Add support for stretching tab bar to fill width of tab bar

Resolves #1914

Cargo.toml

@@ -11,15 +11,15 @@ members = [
   "wezterm-gui",
   "wezterm-mux-server",
   "wezterm-open-url",
-  "wezterm-ssh"
+  "wezterm-ssh",
 ]
 resolver = "2"
-exclude = [
-  "termwiz/codegen"
-]
+exclude = ["termwiz/codegen"]
 
 [profile.release]
 opt-level = 3
+lto = "thin"
+codegen-units = 1
 # debug = 2
 
 [profile.dev]
@@ -28,8 +28,8 @@ opt-level = 3
 #split-debuginfo = "unpacked"
 
 [patch.crates-io]
-xcb = {git="https://github.com/rust-x-bindings/rust-xcb", rev="dbdaa01c178c6fbe68bd51b7ad44c08172181083"} # waiting on a release with https://github.com/rust-x-bindings/rust-xcb/pull/230
+xcb = { git = "https://github.com/rust-x-bindings/rust-xcb", rev = "dbdaa01c178c6fbe68bd51b7ad44c08172181083" } # waiting on a release with https://github.com/rust-x-bindings/rust-xcb/pull/230
 
 # We use our own vendored cairo, which has minimal deps and should just
 # build via cargo.
-cairo-sys-rs = {path="deps/cairo", version="0.18.0"}
+cairo-sys-rs = { path = "deps/cairo", version = "0.18.0" }

config/src/config.rs

@@ -461,6 +461,10 @@ pub struct Config {
     #[dynamic(default)]
     pub tab_and_split_indices_are_zero_based: bool,
 
+    /// Specifies to fill the width of the window with the tab bar
+    #[dynamic(default)]
+    pub tab_bar_fill: bool,
+
     /// Specifies the maximum width that a tab can have in the
     /// tab bar.  Defaults to 16 glyphs in width.
     #[dynamic(default = "default_tab_max_width")]

docs/config/appearance.md

@@ -277,6 +277,8 @@ details.
   bar at the bottom of the window instead of the top
 * [tab_max_width](lua/config/tab_max_width.md) sets the maximum width, measured in cells,
   of a given tab when using retro tab mode.
+* [tab_bar_fill](lua/config/tab_bar_fill.md) sets the fancy tab bar to fill
+  the width of the title bar.
 
 #### Native (Fancy) Tab Bar appearance
 

docs/config/lua/config/tab_bar_title_fill.md

@@ -0,0 +1,15 @@
+---
+tags:
+  - tab_bar
+---
+# `tab_bar_fill`
+
+Specifies that the fancy tab bar should allow tab titles
+to take up the entire width of the tab bar.
+In this mode, maximum tab width is ignored.
+
+Defaults to false.
+
+```lua
+config.tab_bar_fill = true
+```

wezterm-gui/src/tabbar.rs

@@ -324,6 +324,14 @@ impl TabBarState {
 
         let mut active_tab_no = 0;
 
+        let config_tab_max_width = if config.tab_bar_fill {
+            // We have no layout, so this is a rough estimate
+            // The tab bar consits of the tab titles, the new tab button, and some padding
+            title_width.saturating_sub(new_tab.len() + 3) / (tab_info.len())
+        } else {
+            config.tab_max_width
+        };
+
         let tab_titles: Vec<TitleText> = if config.show_tabs_in_tab_bar {
             tab_info
                 .iter()
@@ -337,7 +345,7 @@ impl TabBarState {
                         pane_info,
                         config,
                         false,
-                        config.tab_max_width,
+                        config_tab_max_width,
                     )
                 })
                 .collect()
@@ -346,18 +354,16 @@ 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.len());
         let tab_width_max = if config.use_fancy_tab_bar || available_cells >= titles_len {
             // We can render each title with its full width
-            usize::max_value()
+            usize::MAX
         } else {
             // We need to clamp the length to balance them out
             available_cells / number_of_tabs
         }
-        .min(config.tab_max_width);
-
+        .min(config_tab_max_width);
         let mut line = Line::with_width(0, SEQ_ZERO);
 
         let mut x = 0;
@@ -399,9 +405,10 @@ impl TabBarState {
         }
 
         for (tab_idx, tab_title) in tab_titles.iter().enumerate() {
-            let tab_title_len = tab_title.len.min(tab_width_max);
+            // The title is allowed to grow to the max size of the computed tab width
+            let tab_title_max_len = tab_title.len.max(tab_width_max).min(tab_width_max);
             let active = tab_idx == active_tab_no;
-            let hover = !active && is_tab_hover(mouse_x, x, tab_title_len);
+            let hover = !active && is_tab_hover(mouse_x, x, tab_title_max_len);
 
             // Recompute the title so that it factors in both the hover state
             // and the adjusted maximum tab width based on available space.
@@ -411,7 +418,7 @@ impl TabBarState {
                 pane_info,
                 config,
                 hover,
-                tab_title_len,
+                tab_title_max_len,
             );
 
             let cell_attrs = if active {

wezterm-gui/src/termwindow/render/fancy_tab_bar.rs

@@ -299,9 +299,33 @@ impl crate::TermWindow {
                 _ => 0.,
             })
             .sum();
-        let max_tab_width = ((self.dimensions.pixel_width as f32 / num_tabs)
-            - (1.5 * metrics.cell_size.width as f32))
-            .max(0.);
+
+        // Unlike num tabs this only includes items on the tab bar, since the new tab button is fixed width.
+        let num_tabs_or_status: f32 = items
+            .iter()
+            .map(|item| match item.item {
+                TabBarItem::RightStatus { .. }
+                | TabBarItem::LeftStatus { .. }
+                | TabBarItem::Tab { .. } => 1.,
+                _ => 0.,
+            })
+            .sum();
+        // When filling, we allow the entire title bar to be taken up, leaving
+        // a little space for the new tab button (which is 2x cell width)
+        // and padding.
+        let max_tab_width = if self.config.tab_bar_fill {
+            (self.dimensions.pixel_width as f32 - (5.0 * metrics.cell_size.width as f32)).max(0.)
+                / num_tabs_or_status
+        } else {
+            ((self.dimensions.pixel_width as f32 / num_tabs)
+                - (1.5 * metrics.cell_size.width as f32))
+                .max(0.)
+        };
+        let min_tab_width = if self.config.tab_bar_fill {
+            (max_tab_width - 5.0).max(0.)
+        } else {
+            0.
+        };
 
         // Reserve space for the native titlebar buttons
         if self
@@ -335,6 +359,7 @@ impl crate::TermWindow {
                 }
                 TabBarItem::Tab { tab_idx, active } => {
                     let mut elem = item_to_elem(item);
+                    elem.min_width = Some(Dimension::Pixels(min_tab_width));
                     elem.max_width = Some(Dimension::Pixels(max_tab_width));
                     elem.content = match elem.content {
                         ElementContent::Text(_) => unreachable!(),