Add mode specific styles (#2676)

* Add mode specific styles

In similar vein to neovim's lualine and similar statusline packages this
allows helix users to style their mode based on which mode it is thus
making each mode more visually distinct at a glance

* Add an example based on rosepine

* Add editor.colors-mode config

* Document statusline mode styles

1 files changed, 14 insertions, 7 deletions

diff --git a/helix-term/src/ui/editor.rs b/helix-term/src/ui/editor.rs
index 948803eb..a7c67a21 100644
--- a/helix-term/src/ui/editor.rs
+++ b/helix-term/src/ui/editor.rs
@@ -161,7 +161,7 @@ impl EditorView {
             .area
             .clip_top(view.area.height.saturating_sub(1))
             .clip_bottom(1); // -1 from bottom to remove commandline
-        self.render_statusline(doc, view, statusline_area, surface, theme, is_focused);
+        self.render_statusline(editor, doc, view, statusline_area, surface, is_focused);
     }
 
     pub fn render_rulers(
@@ -732,11 +732,11 @@ impl EditorView {
 
     pub fn render_statusline(
         &self,
+        editor: &Editor,
         doc: &Document,
         view: &View,
         viewport: Rect,
         surface: &mut Surface,
-        theme: &Theme,
         is_focused: bool,
     ) {
         use tui::text::{Span, Spans};
@@ -745,10 +745,11 @@ impl EditorView {
         // Left side of the status line.
         //-------------------------------
 
-        let mode = match doc.mode() {
-            Mode::Insert => "INS",
-            Mode::Select => "SEL",
-            Mode::Normal => "NOR",
+        let theme = &editor.theme;
+        let (mode, mode_style) = match doc.mode() {
+            Mode::Insert => (" INS ", theme.get("ui.statusline.insert")),
+            Mode::Select => (" SEL ", theme.get("ui.statusline.select")),
+            Mode::Normal => (" NOR ", theme.get("ui.statusline.normal")),
         };
         let progress = doc
             .language_server()
@@ -767,7 +768,13 @@ impl EditorView {
         // statusline
         surface.set_style(viewport.with_height(1), base_style);
         if is_focused {
-            surface.set_string(viewport.x + 1, viewport.y, mode, base_style);
+            let color_modes = editor.config().color_modes;
+            surface.set_string(
+                viewport.x,
+                viewport.y,
+                mode,
+                if color_modes { mode_style } else { base_style },
+            );
         }
         surface.set_string(viewport.x + 5, viewport.y, progress, base_style);