diff --git a/docs/dev/code/renderer/editor.md b/docs/dev/code/renderer/editor.md
index 36743589..5c8265d9 100644
--- a/docs/dev/code/renderer/editor.md
+++ b/docs/dev/code/renderer/editor.md
@@ -82,6 +82,7 @@ interface IDocumentState
     index: number
   },
   cursor: any,
+  firstViewportVisibleItem: any,
   wordCount: {
     paragraph: number,
     word: number,
diff --git a/src/muya/lib/contentState/index.js b/src/muya/lib/contentState/index.js
index 250b2578..c33e6cb9 100644
--- a/src/muya/lib/contentState/index.js
+++ b/src/muya/lib/contentState/index.js
@@ -83,6 +83,7 @@ class ContentState {
     this._selectedImage = null
     this.dropAnchor = null
     this.prevCursor = null
+    this.firstViewportVisibleItem = null
     this.historyTimer = null
     this.history = new History(this)
     this.turndownConfig = Object.assign({}, DEFAULT_TURNDOWN_CONFIG, { bulletListMarker })
@@ -347,6 +348,43 @@ class ContentState {
     return this.cursor
   }
 
+  getBlockKeyByIndex (index) {
+    let arr = index.split('.')
+    const travel = blocks => {
+      let pos = arr.shift()
+      let num = parseInt(pos)
+      if (num !== pos || Number.isInteger(num) === false) { return null }
+      pos = num
+      if (blocks.length <= pos) { return null }
+        let block = blocks[pos]
+      if (arr.length === 0) { return block.key } else { return travel(block.children) }
+    }
+    return travel(this.blocks)
+  }
+
+  getBlockIndex (key) {
+    if (!key) return null
+    let result = null
+    const travel = blocks => {
+      for (let index = 0; index < blocks.length; index++) {
+        const block = blocks[index]
+        if (block.key === key) {
+          result = `${index}`
+          return true
+        }
+        if (block.children.length) {
+          if (travel(block.children)) {
+            result = `${index}.${result}`
+            return true
+          }
+        }
+      }
+      return false
+    }
+    travel(this.blocks)
+    return result
+  }
+
   getBlock (key) {
     if (!key) return null
     let result = null
diff --git a/src/renderer/components/editorWithTabs/editor.vue b/src/renderer/components/editorWithTabs/editor.vue
index 0b407039..ccdde598 100644
--- a/src/renderer/components/editorWithTabs/editor.vue
+++ b/src/renderer/components/editorWithTabs/editor.vue
@@ -111,6 +111,7 @@ import '@/assets/themes/codemirror/one-dark.css'
 // import 'view-image/lib/imgViewer.css'
 import CloseIcon from '@/assets/icons/close.svg'
 
+// Minus 67 here is the Y offset of the container itself, before we didn't include that in the scroll calculations, as we do now this keeps the actual Y offset the same
 const STANDAR_Y = 320
 
 export default {
@@ -437,8 +438,20 @@ export default {
     },
 
     currentFile: function (value, oldValue) {
+        if (this.sourceCode === false && oldValue && oldValue !== value) { // Cannot use the changed event above as it happens after we have switched to the new file
+          let firstViewportVisibleItem = this.getFirstElementInViewport()
+          if (firstViewportVisibleItem) { oldValue.firstViewportVisibleItem = 'M' + this.editor.contentState.getBlockIndex(firstViewportVisibleItem.id) } else { oldValue.firstViewportVisibleItem = 'Z' }// undefining if already set
+        }
+
       if (value && value !== oldValue) {
-        this.scrollToCursor(0)
+        if (this.sourceCode === false && value.firstViewportVisibleItem && value.firstViewportVisibleItem.startsWith('M')) {
+          let indexStr = value.firstViewportVisibleItem.substring(1)
+          this.$nextTick(() => {
+            let elemId = this.editor.contentState.getBlockKeyByIndex(indexStr)
+            if (!elemId) { return }
+            this.scrollToElement('#' + elemId, 15, true)
+          })
+        } else { this.scrollToCursor(0) }
         // Hide float tools if needed.
         this.editor && this.editor.hideAllFloatTools()
       }
@@ -630,7 +643,6 @@ export default {
       //
       //   this.setImageViewerVisible(true)
       // })
-
       this.editor.on('selectionChange', changes => {
         const { y } = changes.cursorCoords
         if (this.typewriter) {
@@ -908,14 +920,51 @@ export default {
       return this.scrollToElement(`#${slug}`)
     },
 
-    scrollToElement (selector) {
+    getFirstElementInViewport () {
+    let node = this.editor.container
+    if (node.childNodes.length === 0) { return null }
+    let offsetY = node.scrollTop
+    node = node.childNodes[0]// this gets us to the editors primary div
+    if (offsetY === 0) {
+      if (node.childNodes.length === 0) { return null }
+      return node.childNodes[0]
+    }
+
+    const nodeStack = []
+
+      while (node) {
+            // Only iterate over elements and text nodes
+            if (node.nodeType > 3) {
+              node = nodeStack.pop()
+              continue
+            }
+            if (node.offsetTop >= offsetY) { return node }
+
+            if (node.nodeType === 1) {
+                // this is an element
+                // add all its children to the stack
+                let i = node.childNodes.length - 1
+                while (i >= 0) {
+                  nodeStack.push(node.childNodes[i])
+                  i -= 1
+                }
+              }
+
+              node = nodeStack.pop()
+      }
+    },
+
+    scrollToElement (selector, duration = 300, dontAddStandardHeadroom = false) {
       // Scroll to search highlight word
       const { container } = this.editor
       const anchor = document.querySelector(selector)
       if (anchor) {
-        const { y } = anchor.getBoundingClientRect()
-        const DURATION = 300
-        animatedScrollTo(container, container.scrollTop + y - STANDAR_Y, DURATION)
+        const DURATION = duration
+        const anchorY = anchor.getBoundingClientRect().y
+        const containerY = container.getBoundingClientRect().y
+
+        const add = dontAddStandardHeadroom ? 0 : STANDAR_Y
+        animatedScrollTo(container, container.scrollTop + anchorY - containerY - add, DURATION)
       }
     },
 
@@ -1072,7 +1121,7 @@ export default {
         if (cursor) {
           editor.setMarkdown(markdown, cursor, true)
         } else {
-          editor.setMarkdown(markdown)
+          editor.setMarkdown(markdown, null, true)
         }
       }
     },
diff --git a/src/renderer/components/editorWithTabs/sourceCode.vue b/src/renderer/components/editorWithTabs/sourceCode.vue
index 687a505d..c45d6217 100644
--- a/src/renderer/components/editorWithTabs/sourceCode.vue
+++ b/src/renderer/components/editorWithTabs/sourceCode.vue
@@ -10,10 +10,13 @@
 import codeMirror, { setMode, setCursorAtLastLine, setTextDirection } from '../../codeMirror'
 import { wordCount as getWordCount } from 'muya/lib/utils'
 import { mapState } from 'vuex'
-import { adjustCursor } from '../../util'
+import { adjustCursor, animatedScrollTo } from '../../util'
 import bus from '../../bus'
 import { oneDarkThemes, railscastsThemes } from '@/config'
 
+// Same as editor.vue
+const STANDAR_Y = 320
+
 export default {
   props: {
     markdown: String,
@@ -43,6 +46,18 @@ export default {
   },
 
   watch: {
+    currentTab: function (value, oldValue) {
+      if (!this.sourceCode) { return }
+      // Don't need to worry about setting the line on the oldValue already did in prepareTabSwitch
+      if (value && value !== oldValue) {
+        if (value.firstViewportVisibleItem && value.firstViewportVisibleItem.startsWith('S')) {
+          let line = value.firstViewportVisibleItem.substring(1)
+          this.$nextTick(() => {
+            this.scrollToLineNumberInViewport(line, 15, true)
+          })
+        }
+      }
+    },
     textDirection: function (value, oldValue) {
       const { editor } = this
       if (value !== oldValue && editor) {
@@ -244,15 +259,28 @@ export default {
     },
     // Commit changes from old tab. Problem: tab was already switched, so commit changes with old tab id.
     prepareTabSwitch () {
+      let firstViewportVisibleItem = 'S' + this.getFirstLineNumberInViewport()
+      if (this.sourceCode === false) { // this shouldn't happen
+        firstViewportVisibleItem = undefined
+      }
+
       if (this.commitTimer) clearTimeout(this.commitTimer)
       if (this.tabId) {
         const { editor } = this
         const { cursor, markdown } = this.getMarkdownAndCursor(editor)
-        this.$store.dispatch('LISTEN_FOR_CONTENT_CHANGE', { id: this.tabId, markdown, cursor })
+        this.$store.dispatch('LISTEN_FOR_CONTENT_CHANGE', { id: this.tabId, markdown, cursor, firstViewportVisibleItem })
         this.tabId = null // invalidate tab id
       }
     },
-
+    scrollToLineNumberInViewport (line, duration = 300, dontAddStandardHeadroom = false) {
+      let pos = this.editor.charCoords({ line: line, ch: 0 }, 'local').top
+      const DURATION = duration
+      if (!dontAddStandardHeadroom) { pos -= STANDAR_Y }
+      animatedScrollTo(this.$el, pos, DURATION)
+    },
+    getFirstLineNumberInViewport () {
+      return this.editor.coordsChar({ left: 0, top: this.$el.scrollTop }, 'local').line
+    },
     handleSelectAll () {
       if (!this.sourceCode) {
         return
diff --git a/src/renderer/components/editorWithTabs/sourceCode.vue.orig b/src/renderer/components/editorWithTabs/sourceCode.vue.orig
new file mode 100644
index 00000000..2e766a44
--- /dev/null
+++ b/src/renderer/components/editorWithTabs/sourceCode.vue.orig
@@ -0,0 +1,389 @@
+<template>
+  <div
+    class="source-code"
+    ref="sourceCode"
+  >
+  </div>
+</template>
+
+<script>
+import codeMirror, { setMode, setCursorAtLastLine, setTextDirection } from '../../codeMirror'
+import { wordCount as getWordCount } from 'muya/lib/utils'
+import { mapState } from 'vuex'
+import { adjustCursor, animatedScrollTo } from '../../util'
+import bus from '../../bus'
+import { oneDarkThemes, railscastsThemes } from '@/config'
+
+const STANDAR_Y = 320
+
+export default {
+  props: {
+    markdown: String,
+    cursor: Object,
+    textDirection: {
+      type: String,
+      required: true
+    }
+  },
+
+  computed: {
+    ...mapState({
+      theme: state => state.preferences.theme,
+      sourceCode: state => state.preferences.sourceCode,
+      currentTab: state => state.editor.currentFile
+    })
+  },
+
+  data () {
+    return {
+      contentState: null,
+      editor: null,
+      commitTimer: null,
+      viewDestroyed: false,
+      tabId: null
+    }
+  },
+
+  watch: {
+    currentTab: function (value, oldValue) {
+      if (! this.sourceCode)
+        return;
+      //Don't need to worry about setting the line on the oldValue already did in prepareTabSwitch
+      if (value && value !== oldValue) {
+        if (value.firstViewportVisibleItem && value.firstViewportVisibleItem.startsWith("S")){
+          let line = value.firstViewportVisibleItem.substring(1);
+          this.$nextTick(() => {
+            this.scrollToLineNumberInViewport(line, 15,true);
+          });
+        }
+      }
+
+    },
+    textDirection: function (value, oldValue) {
+      const { editor } = this
+      if (value !== oldValue && editor) {
+        setTextDirection(editor, value)
+      }
+    }
+  },
+
+  created () {
+    this.$nextTick(() => {
+      // TODO: Should we load markdown from the tab or mapped vue property?
+      const { id } = this.currentTab
+      const { markdown = '', theme, cursor, textDirection } = this
+      const container = this.$refs.sourceCode
+      const codeMirrorConfig = {
+        value: markdown,
+        lineNumbers: true,
+        autofocus: true,
+        lineWrapping: true,
+        styleActiveLine: true,
+        direction: textDirection,
+        // The amount of updates needed when scrolling. Settings this to >Infinity< or use CSS
+        // >height: auto< result in bad performance because the whole document is always rendered.
+        // Since we are using >height: auto< setting this to >Infinity< to fix #171. The best
+        // solution would be to set a fixed height like in #791 but then the scrollbar is not on
+        // the right side. Please also see CodeMirror#1104.
+        viewportMargin: Infinity,
+        lineNumberFormatter (line) {
+          if (line % 10 === 0 || line === 1) {
+            return line
+          } else {
+            return ''
+          }
+        }
+      }
+
+      // Set theme
+      if (railscastsThemes.includes(theme)) {
+        codeMirrorConfig.theme = 'railscasts'
+      } else if (oneDarkThemes.includes(theme)) {
+        codeMirrorConfig.theme = 'one-dark'
+      }
+
+      // Init CodeMirror
+      const editor = this.editor = codeMirror(container, codeMirrorConfig)
+
+      bus.$on('file-loaded', this.handleFileChange)
+      bus.$on('invalidate-image-cache', this.handleInvalidateImageCache)
+      bus.$on('file-changed', this.handleFileChange)
+      bus.$on('selectAll', this.handleSelectAll)
+      bus.$on('image-action', this.handleImageAction)
+      bus.$on('undo', this.handleUndo)
+      bus.$on('redo', this.handleRedo)
+      bus.$on('find', this.handleFind)
+      bus.$on('replace', this.handleReplace)
+      bus.$on('findNext', this.handleFindNext)
+      bus.$on('findPrev', this.handleFindPrev)
+      document.addEventListener('click', this.docClick)
+      document.addEventListener('keyup', this.docKeyup)
+
+      setMode(editor, 'markdown')
+      this.listenChange()
+
+      // NOTE: Cursor may be not null but the inner values are.
+      if (cursor && cursor.anchor && cursor.focus) {
+        const { anchor, focus } = cursor
+        editor.setSelection(anchor, focus, { scroll: true }) // Scroll the focus into view.
+      } else {
+        setCursorAtLastLine(editor)
+      }
+      this.tabId = id
+    })
+  },
+  beforeDestroy () {
+    // NOTE: Clear timer and manually commit changes. After mode switching and cleanup may follow
+    // further key inputs, so ignore all inputs.
+    this.viewDestroyed = true
+    if (this.commitTimer) clearTimeout(this.commitTimer)
+
+    bus.$off('file-loaded', this.handleFileChange)
+    bus.$off('invalidate-image-cache', this.handleInvalidateImageCache)
+    bus.$off('file-changed', this.handleFileChange)
+    bus.$off('selectAll', this.handleSelectAll)
+    bus.$off('image-action', this.handleImageAction)
+    bus.$off('undo', this.handleUndo)
+    bus.$off('redo', this.handleRedo)
+    bus.$off('find', this.handleFind)
+    bus.$off('replace', this.handleReplace)
+    bus.$off('findNext', this.handleFindNext)
+    bus.$off('findPrev', this.handleFindPrev)
+    document.removeEventListener('click', this.docClick)
+    document.removeEventListener('keyup', this.docKeyup)
+
+    const { editor } = this
+    const { cursor, markdown } = this.getMarkdownAndCursor(editor)
+    bus.$emit('file-changed', { id: this.tabId, markdown, cursor, renderCursor: true })
+  },
+  methods: {
+    handleImageAction ({ id, result, alt }) {
+      const { editor } = this
+      const value = editor.getValue()
+      const focus = editor.getCursor('focus')
+      const anchor = editor.getCursor('anchor')
+      const lines = value.split('\n')
+      const index = lines.findIndex(line => line.indexOf(id) > 0)
+
+      if (index > -1) {
+        const oldLine = lines[index]
+        lines[index] = oldLine.replace(new RegExp(`!\\[${id}\\]\\(.*\\)`), `![${alt}](${result})`)
+        const newValue = lines.join('\n')
+        editor.setValue(newValue)
+        const match = /(!\[.*\]\(.*\))/.exec(oldLine)
+        if (!match) {
+          // User maybe delete `![]()` structure, and the match is null.
+          return
+        }
+        const range = {
+          start: match.index,
+          end: match.index + match[1].length
+        }
+        const delta = alt.length + result.length + 5 - match[1].length
+
+        const adjust = pointer => {
+          if (!pointer) {
+            return
+          }
+          if (pointer.line !== index) {
+            return
+          }
+          if (pointer.ch <= range.start) {
+            // do nothing.
+          } else if (pointer.ch > range.start && pointer.ch < range.end) {
+            pointer.ch = range.start + alt.length + result.length + 5
+          } else {
+            pointer.ch += delta
+          }
+        }
+
+        adjust(focus)
+        adjust(anchor)
+        if (focus && anchor) {
+          editor.setSelection(anchor, focus, { scroll: true })
+        } else {
+          setCursorAtLastLine()
+        }
+      }
+    },
+    listenChange () {
+      const { editor } = this
+      editor.on('cursorActivity', cm => {
+        const { cursor, markdown } = this.getMarkdownAndCursor(cm)
+        // Attention: the cursor may be `{focus: null, anchor: null}` when press `backspace`
+        const wordCount = getWordCount(markdown)
+        if (this.commitTimer) clearTimeout(this.commitTimer)
+        this.commitTimer = setTimeout(() => {
+          // See "beforeDestroy" note
+          if (!this.viewDestroyed) {
+            if (this.tabId) {
+              this.$store.dispatch('LISTEN_FOR_CONTENT_CHANGE', { id: this.tabId, markdown, wordCount, cursor })
+            } else {
+              // This may occur during tab switching but should not occur otherwise.
+              console.warn('LISTEN_FOR_CONTENT_CHANGE: Cannot commit changes because not tab id was set!')
+            }
+          }
+        }, 1000)
+      })
+    },
+    // Another tab was selected - only listen to get changes but don't set history or other things.
+    handleFileChange ({ id, markdown, cursor }) {
+      this.prepareTabSwitch()
+
+      const { editor } = this
+      if (typeof markdown === 'string') {
+        editor.setValue(markdown)
+      }
+      // Cursor is null when loading a file or creating a new tab in source code mode.
+      if (cursor) {
+        const { anchor, focus } = cursor
+        editor.setSelection(anchor, focus, { scroll: true }) // Scroll the focus into view.
+      } else {
+        setCursorAtLastLine(editor)
+      }
+      this.tabId = id
+    },
+    // Get markdown and cursor from CodeMirror.
+    getMarkdownAndCursor (cm) {
+      let focus = cm.getCursor('head')
+      let anchor = cm.getCursor('anchor')
+      const markdown = cm.getValue()
+      const convertToMuyaCursor = cursor => {
+        const line = cm.getLine(cursor.line)
+        const preLine = cm.getLine(cursor.line - 1)
+        const nextLine = cm.getLine(cursor.line + 1)
+        return adjustCursor(cursor, preLine, line, nextLine)
+      }
+
+      anchor = convertToMuyaCursor(anchor) // Selection start as Muya cursor
+      focus = convertToMuyaCursor(focus) // Selection end as Muya cursor
+
+      // Normalize cursor that `anchor` is always before `focus` because
+      // this is the expected behavior in Muya.
+      if (anchor && focus && anchor.line > focus.line) {
+        const tmpCursor = focus
+        focus = anchor
+        anchor = tmpCursor
+      }
+      return { cursor: { focus, anchor }, markdown }
+    },
+    // Commit changes from old tab. Problem: tab was already switched, so commit changes with old tab id.
+    prepareTabSwitch () {
+
+      let firstViewportVisibleItem = "S" + this.getFirstLineNumberInViewport();
+      if (this.sourceCode == false)//this shouldn't happen
+        firstViewportVisibleItem = undefined;       
+
+      if (this.commitTimer) clearTimeout(this.commitTimer)
+      if (this.tabId) {
+        const { editor } = this
+        const { cursor, markdown } = this.getMarkdownAndCursor(editor)
+        this.$store.dispatch('LISTEN_FOR_CONTENT_CHANGE', { id: this.tabId, markdown, cursor, firstViewportVisibleItem })
+        this.tabId = null // invalidate tab id
+      }
+    },
+<<<<<<< HEAD
+    scrollToLineNumberInViewport(line, duration=300, dontAddStandardHeadroom=false){
+      let pos = this.editor.charCoords({line:line,ch:0},"local").top;
+      const DURATION = duration;
+      if (! dontAddStandardHeadroom)
+        pos -= STANDAR_Y;
+      animatedScrollTo(this.$el, pos, DURATION)
+    },
+    getFirstLineNumberInViewport(){
+      return this.editor.coordsChar({left:0,top:this.$el.scrollTop},"local").line;
+    },
+=======
+    handleUndo () {
+      if (this.editor && this.sourceCode) {
+        this.editor.execCommand('undo')
+      }
+    },
+
+    handleRedo () {
+      if (this.editor && this.sourceCode) {
+        this.editor.execCommand('redo')
+      }
+    },
+    docKeyup (event) {
+      if (this.editor && this.sourceCode && event.key === 'Escape') {
+        this.editor.execCommand('clearSearch')
+      }
+    },
+
+    docClick () {
+      if (this.editor && this.sourceCode)
+      this.editor.execCommand('clearSearch')
+    },
+    handleFind () {
+       if (this.editor && this.sourceCode) {
+        this.editor.execCommand('findPersistent')
+      }
+    },
+
+    handleReplace () {
+       if (this.editor && this.sourceCode) {
+        this.editor.execCommand('replace')
+      }
+    },
+
+    handleFindNext () {
+      if (this.editor && this.sourceCode) {
+        this.editor.execCommand('findNext')
+      }
+    },
+
+    handleFindPrev () {
+      if (this.editor && this.sourceCode) {
+        this.editor.execCommand('findPrev')
+      }
+    },
+
+>>>>>>> sourcecode_editor_find_undo_redo_fixes
+    handleSelectAll () {
+      if (!this.sourceCode) {
+        return
+      }
+
+      const { editor } = this
+      if (editor && editor.hasFocus()) {
+        this.editor.execCommand('selectAll')
+      } else {
+        const activeElement = document.activeElement
+        const nodeName = activeElement.nodeName
+        if (nodeName === 'INPUT' || nodeName === 'TEXTAREA') {
+          activeElement.select()
+        }
+      }
+    },
+
+    handleInvalidateImageCache () {
+      if (this.editor) {
+        this.editor.invalidateImageCache()
+      }
+    }
+  }
+}
+</script>
+
+<style>
+  .source-code {
+    height: calc(100vh - var(--titleBarHeight));
+    box-sizing: border-box;
+    overflow: auto;
+  }
+  .source-code .CodeMirror {
+    height: auto;
+    margin: 50px auto;
+    max-width: var(--editorAreaWidth);
+    background: transparent;
+  }
+  .source-code .CodeMirror-gutters {
+    border-right: none;
+    background-color: transparent;
+  }
+  .source-code .CodeMirror-activeline-background,
+  .source-code .CodeMirror-activeline-gutter {
+    background: var(--floatHoverColor);
+  }
+</style>
diff --git a/src/renderer/store/editor.js b/src/renderer/store/editor.js
index 3b1c3ee6..cd3db027 100644
--- a/src/renderer/store/editor.js
+++ b/src/renderer/store/editor.js
@@ -247,6 +247,11 @@ const mutations = {
       state.currentFile.history = history
     }
   },
+  SET_FIRST_VIS_ITEM (state, firstViewportVisibleItem) {
+    if (hasKeys(state.currentFile)) {
+      state.currentFile.firstViewportVisibleItem = firstViewportVisibleItem
+    }
+  },
   CLOSE_TABS (state, tabIdList) {
     if (!tabIdList || tabIdList.length === 0) return
 
@@ -896,7 +901,7 @@ const actions = {
 
   // Content change from realtime preview editor and source code editor
   // WORKAROUND: id is "muya" if changes come from muya and not source code editor! So we don't have to apply the workaround.
-  LISTEN_FOR_CONTENT_CHANGE ({ commit, dispatch, state, rootState }, { id, markdown, wordCount, cursor, history, toc }) {
+  LISTEN_FOR_CONTENT_CHANGE ({ commit, dispatch, state, rootState }, { id, markdown, wordCount, cursor, history, toc, firstViewportVisibleItem }) {
     const { autoSave } = rootState.preferences
     const {
       id: currentId,
@@ -926,6 +931,10 @@ const actions = {
           if (history) {
             tab.history = history
           }
+          // Set Line or First Visible Item Index
+          if (firstViewportVisibleItem) {
+            tab.firstViewportVisibleItem = firstViewportVisibleItem
+          }
           break
         }
       }
@@ -952,6 +961,9 @@ const actions = {
     if (history) {
       commit('SET_HISTORY', history)
     }
+    if (firstViewportVisibleItem) {
+      commit('SET_FIRST_VIS_ITEM', firstViewportVisibleItem)
+    }
     // Set toc
     if (toc && !equal(toc, listToc)) {
       commit('SET_TOC', toc)