v0.3.7: 修复保存竞争态 + 新增源码编辑模式

Bug修复:
  - BUG-10 修复: 保存文件时 watcher restart 触发虚假 change 事件覆盖编辑器内容
    - ipc-handlers.ts: restart watcher 在 setSelfWriting(true) 保护内执行
    - App.tsx handleReloadModified: 增加 if (tab?.isModified) return 安全守卫

新功能:
  - 新增源码(Source)视图模式，直接用 textarea 编辑原始 Markdown
  - ViewMode 扩展为 editor|preview|source
  - 工具栏增加源码按钮，快捷键 Ctrl+3
  - 内容与 WYSIWYG 编辑器共享 tabStore，切换模式不丢内容

验证: TS 0错误, ESLint 0错误(1个预存警告), 90/90测试通过

src/main/ipc-handlers.ts

@@ -69,13 +69,11 @@ export function registerIpcHandlers(
         fileWatcher.stop()
         fileWatcher.setSelfWriting(true)
         const result = await saveFileContent(data.filePath, data.content)
+        // start watcher while selfWriting is still true so any immediate 'change'
+        // event from the restart is suppressed — prevents overwriting editor content
+        fileWatcher.start(data.filePath)
         fileWatcher.setSelfWriting(false)
         state.activeFilePath = data.filePath
-        setTimeout(() => {
-          if (state.activeFilePath === data.filePath && data.filePath) {
-            fileWatcher.start(data.filePath)
-          }
-        }, 300)
         if (win && !win.isDestroyed()) {
           win.setTitle(`MarkLite - ${basename(data.filePath)}`)
         }
@@ -88,12 +86,12 @@ export function registerIpcHandlers(
         if (!saveResult.canceled) {
           fileWatcher.setSelfWriting(true)
           const result = await saveFileContent(saveResult.filePath, data.content)
-          fileWatcher.setSelfWriting(false)
           if (result.success) {
             state.activeFilePath = saveResult.filePath
             fileWatcher.start(saveResult.filePath)
             win.setTitle(`MarkLite - ${basename(saveResult.filePath)}`)
           }
+          fileWatcher.setSelfWriting(false)
           return result
         }
         return { success: false, canceled: true }
@@ -116,19 +114,14 @@ export function registerIpcHandlers(
         filters: [{ name: 'Markdown 文件', extensions: ['md'] }]
       })
       if (!result.canceled) {
-        fileWatcher.stop()
         fileWatcher.setSelfWriting(true)
         const saveResult = await saveFileContent(result.filePath, data.content)
-        fileWatcher.setSelfWriting(false)
         if (saveResult.success) {
           state.activeFilePath = result.filePath
-          setTimeout(() => {
-            if (state.activeFilePath === result.filePath) {
           fileWatcher.start(result.filePath)
-            }
-          }, 300)
           win.setTitle(`MarkLite - ${basename(result.filePath)}`)
         }
+        fileWatcher.setSelfWriting(false)
         return saveResult
       }
       return { success: false, canceled: true }

src/renderer/App.tsx

@@ -16,6 +16,7 @@ import { useConfirm } from './hooks/useConfirm'
 import { Toolbar } from './components/Toolbar/Toolbar'
 import { TabBar } from './components/TabBar/TabBar'
 import { Editor } from './components/Editor/Editor'
+import { SourceEditor } from './components/SourceEditor/SourceEditor'
 import { Preview } from './components/Preview/Preview'
 import { Sidebar } from './components/Sidebar/Sidebar'
 import { StatusBar } from './components/StatusBar/StatusBar'
@@ -75,10 +76,16 @@ export function App() {
 
   const handleReloadModified = useCallback(async () => {
     if (!externallyModified?.filePath || !window.electronAPI) return
+    const tab = tabs.find(t => t.filePath === externallyModified.filePath)
+    // BUG-10: Don't overwrite editor content the user has modified since the last save.
+    // The watcher restart after save can trigger a false 'change' event, and re-reading
+    // the file at that point would replace newer editor content with the just-saved content.
+    if (tab?.isModified) return
+    if (!tab) return
     const result = await window.electronAPI.readFile(externallyModified.filePath)
     if (result.success && result.content !== undefined) {
-      const tab = tabs.find(t => t.filePath === externallyModified.filePath)
+      updateTabContent(tab.id, result.content)
-      if (tab) { updateTabContent(tab.id, result.content); setModified(tab.id, false) }
+      setModified(tab.id, false)
     }
     setExternallyModified(null)
   }, [externallyModified, tabs, updateTabContent, setModified, setExternallyModified])
@@ -102,6 +109,7 @@ export function App() {
             {tabs.length > 0 ? (
               <div id="content-wrapper">
                 {viewMode === 'editor' && <div id="editor-panel"><Editor darkMode={darkMode} /></div>}
+                {viewMode === 'source' && <div id="editor-panel"><SourceEditor darkMode={darkMode} /></div>}
                 {viewMode === 'preview' && <div id="preview-panel"><Preview /></div>}
               </div>
             ) : (

src/renderer/components/Icons.tsx

@@ -78,6 +78,15 @@ export function PreviewMode({ size = defaultProps.size }: IconProps) {
   )
 }
 
+export function SourceMode({ size = defaultProps.size }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <polyline points="16 18 22 12 16 6"/>
+      <polyline points="8 6 2 12 8 18"/>
+    </svg>
+  )
+}
+
 export function Moon({ size = defaultProps.size }: IconProps) {
   return (
     <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">

src/renderer/components/SourceEditor/SourceEditor.tsx

@@ -0,0 +1,61 @@
+import React, { useCallback, useRef } from 'react'
+import { useTabStore } from '../../stores/tabStore'
+
+interface SourceEditorProps {
+  darkMode: boolean
+}
+
+/**
+ * 源码编辑模式 — 使用原生 textarea 编辑原始 Markdown 文本。
+ * 内容实时同步到 tabStore，与 WYSIWYG 编辑器共享同一数据源。
+ */
+export const SourceEditor = React.memo(function SourceEditor({ darkMode }: SourceEditorProps) {
+  const activeTab = useTabStore(s => s.getActiveTab())
+  const activeTabId = useTabStore(s => s.activeTabId)
+  const updateTabContent = useTabStore(s => s.updateTabContent)
+  const setModified = useTabStore(s => s.setModified)
+  const textareaRef = useRef<HTMLTextAreaElement>(null)
+
+  const handleChange = useCallback((e: React.ChangeEvent<HTMLTextAreaElement>) => {
+    if (!activeTabId) return
+    updateTabContent(activeTabId, e.target.value)
+    setModified(activeTabId, true)
+  }, [activeTabId, updateTabContent, setModified])
+
+  const handleKeyDown = useCallback((e: React.KeyboardEvent<HTMLTextAreaElement>) => {
+    // Tab 插入两个空格而非跳转焦点
+    if (e.key === 'Tab') {
+      e.preventDefault()
+      const textarea = textareaRef.current
+      if (!textarea) return
+      const start = textarea.selectionStart
+      const end = textarea.selectionEnd
+      const value = textarea.value
+      const newValue = value.substring(0, start) + '  ' + value.substring(end)
+      textarea.value = newValue
+      textarea.selectionStart = textarea.selectionEnd = start + 2
+      if (activeTabId) {
+        updateTabContent(activeTabId, newValue)
+        setModified(activeTabId, true)
+      }
+    }
+  }, [activeTabId, updateTabContent, setModified])
+
+  return (
+    <div className={`source-editor-wrapper${darkMode ? ' source-editor-dark' : ''}`}>
+      <textarea
+        ref={textareaRef}
+        className="source-editor-textarea"
+        value={activeTab?.content ?? ''}
+        onChange={handleChange}
+        onKeyDown={handleKeyDown}
+        spellCheck={false}
+        wrap="off"
+        aria-label="Markdown 源码编辑器"
+        placeholder="在此输入 Markdown 内容..."
+      />
+    </div>
+  )
+})
+
+SourceEditor.displayName = 'SourceEditor'

src/renderer/components/Toolbar/Toolbar.tsx

@@ -1,11 +1,12 @@
 import React from 'react'
-import { FolderOpen, Save, EditMode, PreviewMode, Moon, Sun, Info } from '../Icons'
+import { FolderOpen, Save, EditMode, PreviewMode, SourceMode, Moon, Sun, Info } from '../Icons'
+import type { ViewMode } from '../../types/settings'
 
 interface ToolbarProps {
   onOpen: () => void
   onSave: () => void
-  viewMode: 'editor' | 'preview'
+  viewMode: ViewMode
-  onViewModeChange: (mode: 'editor' | 'preview') => void
+  onViewModeChange: (mode: ViewMode) => void
   darkMode: boolean
   onToggleDark: () => void
   onShowAbout: () => void
@@ -27,13 +28,23 @@ export const Toolbar = React.memo(function Toolbar({ onOpen, onSave, viewMode, o
         <button
           className={`toolbar-btn ${viewMode === 'editor' ? 'active' : ''}`}
           onClick={() => onViewModeChange('editor')}
-          title="编辑 (Ctrl+1)"
+          title="WYSIWYG 编辑 (Ctrl+1)"
-          aria-label="编辑模式"
+          aria-label="WYSIWYG 编辑模式"
           aria-pressed={viewMode === 'editor'}
         >
           <EditMode size={18} />
           <span>编辑</span>
         </button>
+        <button
+          className={`toolbar-btn ${viewMode === 'source' ? 'active' : ''}`}
+          onClick={() => onViewModeChange('source')}
+          title="源码编辑 (Ctrl+3)"
+          aria-label="源码编辑模式"
+          aria-pressed={viewMode === 'source'}
+        >
+          <SourceMode size={18} />
+          <span>源码</span>
+        </button>
         <button
           className={`toolbar-btn ${viewMode === 'preview' ? 'active' : ''}`}
           onClick={() => onViewModeChange('preview')}

src/renderer/db/schema.ts

@@ -19,7 +19,7 @@ export interface ActiveTabRecord {
 export interface SettingsRecord {
   id: string // 固定为 'default'
   darkMode: boolean
-  viewMode: 'editor' | 'preview'
+  viewMode: 'editor' | 'preview' | 'source'
   sidebarCollapsed: boolean
   sidebarWidth: number
 }

src/renderer/hooks/useKeyboard.ts

@@ -13,6 +13,7 @@ export function useKeyboard(handleOpenFile: () => void, handleSave: () => void,
     if (isCtrl && e.shiftKey && e.key === 'S') { e.preventDefault(); handleSaveAs(); return }
     if (isCtrl && e.key === '1') { e.preventDefault(); setViewMode('editor'); return }
     if (isCtrl && e.key === '2') { e.preventDefault(); setViewMode('preview'); return }
+    if (isCtrl && e.key === '3') { e.preventDefault(); setViewMode('source'); return }
 
     const tabState = useTabStore.getState()
     if (isCtrl && e.key === 't') { e.preventDefault(); tabState.createTab(null, ''); return }

src/renderer/styles/global.css

@@ -322,6 +322,35 @@ body {
   cursor: text;
 }
 
+/* Source Editor */
+.source-editor-wrapper {
+  flex: 1;
+  display: flex;
+  min-width: 0;
+  min-height: 0;
+}
+
+.source-editor-textarea {
+  flex: 1;
+  border: none;
+  outline: none;
+  resize: none;
+  padding: 16px 20px;
+  font-family: 'Cascadia Code', 'Fira Code', 'JetBrains Mono', 'Consolas', 'Courier New', monospace;
+  font-size: 14px;
+  line-height: 1.6;
+  tab-size: 2;
+  color: #1e1e1e;
+  background: #fafafa;
+  user-select: text;
+  cursor: text;
+}
+
+.source-editor-dark .source-editor-textarea {
+  color: #d4d4d4;
+  background: #1e1e1e;
+}
+
 /* Tab Bar */
 #tab-bar {
   height: 36px;
@@ -583,8 +612,13 @@ body {
 }
 
 @keyframes auto-save-pulse {
-  0%, 100% { opacity: 0.6; }
+  0%,
-  50% { opacity: 1; }
+  100% {
+    opacity: 0.6;
+  }
+  50% {
+    opacity: 1;
+  }
 }
 
 /* Drop Overlay */

src/renderer/types/settings.ts

@@ -1,4 +1,4 @@
-export type ViewMode = 'editor' | 'preview'
+export type ViewMode = 'editor' | 'preview' | 'source'
 
 export interface Settings {
   darkMode: boolean