Add language settings button inside dropdown for non-content pages

Bug: T316559
Change-Id: Ifdf2a529b30e5a2df8867b606a525c9f7b3bdb6c

includes/Hooks.php

@@ -170,6 +170,10 @@ class Hooks implements
 		if ( $this->isEnabled() ) {
 			// Enable UI language selection for the user.
 			$out->addModules( 'ext.uls.interface' );
+
+			$templateData = $skin->getTemplateData();
+			$isLanguageSelectorEmpty = $templateData[ 'data-lang-btn' ][ 'is-language-selector-empty' ] ?? false;
+			$config[ 'wgULSisLanguageSelectorEmpty' ] = $isLanguageSelectorEmpty;
 		}
 
 		// This is added here, and not in onResourceLoaderGetConfigVars to allow skins and extensions

resources/css/ext.uls.interface.less

@@ -70,3 +70,7 @@
 		margin: 1em 0;
 	}
 }
+
+.empty-language-selector__language-settings-button {
+	margin: 12px;
+}

resources/js/ext.uls.interface.js

@@ -717,7 +717,58 @@
 		}
 	}
 
+	/**
+	 * The new Vector 2022 skin uses a less prominent language button for non-content pages.
+	 * For these pages, the ULS should not be displayed, but a dropdown with an appropriate message
+	 * should appear. The UniversalLanguageSelector extension should add a button to open the
+	 * language settings, inside this dropdown.
+	 * This method adds this button inside the dropdown.
+	 */
+	function addLanguageSettingsToNonContentPages() {
+		var $languageBtn = $( '#p-lang-btn' );
+		var clickHandler = function ( event ) {
+			event.stopPropagation();
+
+			mw.loader.using( languageSettingsModules ).then( function () {
+				$( event.target ).languagesettings( {
+					autoOpen: true,
+					onPosition: function () {
+						var offset = $languageBtn.offset();
+						var top = offset.top + $languageBtn.outerHeight();
+						var right = $( window ).width() - offset.left - $languageBtn.outerWidth();
+						return { top: top, right: right };
+					}
+				} );
+			} );
+		};
+		// the first time the language button is clicked inside a non-content page,
+		// we should add the "Open language settings" button inside the dropdown
+		$languageBtn.one( 'mouseover', function () {
+			mw.loader.using( [ 'oojs-ui-widgets', 'oojs-ui.styles.icons-interactions', 'ext.uls.messages' ] )
+				.done( function () {
+					var actionButton = new ActionsMenuItem(
+						'settings',
+						$.i18n( 'ext-uls-actions-menu-language-settings-item-label' ),
+						clickHandler,
+						null
+					).render();
+
+					actionButton.$element.addClass( 'empty-language-selector__language-settings-button' );
+					var $emptyLanguageSelectorBody = $( '.mw-portlet-empty-language-selector-body' );
+					$emptyLanguageSelectorBody.after( actionButton.$element );
+				} );
+		} );
+	}
+
 	function init() {
+		// if it's not Vector skin, nothing to be done here
+		if ( mw.config.get( 'skin' ) === 'vector-2022' && mw.config.get( 'wgULSisLanguageSelectorEmpty' ) ) {
+			// if this is a non-content page, we should add the "Open language settings" button
+			// inside the language dropdown
+			addLanguageSettingsToNonContentPages();
+			// TODO: should we return after here?
+		}
+
 		initLanguageChangeUndoTooltip();
 		initIme();