⚡ perf(vscode): 代码阅读预览的卡片位置量过就记着，内容或大小变了才重量：粘性标题、记滚动位置、上报可见行、跳转按顶层块二分找，滚动时不再每帧量全部卡片，滚动回调里也不读会逼排版的位置

vscode/webview-ui/src/codeReader/occurrences.test.ts

@@ -1,6 +1,6 @@
 import type { Click, Highlight } from './occurrences'
 import type { BlockView, Inline, Occurrence, PreviewText, PropertyItem, Segment, WebviewToExtension } from './types'
-import { describe, expect, it } from 'vitest'
+import { describe, expect, it, vi } from 'vitest'
 import { toBlockViews } from '../../../src/codeReader/blockView'
 import { createPythonAdapter } from '../../../src/codeReader/languages/python'
 import { WASM_DIR, withBlocks } from '../../../src/codeReader/testSupport'
@@ -359,26 +359,38 @@ describe('occurrences：用键盘在各处出现之间跳', () => {
     scroll.press({ x: 0, y: 40 }, 1000)
     scroll.take(1012)
     // 刚回到按键那一刻、还没跳完：守住按键那一刻的位置
-    expect(scroll.scrolled({ x: 0, y: 300 }, 1020)).toEqual({ x: 0, y: 40 })
+    expect(scroll.scrolled(1020, () => ({ x: 0, y: 300 }))).toEqual({ x: 0, y: 40 })
     scroll.hold({ x: 0, y: 900 })
-    expect(scroll.scrolled({ x: 0, y: 900 }, 1030)).toBeUndefined()
-    expect(scroll.scrolled({ x: 0, y: 1200 }, 1040)).toEqual({ x: 0, y: 900 })
-    expect(scroll.scrolled({ x: 0, y: 1200 }, 1000 + KEY_SCROLL_MS + 1)).toBeUndefined()
-    expect(scroll.scrolled({ x: 0, y: 1300 }, 1000 + KEY_SCROLL_MS + 2)).toBeUndefined()
+    expect(scroll.scrolled(1030, () => ({ x: 0, y: 900 }))).toBeUndefined()
+    expect(scroll.scrolled(1040, () => ({ x: 0, y: 1200 }))).toEqual({ x: 0, y: 900 })
+    expect(scroll.scrolled(1000 + KEY_SCROLL_MS + 1, () => ({ x: 0, y: 1200 }))).toBeUndefined()
+    expect(scroll.scrolled(1000 + KEY_SCROLL_MS + 2, () => ({ x: 0, y: 1300 }))).toBeUndefined()
   })
 
   it('不是按键触发的跳转、又按了键、点了鼠标：不守', () => {
     const scroll = new KeyScroll()
     scroll.take(10)
     scroll.hold({ x: 0, y: 900 })
-    expect(scroll.scrolled({ x: 0, y: 0 }, 20)).toBeUndefined()
+    expect(scroll.scrolled(20, () => ({ x: 0, y: 0 }))).toBeUndefined()
     scroll.press({ x: 0, y: 40 }, 1000)
     scroll.take(1010)
     scroll.press({ x: 0, y: 40 }, 1100)
-    expect(scroll.scrolled({ x: 0, y: 300 }, 1110)).toBeUndefined()
+    expect(scroll.scrolled(1110, () => ({ x: 0, y: 300 }))).toBeUndefined()
     scroll.take(1120)
     scroll.forget()
-    expect(scroll.scrolled({ x: 0, y: 300 }, 1130)).toBeUndefined()
+    expect(scroll.scrolled(1130, () => ({ x: 0, y: 300 }))).toBeUndefined()
+  })
+
+  it('不守着时滚动不读滚动位置（读它会逼浏览器先排版）', () => {
+    const scroll = new KeyScroll()
+    const read = vi.fn(() => ({ x: 0, y: 300 }))
+    expect(scroll.scrolled(10, read)).toBeUndefined()
+    scroll.press({ x: 0, y: 40 }, 1000)
+    expect(scroll.scrolled(1005, read)).toBeUndefined()
+    expect(read).not.toHaveBeenCalled()
+    scroll.take(1010)
+    expect(scroll.scrolled(1020, read)).toEqual({ x: 0, y: 40 })
+    expect(read).toHaveBeenCalledTimes(1)
   })
 
   it('我们自己滚过的位置不算浏览器滚走：差 1 像素、滚进视口都不再拉一次，真被滚走仍拉回', () => {
@@ -389,12 +401,12 @@ describe('occurrences：用键盘在各处出现之间跳', () => {
     scroll.own({ x: 0, y: 39 })
     scroll.own({ x: 0, y: 40 })
     scroll.own({ x: 0, y: 800 })
-    expect(scroll.scrolled({ x: 0, y: 39 }, 1020)).toBeUndefined()
-    expect(scroll.scrolled({ x: 0, y: 39 }, 1021)).toBeUndefined()
-    expect(scroll.scrolled({ x: 0, y: 800 }, 1022)).toBeUndefined()
+    expect(scroll.scrolled(1020, () => ({ x: 0, y: 39 }))).toBeUndefined()
+    expect(scroll.scrolled(1021, () => ({ x: 0, y: 39 }))).toBeUndefined()
+    expect(scroll.scrolled(1022, () => ({ x: 0, y: 800 }))).toBeUndefined()
     scroll.hold({ x: 0, y: 800 })
-    expect(scroll.scrolled({ x: 0, y: 39 }, 1030)).toBeUndefined()
-    expect(scroll.scrolled({ x: 0, y: 300 }, 1040)).toEqual({ x: 0, y: 800 })
+    expect(scroll.scrolled(1030, () => ({ x: 0, y: 39 }))).toBeUndefined()
+    expect(scroll.scrolled(1040, () => ({ x: 0, y: 300 }))).toEqual({ x: 0, y: 800 })
   })
 
   it('默认快捷键：mac 是 ⌘↓ / ⌘↑，别的系统是 ctrl；带了别的修饰键不算', () => {