Add automath and fix preview and display button

README.md

@@ -23,8 +23,7 @@ Add it to builtinPlugins
 ```js
 InlineEditor.builtinPlugins = [
 	// ...
-	Mathematics,
-	// ...
+	Mathematics
 ];
 ```
 
@@ -35,8 +34,7 @@ InlineEditor.defaultConfig = {
 	toolbar: {
 		items: [
 			// ...
-			'math',
-			// ...
+			'math'
 		]
 	},
 	// ...
@@ -44,14 +42,56 @@ InlineEditor.defaultConfig = {
 		engine: 'mathjax',
 		outputType: 'script',
 		forceOutputType: false
-	},
-	// ...
+	}
 };
 ```
 ### Copying plugin's theme for Lark
 Copy __theme/ckeditor5-math__ folder from [https://github.com/isaul32/ckeditor5-theme-lark](https://github.com/isaul32/ckeditor5-theme-lark) to your lark theme repository fork.
 
-## Supported input and output formats
+### Styles
+Styles requires PostCSS like offical CKEditor plugins.
+
+## Configuration & Usage
+
+### Available typesetting engines
+__MathJax__
+- Tested by using version __2.7.5__ and __TeX-MML-AM_HTMLorMML__ configuration. It works also with version __3.0.0__ or newer!
+- Use __\\( \\)__ delimiters for inline and __\\[ \\]__ delimiters for display
+
+__KaTeX__
+- Tested by using version __0.11.0__
+- Doesn't support preview feature because __.ck-reset_all *__ css rules from ckeditor5-ui and ckeditor5-theme-lark breaks it.
+
+__Custom__
+It's possible to implement with engine config. For example, this feature can be used when use back end rendering.
+```js
+InlineEditor.defaultConfig = {
+	// ...
+	math: {
+		engine: (equation, element, display) => {
+			// ...
+		}
+	}
+}
+```
+- __equation__ is equation in TeX format without delimiters
+- __element__ is DOM element reserved for rendering
+- __display__ is boolean. Typesetting should be inline when false
+
+
+### Plugin options
+```js
+InlineEditor.defaultConfig = {
+    // ...
+    math: {
+        engine: 'mathjax', // or katex or function (equation, element, display) => { ... }
+        outputType: 'script', // or span or math
+        forceOutputType: false // forces output to use outputType
+    }
+}
+```
+
+### Supported input and output formats
 Supported input and output formats are:
 ```html
 <!-- MathJax style http://docs.mathjax.org/en/v2.7-latest/advanced/model.html#how-mathematics-is-stored-in-the-page -->
@@ -63,38 +103,13 @@ Supported input and output formats are:
 <span class="math-tex">\[ \sqrt{\frac{a}{b}} \]</span>
 ```
 
-## Available typesetting engines
-### MathJax
-- Tested by using version __2.7.5__ and __TeX-MML-AM_HTMLorMML__ configuration. It works also with version __3.0.0__ or newer!
-- Use __\\( \\)__ delimiters for inline and __\\[ \\]__ delimiters for display
-### KaTeX
-- Tested by using version __0.11.0__
-- Doesn't support preview feature because __.ck-reset_all *__ css rules from ckeditor5-ui and ckeditor5-theme-lark breaks it.
-### Custom
-It's possible to implement with _engine: (__equation__, __element__, __display__) => { ... }_ math config.
-- __equation__ is equation in TeX format without delimiters
-- __element__ is DOM element reserved for rendering
-- __display__ is boolean. Typesetting should be inline when false
-
-
-## Plugin options
-```js
-InlineEditor.defaultConfig = {
-    // ...
-    math: {
-        engine: 'mathjax', // or katex or function (equation, element, display) => { ... }
-        outputType: 'script', // or span or math
-        forceOutputType: false // forces output to use outputType
-    }
-    // ...
-}
-```
-## Styles
-- Styles requires PostCSS like offical CKEditor plugins
+### Math paste support
+It's possible to paste equations in mathtex by using __delimiters__. For example:
+- __\\(__ x=\frac{-b\pm\sqrt{b^2-4ac}}{2a} __\\)__ (inline mode)
+- __\\[__ x=\frac{-b\pm\sqrt{b^2-4ac}}{2a} __\\]__ (display mode)
 
 ## Todo
-- AutoMath like AutoMediaEmbed
-- Convert equation to mathtex when paste from word
+- Convert equations to mathtex when paste document from word
 - Fix KaTex preview
 - Make better way to import lark theme for plugin
 - MathML input and output when using MathJax version 3

src/automath.js

@@ -0,0 +1,125 @@
+import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
+import Clipboard from '@ckeditor/ckeditor5-clipboard/src/clipboard';
+import Undo from '@ckeditor/ckeditor5-undo/src/undo';
+import LiveRange from '@ckeditor/ckeditor5-engine/src/model/liverange';
+import LivePosition from '@ckeditor/ckeditor5-engine/src/model/liveposition';
+
+import { defaultConfig, removeDelimiters, EQUATION_REGEXP } from './utils';
+
+export default class AutoMath extends Plugin {
+	static get requires() {
+		return [ Clipboard, Undo ];
+	}
+
+	static get pluginName() {
+		return 'AutoMath';
+	}
+
+	constructor( editor ) {
+		super( editor );
+
+		this._timeoutId = null;
+
+		this._positionToInsert = null;
+	}
+
+	init() {
+		const editor = this.editor;
+		const modelDocument = editor.model.document;
+
+		this.listenTo( editor.plugins.get( Clipboard ), 'inputTransformation', () => {
+			const firstRange = modelDocument.selection.getFirstRange();
+
+			const leftLivePosition = LivePosition.fromPosition( firstRange.start );
+			leftLivePosition.stickiness = 'toPrevious';
+
+			const rightLivePosition = LivePosition.fromPosition( firstRange.end );
+			rightLivePosition.stickiness = 'toNext';
+
+			modelDocument.once( 'change:data', () => {
+				this._mathBetweenPositions( leftLivePosition, rightLivePosition );
+
+				leftLivePosition.detach();
+				rightLivePosition.detach();
+			}, { priority: 'high' } );
+		} );
+
+		editor.commands.get( 'undo' ).on( 'execute', () => {
+			if ( this._timeoutId ) {
+				global.window.clearTimeout( this._timeoutId ); // eslint-disable-line
+				this._positionToInsert.detach();
+
+				this._timeoutId = null;
+				this._positionToInsert = null;
+			}
+		}, { priority: 'high' } );
+	}
+
+	_mathBetweenPositions( leftPosition, rightPosition ) {
+		const editor = this.editor;
+
+		const mathConfig = {
+			...defaultConfig,
+			...this.editor.config.get( 'math' )
+		};
+
+		const equationRange = new LiveRange( leftPosition, rightPosition );
+		const walker = equationRange.getWalker( { ignoreElementEnd: true } );
+
+		let equation = '';
+
+		// Get equation text
+		for ( const node of walker ) {
+			if ( node.item.is( 'textProxy' ) ) {
+				equation += node.item.data;
+			}
+		}
+
+		equation = equation.trim();
+
+		// Check if equation
+		if ( !equation.match( EQUATION_REGEXP ) ) {
+			return;
+		}
+
+		const mathCommand = editor.commands.get( 'math' );
+
+		// Do not anything if math element cannot be inserted at the current position
+		if ( !mathCommand.isEnabled ) {
+			return;
+		}
+
+		this._positionToInsert = LivePosition.fromPosition( leftPosition );
+
+		// With timeout user can undo conversation if want use plain text
+		this._timeoutId = global.window.setTimeout( () => { // eslint-disable-line
+			editor.model.change( writer => {
+				this._timeoutId = null;
+
+				writer.remove( equationRange );
+
+				let insertPosition;
+
+				// Check if position where the math element should be inserted is still valid.
+				if ( this._positionToInsert.root.rootName !== '$graveyard' ) {
+					insertPosition = this._positionToInsert;
+				}
+
+				editor.model.change( writer => {
+					const params = {
+						...removeDelimiters( equation ),
+						type: mathConfig.outputType,
+					};
+					const mathElement = writer.createElement( 'mathtex', params );
+
+					editor.model.insertContent( mathElement, insertPosition );
+
+					writer.setSelection( mathElement, 'on' );
+				} );
+
+				this._positionToInsert.detach();
+				this._positionToInsert = null;
+			} );
+		}, 100 );
+	}
+}

src/math.js

@@ -3,10 +3,11 @@ import Widget from '@ckeditor/ckeditor5-widget/src/widget';
 
 import MathUI from './mathui';
 import MathEditing from './mathediting';
+import AutoMath from './automath';
 
 export default class Math extends Plugin {
 	static get requires() {
-		return [ MathEditing, MathUI, Widget ];
+		return [ MathEditing, MathUI, Widget, AutoMath ];
 	}
 
 	static get pluginName() {

src/mathediting.js

@@ -5,7 +5,7 @@ import Widget from '@ckeditor/ckeditor5-widget/src/widget';
 
 import MathCommand from './mathcommand';
 
-import { defaultConfig, renderEquation } from './utils';
+import { defaultConfig, renderEquation, removeDelimiters } from './utils';
 
 export default class MathEditing extends Plugin {
 	static get requires() {
@@ -105,20 +105,14 @@ export default class MathEditing extends Plugin {
 					classes: [ 'math-tex' ]
 				},
 				model: ( viewElement, modelWriter ) => {
-					let equation = viewElement.getChild( 0 ).data.trim();
+					const equation = viewElement.getChild( 0 ).data.trim();
 
-					// Remove delimiters (e.g. \( \) or \[ \])
-					const hasInlineDelimiters = equation.includes( '\\(' ) && equation.includes( '\\)' );
-					const hasDisplayDelimiters = equation.includes( '\\[' ) && equation.includes( '\\]' );
-					if ( hasInlineDelimiters || hasDisplayDelimiters ) {
-						equation = equation.substring( 2, equation.length - 2 ).trim();
-					}
+					const params = {
+						...removeDelimiters( equation ),
+						type: mathConfig.forceOutputType ? mathConfig.outputType : 'span'
+					};
 
-					return modelWriter.createElement( 'mathtex', {
-						equation,
-						type: mathConfig.forceOutputType ? mathConfig.outputType : 'span',
-						display: hasDisplayDelimiters
-					} );
+					return modelWriter.createElement( 'mathtex', params );
 				}
 			} );
 

src/mathui.js

@@ -67,7 +67,7 @@ export default class MathUI extends Plugin {
 		const formView = new MainFormView( editor.locale, mathConfig.engine );
 
 		formView.mathInputView.bind( 'value' ).to( mathCommand, 'value' );
-		formView.displayButtonView.bind( 'displayIsOn' ).to( mathCommand, 'display' );
+		formView.displayButtonView.bind( 'isOn' ).to( mathCommand, 'display' );
 
 		// Listen to submit button click
 		this.listenTo( formView, 'submit', () => {

src/ui/mainformview.js

@@ -15,6 +15,8 @@ import cancelIcon from '@ckeditor/ckeditor5-core/theme/icons/cancel.svg';
 
 import submitHandler from '@ckeditor/ckeditor5-ui/src/bindings/submithandler';
 
+import { removeDelimiters, EQUATION_REGEXP } from '../utils';
+
 import MathView from './mathview';
 
 import '../../theme/mathform.css';
@@ -53,6 +55,7 @@ export default class MainFormView extends View {
 
 			// Math element
 			this.mathView = new MathView( engine, locale );
+			this.mathView.bind( 'display' ).to( this.displayButtonView, 'isOn' );
 
 			children = [
 				this.mathInputView,
@@ -160,7 +163,25 @@ export default class MainFormView extends View {
 		mathInput.infoText = t( 'Insert equation in TeX format.' );
 		inputView.on( 'input', () => {
 			if ( this.previewEnabled ) {
-				this.mathView.value = inputView.element.value;
+				const equationInput = inputView.element.value.trim();
+
+				// If input has delimiters
+				if ( equationInput.match( EQUATION_REGEXP ) ) {
+					// Get equation without delimiters
+					const params = removeDelimiters( equationInput );
+
+					// Remove delimiters from input field
+					inputView.element.value = params.equation;
+
+					// update display button and preview
+					this.displayButtonView.isOn = params.display;
+					if ( this.previewEnabled ) {
+						// Update preview view
+						this.mathView.value = params.equation;
+					}
+				} else {
+					this.mathView.value = equationInput;
+				}
 			}
 		} );
 
@@ -205,15 +226,13 @@ export default class MainFormView extends View {
 			}
 		} );
 
-		switchButton.bind( 'isOn' ).to( this, 'displayIsOn' );
-
 		switchButton.on( 'execute', () => {
 			// Toggle state
-			this.set( 'displayIsOn', !this.displayIsOn );
+			switchButton.isOn = !switchButton.isOn;
 
 			if ( this.previewEnabled ) {
 				// Update preview view
-				this.mathView.display = this.displayIsOn;
+				this.mathView.display = switchButton.isOn;
 			}
 		} );
 

src/utils.js

@@ -1,4 +1,15 @@
+export const EQUATION_REGEXP = /^\\(\[|\().*?\\(\]|\))$/;
+
+export const defaultConfig = {
+	engine: 'mathjax',
+	outputType: 'script',
+	forceOutputType: false
+};
+
 export function renderEquation( equation, element, engine = 'katex', display = false ) {
+	if ( !element ) {
+		return;
+	}
 	/* eslint-disable */
 	if ( engine === 'mathjax' && typeof MathJax !== 'undefined' ) {
 		const version = MathJax.version;
@@ -22,7 +33,10 @@ export function renderEquation( equation, element, engine = 'katex', display = f
 			} else {
 				element.innerHTML = '\\(' + equation + '\\)';
 			}
+			// Fixme: MathJax render occasionally math processing error without timeout
+			setTimeout( () => {
 				MathJax.Hub.Queue( [ 'Typeset', MathJax.Hub, element ] );
+			}, 100);
 		}
 	} else if ( engine === 'katex' && typeof katex !== 'undefined' ) {
         katex.render( equation, element, {
@@ -38,6 +52,7 @@ export function renderEquation( equation, element, engine = 'katex', display = f
 	/* eslint-enable */
 }
 
+// Simple MathJax 3 version check
 export function isMathJaxVersion3( version ) {
 	return version && typeof version === 'string' && version.split( '.' ).length === 3 && version.split( '.' )[ 0 ] === '3';
 }
@@ -52,8 +67,19 @@ export function getSelectedMathModelWidget( selection ) {
 	return null;
 }
 
-export const defaultConfig = {
-	engine: 'mathjax',
-	outputType: 'script',
-	forceOutputType: false
-};
+// Remove delimiters and figure display mode for the model
+export function removeDelimiters( equation ) {
+	equation = equation.trim();
+
+	// Remove delimiters (e.g. \( \) or \[ \])
+	const hasInlineDelimiters = equation.includes( '\\(' ) && equation.includes( '\\)' );
+	const hasDisplayDelimiters = equation.includes( '\\[' ) && equation.includes( '\\]' );
+	if ( hasInlineDelimiters || hasDisplayDelimiters ) {
+		equation = equation.substring( 2, equation.length - 2 ).trim();
+	}
+
+	return {
+		equation,
+		display: hasDisplayDelimiters
+	};
+}