From 3354872837fb9b0431c371a5b9ef9eaec963b7f6 Mon Sep 17 00:00:00 2001
From: Sauli Anto <sauli.anto@gmail.com>
Date: Sat, 7 Nov 2020 22:19:00 +0200
Subject: [PATCH] Add autoformat support

---
 README.md             | 22 ++++++++++++++++++++++
 src/autoformatmath.js | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)
 create mode 100644 src/autoformatmath.js

diff --git a/README.md b/README.md
index ca87acd5f..9e6cafc7a 100644
--- a/README.md
+++ b/README.md
@@ -16,6 +16,7 @@ This is TeX-based mathematical plugin for CKEditor 5. You can use it to insert,
 	* [Supported input and output formats](#supported-input-and-output-formats)
 - [Paste support](#paste-support)
 	* [From plain text](#from-plain-text)
+- [Autoformat support](#autoformat-support)
 - [Preview workaround](#preview-workaround)
 
 ## Features
@@ -26,6 +27,7 @@ This is TeX-based mathematical plugin for CKEditor 5. You can use it to insert,
 - Have multiple input and output format
 - Paste support
 	- from plain text
+- Autoformat support
 
 # Demos
 - [Classic editor with MathJax](https://jsfiddle.net/isaul32/qktj9h7x/)
@@ -155,6 +157,26 @@ or
 
 __\\(__ x=\frac{-b\pm\sqrt{b^2-4ac}}{2a} __\\)__
 
+### Autoformat support
+
+#### Inline mode
+Ctrl+M can be used to add easily math formulas in inline mode.
+
+#### Display mode
+Autoformat for math can be used to add formula in display mode on a new line by adding `\[` or `$$`. This feature requires additional autoformat plugin to be added.
+
+Add following lines into your build
+
+```js
+// ...
+import AutoformatMathematics from 'ckeditor5-math/src/autoformatmath';
+
+InlineEditor.builtinPlugins = [
+	// ...
+	AutoformatMathematics
+];
+```
+
 ## Preview workaround
 __.ck-reset_all *__ css rules from ckeditor5-ui and ckeditor5-theme-lark break rendering in preview mode.
 
diff --git a/src/autoformatmath.js b/src/autoformatmath.js
new file mode 100644
index 000000000..0220ec53a
--- /dev/null
+++ b/src/autoformatmath.js
@@ -0,0 +1,38 @@
+import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
+import Autoformat from '@ckeditor/ckeditor5-autoformat/src/autoformat';
+import blockAutoformatEditing from '@ckeditor/ckeditor5-autoformat/src/blockautoformatediting';
+
+import Math from './math';
+
+export default class AutoformatMath extends Plugin {
+	static get requires() {
+		return [ Math, Autoformat ];
+	}
+
+	afterInit() {
+		const editor = this.editor;
+		const command = editor.commands.get( 'math' );
+
+		if ( command ) {
+			const mathBlockCallback = getCallbackFunctionForBlockAutoformat( editor, command );
+
+			blockAutoformatEditing( editor, this, /^\\\[$/, mathBlockCallback );
+			blockAutoformatEditing( editor, this, /^\$\$$/, mathBlockCallback );
+		}
+	}
+
+	static get pluginName() {
+		return 'AutoformatMath';
+	}
+}
+
+function getCallbackFunctionForBlockAutoformat( editor, command ) {
+	return () => {
+		if ( !command.isEnabled ) {
+			return false;
+		}
+
+		command.display = true;
+		editor.plugins.get( 'MathUI' )._showUI();
+	}
+}