Remove talk page notification bar if all messages are read

Bug: T106033
Change-Id: I5133896c204be701e0fae582af91c906175f39d1

modules/ext.echo.init.js

@@ -57,6 +57,11 @@
 					mw.echo.ui.messageWidget.badgeButton.debouncedUpdateThemeClasses();
 					// Replace the link button with the ooui button
 					$existingMessageLink.parent().replaceWith( mw.echo.ui.messageWidget.$element );
+
+					mw.echo.ui.messageWidget.getModel().on( 'allRead', function () {
+						// If there was a talk page notification, get rid of it
+						$( '#pt-mytalk' ).detach();
+					} );
 				}
 
 				// Load alerts popup and button

modules/ooui/mw.echo.ui.NotificationBadgeWidget.js

@@ -162,6 +162,13 @@
 
 	mw.echo.ui.NotificationBadgeWidget.static.tagName = 'li';
 
+	/* Events */
+
+	/**
+	 * @event allRead
+	 * All notifications were marked as read
+	 */
+
 	/* Methods */
 
 	/**

modules/viewmodel/mw.echo.dm.NotificationsModel.js

@@ -74,6 +74,12 @@
 	 * Items' read status has changed
 	 */
 
+	/**
+	 * @event allRead
+	 *
+	 * All items are marked as read
+	 */
+
 	/* Methods */
 
 	/**
@@ -117,6 +123,10 @@
 			}
 			this.emit( 'unreadChange', this.unreadNotifications.getItems() );
 		}
+
+		if ( this.unreadNotifications.isEmpty() ) {
+			this.emit( 'allRead' );
+		}
 	};
 
 	/**