Avoid maintaining indent size as state on buffers

Indent size is still hard-coded, but it's now controlled by the
editor and not the buffer.

Co-authored-by: Keith Simmons <keith@zed.dev>

crates/editor/src/editor.rs

@@ -63,6 +63,7 @@ const CURSOR_BLINK_INTERVAL: Duration = Duration::from_millis(500);
 const MAX_LINE_LEN: usize = 1024;
 const MIN_NAVIGATION_HISTORY_ROW_DELTA: i64 = 10;
 const MAX_SELECTION_HISTORY_LEN: usize = 1024;
+const INDENT_SIZE: u32 = 4;
 
 action!(Cancel);
 action!(Backspace);
@@ -2946,7 +2947,7 @@ impl Editor {
                 {
                     let indent_column = buffer.indent_column_for_line(line_buffer_range.start.row);
                     if old_head.column <= indent_column && old_head.column > 0 {
-                        let indent = buffer.indent_size();
+                        let indent = INDENT_SIZE;
                         new_head = cmp::min(
                             new_head,
                             Point::new(old_head.row, ((old_head.column - 1) / indent) * indent),

crates/editor/src/multi_buffer.rs

@@ -287,6 +287,8 @@ impl MultiBuffer {
         S: ToOffset,
         T: Into<String>,
     {
+        let indent_size = crate::INDENT_SIZE;
+
         if self.buffers.borrow().is_empty() {
             return;
         }
@@ -298,7 +300,7 @@ impl MultiBuffer {
                 .map(|range| range.start.to_offset(&snapshot)..range.end.to_offset(&snapshot));
             return buffer.update(cx, |buffer, cx| {
                 if autoindent {
-                    buffer.edit_with_autoindent(ranges, new_text, cx);
+                    buffer.edit_with_autoindent(ranges, new_text, indent_size, cx);
                 } else {
                     buffer.edit(ranges, new_text, cx);
                 }
@@ -394,8 +396,8 @@ impl MultiBuffer {
                     }
 
                     if autoindent {
-                        buffer.edit_with_autoindent(deletions, "", cx);
-                        buffer.edit_with_autoindent(insertions, new_text.clone(), cx);
+                        buffer.edit_with_autoindent(deletions, "", indent_size, cx);
+                        buffer.edit_with_autoindent(insertions, new_text.clone(), indent_size, cx);
                     } else {
                         buffer.edit(deletions, "", cx);
                         buffer.edit(insertions, new_text.clone(), cx);

crates/language/src/buffer.rs

@@ -66,7 +66,6 @@ pub struct Buffer {
     file_update_count: usize,
     completion_triggers: Vec<String>,
     deferred_ops: OperationQueue<Operation>,
-    indent_size: u32,
 }
 
 pub struct BufferSnapshot {
@@ -80,7 +79,6 @@ pub struct BufferSnapshot {
     selections_update_count: usize,
     language: Option<Arc<Language>>,
     parse_count: usize,
-    indent_size: u32,
 }
 
 #[derive(Clone, Debug)]
@@ -214,6 +212,7 @@ struct AutoindentRequest {
     before_edit: BufferSnapshot,
     edited: Vec<Anchor>,
     inserted: Option<Vec<Range<Anchor>>>,
+    indent_size: u32,
 }
 
 #[derive(Debug)]
@@ -427,8 +426,6 @@ impl Buffer {
             file_update_count: 0,
             completion_triggers: Default::default(),
             deferred_ops: OperationQueue::new(),
-            // TODO: make this configurable
-            indent_size: 4,
         }
     }
 
@@ -444,7 +441,6 @@ impl Buffer {
             language: self.language.clone(),
             parse_count: self.parse_count,
             selections_update_count: self.selections_update_count,
-            indent_size: self.indent_size,
         }
     }
 
@@ -786,7 +782,7 @@ impl Buffer {
                                     .indent_column_for_line(suggestion.basis_row)
                             });
                         let delta = if suggestion.indent {
-                            snapshot.indent_size
+                            request.indent_size
                         } else {
                             0
                         };
@@ -809,7 +805,7 @@ impl Buffer {
                         .flatten();
                     for (new_row, suggestion) in new_edited_row_range.zip(suggestions) {
                         let delta = if suggestion.indent {
-                            snapshot.indent_size
+                            request.indent_size
                         } else {
                             0
                         };
@@ -845,7 +841,7 @@ impl Buffer {
                             .flatten();
                         for (row, suggestion) in inserted_row_range.zip(suggestions) {
                             let delta = if suggestion.indent {
-                                snapshot.indent_size
+                                request.indent_size
                             } else {
                                 0
                             };
@@ -1055,7 +1051,7 @@ impl Buffer {
     where
         T: Into<String>,
     {
-        self.edit_internal([0..self.len()], text, false, cx)
+        self.edit_internal([0..self.len()], text, None, cx)
     }
 
     pub fn edit<I, S, T>(
@@ -1069,13 +1065,14 @@ impl Buffer {
         S: ToOffset,
         T: Into<String>,
     {
-        self.edit_internal(ranges_iter, new_text, false, cx)
+        self.edit_internal(ranges_iter, new_text, None, cx)
     }
 
     pub fn edit_with_autoindent<I, S, T>(
         &mut self,
         ranges_iter: I,
         new_text: T,
+        indent_size: u32,
         cx: &mut ModelContext<Self>,
     ) -> Option<clock::Local>
     where
@@ -1083,14 +1080,14 @@ impl Buffer {
         S: ToOffset,
         T: Into<String>,
     {
-        self.edit_internal(ranges_iter, new_text, true, cx)
+        self.edit_internal(ranges_iter, new_text, Some(indent_size), cx)
     }
 
     pub fn edit_internal<I, S, T>(
         &mut self,
         ranges_iter: I,
         new_text: T,
-        autoindent: bool,
+        autoindent_size: Option<u32>,
         cx: &mut ModelContext<Self>,
     ) -> Option<clock::Local>
     where
@@ -1122,23 +1119,27 @@ impl Buffer {
 
         self.start_transaction();
         self.pending_autoindent.take();
-        let autoindent_request = if autoindent && self.language.is_some() {
-            let before_edit = self.snapshot();
-            let edited = ranges
-                .iter()
-                .filter_map(|range| {
-                    let start = range.start.to_point(self);
-                    if new_text.starts_with('\n') && start.column == self.line_len(start.row) {
-                        None
-                    } else {
-                        Some(self.anchor_before(range.start))
-                    }
-                })
-                .collect();
-            Some((before_edit, edited))
-        } else {
-            None
-        };
+        let autoindent_request =
+            self.language
+                .as_ref()
+                .and_then(|_| autoindent_size)
+                .map(|autoindent_size| {
+                    let before_edit = self.snapshot();
+                    let edited = ranges
+                        .iter()
+                        .filter_map(|range| {
+                            let start = range.start.to_point(self);
+                            if new_text.starts_with('\n')
+                                && start.column == self.line_len(start.row)
+                            {
+                                None
+                            } else {
+                                Some(self.anchor_before(range.start))
+                            }
+                        })
+                        .collect();
+                    (before_edit, edited, autoindent_size)
+                });
 
         let first_newline_ix = new_text.find('\n');
         let new_text_len = new_text.len();
@@ -1146,7 +1147,7 @@ impl Buffer {
         let edit = self.text.edit(ranges.iter().cloned(), new_text);
         let edit_id = edit.local_timestamp();
 
-        if let Some((before_edit, edited)) = autoindent_request {
+        if let Some((before_edit, edited, size)) = autoindent_request {
             let mut inserted = None;
             if let Some(first_newline_ix) = first_newline_ix {
                 let mut delta = 0isize;
@@ -1169,6 +1170,7 @@ impl Buffer {
                 before_edit,
                 edited,
                 inserted,
+                indent_size: size,
             }));
         }
 
@@ -1925,10 +1927,6 @@ impl BufferSnapshot {
     pub fn file_update_count(&self) -> usize {
         self.file_update_count
     }
-
-    pub fn indent_size(&self) -> u32 {
-        self.indent_size
-    }
 }
 
 impl Clone for BufferSnapshot {
@@ -1944,7 +1942,6 @@ impl Clone for BufferSnapshot {
             file_update_count: self.file_update_count,
             language: self.language.clone(),
             parse_count: self.parse_count,
-            indent_size: self.indent_size,
         }
     }
 }

crates/language/src/tests.rs

@@ -576,13 +576,13 @@ fn test_edit_with_autoindent(cx: &mut MutableAppContext) {
         let text = "fn a() {}";
         let mut buffer = Buffer::new(0, text, cx).with_language(Arc::new(rust_lang()), cx);
 
-        buffer.edit_with_autoindent([8..8], "\n\n", cx);
+        buffer.edit_with_autoindent([8..8], "\n\n", 4, cx);
         assert_eq!(buffer.text(), "fn a() {\n    \n}");
 
-        buffer.edit_with_autoindent([Point::new(1, 4)..Point::new(1, 4)], "b()\n", cx);
+        buffer.edit_with_autoindent([Point::new(1, 4)..Point::new(1, 4)], "b()\n", 4, cx);
         assert_eq!(buffer.text(), "fn a() {\n    b()\n    \n}");
 
-        buffer.edit_with_autoindent([Point::new(2, 4)..Point::new(2, 4)], ".c", cx);
+        buffer.edit_with_autoindent([Point::new(2, 4)..Point::new(2, 4)], ".c", 4, cx);
         assert_eq!(buffer.text(), "fn a() {\n    b()\n        .c\n}");
 
         buffer
@@ -604,7 +604,12 @@ fn test_autoindent_does_not_adjust_lines_with_unchanged_suggestion(cx: &mut Muta
 
         // Lines 2 and 3 don't match the indentation suggestion. When editing these lines,
         // their indentation is not adjusted.
-        buffer.edit_with_autoindent([empty(Point::new(1, 1)), empty(Point::new(2, 1))], "()", cx);
+        buffer.edit_with_autoindent(
+            [empty(Point::new(1, 1)), empty(Point::new(2, 1))],
+            "()",
+            4,
+            cx,
+        );
         assert_eq!(
             buffer.text(),
             "
@@ -621,6 +626,7 @@ fn test_autoindent_does_not_adjust_lines_with_unchanged_suggestion(cx: &mut Muta
         buffer.edit_with_autoindent(
             [empty(Point::new(1, 1)), empty(Point::new(2, 1))],
             "\n.f\n.g",
+            4,
             cx,
         );
         assert_eq!(
@@ -651,7 +657,7 @@ fn test_autoindent_adjusts_lines_when_only_text_changes(cx: &mut MutableAppConte
 
         let mut buffer = Buffer::new(0, text, cx).with_language(Arc::new(rust_lang()), cx);
 
-        buffer.edit_with_autoindent([5..5], "\nb", cx);
+        buffer.edit_with_autoindent([5..5], "\nb", 4, cx);
         assert_eq!(
             buffer.text(),
             "
@@ -663,7 +669,7 @@ fn test_autoindent_adjusts_lines_when_only_text_changes(cx: &mut MutableAppConte
 
         // The indentation suggestion changed because `@end` node (a close paren)
         // is now at the beginning of the line.
-        buffer.edit_with_autoindent([Point::new(1, 4)..Point::new(1, 5)], "", cx);
+        buffer.edit_with_autoindent([Point::new(1, 4)..Point::new(1, 5)], "", 4, cx);
         assert_eq!(
             buffer.text(),
             "