
+    })
+    .collect()
+}
+
 fn truncate_middle(row: &str, max_length: u16) -> String {
-    if row.len() as u16 > max_length {
-        let first_slice = &row[0..(max_length as usize / 2) - 2];
-        let second_slice = &row[(row.len() - (max_length / 2) as usize + 2)..row.len()];
-        format!("{}[..]{}", first_slice, second_slice)
+    if max_length < 6 {
+        truncate_iter_to_unicode_width(row.chars(), max_length as usize)
+    } else if row.len() as u16 > max_length {
+        let split_point = (max_length as usize / 2) - 2;
+        let first_slice = truncate_iter_to_unicode_width::<_, String>(row.chars(), split_point);
+        let second_slice =
+            truncate_iter_to_unicode_width::<_, Vec<_>>(row.chars().rev(), split_point)
+                .into_iter()
+                .rev()
+                .collect::<String>();
+        if max_length % 2 == 0 {
+            format!("{}[..]{}", first_slice, second_slice)
+        } else {
+            format!("{}[..]{}", first_slice, second_slice)
+        }
     } else {
         row.to_string()
     }