Add entering normal mode as autosave trigger

book/src/configuration.md

@@ -50,7 +50,7 @@ Its settings will be merged with the configuration directory `config.toml` and t
 | `gutters` | Gutters to display: Available are `diagnostics` and `diff` and `line-numbers` and `spacer`, note that `diagnostics` also includes other features like breakpoints, 1-width padding will be inserted if gutters is non-empty | `["diagnostics", "spacer", "line-numbers", "spacer", "diff"]` |
 | `auto-completion` | Enable automatic pop up of auto-completion | `true` |
 | `auto-format` | Enable automatic formatting on save | `true` |
-| `auto-save` | Enable automatic saving on the focus moving away from Helix. Requires [focus event support](https://github.com/helix-editor/helix/wiki/Terminal-Support) from your terminal | `false` |
+| `auto-save` | Enable automatic saving on certain triggers, such as `"unfocused"` (when the terminal looses focus)[^1] or `"normal-mode"` (when entering normal mode) | `[]` |
 | `idle-timeout` | Time in milliseconds since last keypress before idle timers trigger. Used for autocompletion, set to 0 for instant | `400` |
 | `completion-trigger-len` | The min-length of word under cursor to trigger autocompletion | `2` |
 | `completion-replace` | Set to `true` to make completions always replace the entire word and not just the part before the cursor | `false` |
@@ -63,6 +63,8 @@ Its settings will be merged with the configuration directory `config.toml` and t
 | `text-width` | Maximum line length. Used for the `:reflow` command and soft-wrapping if `soft-wrap.wrap_at_text_width` is set | `80` |
 | `workspace-lsp-roots` | Directories relative to the workspace root that are treated as LSP roots. Should only be set in `.helix/config.toml` | `[]` |
 
+[^1]: Requires [focus event support](https://github.com/helix-editor/helix/wiki/Terminal-Support) from your terminal.
+
 ### `[editor.statusline]` Section
 
 Allows configuring the statusline at the bottom of the editor.

helix-term/src/ui/editor.rs

@@ -23,7 +23,7 @@ use helix_core::{
 };
 use helix_view::{
     document::{Mode, SavePoint, SCRATCH_BUFFER_NAME},
-    editor::{CompleteAction, CursorShapeConfig},
+    editor::{AutoSaveTrigger, CompleteAction, CursorShapeConfig},
     graphics::{Color, CursorKind, Modifier, Rect, Style},
     input::{KeyEvent, MouseButton, MouseEvent, MouseEventKind},
     keyboard::{KeyCode, KeyModifiers},
@@ -1346,7 +1346,13 @@ impl Component for EditorView {
             Event::IdleTimeout => self.handle_idle_timeout(&mut cx),
             Event::FocusGained => EventResult::Ignored(None),
             Event::FocusLost => {
-                if context.editor.config().auto_save {
+                // Trigger autosave if configured
+                if context
+                    .editor
+                    .config()
+                    .auto_save
+                    .contains(&AutoSaveTrigger::Unfocused)
+                {
                     if let Err(e) = commands::typed::write_all_impl(context, false, false) {
                         context.editor.set_error(format!("{}", e));
                     }

helix-view/src/editor.rs

@@ -211,6 +211,55 @@ impl Default for FilePickerConfig {
     }
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub enum AutoSaveTrigger {
+    /// Auto save when the terminal window looses focus
+    Unfocused,
+    /// Auto save when the editor (re-)enters normal mode.
+    NormalMode,
+}
+
+/// Parse the value of the `auto-save` key.
+/// Can be either a boolean or a list of [AutoSaveTrigger]s.
+fn deserialize_autosave_compat<'de, D>(deserializer: D) -> Result<Vec<AutoSaveTrigger>, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    struct AutoSaveVisitor;
+
+    impl<'de> serde::de::Visitor<'de> for AutoSaveVisitor {
+        type Value = Vec<AutoSaveTrigger>;
+
+        fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+            formatter.write_str("a list of autosave triggers or a boolean")
+        }
+
+        /// New configuration: a list of AutoSaveTriggers.
+        fn visit_seq<S>(self, seq: S) -> Result<Self::Value, S::Error>
+        where
+            S: serde::de::SeqAccess<'de>,
+        {
+            Deserialize::deserialize(serde::de::value::SeqAccessDeserializer::new(seq))
+        }
+
+        /// Old configuration:
+        /// if false => no trigger
+        /// if true => Only the Unfocused trigger.
+        fn visit_bool<E>(self, value: bool) -> Result<Self::Value, E>
+        where
+            E: serde::de::Error,
+        {
+            match value {
+                false => Ok(Vec::new()),
+                true => Ok(vec![AutoSaveTrigger::Unfocused]),
+            }
+        }
+    }
+
+    deserializer.deserialize_any(AutoSaveVisitor)
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case", default, deny_unknown_fields)]
 pub struct Config {
@@ -241,7 +290,8 @@ pub struct Config {
     /// Automatic formatting on save. Defaults to true.
     pub auto_format: bool,
     /// Automatic save on focus lost. Defaults to false.
-    pub auto_save: bool,
+    #[serde(deserialize_with = "deserialize_autosave_compat")]
+    pub auto_save: Vec<AutoSaveTrigger>,
     /// Set a global text_width
     pub text_width: usize,
     /// Time in milliseconds since last keypress before idle timers trigger.
@@ -732,7 +782,7 @@ impl Default for Config {
             auto_pairs: AutoPairConfig::default(),
             auto_completion: true,
             auto_format: true,
-            auto_save: false,
+            auto_save: Vec::new(),
             idle_timeout: Duration::from_millis(400),
             completion_trigger_len: 2,
             auto_info: true,
@@ -1658,6 +1708,25 @@ impl Editor {
             doc.set_selection(view.id, selection);
             doc.restore_cursor = false;
         }
+
+        // Trigger autosave if configured
+        if self
+            .config()
+            .auto_save
+            .contains(&AutoSaveTrigger::NormalMode)
+        {
+            if self.save::<PathBuf>(doc!(self).id, None, false).is_ok() {
+                // TODO: make 'modified' icon in statusline disappear.
+            }
+
+            // Silently ignore errors.
+            // Common sources of errors include:
+            //  - No file path set on focused document
+            //  - Partent directory doesn't exist.
+            //
+            // In either case, autosave freaking out is probably not
+            // desired.
+        }
     }
 
     pub fn current_stack_frame(&self) -> Option<&StackFrame> {