From fdb0c869fd5bbf6082b7a6e7d46108c0604f3852 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Thu, 6 Jun 2019 17:05:02 +0200
Subject: [PATCH 01/30] Multi command proof of concept.

---
 src/multicommand.js     | 46 +++++++++++++++++++++++++++++++++++++++++
 tests/manual/article.js | 18 +++++++++++++++-
 2 files changed, 63 insertions(+), 1 deletion(-)
 create mode 100644 src/multicommand.js

diff --git a/src/multicommand.js b/src/multicommand.js
new file mode 100644
index 00000000..793ae41d
--- /dev/null
+++ b/src/multicommand.js
@@ -0,0 +1,46 @@
+/**
+ * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+import Command from './command';
+import Collection from '@ckeditor/ckeditor5-utils/src/collection';
+
+/**
+ * @module core/multicommand
+ */
+
+export default class MultiCommand extends Command {
+	constructor( editor ) {
+		super( editor );
+
+		this._childCommands = new Collection();
+	}
+
+	refresh() {
+		// The command listens to child commands rather then acts on refresh.
+		// TODO: check with track changes.
+	}
+
+	execute() {
+		const { command } = this._getEnabled();
+
+		command.execute();
+	}
+
+	registerChildCommand( command ) {
+		this._childCommands.add( { command } );
+
+		command.on( 'change:isEnabled', () => this._checkEnabled() );
+
+		this._checkEnabled();
+	}
+
+	_checkEnabled() {
+		this.isEnabled = !!this._getEnabled();
+	}
+
+	_getEnabled() {
+		return this._childCommands.find( ( { command } ) => command.isEnabled );
+	}
+}
diff --git a/tests/manual/article.js b/tests/manual/article.js
index fc23773d..e19d818e 100644
--- a/tests/manual/article.js
+++ b/tests/manual/article.js
@@ -8,10 +8,26 @@
 import ClassicEditor from '@ckeditor/ckeditor5-editor-classic/src/classiceditor';
 
 import ArticlePluginSet from '../_utils/articlepluginset';
+import MultiCommand from '../../src/multicommand';
+import Plugin from '../../src/plugin';
+
+class IndentOutdent extends Plugin {
+	afterInit() {
+		const editor = this.editor;
+
+		const indentCommand = new MultiCommand( editor );
+		indentCommand.registerChildCommand( editor.commands.get( 'indentList' ) );
+		editor.commands.add( 'indent', indentCommand );
+
+		const outdentCommand = new MultiCommand( editor );
+		outdentCommand.registerChildCommand( editor.commands.get( 'outdentList' ) );
+		editor.commands.add( 'outdent', outdentCommand );
+	}
+}
 
 ClassicEditor
 	.create( document.querySelector( '#editor' ), {
-		plugins: [ ArticlePluginSet ],
+		plugins: [ ArticlePluginSet, IndentOutdent ],
 		toolbar: [
 			'heading',
 			'|',

From 5f6039ef03e17525bd862f30f00b4aa3f38e779b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Thu, 6 Jun 2019 17:17:23 +0200
Subject: [PATCH 02/30] Add indent/outdent buttons stubs.

---
 tests/manual/article.js | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/tests/manual/article.js b/tests/manual/article.js
index e19d818e..5bc44f9e 100644
--- a/tests/manual/article.js
+++ b/tests/manual/article.js
@@ -10,8 +10,39 @@ import ClassicEditor from '@ckeditor/ckeditor5-editor-classic/src/classiceditor'
 import ArticlePluginSet from '../_utils/articlepluginset';
 import MultiCommand from '../../src/multicommand';
 import Plugin from '../../src/plugin';
+import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
 
 class IndentOutdent extends Plugin {
+	init() {
+		const editor = this.editor;
+		const t = editor.t;
+
+		this._createButton( 'indent', t( 'Indent' ) );
+		this._createButton( 'outdent', t( 'Outdent' ) );
+	}
+
+	_createButton( commandName, label ) {
+		const editor = this.editor;
+
+		editor.ui.componentFactory.add( commandName, locale => {
+			const command = editor.commands.get( commandName );
+			const view = new ButtonView( locale );
+
+			view.set( {
+				label,
+				withText: true,
+				tooltip: true
+			} );
+
+			view.bind( 'isOn', 'isEnabled' ).to( command, 'value', 'isEnabled' );
+
+			// Execute command.
+			this.listenTo( view, 'execute', () => editor.execute( commandName ) );
+
+			return view;
+		} );
+	}
+
 	afterInit() {
 		const editor = this.editor;
 
@@ -34,8 +65,13 @@ ClassicEditor
 			'bold',
 			'italic',
 			'link',
+			'|',
+			'indent',
+			'outdent',
+			'|',
 			'bulletedList',
 			'numberedList',
+			'|',
 			'blockQuote',
 			'insertTable',
 			'mediaEmbed',

From c7a9f7b5adf4cd4cb37c9c10d09da352dc783596 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Thu, 6 Jun 2019 17:32:38 +0200
Subject: [PATCH 03/30] Stub indent conversion.

---
 tests/manual/article.html |  2 +-
 tests/manual/article.js   | 38 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/tests/manual/article.html b/tests/manual/article.html
index 4faffd0a..1b8e2bfa 100644
--- a/tests/manual/article.html
+++ b/tests/manual/article.html
@@ -8,7 +8,7 @@
 </head>
 <div id="editor">
 	<h2>Heading 1</h2>
-	<p>Paragraph</p>
+	<p style="margin-left:2em;">Paragraph</p>
 	<p><strong>Bold</strong> <i>Italic</i> <a href="https://ckeditor.com">Link</a></p>
 	<ul>
 		<li>UL List item 1</li>
diff --git a/tests/manual/article.js b/tests/manual/article.js
index 5bc44f9e..8b15c682 100644
--- a/tests/manual/article.js
+++ b/tests/manual/article.js
@@ -56,9 +56,45 @@ class IndentOutdent extends Plugin {
 	}
 }
 
+class IndentBlock extends Plugin {
+	init() {
+		const schema = this.editor.model.schema;
+		const conversion = this.editor.conversion;
+
+		schema.extend( 'paragraph', { allowAttributes: 'indent' } );
+		schema.extend( 'heading1', { allowAttributes: 'indent' } );
+
+		conversion.for( 'upcast' ).attributeToAttribute( {
+			view: {
+				styles: {
+					'margin-left': /[\s\S]+/
+				}
+			},
+			model: {
+				key: 'indent',
+				value: viewElement => {
+					return viewElement.getStyle( 'margin-left' );
+				}
+			}
+		} );
+
+		conversion.for( 'downcast' ).attributeToAttribute( {
+			model: 'indent',
+			view: modelAttributeValue => {
+				return {
+					key: 'style',
+					value: {
+						'margin-left': modelAttributeValue
+					}
+				};
+			}
+		} );
+	}
+}
+
 ClassicEditor
 	.create( document.querySelector( '#editor' ), {
-		plugins: [ ArticlePluginSet, IndentOutdent ],
+		plugins: [ ArticlePluginSet, IndentOutdent, IndentBlock ],
 		toolbar: [
 			'heading',
 			'|',

From db2d11f9c577dbf94ee7697609a8072f8c09ee8e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Fri, 7 Jun 2019 11:56:38 +0200
Subject: [PATCH 04/30] Prepare buttons POC.

---
 tests/manual/article.js | 83 +++++++++++++++++++++++++++++++++++++----
 1 file changed, 75 insertions(+), 8 deletions(-)

diff --git a/tests/manual/article.js b/tests/manual/article.js
index 8b15c682..10a30050 100644
--- a/tests/manual/article.js
+++ b/tests/manual/article.js
@@ -11,6 +11,53 @@ import ArticlePluginSet from '../_utils/articlepluginset';
 import MultiCommand from '../../src/multicommand';
 import Plugin from '../../src/plugin';
 import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
+import Command from '../../src/command';
+import first from '@ckeditor/ckeditor5-utils/src/first';
+
+class IndentBlockCommand extends Command {
+	/**
+	 * @inheritDoc
+	 */
+	refresh() {
+		this.isEnabled = this._checkEnabled();
+	}
+
+	/**
+	 * Indents or outdents (depends on the {@link #constructor}'s `indentDirection` parameter) selected list items.
+	 *
+	 * @fires execute
+	 */
+	execute() {
+		const model = this.editor.model;
+		const doc = model.document;
+
+		const itemsToChange = Array.from( doc.selection.getSelectedBlocks() );
+
+		model.change( () => {
+			for ( const item of itemsToChange ) {
+				console.log( 'indent block', item );
+			}
+		} );
+	}
+
+	/**
+	 * Checks whether the command can be enabled in the current context.
+	 *
+	 * @private
+	 * @returns {Boolean} Whether the command should be enabled.
+	 */
+	_checkEnabled() {
+		// Check whether any of position's ancestor is a list item.
+		const block = first( this.editor.model.document.selection.getSelectedBlocks() );
+
+		// If selection is not in a list item, the command is disabled.
+		if ( !block || !this.editor.model.schema.checkAttribute( block, 'indent' ) ) {
+			return false;
+		}
+
+		return true;
+	}
+}
 
 class IndentOutdent extends Plugin {
 	init() {
@@ -18,7 +65,11 @@ class IndentOutdent extends Plugin {
 		const t = editor.t;
 
 		this._createButton( 'indent', t( 'Indent' ) );
-		this._createButton( 'outdent', t( 'Outdent' ) );
+		// this._createButton( 'outdent', t( 'Outdent' ) );
+		this._createButton( 'indentList', t( 'Indent List' ) );
+		// this._createButton( 'outdentList', t( 'Outdent List' ) );
+		this._createButton( 'indentBlock', t( 'Indent Block' ) );
+		// this._createButton( 'outdentBlock', t( 'Outdent Block' ) );
 	}
 
 	_createButton( commandName, label ) {
@@ -46,10 +97,20 @@ class IndentOutdent extends Plugin {
 	afterInit() {
 		const editor = this.editor;
 
+		editor.commands.add( 'indentBlock', new IndentBlockCommand( editor ) );
+
 		const indentCommand = new MultiCommand( editor );
+
 		indentCommand.registerChildCommand( editor.commands.get( 'indentList' ) );
+		indentCommand.registerChildCommand( editor.commands.get( 'indentBlock' ) );
+
 		editor.commands.add( 'indent', indentCommand );
 
+		// TODO nicer API?
+		// editor.commands.add( 'indentList', new Command(), 'indent' );
+		// editor.commands.addMulti( 'indentList', new Command(), 'indent' );
+		// editor.commands.addMulti( 'indentList', 'indent' );
+
 		const outdentCommand = new MultiCommand( editor );
 		outdentCommand.registerChildCommand( editor.commands.get( 'outdentList' ) );
 		editor.commands.add( 'outdent', outdentCommand );
@@ -97,20 +158,26 @@ ClassicEditor
 		plugins: [ ArticlePluginSet, IndentOutdent, IndentBlock ],
 		toolbar: [
 			'heading',
-			'|',
-			'bold',
-			'italic',
-			'link',
+			// '|',
+			// 'bold',
+			// 'italic',
+			// 'link',
 			'|',
 			'indent',
 			'outdent',
 			'|',
+			'indentList',
+			'outdentList',
+			'|',
+			'indentBlock',
+			'outdentBlock',
+			'|',
 			'bulletedList',
 			'numberedList',
 			'|',
-			'blockQuote',
-			'insertTable',
-			'mediaEmbed',
+			// 'blockQuote',
+			// 'insertTable',
+			// 'mediaEmbed',
 			'undo',
 			'redo'
 		],

From e83aaacb7ae57533f86f04b590b6b9c502ec8c1e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Fri, 7 Jun 2019 12:58:11 +0200
Subject: [PATCH 05/30] Remove block indentation POC.

---
 tests/manual/article.js | 169 ++--------------------------------------
 1 file changed, 7 insertions(+), 162 deletions(-)

diff --git a/tests/manual/article.js b/tests/manual/article.js
index 10a30050..fc23773d 100644
--- a/tests/manual/article.js
+++ b/tests/manual/article.js
@@ -8,176 +8,21 @@
 import ClassicEditor from '@ckeditor/ckeditor5-editor-classic/src/classiceditor';
 
 import ArticlePluginSet from '../_utils/articlepluginset';
-import MultiCommand from '../../src/multicommand';
-import Plugin from '../../src/plugin';
-import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
-import Command from '../../src/command';
-import first from '@ckeditor/ckeditor5-utils/src/first';
-
-class IndentBlockCommand extends Command {
-	/**
-	 * @inheritDoc
-	 */
-	refresh() {
-		this.isEnabled = this._checkEnabled();
-	}
-
-	/**
-	 * Indents or outdents (depends on the {@link #constructor}'s `indentDirection` parameter) selected list items.
-	 *
-	 * @fires execute
-	 */
-	execute() {
-		const model = this.editor.model;
-		const doc = model.document;
-
-		const itemsToChange = Array.from( doc.selection.getSelectedBlocks() );
-
-		model.change( () => {
-			for ( const item of itemsToChange ) {
-				console.log( 'indent block', item );
-			}
-		} );
-	}
-
-	/**
-	 * Checks whether the command can be enabled in the current context.
-	 *
-	 * @private
-	 * @returns {Boolean} Whether the command should be enabled.
-	 */
-	_checkEnabled() {
-		// Check whether any of position's ancestor is a list item.
-		const block = first( this.editor.model.document.selection.getSelectedBlocks() );
-
-		// If selection is not in a list item, the command is disabled.
-		if ( !block || !this.editor.model.schema.checkAttribute( block, 'indent' ) ) {
-			return false;
-		}
-
-		return true;
-	}
-}
-
-class IndentOutdent extends Plugin {
-	init() {
-		const editor = this.editor;
-		const t = editor.t;
-
-		this._createButton( 'indent', t( 'Indent' ) );
-		// this._createButton( 'outdent', t( 'Outdent' ) );
-		this._createButton( 'indentList', t( 'Indent List' ) );
-		// this._createButton( 'outdentList', t( 'Outdent List' ) );
-		this._createButton( 'indentBlock', t( 'Indent Block' ) );
-		// this._createButton( 'outdentBlock', t( 'Outdent Block' ) );
-	}
-
-	_createButton( commandName, label ) {
-		const editor = this.editor;
-
-		editor.ui.componentFactory.add( commandName, locale => {
-			const command = editor.commands.get( commandName );
-			const view = new ButtonView( locale );
-
-			view.set( {
-				label,
-				withText: true,
-				tooltip: true
-			} );
-
-			view.bind( 'isOn', 'isEnabled' ).to( command, 'value', 'isEnabled' );
-
-			// Execute command.
-			this.listenTo( view, 'execute', () => editor.execute( commandName ) );
-
-			return view;
-		} );
-	}
-
-	afterInit() {
-		const editor = this.editor;
-
-		editor.commands.add( 'indentBlock', new IndentBlockCommand( editor ) );
-
-		const indentCommand = new MultiCommand( editor );
-
-		indentCommand.registerChildCommand( editor.commands.get( 'indentList' ) );
-		indentCommand.registerChildCommand( editor.commands.get( 'indentBlock' ) );
-
-		editor.commands.add( 'indent', indentCommand );
-
-		// TODO nicer API?
-		// editor.commands.add( 'indentList', new Command(), 'indent' );
-		// editor.commands.addMulti( 'indentList', new Command(), 'indent' );
-		// editor.commands.addMulti( 'indentList', 'indent' );
-
-		const outdentCommand = new MultiCommand( editor );
-		outdentCommand.registerChildCommand( editor.commands.get( 'outdentList' ) );
-		editor.commands.add( 'outdent', outdentCommand );
-	}
-}
-
-class IndentBlock extends Plugin {
-	init() {
-		const schema = this.editor.model.schema;
-		const conversion = this.editor.conversion;
-
-		schema.extend( 'paragraph', { allowAttributes: 'indent' } );
-		schema.extend( 'heading1', { allowAttributes: 'indent' } );
-
-		conversion.for( 'upcast' ).attributeToAttribute( {
-			view: {
-				styles: {
-					'margin-left': /[\s\S]+/
-				}
-			},
-			model: {
-				key: 'indent',
-				value: viewElement => {
-					return viewElement.getStyle( 'margin-left' );
-				}
-			}
-		} );
-
-		conversion.for( 'downcast' ).attributeToAttribute( {
-			model: 'indent',
-			view: modelAttributeValue => {
-				return {
-					key: 'style',
-					value: {
-						'margin-left': modelAttributeValue
-					}
-				};
-			}
-		} );
-	}
-}
 
 ClassicEditor
 	.create( document.querySelector( '#editor' ), {
-		plugins: [ ArticlePluginSet, IndentOutdent, IndentBlock ],
+		plugins: [ ArticlePluginSet ],
 		toolbar: [
 			'heading',
-			// '|',
-			// 'bold',
-			// 'italic',
-			// 'link',
-			'|',
-			'indent',
-			'outdent',
-			'|',
-			'indentList',
-			'outdentList',
-			'|',
-			'indentBlock',
-			'outdentBlock',
 			'|',
+			'bold',
+			'italic',
+			'link',
 			'bulletedList',
 			'numberedList',
-			'|',
-			// 'blockQuote',
-			// 'insertTable',
-			// 'mediaEmbed',
+			'blockQuote',
+			'insertTable',
+			'mediaEmbed',
 			'undo',
 			'redo'
 		],

From 7833999ac4c00a63903d46798157280044811c03 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Tue, 11 Jun 2019 13:29:38 +0200
Subject: [PATCH 06/30] Extract Indent plugin stub.

---
 src/indent.js | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 src/indent.js

diff --git a/src/indent.js b/src/indent.js
new file mode 100644
index 00000000..d1f6eaac
--- /dev/null
+++ b/src/indent.js
@@ -0,0 +1,55 @@
+/**
+ * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/**
+ * @module core/indent
+ */
+import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
+
+import Plugin from './plugin';
+import MultiCommand from './multicommand';
+
+export default class Indent extends Plugin {
+	init() {
+		const editor = this.editor;
+		const t = editor.t;
+
+		editor.commands.add( 'indent', new MultiCommand( editor ) );
+		editor.commands.add( 'outdent', new MultiCommand( editor ) );
+
+		this._createButton( 'indent', t( '>' ) );
+		this._createButton( 'outdent', t( '<' ) );
+
+		// TODO: temporary - tests only
+		this._createButton( 'indentList', t( '> List' ) );
+		this._createButton( 'outdentList', t( '< List' ) );
+
+		// TODO: temporary - tests only
+		this._createButton( 'indentBlock', t( '> Block' ) );
+		this._createButton( 'outdentBlock', t( '< Block' ) );
+	}
+
+	_createButton( commandName, label ) {
+		const editor = this.editor;
+
+		editor.ui.componentFactory.add( commandName, locale => {
+			const command = editor.commands.get( commandName );
+			const view = new ButtonView( locale );
+
+			view.set( {
+				label,
+				withText: true,
+				tooltip: true
+			} );
+
+			view.bind( 'isOn', 'isEnabled' ).to( command, 'value', 'isEnabled' );
+
+			// Execute command.
+			this.listenTo( view, 'execute', () => editor.execute( commandName ) );
+
+			return view;
+		} );
+	}
+}

From a53d8c503ca1b4defda9b301524d8949b966e7f7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Wed, 12 Jun 2019 16:53:57 +0200
Subject: [PATCH 07/30] Add docs for indent plugin.

---
 src/indent.js   | 46 +++++++++++++++++++++++---------
 tests/indent.js | 70 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 104 insertions(+), 12 deletions(-)
 create mode 100644 tests/indent.js

diff --git a/src/indent.js b/src/indent.js
index d1f6eaac..79f8221b 100644
--- a/src/indent.js
+++ b/src/indent.js
@@ -11,7 +11,31 @@ import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
 import Plugin from './plugin';
 import MultiCommand from './multicommand';
 
+/**
+ * The indent feature.
+ *
+ * This plugin acts as a single entry point plugin for other features that implements indenting of elements like list or paragraphs.
+ *
+ * It registers the `'indent'` and `'outdent'` commands and it introduces the `'indent'` and `'outdent'` buttons that allow to
+ * increase or decrease text indentation of supported elements.
+ *
+ * The compatible features are:
+ * - the {@link module:list/list~List list} or {@link module:list/listediting~ListEditing list editing} feature for list indentation
+ * - the {@link module:indent-block/indentblock~IndentBlock block indentation} feature for indenting text blocks like paragraphs or headings
+ *
+ * **Note**: In order the commands and buttons to work at least one of compatible features is required.
+ */
 export default class Indent extends Plugin {
+	/**
+	 * @inheritDoc
+	 */
+	static get pluginName() {
+		return 'Indent';
+	}
+
+	/**
+	 * @inheritDoc
+	 */
 	init() {
 		const editor = this.editor;
 		const t = editor.t;
@@ -19,19 +43,18 @@ export default class Indent extends Plugin {
 		editor.commands.add( 'indent', new MultiCommand( editor ) );
 		editor.commands.add( 'outdent', new MultiCommand( editor ) );
 
-		this._createButton( 'indent', t( '>' ) );
-		this._createButton( 'outdent', t( '<' ) );
-
-		// TODO: temporary - tests only
-		this._createButton( 'indentList', t( '> List' ) );
-		this._createButton( 'outdentList', t( '< List' ) );
-
-		// TODO: temporary - tests only
-		this._createButton( 'indentBlock', t( '> Block' ) );
-		this._createButton( 'outdentBlock', t( '< Block' ) );
+		this._defineButton( 'indent', t( 'Increase indent' ) );
+		this._defineButton( 'outdent', t( 'Decrease indent' ) );
 	}
 
-	_createButton( commandName, label ) {
+	/**
+	 * Defines an UI button.
+	 *
+	 * @param {String} commandName
+	 * @param {String} label
+	 * @private
+	 */
+	_defineButton( commandName, label ) {
 		const editor = this.editor;
 
 		editor.ui.componentFactory.add( commandName, locale => {
@@ -46,7 +69,6 @@ export default class Indent extends Plugin {
 
 			view.bind( 'isOn', 'isEnabled' ).to( command, 'value', 'isEnabled' );
 
-			// Execute command.
 			this.listenTo( view, 'execute', () => editor.execute( commandName ) );
 
 			return view;
diff --git a/tests/indent.js b/tests/indent.js
new file mode 100644
index 00000000..faa890ae
--- /dev/null
+++ b/tests/indent.js
@@ -0,0 +1,70 @@
+/**
+ * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/* global document */
+
+import ClassicTestEditor from '@ckeditor/ckeditor5-core/tests/_utils/classictesteditor';
+import testUtils from '@ckeditor/ckeditor5-core/tests/_utils/utils';
+import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
+
+import Indent from '../src/indent';
+import MultiCommand from '../src/multicommand';
+
+describe.only( 'indent', () => {
+	let editor, element;
+
+	testUtils.createSinonSandbox();
+
+	beforeEach( () => {
+		element = document.createElement( 'div' );
+		document.body.appendChild( element );
+
+		return ClassicTestEditor
+			.create( element, { plugins: [ Indent ] } )
+			.then( newEditor => {
+				editor = newEditor;
+			} );
+	} );
+
+	afterEach( () => {
+		element.remove();
+
+		if ( editor ) {
+			return editor.destroy();
+		}
+	} );
+
+	it( 'should be named', () => {
+		expect( Indent.pluginName ).to.equal( 'Indent' );
+	} );
+
+	it( 'should be loaded', () => {
+		expect( editor.plugins.get( Indent ) ).to.be.instanceOf( Indent );
+	} );
+
+	it( 'should register indent command', () => {
+		const command = editor.commands.get( 'indent' );
+
+		expect( command ).to.be.instanceof( MultiCommand );
+	} );
+
+	it( 'should register outdent command', () => {
+		const command = editor.commands.get( 'outdent' );
+
+		expect( command ).to.be.instanceof( MultiCommand );
+	} );
+
+	it( 'should set up button for indent', () => {
+		const indentButton = editor.ui.componentFactory.create( 'indent' );
+
+		expect( indentButton ).to.be.instanceOf( ButtonView );
+	} );
+
+	it( 'should set up button for indent', () => {
+		const outdentButton = editor.ui.componentFactory.create( 'outdent' );
+
+		expect( outdentButton ).to.be.instanceOf( ButtonView );
+	} );
+} );

From efc9fa006fa788f83afff10cfdae4c5f87ad47d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Wed, 12 Jun 2019 16:58:38 +0200
Subject: [PATCH 08/30] Remove .only from tests.

---
 tests/indent.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/indent.js b/tests/indent.js
index faa890ae..583f186c 100644
--- a/tests/indent.js
+++ b/tests/indent.js
@@ -12,7 +12,7 @@ import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
 import Indent from '../src/indent';
 import MultiCommand from '../src/multicommand';
 
-describe.only( 'indent', () => {
+describe( 'indent', () => {
 	let editor, element;
 
 	testUtils.createSinonSandbox();

From 2c351985db091922e4a501239fcd8c5ca44e1680 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Wed, 12 Jun 2019 17:38:43 +0200
Subject: [PATCH 09/30] Update docs.

---
 src/indent.js       |  6 +++--
 src/multicommand.js | 53 +++++++++++++++++++++++++++++++++++++++------
 2 files changed, 50 insertions(+), 9 deletions(-)

diff --git a/src/indent.js b/src/indent.js
index 79f8221b..c5670001 100644
--- a/src/indent.js
+++ b/src/indent.js
@@ -20,10 +20,12 @@ import MultiCommand from './multicommand';
  * increase or decrease text indentation of supported elements.
  *
  * The compatible features are:
- * - the {@link module:list/list~List list} or {@link module:list/listediting~ListEditing list editing} feature for list indentation
- * - the {@link module:indent-block/indentblock~IndentBlock block indentation} feature for indenting text blocks like paragraphs or headings
+ * - the {@link module:list/list~List} or {@link module:list/listediting~ListEditing} feature for list indentation
+ * - the {@link module:indent-block/indentblock~IndentBlock} feature for indenting text blocks like paragraphs or headings
  *
  * **Note**: In order the commands and buttons to work at least one of compatible features is required.
+ *
+ * @extends module:core/plugin~Plugin
  */
 export default class Indent extends Plugin {
 	/**
diff --git a/src/multicommand.js b/src/multicommand.js
index 793ae41d..d486093a 100644
--- a/src/multicommand.js
+++ b/src/multicommand.js
@@ -10,37 +10,76 @@ import Collection from '@ckeditor/ckeditor5-utils/src/collection';
  * @module core/multicommand
  */
 
+/**
+ * A CKEditor command that aggregates other commands.
+ *
+ * This command is used to proxy multiple commands. The multi command is enabled when one of its registered child commands is enabled.
+ * Whe executing multi command the first command that is enabled will be executed.
+ *
+ * @extends module:core/command~Command
+ */
 export default class MultiCommand extends Command {
+	/**
+	 * @inheritDoc
+	 */
 	constructor( editor ) {
 		super( editor );
 
+		/**
+		 * Registered child commands.
+		 *
+		 * @type {module:utils/collection~Collection.<module:core/command~Command>}
+		 * @private
+		 */
 		this._childCommands = new Collection();
 	}
 
+	/**
+	 * @inheritDoc
+	 */
 	refresh() {
-		// The command listens to child commands rather then acts on refresh.
-		// TODO: check with track changes.
+		// Override base command refresh(): the command's state is changed when one of child commands changes states.
 	}
 
-	execute() {
-		const { command } = this._getEnabled();
+	/**
+	 * Executes the first of it registered child commands.
+	 */
+	execute( ...args ) {
+		const { command } = this._getFirstEnabledCommand();
 
-		command.execute();
+		command.execute( args );
 	}
 
+	/**
+	 * Registers a command as child command.
+	 *
+	 * @param {module:core/command~Command} command
+	 */
 	registerChildCommand( command ) {
 		this._childCommands.add( { command } );
 
+		// Change multi command enabled state when one of registered commands changes state.
 		command.on( 'change:isEnabled', () => this._checkEnabled() );
 
 		this._checkEnabled();
 	}
 
+	/**
+	 * Checks if any of child commands is enabled.
+	 *
+	 * @private
+	 */
 	_checkEnabled() {
-		this.isEnabled = !!this._getEnabled();
+		this.isEnabled = !!this._getFirstEnabledCommand();
 	}
 
-	_getEnabled() {
+	/**
+	 * Returns a first enabled command or undefined if none of them is enabled.
+	 *
+	 * @returns {module:core/command~Command|undefined}
+	 * @private
+	 */
+	_getFirstEnabledCommand() {
 		return this._childCommands.find( ( { command } ) => command.isEnabled );
 	}
 }

From 618b31aeee50e3a9f218b69adb7d1ce73e2e928a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Thu, 13 Jun 2019 17:56:58 +0200
Subject: [PATCH 10/30] Add missing test for MultiCommand.

---
 tests/multicommand.js | 124 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)
 create mode 100644 tests/multicommand.js

diff --git a/tests/multicommand.js b/tests/multicommand.js
new file mode 100644
index 00000000..e67742ce
--- /dev/null
+++ b/tests/multicommand.js
@@ -0,0 +1,124 @@
+/**
+ * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+import MultiCommand from '../src/multicommand';
+import ModelTestEditor from './_utils/modeltesteditor';
+import Command from '../src/command';
+
+describe( 'MultiCommand', () => {
+	let editor, multiCommand;
+
+	beforeEach( () => {
+		return ModelTestEditor
+			.create()
+			.then( newEditor => {
+				editor = newEditor;
+				multiCommand = new MultiCommand( editor );
+			} );
+	} );
+
+	afterEach( () => {
+		multiCommand.destroy();
+
+		return editor.destroy();
+	} );
+
+	describe( 'isEnabled', () => {
+		it( 'is always falsy when no child commands are registered', () => {
+			expect( multiCommand.isEnabled ).to.false;
+
+			multiCommand.refresh();
+
+			expect( multiCommand.isEnabled ).to.false;
+		} );
+
+		it( 'is set to true if one of registered commands is true', () => {
+			expect( multiCommand.isEnabled ).to.false;
+
+			const commandA = new Command( editor );
+			const commandB = new Command( editor );
+
+			multiCommand.registerChildCommand( commandA );
+			multiCommand.registerChildCommand( commandB );
+
+			expect( multiCommand.isEnabled ).to.false;
+
+			commandA.isEnabled = true;
+
+			expect( multiCommand.isEnabled ).to.be.true;
+
+			commandA.isEnabled = false;
+
+			expect( multiCommand.isEnabled ).to.be.false;
+
+			commandB.isEnabled = true;
+
+			expect( multiCommand.isEnabled ).to.be.true;
+		} );
+	} );
+
+	describe( 'execute()', () => {
+		it( 'does not call any command if all are disabled', () => {
+			const commandA = new Command( editor );
+			const commandB = new Command( editor );
+
+			multiCommand.registerChildCommand( commandA );
+			multiCommand.registerChildCommand( commandB );
+
+			const spyA = sinon.spy( commandA, 'execute' );
+			const spyB = sinon.spy( commandB, 'execute' );
+
+			multiCommand.execute();
+
+			sinon.assert.notCalled( spyA );
+			sinon.assert.notCalled( spyB );
+		} );
+
+		it( 'executes enabled command', () => {
+			const commandA = new Command( editor );
+			const commandB = new Command( editor );
+			const commandC = new Command( editor );
+
+			multiCommand.registerChildCommand( commandA );
+			multiCommand.registerChildCommand( commandB );
+			multiCommand.registerChildCommand( commandC );
+
+			const spyA = sinon.spy( commandA, 'execute' );
+			const spyB = sinon.spy( commandB, 'execute' );
+			const spyC = sinon.spy( commandC, 'execute' );
+
+			commandC.isEnabled = true;
+
+			multiCommand.execute();
+
+			sinon.assert.notCalled( spyA );
+			sinon.assert.notCalled( spyB );
+			sinon.assert.calledOnce( spyC );
+		} );
+
+		it( 'executes first registered command if many are enabled', () => {
+			const commandA = new Command( editor );
+			const commandB = new Command( editor );
+			const commandC = new Command( editor );
+
+			multiCommand.registerChildCommand( commandA );
+			multiCommand.registerChildCommand( commandB );
+			multiCommand.registerChildCommand( commandC );
+
+			const spyA = sinon.spy( commandA, 'execute' );
+			const spyB = sinon.spy( commandB, 'execute' );
+			const spyC = sinon.spy( commandC, 'execute' );
+
+			commandC.isEnabled = true;
+			commandB.isEnabled = true;
+
+			multiCommand.execute();
+
+			sinon.assert.notCalled( spyA );
+			sinon.assert.calledOnce( spyB );
+			sinon.assert.notCalled( spyC );
+		} );
+	} );
+} );

From 900aeaf3ec6cbdfb853c860aeccaf0b740912aac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Thu, 13 Jun 2019 17:57:18 +0200
Subject: [PATCH 11/30] Add missing test for indent.

---
 tests/indent.js | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/tests/indent.js b/tests/indent.js
index 583f186c..3d6ef789 100644
--- a/tests/indent.js
+++ b/tests/indent.js
@@ -67,4 +67,24 @@ describe( 'indent', () => {
 
 		expect( outdentButton ).to.be.instanceOf( ButtonView );
 	} );
+
+	it( 'should execute indent command on button execute', () => {
+		const button = editor.ui.componentFactory.create( 'indent' );
+		const spy = sinon.spy( editor, 'execute' );
+
+		button.fire( 'execute' );
+
+		sinon.assert.calledOnce( spy );
+		sinon.assert.calledWithExactly( spy, 'indent' );
+	} );
+
+	it( 'should execute outdent command on button execute', () => {
+		const button = editor.ui.componentFactory.create( 'outdent' );
+		const spy = sinon.spy( editor, 'execute' );
+
+		button.fire( 'execute' );
+
+		sinon.assert.calledOnce( spy );
+		sinon.assert.calledWithExactly( spy, 'outdent' );
+	} );
 } );

From 79a6aa4392b50fbcd479af3262e02f3294125fb9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Fri, 14 Jun 2019 10:37:53 +0200
Subject: [PATCH 12/30] Split the Indent plugin to Indent, IndentEditing and
 IndentUI.

---
 src/indent.js          | 55 +++++++----------------------
 src/indentediting.js   | 40 ++++++++++++++++++++++
 src/indentui.js        | 69 +++++++++++++++++++++++++++++++++++++
 tests/indent.js        | 54 ++++-------------------------
 tests/indentediting.js | 57 ++++++++++++++++++++++++++++++
 tests/indentui.js      | 78 ++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 264 insertions(+), 89 deletions(-)
 create mode 100644 src/indentediting.js
 create mode 100644 src/indentui.js
 create mode 100644 tests/indentediting.js
 create mode 100644 tests/indentui.js

diff --git a/src/indent.js b/src/indent.js
index c5670001..27901897 100644
--- a/src/indent.js
+++ b/src/indent.js
@@ -6,23 +6,29 @@
 /**
  * @module core/indent
  */
-import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
 
 import Plugin from './plugin';
-import MultiCommand from './multicommand';
+
+import IndentEditing from './indentediting';
+import IndentUI from './indentui';
 
 /**
  * The indent feature.
  *
  * This plugin acts as a single entry point plugin for other features that implements indenting of elements like list or paragraphs.
  *
- * It registers the `'indent'` and `'outdent'` commands and it introduces the `'indent'` and `'outdent'` buttons that allow to
- * increase or decrease text indentation of supported elements.
- *
  * The compatible features are:
  * - the {@link module:list/list~List} or {@link module:list/listediting~ListEditing} feature for list indentation
  * - the {@link module:indent-block/indentblock~IndentBlock} feature for indenting text blocks like paragraphs or headings
  *
+ * This is a "glue" plugin which loads the following plugins:
+ *
+ * * The {@link module:core/indentediting~IndentEditing indent editing feature} and
+ * * The {@link module:core/indentui~IndentUI indent UI feature}.
+ *
+ * The dependent plugins registers the `'indent'` and `'outdent'` commands and it introduces the `'indent'` and `'outdent'` buttons
+ * that allow to increase or decrease text indentation of supported elements.
+ *
  * **Note**: In order the commands and buttons to work at least one of compatible features is required.
  *
  * @extends module:core/plugin~Plugin
@@ -38,42 +44,7 @@ export default class Indent extends Plugin {
 	/**
 	 * @inheritDoc
 	 */
-	init() {
-		const editor = this.editor;
-		const t = editor.t;
-
-		editor.commands.add( 'indent', new MultiCommand( editor ) );
-		editor.commands.add( 'outdent', new MultiCommand( editor ) );
-
-		this._defineButton( 'indent', t( 'Increase indent' ) );
-		this._defineButton( 'outdent', t( 'Decrease indent' ) );
-	}
-
-	/**
-	 * Defines an UI button.
-	 *
-	 * @param {String} commandName
-	 * @param {String} label
-	 * @private
-	 */
-	_defineButton( commandName, label ) {
-		const editor = this.editor;
-
-		editor.ui.componentFactory.add( commandName, locale => {
-			const command = editor.commands.get( commandName );
-			const view = new ButtonView( locale );
-
-			view.set( {
-				label,
-				withText: true,
-				tooltip: true
-			} );
-
-			view.bind( 'isOn', 'isEnabled' ).to( command, 'value', 'isEnabled' );
-
-			this.listenTo( view, 'execute', () => editor.execute( commandName ) );
-
-			return view;
-		} );
+	static get requires() {
+		return [ IndentEditing, IndentUI ];
 	}
 }
diff --git a/src/indentediting.js b/src/indentediting.js
new file mode 100644
index 00000000..f7c63f3e
--- /dev/null
+++ b/src/indentediting.js
@@ -0,0 +1,40 @@
+/**
+ * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/**
+ * @module core/indentediting
+ */
+
+import Plugin from './plugin';
+import MultiCommand from './multicommand';
+
+/**
+ * The indent editing feature.
+ *
+ * This plugin registers the `'indent'` and `'outdent'` commands.
+ *
+ * **Note**: In order the commands to work at least one of compatible features is required. Read more in
+ * {@link module:core/indent~Indent indent feature} api docs.
+ *
+ * @extends module:core/plugin~Plugin
+ */
+export default class IndentEditing extends Plugin {
+	/**
+	 * @inheritDoc
+	 */
+	static get pluginName() {
+		return 'IndentEditing';
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	init() {
+		const editor = this.editor;
+
+		editor.commands.add( 'indent', new MultiCommand( editor ) );
+		editor.commands.add( 'outdent', new MultiCommand( editor ) );
+	}
+}
diff --git a/src/indentui.js b/src/indentui.js
new file mode 100644
index 00000000..ef6ee955
--- /dev/null
+++ b/src/indentui.js
@@ -0,0 +1,69 @@
+/**
+ * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/**
+ * @module core/indentui
+ */
+import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
+
+import Plugin from './plugin';
+
+/**
+ * The indent feature.
+ *
+ * This plugin registers the `'indent'` and `'outdent'` buttons.
+ *
+ * **Note**: In order the commands to work at least one of compatible features is required. Read more in
+ * {@link module:core/indent~Indent indent feature} api docs.
+ *
+ * @extends module:core/plugin~Plugin
+ */
+export default class IndentUI extends Plugin {
+	/**
+	 * @inheritDoc
+	 */
+	static get pluginName() {
+		return 'IndentUI';
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	init() {
+		const editor = this.editor;
+		const t = editor.t;
+
+		this._defineButton( 'indent', t( 'Increase indent' ) );
+		this._defineButton( 'outdent', t( 'Decrease indent' ) );
+	}
+
+	/**
+	 * Defines an UI button.
+	 *
+	 * @param {String} commandName
+	 * @param {String} label
+	 * @private
+	 */
+	_defineButton( commandName, label ) {
+		const editor = this.editor;
+
+		editor.ui.componentFactory.add( commandName, locale => {
+			const command = editor.commands.get( commandName );
+			const view = new ButtonView( locale );
+
+			view.set( {
+				label,
+				withText: true,
+				tooltip: true
+			} );
+
+			view.bind( 'isOn', 'isEnabled' ).to( command, 'value', 'isEnabled' );
+
+			this.listenTo( view, 'execute', () => editor.execute( commandName ) );
+
+			return view;
+		} );
+	}
+}
diff --git a/tests/indent.js b/tests/indent.js
index 3d6ef789..96d5a6f1 100644
--- a/tests/indent.js
+++ b/tests/indent.js
@@ -7,12 +7,12 @@
 
 import ClassicTestEditor from '@ckeditor/ckeditor5-core/tests/_utils/classictesteditor';
 import testUtils from '@ckeditor/ckeditor5-core/tests/_utils/utils';
-import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
 
 import Indent from '../src/indent';
-import MultiCommand from '../src/multicommand';
+import IndentEditing from '../src/indentediting';
+import IndentUI from '../src/indentui';
 
-describe( 'indent', () => {
+describe( 'Indent', () => {
 	let editor, element;
 
 	testUtils.createSinonSandbox();
@@ -40,51 +40,11 @@ describe( 'indent', () => {
 		expect( Indent.pluginName ).to.equal( 'Indent' );
 	} );
 
-	it( 'should be loaded', () => {
-		expect( editor.plugins.get( Indent ) ).to.be.instanceOf( Indent );
+	it( 'should load the IndentUI plugin', () => {
+		expect( editor.plugins.get( IndentUI ) ).to.be.instanceOf( IndentUI );
 	} );
 
-	it( 'should register indent command', () => {
-		const command = editor.commands.get( 'indent' );
-
-		expect( command ).to.be.instanceof( MultiCommand );
-	} );
-
-	it( 'should register outdent command', () => {
-		const command = editor.commands.get( 'outdent' );
-
-		expect( command ).to.be.instanceof( MultiCommand );
-	} );
-
-	it( 'should set up button for indent', () => {
-		const indentButton = editor.ui.componentFactory.create( 'indent' );
-
-		expect( indentButton ).to.be.instanceOf( ButtonView );
-	} );
-
-	it( 'should set up button for indent', () => {
-		const outdentButton = editor.ui.componentFactory.create( 'outdent' );
-
-		expect( outdentButton ).to.be.instanceOf( ButtonView );
-	} );
-
-	it( 'should execute indent command on button execute', () => {
-		const button = editor.ui.componentFactory.create( 'indent' );
-		const spy = sinon.spy( editor, 'execute' );
-
-		button.fire( 'execute' );
-
-		sinon.assert.calledOnce( spy );
-		sinon.assert.calledWithExactly( spy, 'indent' );
-	} );
-
-	it( 'should execute outdent command on button execute', () => {
-		const button = editor.ui.componentFactory.create( 'outdent' );
-		const spy = sinon.spy( editor, 'execute' );
-
-		button.fire( 'execute' );
-
-		sinon.assert.calledOnce( spy );
-		sinon.assert.calledWithExactly( spy, 'outdent' );
+	it( 'should load the IndentEditing plugin', () => {
+		expect( editor.plugins.get( IndentEditing ) ).to.be.instanceOf( IndentEditing );
 	} );
 } );
diff --git a/tests/indentediting.js b/tests/indentediting.js
new file mode 100644
index 00000000..2d5ea72f
--- /dev/null
+++ b/tests/indentediting.js
@@ -0,0 +1,57 @@
+/**
+ * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/* global document */
+
+import ClassicTestEditor from '@ckeditor/ckeditor5-core/tests/_utils/classictesteditor';
+import testUtils from '@ckeditor/ckeditor5-core/tests/_utils/utils';
+
+import MultiCommand from '../src/multicommand';
+import IndentEditing from '../src/indentediting';
+
+describe( 'IndentEditing', () => {
+	let editor, element;
+
+	testUtils.createSinonSandbox();
+
+	beforeEach( () => {
+		element = document.createElement( 'div' );
+		document.body.appendChild( element );
+
+		return ClassicTestEditor
+			.create( element, { plugins: [ IndentEditing ] } )
+			.then( newEditor => {
+				editor = newEditor;
+			} );
+	} );
+
+	afterEach( () => {
+		element.remove();
+
+		if ( editor ) {
+			return editor.destroy();
+		}
+	} );
+
+	it( 'should be named', () => {
+		expect( IndentEditing.pluginName ).to.equal( 'IndentEditing' );
+	} );
+
+	it( 'should be loaded', () => {
+		expect( editor.plugins.get( IndentEditing ) ).to.be.instanceOf( IndentEditing );
+	} );
+
+	it( 'should register indent command', () => {
+		const command = editor.commands.get( 'indent' );
+
+		expect( command ).to.be.instanceof( MultiCommand );
+	} );
+
+	it( 'should register outdent command', () => {
+		const command = editor.commands.get( 'outdent' );
+
+		expect( command ).to.be.instanceof( MultiCommand );
+	} );
+} );
diff --git a/tests/indentui.js b/tests/indentui.js
new file mode 100644
index 00000000..512dbe0d
--- /dev/null
+++ b/tests/indentui.js
@@ -0,0 +1,78 @@
+/**
+ * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/* global document */
+
+import ClassicTestEditor from '@ckeditor/ckeditor5-core/tests/_utils/classictesteditor';
+import testUtils from '@ckeditor/ckeditor5-core/tests/_utils/utils';
+import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
+
+import IndentEditing from '../src/indentediting';
+import IndentUI from '../src/indentui';
+
+describe( 'IndentUI', () => {
+	let editor, element;
+
+	testUtils.createSinonSandbox();
+
+	beforeEach( () => {
+		element = document.createElement( 'div' );
+		document.body.appendChild( element );
+
+		return ClassicTestEditor
+			.create( element, { plugins: [ IndentUI, IndentEditing ] } )
+			.then( newEditor => {
+				editor = newEditor;
+			} );
+	} );
+
+	afterEach( () => {
+		element.remove();
+
+		if ( editor ) {
+			return editor.destroy();
+		}
+	} );
+
+	it( 'should be named', () => {
+		expect( IndentUI.pluginName ).to.equal( 'IndentUI' );
+	} );
+
+	it( 'should be loaded', () => {
+		expect( editor.plugins.get( IndentUI ) ).to.be.instanceOf( IndentUI );
+	} );
+
+	it( 'should set up button for indent', () => {
+		const indentButton = editor.ui.componentFactory.create( 'indent' );
+
+		expect( indentButton ).to.be.instanceOf( ButtonView );
+	} );
+
+	it( 'should set up button for indent', () => {
+		const outdentButton = editor.ui.componentFactory.create( 'outdent' );
+
+		expect( outdentButton ).to.be.instanceOf( ButtonView );
+	} );
+
+	it( 'should execute indent command on button execute', () => {
+		const button = editor.ui.componentFactory.create( 'indent' );
+		const spy = sinon.spy( editor, 'execute' );
+
+		button.fire( 'execute' );
+
+		sinon.assert.calledOnce( spy );
+		sinon.assert.calledWithExactly( spy, 'indent' );
+	} );
+
+	it( 'should execute outdent command on button execute', () => {
+		const button = editor.ui.componentFactory.create( 'outdent' );
+		const spy = sinon.spy( editor, 'execute' );
+
+		button.fire( 'execute' );
+
+		sinon.assert.calledOnce( spy );
+		sinon.assert.calledWithExactly( spy, 'outdent' );
+	} );
+} );

From 569eba3e4d603ea595404fbc730d62d44c5f8a9f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Fri, 14 Jun 2019 10:49:41 +0200
Subject: [PATCH 13/30] Use VirtualTestEditor in IndentEditing tests.

---
 tests/indentediting.js | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/tests/indentediting.js b/tests/indentediting.js
index 2d5ea72f..b4a1f01c 100644
--- a/tests/indentediting.js
+++ b/tests/indentediting.js
@@ -3,33 +3,26 @@
  * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
  */
 
-/* global document */
-
-import ClassicTestEditor from '@ckeditor/ckeditor5-core/tests/_utils/classictesteditor';
+import VirtualTestEditor from './_utils/virtualtesteditor';
 import testUtils from '@ckeditor/ckeditor5-core/tests/_utils/utils';
 
 import MultiCommand from '../src/multicommand';
 import IndentEditing from '../src/indentediting';
 
 describe( 'IndentEditing', () => {
-	let editor, element;
+	let editor;
 
 	testUtils.createSinonSandbox();
 
 	beforeEach( () => {
-		element = document.createElement( 'div' );
-		document.body.appendChild( element );
-
-		return ClassicTestEditor
-			.create( element, { plugins: [ IndentEditing ] } )
+		return VirtualTestEditor
+			.create( { plugins: [ IndentEditing ] } )
 			.then( newEditor => {
 				editor = newEditor;
 			} );
 	} );
 
 	afterEach( () => {
-		element.remove();
-
 		if ( editor ) {
 			return editor.destroy();
 		}

From b1e2f8de2b769465e83e06c16c59fd51f407a23a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Fri, 14 Jun 2019 10:55:04 +0200
Subject: [PATCH 14/30] Move Indent* plugins to indent/Indent.

---
 src/{ => indent}/indent.js          | 8 ++++----
 src/{ => indent}/indentediting.js   | 8 ++++----
 src/{ => indent}/indentui.js        | 6 +++---
 tests/{ => indent}/indent.js        | 6 +++---
 tests/{ => indent}/indentediting.js | 8 ++++----
 tests/{ => indent}/indentui.js      | 4 ++--
 6 files changed, 20 insertions(+), 20 deletions(-)
 rename src/{ => indent}/indent.js (85%)
 rename src/{ => indent}/indentediting.js (81%)
 rename src/{ => indent}/indentui.js (91%)
 rename tests/{ => indent}/indent.js (88%)
 rename tests/{ => indent}/indentediting.js (82%)
 rename tests/{ => indent}/indentui.js (94%)

diff --git a/src/indent.js b/src/indent/indent.js
similarity index 85%
rename from src/indent.js
rename to src/indent/indent.js
index 27901897..afdbbdd1 100644
--- a/src/indent.js
+++ b/src/indent/indent.js
@@ -4,10 +4,10 @@
  */
 
 /**
- * @module core/indent
+ * @module core/indent/indent
  */
 
-import Plugin from './plugin';
+import Plugin from '../plugin';
 
 import IndentEditing from './indentediting';
 import IndentUI from './indentui';
@@ -23,8 +23,8 @@ import IndentUI from './indentui';
  *
  * This is a "glue" plugin which loads the following plugins:
  *
- * * The {@link module:core/indentediting~IndentEditing indent editing feature} and
- * * The {@link module:core/indentui~IndentUI indent UI feature}.
+ * * The {@link module:core/indent/indentediting~IndentEditing indent editing feature} and
+ * * The {@link module:core/indent/indentui~IndentUI indent UI feature}.
  *
  * The dependent plugins registers the `'indent'` and `'outdent'` commands and it introduces the `'indent'` and `'outdent'` buttons
  * that allow to increase or decrease text indentation of supported elements.
diff --git a/src/indentediting.js b/src/indent/indentediting.js
similarity index 81%
rename from src/indentediting.js
rename to src/indent/indentediting.js
index f7c63f3e..c465697b 100644
--- a/src/indentediting.js
+++ b/src/indent/indentediting.js
@@ -4,11 +4,11 @@
  */
 
 /**
- * @module core/indentediting
+ * @module core/indent/indentediting
  */
 
-import Plugin from './plugin';
-import MultiCommand from './multicommand';
+import Plugin from '../plugin';
+import MultiCommand from '../multicommand';
 
 /**
  * The indent editing feature.
@@ -16,7 +16,7 @@ import MultiCommand from './multicommand';
  * This plugin registers the `'indent'` and `'outdent'` commands.
  *
  * **Note**: In order the commands to work at least one of compatible features is required. Read more in
- * {@link module:core/indent~Indent indent feature} api docs.
+ * {@link module:core/indent/indent~Indent indent feature} api docs.
  *
  * @extends module:core/plugin~Plugin
  */
diff --git a/src/indentui.js b/src/indent/indentui.js
similarity index 91%
rename from src/indentui.js
rename to src/indent/indentui.js
index ef6ee955..95000314 100644
--- a/src/indentui.js
+++ b/src/indent/indentui.js
@@ -4,11 +4,11 @@
  */
 
 /**
- * @module core/indentui
+ * @module core/indent/indentui
  */
 import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
 
-import Plugin from './plugin';
+import Plugin from '../plugin';
 
 /**
  * The indent feature.
@@ -16,7 +16,7 @@ import Plugin from './plugin';
  * This plugin registers the `'indent'` and `'outdent'` buttons.
  *
  * **Note**: In order the commands to work at least one of compatible features is required. Read more in
- * {@link module:core/indent~Indent indent feature} api docs.
+ * {@link module:core/indent/indent~Indent indent feature} api docs.
  *
  * @extends module:core/plugin~Plugin
  */
diff --git a/tests/indent.js b/tests/indent/indent.js
similarity index 88%
rename from tests/indent.js
rename to tests/indent/indent.js
index 96d5a6f1..de1fd7c3 100644
--- a/tests/indent.js
+++ b/tests/indent/indent.js
@@ -8,9 +8,9 @@
 import ClassicTestEditor from '@ckeditor/ckeditor5-core/tests/_utils/classictesteditor';
 import testUtils from '@ckeditor/ckeditor5-core/tests/_utils/utils';
 
-import Indent from '../src/indent';
-import IndentEditing from '../src/indentediting';
-import IndentUI from '../src/indentui';
+import Indent from '../../src/indent/indent';
+import IndentEditing from '../../src/indent/indentediting';
+import IndentUI from '../../src/indent/indentui';
 
 describe( 'Indent', () => {
 	let editor, element;
diff --git a/tests/indentediting.js b/tests/indent/indentediting.js
similarity index 82%
rename from tests/indentediting.js
rename to tests/indent/indentediting.js
index b4a1f01c..3dc64bbc 100644
--- a/tests/indentediting.js
+++ b/tests/indent/indentediting.js
@@ -3,11 +3,11 @@
  * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
  */
 
-import VirtualTestEditor from './_utils/virtualtesteditor';
-import testUtils from '@ckeditor/ckeditor5-core/tests/_utils/utils';
+import VirtualTestEditor from '../_utils/virtualtesteditor';
+import testUtils from '../_utils/utils';
 
-import MultiCommand from '../src/multicommand';
-import IndentEditing from '../src/indentediting';
+import MultiCommand from '../../src/multicommand';
+import IndentEditing from '../../src/indent/indentediting';
 
 describe( 'IndentEditing', () => {
 	let editor;
diff --git a/tests/indentui.js b/tests/indent/indentui.js
similarity index 94%
rename from tests/indentui.js
rename to tests/indent/indentui.js
index 512dbe0d..0db7fe9e 100644
--- a/tests/indentui.js
+++ b/tests/indent/indentui.js
@@ -9,8 +9,8 @@ import ClassicTestEditor from '@ckeditor/ckeditor5-core/tests/_utils/classictest
 import testUtils from '@ckeditor/ckeditor5-core/tests/_utils/utils';
 import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
 
-import IndentEditing from '../src/indentediting';
-import IndentUI from '../src/indentui';
+import IndentEditing from '../../src/indent/indentediting';
+import IndentUI from '../../src/indent/indentui';
 
 describe( 'IndentUI', () => {
 	let editor, element;

From 7e7b4c77fbcadf91e63914633fc5768dda47860e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Fri, 14 Jun 2019 13:09:29 +0200
Subject: [PATCH 15/30] Add example to MultiCommand.

---
 src/multicommand.js | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/multicommand.js b/src/multicommand.js
index d486093a..3687add2 100644
--- a/src/multicommand.js
+++ b/src/multicommand.js
@@ -16,6 +16,20 @@ import Collection from '@ckeditor/ckeditor5-utils/src/collection';
  * This command is used to proxy multiple commands. The multi command is enabled when one of its registered child commands is enabled.
  * Whe executing multi command the first command that is enabled will be executed.
  *
+ *		const multiCommand = new MultiCommand( editor );
+ *
+ *		const commandFoo = new Command( editor );
+ *		const commandBar = new Command( editor );
+ *
+ *		// Register child commands.
+ *		multiCommand.registerChildCommand( commandFoo );
+ *		multiCommand.registerChildCommand( commandBar );
+ *
+ *		// Enable one of commands
+ *		commandBar.isEnabled = true;
+ *
+ *		multiCommand.execute(); // Will execute commandBar.
+ *
  * @extends module:core/command~Command
  */
 export default class MultiCommand extends Command {

From dd39d16088cae997a5a4ddec1194e9180f4bc7d9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Fri, 14 Jun 2019 13:45:36 +0200
Subject: [PATCH 16/30] Remove invalid itself inports.

---
 tests/indent/indent.js   | 4 ++--
 tests/indent/indentui.js | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/indent/indent.js b/tests/indent/indent.js
index de1fd7c3..8f07f3ea 100644
--- a/tests/indent/indent.js
+++ b/tests/indent/indent.js
@@ -5,8 +5,8 @@
 
 /* global document */
 
-import ClassicTestEditor from '@ckeditor/ckeditor5-core/tests/_utils/classictesteditor';
-import testUtils from '@ckeditor/ckeditor5-core/tests/_utils/utils';
+import ClassicTestEditor from '../_utils/classictesteditor';
+import testUtils from '../_utils/utils';
 
 import Indent from '../../src/indent/indent';
 import IndentEditing from '../../src/indent/indentediting';
diff --git a/tests/indent/indentui.js b/tests/indent/indentui.js
index 0db7fe9e..8986ad6c 100644
--- a/tests/indent/indentui.js
+++ b/tests/indent/indentui.js
@@ -5,8 +5,8 @@
 
 /* global document */
 
-import ClassicTestEditor from '@ckeditor/ckeditor5-core/tests/_utils/classictesteditor';
-import testUtils from '@ckeditor/ckeditor5-core/tests/_utils/utils';
+import ClassicTestEditor from '../_utils/classictesteditor';
+import testUtils from '../_utils/utils';
 import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
 
 import IndentEditing from '../../src/indent/indentediting';

From ccb9c2c8213c4cfc1b426967ae444fb5511c9c46 Mon Sep 17 00:00:00 2001
From: Maciej <jodator@gmail.com>
Date: Wed, 26 Jun 2019 15:27:47 +0200
Subject: [PATCH 17/30] Update src/multicommand.js
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-Authored-By: Piotrek Koszuliński <pkoszulinski@gmail.com>
---
 src/multicommand.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/multicommand.js b/src/multicommand.js
index 3687add2..ff12190b 100644
--- a/src/multicommand.js
+++ b/src/multicommand.js
@@ -25,7 +25,7 @@ import Collection from '@ckeditor/ckeditor5-utils/src/collection';
  *		multiCommand.registerChildCommand( commandFoo );
  *		multiCommand.registerChildCommand( commandBar );
  *
- *		// Enable one of commands
+ *		// Enable one of the commands.
  *		commandBar.isEnabled = true;
  *
  *		multiCommand.execute(); // Will execute commandBar.

From e970541315f016e218cd29c4527d64c67dfd256b Mon Sep 17 00:00:00 2001
From: Maciej <jodator@gmail.com>
Date: Wed, 26 Jun 2019 15:28:18 +0200
Subject: [PATCH 18/30] Update src/multicommand.js
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-Authored-By: Piotrek Koszuliński <pkoszulinski@gmail.com>
---
 src/multicommand.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/multicommand.js b/src/multicommand.js
index ff12190b..01ec6bd8 100644
--- a/src/multicommand.js
+++ b/src/multicommand.js
@@ -13,7 +13,7 @@ import Collection from '@ckeditor/ckeditor5-utils/src/collection';
 /**
  * A CKEditor command that aggregates other commands.
  *
- * This command is used to proxy multiple commands. The multi command is enabled when one of its registered child commands is enabled.
+ * This command is used to proxy multiple commands. The multi-command is enabled when at least one of its registered child commands is enabled.
  * Whe executing multi command the first command that is enabled will be executed.
  *
  *		const multiCommand = new MultiCommand( editor );

From d531bb957eced124dbb3d23d142b8055bcb303cf Mon Sep 17 00:00:00 2001
From: Maciej <jodator@gmail.com>
Date: Wed, 26 Jun 2019 15:28:32 +0200
Subject: [PATCH 19/30] Update src/multicommand.js
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-Authored-By: Piotrek Koszuliński <pkoszulinski@gmail.com>
---
 src/multicommand.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/multicommand.js b/src/multicommand.js
index 01ec6bd8..02c65dfc 100644
--- a/src/multicommand.js
+++ b/src/multicommand.js
@@ -14,7 +14,7 @@ import Collection from '@ckeditor/ckeditor5-utils/src/collection';
  * A CKEditor command that aggregates other commands.
  *
  * This command is used to proxy multiple commands. The multi-command is enabled when at least one of its registered child commands is enabled.
- * Whe executing multi command the first command that is enabled will be executed.
+ * When executing a multi-command the first command that is enabled will be executed.
  *
  *		const multiCommand = new MultiCommand( editor );
  *

From 2ef389a782ba1eabcfab0088278450f60e7bef7b Mon Sep 17 00:00:00 2001
From: Maciej <jodator@gmail.com>
Date: Wed, 26 Jun 2019 15:28:46 +0200
Subject: [PATCH 20/30] Update src/multicommand.js
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-Authored-By: Piotrek Koszuliński <pkoszulinski@gmail.com>
---
 src/multicommand.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/multicommand.js b/src/multicommand.js
index 02c65dfc..8c7a426f 100644
--- a/src/multicommand.js
+++ b/src/multicommand.js
@@ -65,7 +65,7 @@ export default class MultiCommand extends Command {
 	}
 
 	/**
-	 * Registers a command as child command.
+	 * Registers a child command.
 	 *
 	 * @param {module:core/command~Command} command
 	 */

From 7340ad2bbca73377c7f1a1ffb20ca1414fb7ee0d Mon Sep 17 00:00:00 2001
From: Maciej <jodator@gmail.com>
Date: Wed, 26 Jun 2019 15:29:03 +0200
Subject: [PATCH 21/30] Update src/indent/indent.js
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-Authored-By: Piotrek Koszuliński <pkoszulinski@gmail.com>
---
 src/indent/indent.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/indent/indent.js b/src/indent/indent.js
index afdbbdd1..53d6d0ae 100644
--- a/src/indent/indent.js
+++ b/src/indent/indent.js
@@ -15,7 +15,7 @@ import IndentUI from './indentui';
 /**
  * The indent feature.
  *
- * This plugin acts as a single entry point plugin for other features that implements indenting of elements like list or paragraphs.
+ * This plugin acts as a single entry point plugin for other features that implement indenting of elements like lists or paragraphs.
  *
  * The compatible features are:
  * - the {@link module:list/list~List} or {@link module:list/listediting~ListEditing} feature for list indentation

From dafe54dcbf2982c04cbdf98d399a1626f7f7c37a Mon Sep 17 00:00:00 2001
From: Maciej <jodator@gmail.com>
Date: Wed, 26 Jun 2019 15:29:22 +0200
Subject: [PATCH 22/30] Update src/indent/indent.js
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-Authored-By: Piotrek Koszuliński <pkoszulinski@gmail.com>
---
 src/indent/indent.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/indent/indent.js b/src/indent/indent.js
index 53d6d0ae..be39b1bb 100644
--- a/src/indent/indent.js
+++ b/src/indent/indent.js
@@ -26,7 +26,7 @@ import IndentUI from './indentui';
  * * The {@link module:core/indent/indentediting~IndentEditing indent editing feature} and
  * * The {@link module:core/indent/indentui~IndentUI indent UI feature}.
  *
- * The dependent plugins registers the `'indent'` and `'outdent'` commands and it introduces the `'indent'` and `'outdent'` buttons
+ * The dependent plugins register the `'indent'` and `'outdent'` commands and it introduce the `'indent'` and `'outdent'` buttons
  * that allow to increase or decrease text indentation of supported elements.
  *
  * **Note**: In order the commands and buttons to work at least one of compatible features is required.

From e1661d0c0e753ef49306949b811cdcb863fd265e Mon Sep 17 00:00:00 2001
From: Maciej <jodator@gmail.com>
Date: Wed, 26 Jun 2019 15:29:37 +0200
Subject: [PATCH 23/30] Update src/indent/indent.js
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-Authored-By: Piotrek Koszuliński <pkoszulinski@gmail.com>
---
 src/indent/indent.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/indent/indent.js b/src/indent/indent.js
index be39b1bb..274efe24 100644
--- a/src/indent/indent.js
+++ b/src/indent/indent.js
@@ -18,6 +18,7 @@ import IndentUI from './indentui';
  * This plugin acts as a single entry point plugin for other features that implement indenting of elements like lists or paragraphs.
  *
  * The compatible features are:
+ 
  * - the {@link module:list/list~List} or {@link module:list/listediting~ListEditing} feature for list indentation
  * - the {@link module:indent-block/indentblock~IndentBlock} feature for indenting text blocks like paragraphs or headings
  *

From f2296c8557334ec9ed9476d290ac3dacba73c0e9 Mon Sep 17 00:00:00 2001
From: Maciej <jodator@gmail.com>
Date: Wed, 26 Jun 2019 15:29:49 +0200
Subject: [PATCH 24/30] Update src/indent/indent.js
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-Authored-By: Piotrek Koszuliński <pkoszulinski@gmail.com>
---
 src/indent/indent.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/indent/indent.js b/src/indent/indent.js
index 274efe24..7fa97d3d 100644
--- a/src/indent/indent.js
+++ b/src/indent/indent.js
@@ -20,7 +20,7 @@ import IndentUI from './indentui';
  * The compatible features are:
  
  * - the {@link module:list/list~List} or {@link module:list/listediting~ListEditing} feature for list indentation
- * - the {@link module:indent-block/indentblock~IndentBlock} feature for indenting text blocks like paragraphs or headings
+ * * the {@link module:list/list~List} or {@link module:list/listediting~ListEditing} feature for list indentation
  *
  * This is a "glue" plugin which loads the following plugins:
  *

From 401ac7afb2360abb1d17b573769ec13d8c56b856 Mon Sep 17 00:00:00 2001
From: Maciej <jodator@gmail.com>
Date: Wed, 26 Jun 2019 15:30:02 +0200
Subject: [PATCH 25/30] Update src/indent/indent.js
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-Authored-By: Piotrek Koszuliński <pkoszulinski@gmail.com>
---
 src/indent/indent.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/indent/indent.js b/src/indent/indent.js
index 7fa97d3d..ff05de15 100644
--- a/src/indent/indent.js
+++ b/src/indent/indent.js
@@ -28,7 +28,7 @@ import IndentUI from './indentui';
  * * The {@link module:core/indent/indentui~IndentUI indent UI feature}.
  *
  * The dependent plugins register the `'indent'` and `'outdent'` commands and it introduce the `'indent'` and `'outdent'` buttons
- * that allow to increase or decrease text indentation of supported elements.
+ * which allow to increase or decrease text indentation of supported elements.
  *
  * **Note**: In order the commands and buttons to work at least one of compatible features is required.
  *

From 75b3176a34a0852afae5e095a59e369c59e499fb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Wed, 26 Jun 2019 15:53:14 +0200
Subject: [PATCH 26/30] Move Indent* classes from core to intend plugin.

---
 src/indent/indent.js        | 51 ---------------------------
 src/indent/indentediting.js | 40 ---------------------
 src/indent/indentui.js      | 69 -------------------------------------
 3 files changed, 160 deletions(-)
 delete mode 100644 src/indent/indent.js
 delete mode 100644 src/indent/indentediting.js
 delete mode 100644 src/indent/indentui.js

diff --git a/src/indent/indent.js b/src/indent/indent.js
deleted file mode 100644
index ff05de15..00000000
--- a/src/indent/indent.js
+++ /dev/null
@@ -1,51 +0,0 @@
-/**
- * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
- * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
- */
-
-/**
- * @module core/indent/indent
- */
-
-import Plugin from '../plugin';
-
-import IndentEditing from './indentediting';
-import IndentUI from './indentui';
-
-/**
- * The indent feature.
- *
- * This plugin acts as a single entry point plugin for other features that implement indenting of elements like lists or paragraphs.
- *
- * The compatible features are:
- 
- * - the {@link module:list/list~List} or {@link module:list/listediting~ListEditing} feature for list indentation
- * * the {@link module:list/list~List} or {@link module:list/listediting~ListEditing} feature for list indentation
- *
- * This is a "glue" plugin which loads the following plugins:
- *
- * * The {@link module:core/indent/indentediting~IndentEditing indent editing feature} and
- * * The {@link module:core/indent/indentui~IndentUI indent UI feature}.
- *
- * The dependent plugins register the `'indent'` and `'outdent'` commands and it introduce the `'indent'` and `'outdent'` buttons
- * which allow to increase or decrease text indentation of supported elements.
- *
- * **Note**: In order the commands and buttons to work at least one of compatible features is required.
- *
- * @extends module:core/plugin~Plugin
- */
-export default class Indent extends Plugin {
-	/**
-	 * @inheritDoc
-	 */
-	static get pluginName() {
-		return 'Indent';
-	}
-
-	/**
-	 * @inheritDoc
-	 */
-	static get requires() {
-		return [ IndentEditing, IndentUI ];
-	}
-}
diff --git a/src/indent/indentediting.js b/src/indent/indentediting.js
deleted file mode 100644
index c465697b..00000000
--- a/src/indent/indentediting.js
+++ /dev/null
@@ -1,40 +0,0 @@
-/**
- * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
- * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
- */
-
-/**
- * @module core/indent/indentediting
- */
-
-import Plugin from '../plugin';
-import MultiCommand from '../multicommand';
-
-/**
- * The indent editing feature.
- *
- * This plugin registers the `'indent'` and `'outdent'` commands.
- *
- * **Note**: In order the commands to work at least one of compatible features is required. Read more in
- * {@link module:core/indent/indent~Indent indent feature} api docs.
- *
- * @extends module:core/plugin~Plugin
- */
-export default class IndentEditing extends Plugin {
-	/**
-	 * @inheritDoc
-	 */
-	static get pluginName() {
-		return 'IndentEditing';
-	}
-
-	/**
-	 * @inheritDoc
-	 */
-	init() {
-		const editor = this.editor;
-
-		editor.commands.add( 'indent', new MultiCommand( editor ) );
-		editor.commands.add( 'outdent', new MultiCommand( editor ) );
-	}
-}
diff --git a/src/indent/indentui.js b/src/indent/indentui.js
deleted file mode 100644
index 95000314..00000000
--- a/src/indent/indentui.js
+++ /dev/null
@@ -1,69 +0,0 @@
-/**
- * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
- * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
- */
-
-/**
- * @module core/indent/indentui
- */
-import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
-
-import Plugin from '../plugin';
-
-/**
- * The indent feature.
- *
- * This plugin registers the `'indent'` and `'outdent'` buttons.
- *
- * **Note**: In order the commands to work at least one of compatible features is required. Read more in
- * {@link module:core/indent/indent~Indent indent feature} api docs.
- *
- * @extends module:core/plugin~Plugin
- */
-export default class IndentUI extends Plugin {
-	/**
-	 * @inheritDoc
-	 */
-	static get pluginName() {
-		return 'IndentUI';
-	}
-
-	/**
-	 * @inheritDoc
-	 */
-	init() {
-		const editor = this.editor;
-		const t = editor.t;
-
-		this._defineButton( 'indent', t( 'Increase indent' ) );
-		this._defineButton( 'outdent', t( 'Decrease indent' ) );
-	}
-
-	/**
-	 * Defines an UI button.
-	 *
-	 * @param {String} commandName
-	 * @param {String} label
-	 * @private
-	 */
-	_defineButton( commandName, label ) {
-		const editor = this.editor;
-
-		editor.ui.componentFactory.add( commandName, locale => {
-			const command = editor.commands.get( commandName );
-			const view = new ButtonView( locale );
-
-			view.set( {
-				label,
-				withText: true,
-				tooltip: true
-			} );
-
-			view.bind( 'isOn', 'isEnabled' ).to( command, 'value', 'isEnabled' );
-
-			this.listenTo( view, 'execute', () => editor.execute( commandName ) );
-
-			return view;
-		} );
-	}
-}

From 3849a8c5f9dad7eff83c3abb8899dddec4d6bf0a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Thu, 27 Jun 2019 10:19:51 +0200
Subject: [PATCH 27/30] Use an Array for internal commands store in
 MultiCommand.

---
 src/multicommand.js | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/multicommand.js b/src/multicommand.js
index 8c7a426f..6afad569 100644
--- a/src/multicommand.js
+++ b/src/multicommand.js
@@ -13,7 +13,8 @@ import Collection from '@ckeditor/ckeditor5-utils/src/collection';
 /**
  * A CKEditor command that aggregates other commands.
  *
- * This command is used to proxy multiple commands. The multi-command is enabled when at least one of its registered child commands is enabled.
+ * This command is used to proxy multiple commands. The multi-command is enabled when
+ * at least one of its registered child commands is enabled.
  * When executing a multi-command the first command that is enabled will be executed.
  *
  *		const multiCommand = new MultiCommand( editor );
@@ -42,10 +43,10 @@ export default class MultiCommand extends Command {
 		/**
 		 * Registered child commands.
 		 *
-		 * @type {module:utils/collection~Collection.<module:core/command~Command>}
+		 * @type {Array.<module:core/command~Command>}
 		 * @private
 		 */
-		this._childCommands = new Collection();
+		this._childCommands = [];
 	}
 
 	/**
@@ -59,7 +60,7 @@ export default class MultiCommand extends Command {
 	 * Executes the first of it registered child commands.
 	 */
 	execute( ...args ) {
-		const { command } = this._getFirstEnabledCommand();
+		const command = this._getFirstEnabledCommand();
 
 		command.execute( args );
 	}
@@ -70,7 +71,7 @@ export default class MultiCommand extends Command {
 	 * @param {module:core/command~Command} command
 	 */
 	registerChildCommand( command ) {
-		this._childCommands.add( { command } );
+		this._childCommands.push( command );
 
 		// Change multi command enabled state when one of registered commands changes state.
 		command.on( 'change:isEnabled', () => this._checkEnabled() );
@@ -94,6 +95,6 @@ export default class MultiCommand extends Command {
 	 * @private
 	 */
 	_getFirstEnabledCommand() {
-		return this._childCommands.find( ( { command } ) => command.isEnabled );
+		return this._childCommands.find( command => command.isEnabled );
 	}
 }

From f23cd7000826b70a4aa4284e46f2335b6ace6e82 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Thu, 27 Jun 2019 10:21:16 +0200
Subject: [PATCH 28/30] Move Indent* tests to indent also.

---
 tests/indent/indent.js        | 50 ----------------------
 tests/indent/indentediting.js | 50 ----------------------
 tests/indent/indentui.js      | 78 -----------------------------------
 3 files changed, 178 deletions(-)
 delete mode 100644 tests/indent/indent.js
 delete mode 100644 tests/indent/indentediting.js
 delete mode 100644 tests/indent/indentui.js

diff --git a/tests/indent/indent.js b/tests/indent/indent.js
deleted file mode 100644
index 8f07f3ea..00000000
--- a/tests/indent/indent.js
+++ /dev/null
@@ -1,50 +0,0 @@
-/**
- * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
- * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
- */
-
-/* global document */
-
-import ClassicTestEditor from '../_utils/classictesteditor';
-import testUtils from '../_utils/utils';
-
-import Indent from '../../src/indent/indent';
-import IndentEditing from '../../src/indent/indentediting';
-import IndentUI from '../../src/indent/indentui';
-
-describe( 'Indent', () => {
-	let editor, element;
-
-	testUtils.createSinonSandbox();
-
-	beforeEach( () => {
-		element = document.createElement( 'div' );
-		document.body.appendChild( element );
-
-		return ClassicTestEditor
-			.create( element, { plugins: [ Indent ] } )
-			.then( newEditor => {
-				editor = newEditor;
-			} );
-	} );
-
-	afterEach( () => {
-		element.remove();
-
-		if ( editor ) {
-			return editor.destroy();
-		}
-	} );
-
-	it( 'should be named', () => {
-		expect( Indent.pluginName ).to.equal( 'Indent' );
-	} );
-
-	it( 'should load the IndentUI plugin', () => {
-		expect( editor.plugins.get( IndentUI ) ).to.be.instanceOf( IndentUI );
-	} );
-
-	it( 'should load the IndentEditing plugin', () => {
-		expect( editor.plugins.get( IndentEditing ) ).to.be.instanceOf( IndentEditing );
-	} );
-} );
diff --git a/tests/indent/indentediting.js b/tests/indent/indentediting.js
deleted file mode 100644
index 3dc64bbc..00000000
--- a/tests/indent/indentediting.js
+++ /dev/null
@@ -1,50 +0,0 @@
-/**
- * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
- * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
- */
-
-import VirtualTestEditor from '../_utils/virtualtesteditor';
-import testUtils from '../_utils/utils';
-
-import MultiCommand from '../../src/multicommand';
-import IndentEditing from '../../src/indent/indentediting';
-
-describe( 'IndentEditing', () => {
-	let editor;
-
-	testUtils.createSinonSandbox();
-
-	beforeEach( () => {
-		return VirtualTestEditor
-			.create( { plugins: [ IndentEditing ] } )
-			.then( newEditor => {
-				editor = newEditor;
-			} );
-	} );
-
-	afterEach( () => {
-		if ( editor ) {
-			return editor.destroy();
-		}
-	} );
-
-	it( 'should be named', () => {
-		expect( IndentEditing.pluginName ).to.equal( 'IndentEditing' );
-	} );
-
-	it( 'should be loaded', () => {
-		expect( editor.plugins.get( IndentEditing ) ).to.be.instanceOf( IndentEditing );
-	} );
-
-	it( 'should register indent command', () => {
-		const command = editor.commands.get( 'indent' );
-
-		expect( command ).to.be.instanceof( MultiCommand );
-	} );
-
-	it( 'should register outdent command', () => {
-		const command = editor.commands.get( 'outdent' );
-
-		expect( command ).to.be.instanceof( MultiCommand );
-	} );
-} );
diff --git a/tests/indent/indentui.js b/tests/indent/indentui.js
deleted file mode 100644
index 8986ad6c..00000000
--- a/tests/indent/indentui.js
+++ /dev/null
@@ -1,78 +0,0 @@
-/**
- * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
- * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
- */
-
-/* global document */
-
-import ClassicTestEditor from '../_utils/classictesteditor';
-import testUtils from '../_utils/utils';
-import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
-
-import IndentEditing from '../../src/indent/indentediting';
-import IndentUI from '../../src/indent/indentui';
-
-describe( 'IndentUI', () => {
-	let editor, element;
-
-	testUtils.createSinonSandbox();
-
-	beforeEach( () => {
-		element = document.createElement( 'div' );
-		document.body.appendChild( element );
-
-		return ClassicTestEditor
-			.create( element, { plugins: [ IndentUI, IndentEditing ] } )
-			.then( newEditor => {
-				editor = newEditor;
-			} );
-	} );
-
-	afterEach( () => {
-		element.remove();
-
-		if ( editor ) {
-			return editor.destroy();
-		}
-	} );
-
-	it( 'should be named', () => {
-		expect( IndentUI.pluginName ).to.equal( 'IndentUI' );
-	} );
-
-	it( 'should be loaded', () => {
-		expect( editor.plugins.get( IndentUI ) ).to.be.instanceOf( IndentUI );
-	} );
-
-	it( 'should set up button for indent', () => {
-		const indentButton = editor.ui.componentFactory.create( 'indent' );
-
-		expect( indentButton ).to.be.instanceOf( ButtonView );
-	} );
-
-	it( 'should set up button for indent', () => {
-		const outdentButton = editor.ui.componentFactory.create( 'outdent' );
-
-		expect( outdentButton ).to.be.instanceOf( ButtonView );
-	} );
-
-	it( 'should execute indent command on button execute', () => {
-		const button = editor.ui.componentFactory.create( 'indent' );
-		const spy = sinon.spy( editor, 'execute' );
-
-		button.fire( 'execute' );
-
-		sinon.assert.calledOnce( spy );
-		sinon.assert.calledWithExactly( spy, 'indent' );
-	} );
-
-	it( 'should execute outdent command on button execute', () => {
-		const button = editor.ui.componentFactory.create( 'outdent' );
-		const spy = sinon.spy( editor, 'execute' );
-
-		button.fire( 'execute' );
-
-		sinon.assert.calledOnce( spy );
-		sinon.assert.calledWithExactly( spy, 'outdent' );
-	} );
-} );

From d8517ce0683a563d8faff0773b1921c1380f562e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Thu, 27 Jun 2019 10:54:18 +0200
Subject: [PATCH 29/30] Revert article manual tests html file.

---
 tests/manual/article.html | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/manual/article.html b/tests/manual/article.html
index 1b8e2bfa..4faffd0a 100644
--- a/tests/manual/article.html
+++ b/tests/manual/article.html
@@ -8,7 +8,7 @@
 </head>
 <div id="editor">
 	<h2>Heading 1</h2>
-	<p style="margin-left:2em;">Paragraph</p>
+	<p>Paragraph</p>
 	<p><strong>Bold</strong> <i>Italic</i> <a href="https://ckeditor.com">Link</a></p>
 	<ul>
 		<li>UL List item 1</li>

From 0b23e78f57bb319e5f39bbce7a7294596d677570 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Go=C5=82aszewski?= <jodator@jodator.net>
Date: Thu, 27 Jun 2019 14:14:36 +0200
Subject: [PATCH 30/30] Remove useless import from MultiCommand.

---
 src/multicommand.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/multicommand.js b/src/multicommand.js
index 6afad569..a7ba6524 100644
--- a/src/multicommand.js
+++ b/src/multicommand.js
@@ -4,7 +4,6 @@
  */
 
 import Command from './command';
-import Collection from '@ckeditor/ckeditor5-utils/src/collection';
 
 /**
  * @module core/multicommand