Editor: Performance improvement

src/components/Widgets/MarkdownControl.js

@@ -1,4 +1,5 @@
 import React, { PropTypes } from 'react';
+import _ from 'lodash';
 import { Editor, Plain } from 'slate';
 import position from 'selection-position';
 import Markdown from 'slate-markdown-serializer';
@@ -41,7 +42,8 @@ class MarkdownControl extends React.Component {
     this.handleInlineClick = this.handleInlineClick.bind(this);
     this.handleBlockTypeClick = this.handleBlockTypeClick.bind(this);
     this.handleKeyDown = this.handleKeyDown.bind(this);
-    this.calculateMenuPositions = this.calculateMenuPositions.bind(this);
+    this.calculateHoverMenuPosition = _.throttle(this.calculateHoverMenuPosition.bind(this), 100);
+    this.calculateBlockMenuPosition = _.throttle(this.calculateBlockMenuPosition.bind(this), 100);
     this.renderBlockTypesMenu = this.renderBlockTypesMenu.bind(this);
     this.renderNode = this.renderNode.bind(this);
     this.renderMark = this.renderMark.bind(this);
@@ -57,7 +59,8 @@ class MarkdownControl extends React.Component {
     if (this.blockEdit) {
       this.blockEdit = false;
     } else {
-      this.setState({ state }, this.calculateMenuPositions);
+      this.calculateHoverMenuPosition();
+      this.setState({ state }, this.calculateBlockMenuPosition);
     }
   }
 
@@ -65,29 +68,30 @@ class MarkdownControl extends React.Component {
     this.props.onChange(markdown.serialize(state));
   }
 
-  /**
-   * All menu positions are calculated accessing dom elements
-   * That's why calculateMenuPositions is called on handleChange's setState callback
-   */
-  calculateMenuPositions() {
-    const rect1 = position();
+  calculateHoverMenuPosition() {
+    const rect = position();
     this.menuPositions.stylesMenu = {
-      top: rect1.top + window.scrollY,
-      left: rect1.left + window.scrollX,
-      width: rect1.width,
-      height: rect1.height
+      top: rect.top + window.scrollY,
+      left: rect.left + window.scrollX,
+      width: rect.width,
+      height: rect.height
     };
+  }
 
-    const blockElement = document.querySelectorAll(`[data-key='${this.state.state.selection.focusKey}']`);
-    if (blockElement.length > 0) {
-      const rect2 = blockElement[0].getBoundingClientRect();
-      this.menuPositions.blockTypesMenu = {
-        top: rect2.top + window.scrollY,
-        left: rect2.left + window.scrollX
-      };
-      this.forceUpdate();
+  calculateBlockMenuPosition() {
+    // Don't bother calculating position if block is not empty
+    if (this.state.state.blocks.get(0).isEmpty) {
+      const blockElement = document.querySelectorAll(`[data-key='${this.state.state.selection.focusKey}']`);
+      if (blockElement.length > 0) {
+        const rect = blockElement[0].getBoundingClientRect();
+        this.menuPositions.blockTypesMenu = {
+          top: rect.top + window.scrollY,
+          left: rect.left + window.scrollX
+        };
+        // Force re-render so the menu is positioned on these new coordinates
+        this.forceUpdate();
+      }
     }
-
   }
 
   /**
@@ -191,7 +195,10 @@ class MarkdownControl extends React.Component {
 
     state = state
     .transform()
-    .insertBlock(type)
+    .insertBlock({
+      type: type,
+      isVoid: true
+    })
     .apply();
 
     this.setState({ state }, () => {
@@ -235,7 +242,7 @@ class MarkdownControl extends React.Component {
 
   renderBlockTypesMenu() {
     const currentBlock = this.state.state.blocks.get(0);
-    const isOpen = (currentBlock.isEmpty && currentBlock.type !== 'list-item' && currentBlock.type !== 'horizontal-rule');
+    const isOpen = (currentBlock.isEmpty && currentBlock.type !== 'horizontal-rule');
 
     return (
       <BlockTypesMenu

src/components/Widgets/MarkdownControlElements/BlockStatic.css

@@ -1,14 +0,0 @@
-.divider {
-
-}
-
-.divider:before {
-    font-family: Georgia,Cambria,"Times New Roman",Times,serif;
-    font-size: 28px;
-    letter-spacing: .6em;
-    content: '...';
-    color: rgba(0,0,0,.6);
-    position: relative;
-    top: -12px;
-    margin-left: calc(50% - 60px);
-}

src/components/Widgets/MarkdownControlElements/BlockStatic.js

@@ -1,19 +0,0 @@
-import React, { PropTypes } from 'react';
-import styles from './BlockStatic.css';
-
-const AVAILABLE_TYPES = [
-  'divider'
-];
-
-export function BlockStatic({ type, children }) {
-  return (
-    <div className={`${styles[type]}`} contentEditable={false}>{children}</div>
-  );
-}
-
-BlockStatic.propTypes = {
-  children: PropTypes.node.isRequired,
-  type: PropTypes.oneOf(AVAILABLE_TYPES).isRequired
-};
-
-export default BlockStatic;

src/components/Widgets/MarkdownControlElements/localRenderers.css

@@ -0,0 +1,3 @@
+.active  {
+  box-shadow: 0 0 0 2px blue;
+}

src/components/Widgets/MarkdownControlElements/localRenderers.js

@@ -1,6 +1,6 @@
 import React from 'react';
 import Block from './Block';
-import BlockStatic from './BlockStatic';
+import styles from './localRenderers.css'
 
 /* eslint react/prop-types: 0, react/no-multi-comp: 0 */
 
@@ -19,7 +19,14 @@ export const NODES = {
   'heading6': props => <Block type='Heading2' {...props.attributes}>{props.children}</Block>,
   'list-item': props => <li {...props.attributes}>{props.children}</li>,
   'paragraph': props => <Block type='Paragraph' {...props.attributes}>{props.children}</Block>,
-  'horizontal-rule': props => <BlockStatic type='divider' {...props.attributes}>{props.children}</BlockStatic>,
+  'horizontal-rule': props => {
+    const { node, state } = props;
+    const isFocused = state.selection.hasEdgeIn(node);
+    const className = isFocused ? styles.active : null;
+    return (
+      <hr className={className} {...props.attributes} />
+    );
+  },
   'link': (props) => {
     const { data } = props.node;
     const href = data.get('href');