Allow styling of the whole new tab button

config/src/color.rs

@@ -141,6 +141,14 @@ pub struct TabBarColors {
     /// Styling for an inactive tab with a mouse hovering
     #[serde(default = "default_inactive_tab_hover")]
     pub inactive_tab_hover: TabBarColor,
+
+    /// Styling for the new tab button
+    #[serde(default = "default_inactive_tab")]
+    pub new_tab: TabBarColor,
+
+    /// Styling for the new tab button with a mouse hovering
+    #[serde(default = "default_inactive_tab_hover")]
+    pub new_tab_hover: TabBarColor,
 }
 impl_lua_conversion!(TabBarColors);
 
@@ -178,39 +186,31 @@ impl Default for TabBarColors {
             inactive_tab: default_inactive_tab(),
             inactive_tab_hover: default_inactive_tab_hover(),
             active_tab: default_active_tab(),
+            new_tab: default_inactive_tab(),
+            new_tab_hover: default_inactive_tab_hover(),
         }
     }
 }
 
 #[derive(Debug, Deserialize, Serialize, Clone)]
 pub struct TabBarStyle {
-    #[serde(default = "default_tab_left")]
-    pub new_tab_left: String,
-    #[serde(default = "default_tab_right")]
-    pub new_tab_right: String,
-    #[serde(default = "default_tab_left")]
-    pub new_tab_hover_left: String,
-    #[serde(default = "default_tab_right")]
-    pub new_tab_hover_right: String,
+    #[serde(default = "default_new_tab")]
+    pub new_tab: String,
+    #[serde(default = "default_new_tab")]
+    pub new_tab_hover: String,
 }
 
 impl Default for TabBarStyle {
     fn default() -> Self {
         Self {
-            new_tab_left: default_tab_left(),
-            new_tab_right: default_tab_right(),
-            new_tab_hover_left: default_tab_left(),
-            new_tab_hover_right: default_tab_right(),
+            new_tab: default_new_tab(),
+            new_tab_hover: default_new_tab(),
         }
     }
 }
 
-fn default_tab_left() -> String {
-    format_as_escapes(vec![FormatItem::Text(" ".to_string())]).unwrap()
-}
-
-fn default_tab_right() -> String {
-    format_as_escapes(vec![FormatItem::Text(" ".to_string())]).unwrap()
+fn default_new_tab() -> String {
+    format_as_escapes(vec![FormatItem::Text(" + ".to_string())]).unwrap()
 }
 
 #[derive(Debug, Deserialize, Serialize, Clone)]

docs/config/appearance.md

@@ -195,6 +195,26 @@ return {
 
         -- The same options that were listed under the `active_tab` section above
         -- can also be used for `inactive_tab_hover`.
+      },
+
+      -- The new tab button that let you create new tabs
+      new_tab = {
+        bg_color = "#1b1032",
+        fg_color = "#808080",
+
+        -- The same options that were listed under the `active_tab` section above
+        -- can also be used for `new_tab`.
+      },
+
+      -- You can configure some alternate styling when the mouse pointer
+      -- moves over the new tab button
+      new_tab_hover = {
+        bg_color = "#3b3052",
+        fg_color = "#909090",
+        italic = true,
+
+        -- The same options that were listed under the `active_tab` section above
+        -- can also be used for `new_tab_hover`.
       }
     }
   }

docs/config/lua/config/tab_bar_style.md

@@ -1,5 +1,10 @@
 # `tab_bar_style`
 
+*Since: nightly builds only*
+
+`new_tab_left`, `new_tab_right`, `new_tab_hover_left`, `new_tab_hover_right`
+have been removed and replaced by the more flexible `new_tab` and `new_tab_hover` elements.
+
 *Since: 20210502-154244-3f7122cb*
 
 `active_tab_left`, `active_tab_right`, `inactive_tab_left`,

wezterm-gui/src/tabbar.rs

@@ -143,6 +143,12 @@ fn compute_tab_title(
     }
 }
 
+fn is_tab_hover(mouse_x: Option<usize>, x: usize, tab_title_len: usize) -> bool {
+    return mouse_x
+        .map(|mouse_x| mouse_x >= x && mouse_x < x + tab_title_len)
+        .unwrap_or(false);
+}
+
 impl TabBarState {
     pub fn default() -> Self {
         Self {
@@ -173,22 +179,13 @@ impl TabBarState {
         let active_cell_attrs = colors.active_tab.as_cell_attributes();
         let inactive_hover_attrs = colors.inactive_tab_hover.as_cell_attributes();
         let inactive_cell_attrs = colors.inactive_tab.as_cell_attributes();
+        let new_tab_hover_attrs = colors.new_tab_hover.as_cell_attributes();
+        let new_tab_attrs = colors.new_tab.as_cell_attributes();
 
-        let new_tab_left = parse_status_text(
-            &config.tab_bar_style.new_tab_left,
-            inactive_cell_attrs.clone(),
-        );
-        let new_tab_right = parse_status_text(
-            &config.tab_bar_style.new_tab_right,
-            inactive_cell_attrs.clone(),
-        );
-        let new_tab_hover_left = parse_status_text(
-            &config.tab_bar_style.new_tab_hover_left,
-            inactive_hover_attrs.clone(),
-        );
-        let new_tab_hover_right = parse_status_text(
-            &config.tab_bar_style.new_tab_hover_right,
-            inactive_hover_attrs.clone(),
+        let new_tab = parse_status_text(&config.tab_bar_style.new_tab, new_tab_attrs.clone());
+        let new_tab_hover = parse_status_text(
+            &config.tab_bar_style.new_tab_hover,
+            new_tab_hover_attrs.clone(),
         );
 
         // We ultimately want to produce a line looking like this:
@@ -218,9 +215,8 @@ impl TabBarState {
         let titles_len: usize = tab_titles.iter().map(|s| s.len).sum();
         let number_of_tabs = tab_titles.len();
 
-        let available_cells = title_width.saturating_sub(
-            (number_of_tabs.saturating_sub(1)) + (new_tab_left.len() + new_tab_right.len() + 1),
-        );
+        let available_cells =
+            title_width.saturating_sub((number_of_tabs.saturating_sub(1)) + (new_tab.len()));
         let tab_width_max = if available_cells >= titles_len {
             // We can render each title with its full width
             usize::max_value()
@@ -238,10 +234,7 @@ impl TabBarState {
         for (tab_idx, tab_title) in tab_titles.iter().enumerate() {
             let tab_title_len = tab_title.len.min(tab_width_max);
             let active = tab_idx == active_tab_no;
-            let hover = !active
-                && mouse_x
-                    .map(|mouse_x| mouse_x >= x && mouse_x < x + tab_title_len)
-                    .unwrap_or(false);
+            let hover = !active && is_tab_hover(mouse_x, x, tab_title_len);
 
             // Recompute the title so that it factors in both the hover state
             // and the adjusted maximum tab width based on available space.
@@ -286,35 +279,16 @@ impl TabBarState {
 
         // New tab button
         {
-            let hover = mouse_x
-                .map(|mouse_x| {
-                    mouse_x >= x
-                        && mouse_x < x + new_tab_hover_left.len() + new_tab_hover_right.len() + 1
-                })
-                .unwrap_or(false);
-
-            let (cell_attrs, left, right) = if hover {
-                (
-                    &inactive_hover_attrs,
-                    &new_tab_hover_left,
-                    &new_tab_hover_right,
-                )
-            } else {
-                (&inactive_cell_attrs, &new_tab_left, &new_tab_right)
-            };
+            let hover = is_tab_hover(mouse_x, x, new_tab_hover.len());
 
-            let button_start = x;
+            let cells = if hover { &new_tab_hover } else { &new_tab };
 
-            for c in left {
-                line.set_cell(x, c.clone());
-                x += 1;
-            }
-            line.set_cell(x, Cell::new('+', cell_attrs.clone()));
-            x += 1;
+            let button_start = x;
 
-            for c in right {
+            for c in cells {
+                let len = c.width();
                 line.set_cell(x, c.clone());
-                x += 1;
+                x += len;
             }
 
             items.push(TabEntry {