🐛 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/previewEditor.ts

@@ -1,4 +1,4 @@
-import type { CustomTextEditorProvider, Disposable, TextDocument, Uri, Webview, WebviewPanel } from 'vscode'
+import type { CustomTextEditorProvider, Disposable, TextDocument, Uri, WebviewPanel } from 'vscode'
 import type { CodeReaderRegistry } from '../registry'
 import type { TreeSitterRuntime } from '../runtime'
 import type { ExtensionToWebview, WebviewToExtension } from './messages'
@@ -19,6 +19,8 @@ const REFRESH_DELAY_MS = 150
  */
 export class PreviewEditorProvider implements CustomTextEditorProvider {
   private readonly previews = new Set<Preview>()
+  /** 按文档 uri：从文本编辑器切过来时它顶部那一行，等着交给马上要打开的新预览 */
+  private readonly revealLines = new Map<string, number>()
 
   constructor(
     private readonly extensionUri: Uri,
@@ -29,7 +31,9 @@ export class PreviewEditorProvider implements CustomTextEditorProvider {
   resolveCustomTextEditor(document: TextDocument, panel: WebviewPanel): void {
     panel.webview.options = { enableScripts: true, localResourceRoots: [webviewUiRoot(this.extensionUri)] }
     panel.webview.html = webviewHtml(panel.webview, this.extensionUri, 'code-reader.html')
-    const preview = new Preview(document, panel.webview, this.registry, this.runtime, languageId => this.refresh(languageId))
+    const key = document.uri.toString()
+    const preview = new Preview(document, panel, this.registry, this.runtime, this.revealLines.get(key), languageId => this.refresh(languageId))
+    this.revealLines.delete(key)
     this.previews.add(preview)
     panel.onDidDispose(() => {
       this.previews.delete(preview)
@@ -44,6 +48,26 @@ export class PreviewEditorProvider implements CustomTextEditorProvider {
         void preview.push()
     }
   }
+
+  /** 用 open 打开 uri 的预览，新预览先滚到包含 line 的块。 */
+  async openAtLine(uri: Uri, line: number, open: () => Thenable<unknown>): Promise<void> {
+    const key = uri.toString()
+    this.revealLines.set(key, line)
+    try {
+      await open()
+    }
+    finally {
+      // 切换命令等新预览解析完才返回；切换没成时也不能把这行留给以后别处的打开
+      this.revealLines.delete(key)
+    }
+  }
+
+  /** uri 的预览视口顶部那块的起始行；几个编辑器组里都开着这个文件的预览时取活动的那个。 */
+  visibleLine(uri: Uri): number | undefined {
+    const key = uri.toString()
+    const previews = [...this.previews].filter(p => p.uri.toString() === key)
+    return (previews.find(p => p.active) ?? previews[0])?.visibleLine
+  }
 }
 
 class Preview {
@@ -53,16 +77,20 @@ class Preview {
   private latest = 0
   private timer: NodeJS.Timeout | undefined
   private readonly disposables: Disposable[]
+  /** webview 报来的视口顶部那块的起始行 */
+  visibleLine: number | undefined
 
   constructor(
     private readonly document: TextDocument,
-    private readonly webview: Webview,
+    private readonly panel: WebviewPanel,
     private readonly registry: CodeReaderRegistry,
     private readonly runtime: TreeSitterRuntime,
+    /** 只随第一份真正发出去的文档走：之后页面因标签页切走重新加载，要按 webview 自己记的位置恢复 */
+    private revealLine: number | undefined,
     private readonly onTranslatorSelected: (languageId: string) => void,
   ) {
     this.disposables = [
-      webview.onDidReceiveMessage((msg: WebviewToExtension) => this.handleMessage(msg)),
+      panel.webview.onDidReceiveMessage((msg: WebviewToExtension) => this.handleMessage(msg)),
       workspace.onDidChangeTextDocument((e) => {
         if (e.document === document && e.contentChanges.length > 0)
           this.schedulePush()
@@ -74,14 +102,25 @@ class Preview {
     return this.document.languageId
   }
 
+  get uri(): Uri {
+    return this.document.uri
+  }
+
+  get active(): boolean {
+    return this.panel.active
+  }
+
   async push(): Promise<void> {
     clearTimeout(this.timer)
     if (!this.ready)
       return
     const request = ++this.latest
     const message: ExtensionToWebview = await documentMessage(this.document, this.registry, this.runtime)
-    if (request === this.latest)
-      void this.webview.postMessage(message)
+    if (request !== this.latest)
+      return
+    const { revealLine } = this
+    this.revealLine = undefined
+    void this.panel.webview.postMessage(revealLine === undefined ? message : { ...message, revealLine })
   }
 
   dispose(): void {
@@ -107,6 +146,9 @@ class Preview {
       case 'selectTranslator':
         await this.registry.selectTranslator(this.languageId, msg.id)
         this.onTranslatorSelected(this.languageId)
+        return
+      case 'visibleLine':
+        this.visibleLine = msg.line
     }
   }