Add focus selection UI

Closes: https://github.com/sayanarijit/xplr/issues/322

src/config.rs

@@ -469,6 +469,9 @@ pub struct GeneralConfig {
     #[serde(default)]
     pub selection_ui: UiConfig,
 
+    #[serde(default)]
+    pub focus_selection_ui: UiConfig,
+
     #[serde(default)]
     pub sort_and_filter_ui: SortAndFilterUi,
 
@@ -578,6 +581,11 @@ impl GeneralConfig {
     pub fn start_fifo(&self) -> Option<&String> {
         self.start_fifo.as_ref()
     }
+
+    /// Get a reference to the general config's focus selection ui.
+    pub fn focus_selection_ui(&self) -> &UiConfig {
+        &self.focus_selection_ui
+    }
 }
 
 #[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize)]

src/init.lua

@@ -98,6 +98,14 @@ xplr.config.general.selection_ui.style.sub_modifiers = nil
 xplr.config.general.selection_ui.style.bg = nil
 xplr.config.general.selection_ui.style.fg = "LightGreen"
 
+------ Focus UI
+xplr.config.general.focus_selection_ui.prefix = "▸["
+xplr.config.general.focus_selection_ui.suffix = "]"
+xplr.config.general.focus_selection_ui.style.add_modifiers = { "Bold" }
+xplr.config.general.focus_selection_ui.style.sub_modifiers = nil
+xplr.config.general.focus_selection_ui.style.bg = nil
+xplr.config.general.focus_selection_ui.style.fg = "LightGreen"
+
 ------ Sort & filter UI
 -------- Separator
 xplr.config.general.sort_and_filter_ui.separator.format = " › "

src/ui.rs

@@ -523,14 +523,17 @@ fn draw_table<B: Backend>(
                         )
                     };
 
-                    if is_selected {
+                    if is_focused && is_selected {
+                        let ui = app_config.general().focus_selection_ui().to_owned();
+                        prefix = ui.prefix().to_owned().or(prefix);
+                        suffix = ui.suffix().to_owned().or(suffix);
+                        style = style.extend(ui.style());
+                    } else if is_selected {
                         let ui = app_config.general().selection_ui().to_owned();
                         prefix = ui.prefix().to_owned().or(prefix);
                         suffix = ui.suffix().to_owned().or(suffix);
                         style = style.extend(ui.style());
-                    };
-
-                    if is_focused {
+                    } else if is_focused {
                         let ui = app_config.general().focus_ui().to_owned();
                         prefix = ui.prefix().to_owned().or(prefix);
                         suffix = ui.suffix().to_owned().or(suffix);