From 1ff482f668d5b5af54f8e14284dc4e8127824f11 Mon Sep 17 00:00:00 2001
From: Aleksander Nowodzinski <a.nowodzinski@cksource.com>
Date: Mon, 29 Jul 2019 15:42:34 +0200
Subject: [PATCH 1/2] Made the undo and redo button icons match the editor UI
 language direction.

---
 src/undoui.js   |  8 +++++--
 tests/undoui.js | 63 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/src/undoui.js b/src/undoui.js
index b6efb75..540ad9f 100644
--- a/src/undoui.js
+++ b/src/undoui.js
@@ -24,10 +24,14 @@ export default class UndoUI extends Plugin {
 	 */
 	init() {
 		const editor = this.editor;
+		const locale = editor.locale;
 		const t = editor.t;
 
-		this._addButton( 'undo', t( 'Undo' ), 'CTRL+Z', undoIcon );
-		this._addButton( 'redo', t( 'Redo' ), 'CTRL+Y', redoIcon );
+		const localizedUndoIcon = locale.languageDirection == 'ltr' ? undoIcon : redoIcon;
+		const localizedRedoIcon = locale.languageDirection == 'ltr' ? redoIcon : undoIcon;
+
+		this._addButton( 'undo', t( 'Undo' ), 'CTRL+Z', localizedUndoIcon );
+		this._addButton( 'redo', t( 'Redo' ), 'CTRL+Y', localizedRedoIcon );
 	}
 
 	/**
diff --git a/tests/undoui.js b/tests/undoui.js
index 04c7050..acffb9f 100644
--- a/tests/undoui.js
+++ b/tests/undoui.js
@@ -11,6 +11,9 @@ import UndoUI from '../src/undoui';
 import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
 import testUtils from '@ckeditor/ckeditor5-core/tests/_utils/utils';
 
+import undoIcon from '../theme/icons/undo.svg';
+import redoIcon from '../theme/icons/redo.svg';
+
 describe( 'UndoUI', () => {
 	let editor, editorElement;
 
@@ -35,6 +38,66 @@ describe( 'UndoUI', () => {
 	testButton( 'undo', 'Undo', 'CTRL+Z' );
 	testButton( 'redo', 'Redo', 'CTRL+Y' );
 
+	describe( 'icons', () => {
+		describe( 'left–to–right UI', () => {
+			it( 'should display the right icon for undo', () => {
+				const undoButton = editor.ui.componentFactory.create( 'undo' );
+
+				expect( undoButton.icon ).to.equal( undoIcon );
+			} );
+
+			it( 'should display the right icon for redo', () => {
+				const redoButton = editor.ui.componentFactory.create( 'redo' );
+
+				expect( redoButton.icon ).to.equal( redoIcon );
+			} );
+		} );
+
+		describe( 'right–to–left UI', () => {
+			it( 'should display the right icon for undo', () => {
+				const element = document.createElement( 'div' );
+				document.body.appendChild( element );
+
+				return ClassicTestEditor
+					.create( element, {
+						plugins: [ UndoEditing, UndoUI ],
+						language: 'ar'
+					} )
+					.then( newEditor => {
+						const undoButton = newEditor.ui.componentFactory.create( 'undo' );
+
+						expect( undoButton.icon ).to.equal( redoIcon );
+
+						return newEditor.destroy();
+					} )
+					.then( () => {
+						element.remove();
+					} );
+			} );
+
+			it( 'should display the right icon for redo', () => {
+				const element = document.createElement( 'div' );
+				document.body.appendChild( element );
+
+				return ClassicTestEditor
+					.create( element, {
+						plugins: [ UndoEditing, UndoUI ],
+						language: 'ar'
+					} )
+					.then( newEditor => {
+						const redoButton = newEditor.ui.componentFactory.create( 'redo' );
+
+						expect( redoButton.icon ).to.equal( undoIcon );
+
+						return newEditor.destroy();
+					} )
+					.then( () => {
+						element.remove();
+					} );
+			} );
+		} );
+	} );
+
 	function testButton( featureName, label, featureKeystroke ) {
 		describe( `${ featureName } button`, () => {
 			let button;

From a74775b1eddce4d68d53a845bdd6607fac63af77 Mon Sep 17 00:00:00 2001
From: Aleksander Nowodzinski <a.nowodzinski@cksource.com>
Date: Fri, 9 Aug 2019 15:56:04 +0200
Subject: [PATCH 2/2] Aligned the code to the latest Locale class API.

---
 src/undoui.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/undoui.js b/src/undoui.js
index 540ad9f..1d285ca 100644
--- a/src/undoui.js
+++ b/src/undoui.js
@@ -27,8 +27,8 @@ export default class UndoUI extends Plugin {
 		const locale = editor.locale;
 		const t = editor.t;
 
-		const localizedUndoIcon = locale.languageDirection == 'ltr' ? undoIcon : redoIcon;
-		const localizedRedoIcon = locale.languageDirection == 'ltr' ? redoIcon : undoIcon;
+		const localizedUndoIcon = locale.uiLanguageDirection == 'ltr' ? undoIcon : redoIcon;
+		const localizedRedoIcon = locale.uiLanguageDirection == 'ltr' ? redoIcon : undoIcon;
 
 		this._addButton( 'undo', t( 'Undo' ), 'CTRL+Z', localizedUndoIcon );
 		this._addButton( 'redo', t( 'Redo' ), 'CTRL+Y', localizedRedoIcon );