[cm6] Change Emacs commands to visual-line-mode (#12523)

* [cm6] Change Emacs commands to visual-line-mode * [cm6] Change line deletion commands to visual line mode GitOrigin-RevId: 7a4f3d66bec611de410b6c1fbafbfe33b974e37b
2026-11-15 14:43:46 +01:00 · 2023-04-17 08:05:08 +00:00
parent e09a5f3adf
commit 4b2cc907e2
6 changed files with 214 additions and 9 deletions
@@ -0,0 +1,160 @@
+import {
+  SelectionRange,
+  EditorSelection,
+  EditorState,
+  Transaction,
+} from '@codemirror/state'
+import { Command, EditorView } from '@codemirror/view'
+
+const getNextLineBoundary = (
+  selection: SelectionRange,
+  forward: boolean,
+  view: EditorView,
+  includeWrappingCharacter = false
+) => {
+  const newSelection = view.moveToLineBoundary(
+    EditorSelection.cursor(
+      selection.head,
+      1,
+      selection.bidiLevel || undefined,
+      selection.goalColumn
+    ),
+    forward
+  )
+  // Adjust to be "before" the simulated line break
+  let offset = 0
+  if (
+    forward &&
+    !includeWrappingCharacter &&
+    view.lineBlockAt(selection.head).to !== newSelection.head
+  ) {
+    offset = 1
+  }
+  return EditorSelection.cursor(
+    newSelection.head - offset,
+    selection.assoc,
+    selection.bidiLevel || undefined,
+    newSelection.goalColumn
+  )
+}
+
+const changeSelection = (
+  view: EditorView,
+  how: (selection: SelectionRange) => SelectionRange,
+  extend = false
+) => {
+  view.dispatch({
+    selection: EditorSelection.create(
+      view.state.selection.ranges.map(start => {
+        const newSelection = how(start)
+        const anchor = extend ? start.anchor : newSelection.head
+        return EditorSelection.range(
+          anchor,
+          newSelection.head,
+          newSelection.goalColumn,
+          newSelection.bidiLevel || undefined
+        )
+      }),
+      view.state.selection.mainIndex
+    ),
+    scrollIntoView: true,
+    userEvent: 'select',
+  })
+}
+
+export const cursorToEndOfVisualLine = (view: EditorView) =>
+  changeSelection(view, range => getNextLineBoundary(range, true, view), false)
+
+export const selectToEndOfVisualLine = (view: EditorView) =>
+  changeSelection(view, range => getNextLineBoundary(range, true, view), true)
+
+export const selectRestOfVisualLine = (view: EditorView) =>
+  changeSelection(
+    view,
+    range => getNextLineBoundary(range, true, view, true),
+    true
+  )
+
+export const cursorToBeginningOfVisualLine = (view: EditorView) =>
+  changeSelection(view, range => getNextLineBoundary(range, false, view), false)
+
+export const selectToBeginningOfVisualLine = (view: EditorView) =>
+  changeSelection(view, range => getNextLineBoundary(range, false, view), true)
+
+export const deleteToVisualLineEnd: Command = view =>
+  deleteBy(view, pos => {
+    const lineEnd = getNextLineBoundary(
+      EditorSelection.cursor(pos),
+      true,
+      view,
+      true
+    ).to
+    return pos < lineEnd ? lineEnd : Math.min(view.state.doc.length, pos + 1)
+  })
+
+export const deleteToVisualLineStart: Command = view =>
+  deleteBy(view, pos => {
+    const lineStart = getNextLineBoundary(
+      EditorSelection.cursor(pos),
+      false,
+      view
+    ).to
+    return pos > lineStart ? lineStart : Math.max(0, pos - 1)
+  })
+
+/* eslint-disable */
+/**
+ * The following definitions are from CodeMirror 6, licensed under the MIT license:
+ * https://github.com/codemirror/commands/blob/main/src/commands.ts
+ */
+type CommandTarget = { state: EditorState; dispatch: (tr: Transaction) => void }
+
+function deleteBy(target: CommandTarget, by: (start: number) => number) {
+  if (target.state.readOnly) return false
+  let event = 'delete.selection',
+    { state } = target
+  let changes = state.changeByRange(range => {
+    let { from, to } = range
+    if (from == to) {
+      let towards = by(from)
+      if (towards < from) {
+        event = 'delete.backward'
+        towards = skipAtomic(target, towards, false)
+      } else if (towards > from) {
+        event = 'delete.forward'
+        towards = skipAtomic(target, towards, true)
+      }
+      from = Math.min(from, towards)
+      to = Math.max(to, towards)
+    } else {
+      from = skipAtomic(target, from, false)
+      to = skipAtomic(target, to, true)
+    }
+    return from == to
+      ? { range }
+      : { changes: { from, to }, range: EditorSelection.cursor(from) }
+  })
+  if (changes.changes.empty) return false
+  target.dispatch(
+    state.update(changes, {
+      scrollIntoView: true,
+      userEvent: event,
+      effects:
+        event == 'delete.selection'
+          ? EditorView.announce.of(state.phrase('Selection deleted'))
+          : undefined,
+    })
+  )
+  return true
+}
+
+function skipAtomic(target: CommandTarget, pos: number, forward: boolean) {
+  if (target instanceof EditorView)
+    for (let ranges of target.state
+      .facet(EditorView.atomicRanges)
+      .map(f => f(target)))
+      ranges.between(pos, pos, (from, to) => {
+        if (from < pos && to > pos) pos = forward ? to : from
+      })
+  return pos
+}