Auto indent change if selection is linewise

helix-term/src/commands.rs

@@ -296,6 +296,8 @@ impl MappableCommand {
         delete_selection, "Delete selection",
         delete_selection_noyank, "Delete selection without yanking",
         change_selection, "Change selection",
+        change_selection_with_indent, "Change selection and place the cursor at the appropriated indent",
+        change_selection_with_indent_noyank, "Change selection without yanking and place the cursor at the appropriated indent",
         change_selection_noyank, "Change selection without yanking",
         collapse_selection, "Collapse selection into single cursor",
         flip_selections, "Flip selection cursor and anchor",
@@ -2313,12 +2315,28 @@ fn shrink_to_line_bounds(cx: &mut Context) {
 enum Operation {
     Delete,
     Change,
+    ChangeWithIndent,
+}
+
+fn only_whole_lines(selection: &Selection, text: &Rope) -> bool {
+    selection.ranges().iter().all(|range| {
+        // If not at least a full line is selected (strange require 2).
+        if range.slice(text.slice(..)).len_lines() < 2 {
+            return false;
+        }
+        // If the start of the selection is at the start of a line and the end at the end of a line.
+        let (start_line, end_line) = range.line_range(text.slice(..));
+        let start = text.line_to_char(start_line);
+        let end = text.line_to_char((end_line + 1).min(text.len_lines()));
+        start == range.from() && end == range.to()
+    })
 }
 
 fn delete_selection_impl(cx: &mut Context, op: Operation) {
     let (view, doc) = current!(cx.editor);
 
     let selection = doc.selection(view.id);
+    let only_whole_lines = only_whole_lines(selection, doc.text());
 
     if cx.register != Some('_') {
         // first yank the selection
@@ -2341,6 +2359,13 @@ fn delete_selection_impl(cx: &mut Context, op: Operation) {
         Operation::Change => {
             enter_insert_mode(cx);
         }
+        Operation::ChangeWithIndent => {
+            if only_whole_lines {
+                open_above(cx);
+            } else {
+                enter_insert_mode(cx);
+            }
+        }
     }
 }
 
@@ -2408,6 +2433,15 @@ fn change_selection_noyank(cx: &mut Context) {
     delete_selection_impl(cx, Operation::Change);
 }
 
+fn change_selection_with_indent(cx: &mut Context) {
+    delete_selection_impl(cx, Operation::ChangeWithIndent);
+}
+
+fn change_selection_with_indent_noyank(cx: &mut Context) {
+    cx.register = Some('_');
+    delete_selection_impl(cx, Operation::ChangeWithIndent);
+}
+
 fn collapse_selection(cx: &mut Context) {
     let (view, doc) = current!(cx.editor);
     let text = doc.text().slice(..);