Add CodeEditor::setLineContent method to manipulate line contents, related #3163

Avoid changing all CodeMirror instance's contents

Author: hikerpig

browser/components/CodeEditor.js

@@ -836,6 +836,17 @@ export default class CodeEditor extends React.Component {
     this.editor.setCursor(cursor)
   }
 
+  /**
+   * Update content of one line
+   * @param {Number} lineNumber
+   * @param {String} content
+   */
+  setLineContent (lineNumber, content) {
+    const prevContent = this.editor.getLine(lineNumber)
+    const prevContentLength = prevContent ? prevContent.length : 0
+    this.editor.replaceRange(content, { line: lineNumber, ch: 0 }, { line: lineNumber, ch: prevContentLength })
+  }
+
   handleDropImage (dropEvent) {
     dropEvent.preventDefault()
     const {

browser/components/MarkdownEditor.js

@@ -169,14 +169,15 @@ class MarkdownEditor extends React.Component {
         .split('\n')
 
       const targetLine = lines[lineIndex]
+      let newLine = targetLine
 
       if (targetLine.match(checkedMatch)) {
-        lines[lineIndex] = targetLine.replace(checkReplace, '[ ]')
+        newLine = targetLine.replace(checkReplace, '[ ]')
       }
       if (targetLine.match(uncheckedMatch)) {
-        lines[lineIndex] = targetLine.replace(uncheckReplace, '[x]')
+        newLine = targetLine.replace(uncheckReplace, '[x]')
       }
-      this.refs.code.setValue(lines.join('\n'))
+      this.refs.code.setLineContent(lineIndex, newLine)
     }
   }
 

browser/components/MarkdownSplitEditor.js

@@ -88,14 +88,15 @@ class MarkdownSplitEditor extends React.Component {
         .split('\n')
 
       const targetLine = lines[lineIndex]
+      let newLine = targetLine
 
       if (targetLine.match(checkedMatch)) {
-        lines[lineIndex] = targetLine.replace(checkReplace, '[ ]')
+        newLine = targetLine.replace(checkReplace, '[ ]')
       }
       if (targetLine.match(uncheckedMatch)) {
-        lines[lineIndex] = targetLine.replace(uncheckReplace, '[x]')
+        newLine = targetLine.replace(uncheckReplace, '[x]')
       }
-      this.refs.code.setValue(lines.join('\n'))
+      this.refs.code.setLineContent(lineIndex, newLine)
     }
   }