feat(collaboration): implement multiple users (#957)

* work

* feat(collaboration): implement multiple users

* style(cleanup): some leftovers

2 files changed, 52 insertions, 25 deletions

diff --git a/default-plugins/tab-bar/src/main.rs b/default-plugins/tab-bar/src/main.rs
index 31b2f2d37..3db531384 100644
--- a/default-plugins/tab-bar/src/main.rs
+++ b/default-plugins/tab-bar/src/main.rs
@@ -85,6 +85,7 @@ impl ZellijPlugin for State {
                 t.is_sync_panes_active,
                 self.mode_info.palette,
                 self.mode_info.capabilities,
+                t.other_focused_clients.as_slice(),
             );
             all_tabs.push(tab);
         }
diff --git a/default-plugins/tab-bar/src/tab.rs b/default-plugins/tab-bar/src/tab.rs
index db960fd52..4ed3b2076 100644
--- a/default-plugins/tab-bar/src/tab.rs
+++ b/default-plugins/tab-bar/src/tab.rs
@@ -1,33 +1,62 @@
 use crate::{line::tab_separator, LinePart};
-use ansi_term::ANSIStrings;
+use ansi_term::{ANSIString, ANSIStrings};
 use unicode_width::UnicodeWidthStr;
 use zellij_tile::prelude::*;
 use zellij_tile_utils::style;
 
-pub fn active_tab(text: String, palette: Palette, separator: &str) -> LinePart {
-    let left_separator = style!(palette.gray, palette.green).paint(separator);
-    let tab_text_len = text.width() + 2 + separator.width() * 2; // 2 for left and right separators, 2 for the text padding
-    let tab_styled_text = style!(palette.black, palette.green)
-        .bold()
-        .paint(format!(" {} ", text));
-    let right_separator = style!(palette.green, palette.gray).paint(separator);
-    let tab_styled_text =
-        ANSIStrings(&[left_separator, tab_styled_text, right_separator]).to_string();
-    LinePart {
-        part: tab_styled_text,
-        len: tab_text_len,
+fn cursors(focused_clients: &[ClientId], palette: Palette) -> (Vec<ANSIString>, usize) {
+    // cursor section, text length
+    let mut len = 0;
+    let mut cursors = vec![];
+    for client_id in focused_clients.iter() {
+        if let Some(color) = client_id_to_colors(*client_id, palette) {
+            cursors.push(style!(color.1, color.0).paint(" "));
+            len += 1;
+        }
     }
+    (cursors, len)
 }
 
-pub fn non_active_tab(text: String, palette: Palette, separator: &str) -> LinePart {
-    let left_separator = style!(palette.gray, palette.fg).paint(separator);
-    let tab_text_len = text.width() + 2 + separator.width() * 2; // 2 for left and right separators, 2 for the text padding
-    let tab_styled_text = style!(palette.black, palette.fg)
+pub fn render_tab(
+    text: String,
+    palette: Palette,
+    separator: &str,
+    focused_clients: &[ClientId],
+    active: bool,
+) -> LinePart {
+    let background_color = if active { palette.green } else { palette.fg };
+    let left_separator = style!(palette.gray, background_color).paint(separator);
+    let mut tab_text_len = text.width() + 2 + separator.width() * 2; // 2 for left and right separators, 2 for the text padding
+
+    let tab_styled_text = style!(palette.black, background_color)
         .bold()
         .paint(format!(" {} ", text));
-    let right_separator = style!(palette.fg, palette.gray).paint(separator);
-    let tab_styled_text =
-        ANSIStrings(&[left_separator, tab_styled_text, right_separator]).to_string();
+
+    let right_separator = style!(background_color, palette.gray).paint(separator);
+    let tab_styled_text = if !focused_clients.is_empty() {
+        let (cursor_section, extra_length) = cursors(focused_clients, palette);
+        tab_text_len += extra_length;
+        let mut s = String::new();
+        let cursor_beginning = style!(palette.black, background_color)
+            .bold()
+            .paint("[")
+            .to_string();
+        let cursor_section = ANSIStrings(&cursor_section).to_string();
+        let cursor_end = style!(palette.black, background_color)
+            .bold()
+            .paint("]")
+            .to_string();
+        s.push_str(&left_separator.to_string());
+        s.push_str(&tab_styled_text.to_string());
+        s.push_str(&cursor_beginning);
+        s.push_str(&cursor_section);
+        s.push_str(&cursor_end);
+        s.push_str(&right_separator.to_string());
+        s
+    } else {
+        ANSIStrings(&[left_separator, tab_styled_text, right_separator]).to_string()
+    };
+
     LinePart {
         part: tab_styled_text,
         len: tab_text_len,
@@ -40,15 +69,12 @@ pub fn tab_style(
     is_sync_panes_active: bool,
     palette: Palette,
     capabilities: PluginCapabilities,
+    focused_clients: &[ClientId],
 ) -> LinePart {
     let separator = tab_separator(capabilities);
     let mut tab_text = text;
     if is_sync_panes_active {
         tab_text.push_str(" (Sync)");
     }
-    if is_active_tab {
-        active_tab(tab_text, palette, separator)
-    } else {
-        non_active_tab(tab_text, palette, separator)
-    }
+    render_tab(tab_text, palette, separator, focused_clients, is_active_tab)
 }