Extract LanguageSwitcher to separate class

The Language switcher will be used in couple places:
 - Toolbar, if the AMC is off
 - both overflow mmenus when AMC is on

To make code DRY, first we should provide a single way to
create Language Switcher menu element, so we can use same way
in all possible scenarios.

Bug: T224735
Change-Id: I5ba0dbad7089012c7fd1bfc43787775c7e36d575

includes/menu/LanguageSelectorEntry.php

@@ -0,0 +1,101 @@
+<?php
+/**
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+namespace MediaWiki\Minerva\Menu;
+
+use MessageLocalizer;
+use MinervaUI;
+use SpecialPage;
+use Title;
+
+/**
+ * Model for a menu entry that represents a language selector for current title
+ */
+class LanguageSelectorEntry implements IMenuEntry {
+
+	/**
+	 * @var MessageLocalizer
+	 */
+	private $messageLocalizer;
+	/**
+	 * @var Title
+	 */
+	private $title;
+	/**
+	 * @var bool
+	 */
+	private $doesPageHaveLanguages;
+	/**
+	 * LanguageSelectorEntry constructor.
+	 * @param Title $title Current Title
+	 * @param bool $doesPageHaveLanguages Whether the page is also available in other
+	 * languages or variants
+	 * @param MessageLocalizer $messageLocalizer Used for translation texts
+	 *
+	 */
+	public function __construct(
+		Title $title,
+		$doesPageHaveLanguages,
+		MessageLocalizer $messageLocalizer
+	) {
+		$this->title = $title;
+		$this->doesPageHaveLanguages = $doesPageHaveLanguages;
+		$this->messageLocalizer = $messageLocalizer;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getName() {
+		return 'language-selector';
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getCSSClasses(): array {
+		return [];
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getComponents(): array {
+		$switcherLink = false;
+		$switcherClasses = ' language-selector';
+
+		if ( $this->doesPageHaveLanguages ) {
+			$switcherLink = SpecialPage::getTitleFor(
+				'MobileLanguages',
+				$this->title
+			)->getLocalURL();
+		} else {
+			$switcherClasses .= ' disabled';
+		}
+		$iconClass = MinervaUI::iconClass( 'language-switcher', 'element', $switcherClasses );
+
+		return [
+			[
+				'href' => $switcherLink,
+				'class' => $iconClass,
+				'text' => $this->messageLocalizer->msg( 'mobile-frontend-language-article-heading' ),
+				'title' => $this->messageLocalizer->msg( 'mobile-frontend-language-article-heading' )
+			]
+
+		];
+	}
+}

includes/menu/PageActions/ToolbarBuilder.php

@@ -23,6 +23,7 @@ namespace MediaWiki\Minerva\Menu\PageActions;
 use ExtensionRegistry;
 use Hooks;
 use MediaWiki\Minerva\Menu\Group;
+use MediaWiki\Minerva\Menu\LanguageSelectorEntry;
 use MediaWiki\Permissions\PermissionManager;
 use MessageLocalizer;
 use MinervaUI;
@@ -85,7 +86,9 @@ class ToolbarBuilder {
 		$group = new Group();
 
 		if ( $this->skin->isAllowedPageAction( 'switch-language' ) ) {
-			$group->insertEntry( $this->createSwitchLanguageAction( $doesPageHaveLanguages ) );
+			$group->insertEntry(
+				new LanguageSelectorEntry( $this->title, $doesPageHaveLanguages, $this->messageLocalizer )
+			);
 		}
 
 		if ( $this->skin->isAllowedPageAction( 'watch' ) ) {
@@ -147,38 +150,6 @@ class ToolbarBuilder {
 			->setNodeID( 'ca-edit' );
 	}
 
-	/**
-	 * Creates the "switch-language" action: the icon that, when tapped, opens the language
-	 * switcher.
-	 * @param bool $doesPageHaveLanguages Whether the page is also available in other
-	 * languages or variants
-	 * @return PageActionMenuEntry A menu entry object that represents a map of HTML attributes
-	 * and a 'text' property to be used with the pageActionMenu.mustache template.
-	 * @throws MWException
-	 */
-	protected function createSwitchLanguageAction( $doesPageHaveLanguages ) {
-		$languageSwitcherLink = false;
-		$languageSwitcherClasses = ' language-selector';
-
-		if ( $doesPageHaveLanguages ) {
-			$languageSwitcherLink = SpecialPage::getTitleFor(
-				'MobileLanguages',
-				$this->title
-			)->getLocalURL();
-		} else {
-			$languageSwitcherClasses .= ' disabled';
-		}
-		$entry = new PageActionMenuEntry(
-			'page-actions-languages',
-			$languageSwitcherLink,
-			MinervaUI::iconClass( 'language-switcher', 'element', $languageSwitcherClasses ),
-			$this->messageLocalizer->msg( 'mobile-frontend-language-article-heading' )
-		);
-		return $entry->setTitle(
-			$this->messageLocalizer->msg( 'mobile-frontend-language-article-heading' )
-		);
-	}
-
 	/**
 	 * Creates the "watch" or "unwatch" action: the well-known star icon that, when tapped, will
 	 * add the page to or remove the page from the user's watchlist; or, if the user is logged out,