fix(editor): prevent editor from scrolling on focus

Capture scroll position before focus and restore it via
requestAnimationFrame to undo CodeMirror's automatic scrollIntoView.

Author: yanglbme

packages/shared/src/editor/themes.ts

@@ -2,7 +2,29 @@ import { EditorView } from '@codemirror/view'
 import { vsCodeDark } from '@fsegurai/codemirror-theme-vscode-dark'
 import { vsCodeLight } from '@fsegurai/codemirror-theme-vscode-light'
 
+// Prevent CodeMirror's scrollIntoView on focus by restoring scroll position
+// after CodeMirror performs its automatic scroll.
+const noScrollOnFocus = EditorView.domEventHandlers({
+  focus(_event, _view) {
+    const scrollDOM = _view.scrollDOM
+    const { scrollTop, scrollLeft } = scrollDOM
+    requestAnimationFrame(() => {
+      scrollDOM.scrollTop = scrollTop
+      scrollDOM.scrollLeft = scrollLeft
+    })
+    return false
+  },
+})
+
 const customStyles = EditorView.theme({
+  // 移除聚焦时的蓝色边框
+  '&.cm-focused': {
+    outline: `none`,
+  },
+  // 防止滚动链接效应
+  '.cm-scroller': {
+    overscrollBehavior: `contain`,
+  },
   // 装订线：垂直居中、无背景无边框无内边距
   '.cm-gutterElement': {
     display: `flex`,
@@ -37,11 +59,11 @@ const customStyles = EditorView.theme({
 })
 
 export function lightTheme() {
-  return [vsCodeLight, customStyles]
+  return [vsCodeLight, customStyles, noScrollOnFocus]
 }
 
 export function darkTheme() {
-  return [vsCodeDark, customStyles]
+  return [vsCodeDark, customStyles, noScrollOnFocus]
 }
 
 // 根据主题模式获取主题扩展