Make initial editing mode configurable

ref: helix-editor#3366

Author: omentic

book/src/configuration.md

@@ -59,6 +59,7 @@ Its settings will be merged with the configuration directory `config.toml` and t
 | `true-color` | Set to `true` to override automatic detection of terminal truecolor support in the event of a false negative | `false` |
 | `undercurl` | Set to `true` to override automatic detection of terminal undercurl support in the event of a false negative | `false` |
 | `rulers` | List of column positions at which to display the rulers. Can be overridden by language specific `rulers` in `languages.toml` file | `[]` |
+| `initial-mode` | The initial mode for newly opened editors. | `"normal"` |
 | `bufferline` | Renders a line at the top of the editor displaying open buffers. Can be `always`, `never` or `multiple` (only shown if more than one buffer is in use) | `never` |
 | `color-modes` | Whether to color the mode indicator with different colors depending on the mode itself | `false` |
 | `text-width` | Maximum line length. Used for the `:reflow` command and soft-wrapping if `soft-wrap.wrap-at-text-width` is set | `80` |

helix-view/src/editor.rs

@@ -281,6 +281,8 @@ pub struct Config {
     pub bufferline: BufferLine,
     /// Vertical indent width guides.
     pub indent_guides: IndentGuidesConfig,
+    /// The initial mode for newly opened editors. Defaults to `"normal"`.
+    pub initial_mode: Mode,
     /// Whether to color modes with different colors. Defaults to `false`.
     pub color_modes: bool,
     pub soft_wrap: SoftWrap,
@@ -812,6 +814,7 @@ impl Default for Config {
             whitespace: WhitespaceConfig::default(),
             bufferline: BufferLine::default(),
             indent_guides: IndentGuidesConfig::default(),
+            initial_mode: Mode::Normal,
             color_modes: false,
             soft_wrap: SoftWrap {
                 enable: Some(false),
@@ -1363,6 +1366,7 @@ impl Editor {
 
     /// Generate an id for a new document and register it.
     fn new_document(&mut self, mut doc: Document) -> DocumentId {
+        self.mode = self.config().initial_mode;
         let id = self.next_document_id;
         // Safety: adding 1 from 1 is fine, probably impossible to reach usize max
         self.next_document_id =