Add configureable statusline mode names (#3311)

* Added 'long-mode' statusline element

* Added customizable statusline mode names

* Removed a string clone

* Added documentation

* Updated documentation, moved modenames to a seperate section

* Update configuration.md

* Documentation update

* Documentation update

* Documentation update

* Update configuration.md

* Update configuration.md

* Fixed merge error

* Update configuration.md

* Update configuration.md

3 files changed, 40 insertions, 6 deletions

diff --git a/book/src/configuration.md b/book/src/configuration.md
index fdabe768..d44855c7 100644
--- a/book/src/configuration.md
+++ b/book/src/configuration.md
@@ -68,13 +68,27 @@ left = ["mode", "spinner"]
 center = ["file-name"]
 right = ["diagnostics", "selections", "position", "file-encoding", "file-line-ending", "file-type"]
 separator = "│"
+mode.normal = "NORMAL"
+mode.insert = "INSERT"
+mode.select = "SELECT"
 ```
+The `[editor.statusline]` key takes the following sub-keys:
 
-The following elements can be configured:
+| Key           | Description | Default |
+| ---           | ---         | ---     |
+| `left`        | A list of elements aligned to the left of the statusline | `["mode", "spinner", "file-name"]` |
+| `center`      | A list of elements aligned to the middle of the statusline | `[]` |
+| `right`       | A list of elements aligned to the right of the statusline | `["diagnostics", "selections", "position", "file-encoding"]` |
+| `separator`   | The character used to separate elements in the statusline | `"│"` |
+| `mode.normal` | The text shown in the `mode` element for normal mode | `"NOR"` |
+| `mode.insert` | The text shown in the `mode` element for insert mode | `"INS"` |
+| `mode.select` | The text shown in the `mode` element for select mode | `"SEL"` |
+
+The following statusline elements can be configured:
 
 | Key    | Description |
 | ------ | ----------- |
-| `mode` | The current editor mode (`NOR`/`INS`/`SEL`) |
+| `mode` | The current editor mode (`mode.normal`/`mode.insert`/`mode.select`) |
 | `spinner` | A progress spinner indicating LSP activity |
 | `file-name` | The path/name of the opened file |
 | `file-encoding` | The encoding of the opened file if it differs from UTF-8 |
diff --git a/helix-term/src/ui/statusline.rs b/helix-term/src/ui/statusline.rs
index 365e1ca9..9bbb268f 100644
--- a/helix-term/src/ui/statusline.rs
+++ b/helix-term/src/ui/statusline.rs
@@ -154,16 +154,16 @@ where
     F: Fn(&mut RenderContext, String, Option<Style>) + Copy,
 {
     let visible = context.focused;
-
+    let modenames = &context.editor.config().statusline.mode;
     write(
         context,
         format!(
             " {} ",
             if visible {
                 match context.editor.mode() {
-                    Mode::Insert => "INS",
-                    Mode::Select => "SEL",
-                    Mode::Normal => "NOR",
+                    Mode::Insert => &modenames.insert,
+                    Mode::Select => &modenames.select,
+                    Mode::Normal => &modenames.normal,
                 }
             } else {
                 // If not focused, explicitly leave an empty space instead of returning None.
diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index e804a864..70c49872 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -260,6 +260,7 @@ pub struct StatusLineConfig {
     pub center: Vec<StatusLineElement>,
     pub right: Vec<StatusLineElement>,
     pub separator: String,
+    pub mode: ModeConfig,
 }
 
 impl Default for StatusLineConfig {
@@ -271,6 +272,25 @@ impl Default for StatusLineConfig {
             center: vec![],
             right: vec![E::Diagnostics, E::Selections, E::Position, E::FileEncoding],
             separator: String::from("│"),
+            mode: ModeConfig::default(),
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case", default, deny_unknown_fields)]
+pub struct ModeConfig {
+    pub normal: String,
+    pub insert: String,
+    pub select: String,
+}
+
+impl Default for ModeConfig {
+    fn default() -> Self {
+        Self {
+            normal: String::from("NOR"),
+            insert: String::from("INS"),
+            select: String::from("SEL"),
         }
     }
 }