tab indicator: Add gaps-between-tabs

niri-config/src/lib.rs

@@ -695,6 +695,8 @@ pub struct TabIndicator {
     pub length: TabIndicatorLength,
     #[knuffel(child, unwrap(argument), default = Self::default().position)]
     pub position: TabIndicatorPosition,
+    #[knuffel(child, unwrap(argument), default = Self::default().gaps_between_tabs)]
+    pub gaps_between_tabs: FloatOrInt<0, 65535>,
     #[knuffel(child)]
     pub active_color: Option<Color>,
     #[knuffel(child)]
@@ -717,6 +719,7 @@ impl Default for TabIndicator {
                 total_proportion: Some(0.5),
             },
             position: TabIndicatorPosition::Left,
+            gaps_between_tabs: FloatOrInt(0.),
             active_color: None,
             inactive_color: None,
             active_gradient: None,

src/layout/tab_indicator.rs

@@ -78,6 +78,7 @@ impl TabIndicator {
 
         let width = round(self.config.width.0);
         let gap = round(self.config.gap.0);
+        let gaps_between = round(self.config.gaps_between_tabs.0);
 
         let side = match self.config.position {
             TabIndicatorPosition::Left | TabIndicatorPosition::Right => tile_size.h,
@@ -90,11 +91,11 @@ impl TabIndicator {
         self.shader_locs.resize_with(count, Default::default);
 
         let pixel = 1. / scale;
-        let shortest_length = count as f64 * pixel;
+        let shortest_length = count as f64 * (pixel + gaps_between) - gaps_between;
         let length = f64::max(min_length, shortest_length);
-        let px_per_tab = length / count as f64;
+        let px_per_tab = (length + gaps_between) / count as f64 - gaps_between;
         let px_per_tab = floor_logical_in_physical_max1(scale, px_per_tab);
-        let floored_length = count as f64 * px_per_tab;
+        let floored_length = count as f64 * (px_per_tab + gaps_between) - gaps_between;
         let mut ones_left = ((length - floored_length) / pixel).max(0.).round() as usize;
 
         let mut shader_loc = Point::from((-gap - width, round((side - length) / 2.)));
@@ -119,10 +120,10 @@ impl TabIndicator {
 
             match self.config.position {
                 TabIndicatorPosition::Left | TabIndicatorPosition::Right => {
-                    shader_loc.y += px_per_tab
+                    shader_loc.y += px_per_tab + gaps_between
                 }
                 TabIndicatorPosition::Top | TabIndicatorPosition::Bottom => {
-                    shader_loc.x += px_per_tab
+                    shader_loc.x += px_per_tab + gaps_between
                 }
             }
 

wiki/Configuration:-Layout.md

@@ -62,6 +62,7 @@ layout {
         width 4
         length total-proportion=1.0
         position "right"
+        gaps-between-tabs 2
         active-color "red"
         inactive-color "gray"
         // active-gradient from="#80c8ff" to="#bbddff" angle=45
@@ -436,6 +437,8 @@ By default, the tab indicator has length equal to half of the window size, or `l
 `position` sets the position of the tab indicator relative to the window.
 It can be `left`, `right`, `top`, or `bottom`.
 
+`gaps-between-tabs` controls the gap between individual tabs.
+
 `active-color`, `inactive-color`, `active-gradient`, `inactive-gradient` let you override the colors for the tabs.
 They have the same semantics as the border and focus ring colors and gradients.