tab indicator: Add hide-when-single-tab

niri-config/src/lib.rs

@@ -683,6 +683,8 @@ pub struct ShadowOffset {
 pub struct TabIndicator {
     #[knuffel(child)]
     pub off: bool,
+    #[knuffel(child)]
+    pub hide_when_single_tab: bool,
     #[knuffel(child, unwrap(argument), default = Self::default().gap)]
     pub gap: FloatOrInt<-65535, 65535>,
     #[knuffel(child, unwrap(argument), default = Self::default().width)]
@@ -703,6 +705,7 @@ impl Default for TabIndicator {
     fn default() -> Self {
         Self {
             off: false,
+            hide_when_single_tab: false,
             gap: FloatOrInt(5.),
             width: FloatOrInt(4.),
             length: TabIndicatorLength {

src/layout/tab_indicator.rs

@@ -63,6 +63,13 @@ impl TabIndicator {
             return;
         }
 
+        let count = tabs.clone().count();
+        if self.config.hide_when_single_tab && count == 1 {
+            self.shader_locs.clear();
+            self.shaders.clear();
+            return;
+        }
+
         // Tab indicators are rendered relative to the tile geometry.
         let tile_geo = Rectangle::new(Point::from((0., 0.)), tile_size);
 
@@ -74,7 +81,6 @@ impl TabIndicator {
         let total_prop = self.config.length.total_proportion.unwrap_or(0.5);
         let min_length = round(tile_size.h * total_prop.clamp(0., 2.));
 
-        let count = tabs.clone().count();
         self.shaders.resize_with(count, Default::default);
         self.shader_locs.resize_with(count, Default::default);
 

src/layout/tests.rs

@@ -3242,12 +3242,14 @@ prop_compose! {
 prop_compose! {
     fn arbitrary_tab_indicator()(
         off in any::<bool>(),
+        hide_when_single_tab in any::<bool>(),
         width in arbitrary_spacing(),
         gap in arbitrary_spacing_neg(),
         length in (0f64..2f64),
     ) -> niri_config::TabIndicator {
         niri_config::TabIndicator {
             off,
+            hide_when_single_tab,
             width: FloatOrInt(width),
             gap: FloatOrInt(gap),
             length: TabIndicatorLength { total_proportion: Some(length) },