🐛 fix(vscode): 代码阅读预览记住浏览位置，编辑 / 预览互切位置对齐

vscode/src/codeReader/editor/switchEditor.ts

@@ -0,0 +1,77 @@
+import type { Disposable, TextEditor } from 'vscode'
+import type { PreviewEditorProvider } from './previewEditor'
+import { commands, Range, TabInputCustom, TextEditorRevealType, Uri, window } from 'vscode'
+import { PREVIEW_VIEW_TYPE } from './previewEditor'
+
+/** VS Code 自带普通文本编辑器的 editor id。 */
+const TEXT_EDITOR = 'default'
+/**
+ * VS Code 自带的「重新打开编辑器的方式」：在原标签页位置换成另一种编辑器，新编辑器打开后才返回。
+ * 原文件有未保存改动也不弹保存框——改动在 TextDocument 里，不跟着标签页走。
+ */
+const REOPEN_WITH = 'reopenActiveEditorWith'
+/** 切换命令返回时文本编辑器还没同步到扩展这边的话，最多再等这么久 */
+const EDITOR_WAIT_MS = 1000
+
+function sameUri(a: Uri, b: Uri): boolean {
+  return a.toString() === b.toString()
+}
+
+/** 标题栏按钮传来的是 (文件 Uri, { groupId })，命令面板里调用时没有参数。 */
+function resourceArg(args: unknown[]): Uri | undefined {
+  return args[0] instanceof Uri ? args[0] : undefined
+}
+
+function activeCustomEditorUri(): Uri | undefined {
+  const input = window.tabGroups.activeTabGroup.activeTab?.input
+  return input instanceof TabInputCustom ? input.uri : undefined
+}
+
+function textEditorOf(uri: Uri): TextEditor | undefined {
+  const active = window.activeTextEditor
+  if (active && sameUri(active.document.uri, uri))
+    return active
+  return window.visibleTextEditors.find(editor => sameUri(editor.document.uri, uri))
+}
+
+/** 编辑器变化和命令结果是分开通知到扩展这边的：没看到 uri 的文本编辑器就等它出现。 */
+function waitForTextEditor(uri: Uri): Promise<TextEditor | undefined> {
+  const found = textEditorOf(uri)
+  if (found)
+    return Promise.resolve(found)
+  const disposables: Disposable[] = []
+  return new Promise<TextEditor | undefined>((resolve) => {
+    disposables.push(window.onDidChangeVisibleTextEditors(() => {
+      const editor = textEditorOf(uri)
+      if (editor)
+        resolve(editor)
+    }))
+    const timer = setTimeout(resolve, EDITOR_WAIT_MS, undefined)
+    disposables.push({ dispose: () => clearTimeout(timer) })
+  }).finally(() => disposables.forEach(d => d.dispose()))
+}
+
+/** 文本编辑器 → 预览（同一标签页原位替换）：新预览先滚到文本编辑器顶部那一行所在的块。 */
+export async function showPreview(previews: PreviewEditorProvider, args: unknown[]): Promise<void> {
+  const uri = resourceArg(args) ?? window.activeTextEditor?.document.uri
+  const topLine = uri ? textEditorOf(uri)?.visibleRanges[0]?.start.line : undefined
+  const reopen = (): Thenable<unknown> => commands.executeCommand(REOPEN_WITH, PREVIEW_VIEW_TYPE, ...args)
+  if (uri && topLine !== undefined)
+    await previews.openAtLine(uri, topLine, reopen)
+  else
+    await reopen()
+}
+
+/** 预览 → 文本编辑器（同一标签页原位替换）：把预览视口顶部那块的起始行放到文本编辑器顶部。 */
+export async function showSource(previews: PreviewEditorProvider, args: unknown[]): Promise<void> {
+  const uri = resourceArg(args) ?? activeCustomEditorUri()
+  const line = uri ? previews.visibleLine(uri) : undefined
+  await commands.executeCommand(REOPEN_WITH, TEXT_EDITOR, ...args)
+  if (!uri || line === undefined)
+    return
+  const editor = await waitForTextEditor(uri)
+  if (!editor)
+    return
+  const target = Math.min(line, editor.document.lineCount - 1)
+  editor.revealRange(new Range(target, 0, target, 0), TextEditorRevealType.AtTop)
+}