[lhc/web/wiklou.git] / resources / src / mediawiki / mediawiki.notification.js

( function ( mw, $ ) {
        'use strict';

        var notification,
                // The #mw-notification-area div that all notifications are contained inside.
                $area,
                // Number of open notification boxes at any time
                openNotificationCount = 0,
                isPageReady = false,
                preReadyNotifQueue = [],
                rAF = window.requestAnimationFrame || setTimeout;

        /**
         * A Notification object for 1 message.
         *
         * The underscore in the name is to avoid a bug <https://github.com/senchalabs/jsduck/issues/304>.
         * It is not part of the actual class name.
         *
         * @class mw.Notification_
         * @alternateClassName mw.Notification
         *
         * @constructor The constructor is not publicly accessible; use mw.notification#notify instead.
         *  This does not insert anything into the document (see #start).
         * @private
         */
        function Notification( message, options ) {
                var $notification, $notificationTitle, $notificationContent;

                $notification = $( '<div class="mw-notification"></div>' )
                        .data( 'mw.notification', this )
                        .addClass( options.autoHide ? 'mw-notification-autohide' : 'mw-notification-noautohide' );

                if ( options.tag ) {
                        // Sanitize options.tag before it is used by any code. (Including Notification class methods)
                        options.tag = options.tag.replace( /[ _\-]+/g, '-' ).replace( /[^\-a-z0-9]+/ig, '' );
                        if ( options.tag ) {
                                $notification.addClass( 'mw-notification-tag-' + options.tag );
                        } else {
                                delete options.tag;
                        }
                }

                if ( options.type ) {
                        // Sanitize options.type
                        options.type = options.type.replace( /[ _\-]+/g, '-' ).replace( /[^\-a-z0-9]+/ig, '' );
                        $notification.addClass( 'mw-notification-type-' + options.type );
                }

                if ( options.title ) {
                        $notificationTitle = $( '<div class="mw-notification-title"></div>' )
                                .text( options.title )
                                .appendTo( $notification );
                }

                $notificationContent = $( '<div class="mw-notification-content"></div>' );

                if ( typeof message === 'object' ) {
                        // Handle mw.Message objects separately from DOM nodes and jQuery objects
                        if ( message instanceof mw.Message ) {
                                $notificationContent.html( message.parse() );
                        } else {
                                $notificationContent.append( message );
                        }
                } else {
                        $notificationContent.text( message );
                }

                $notificationContent.appendTo( $notification );

                // Private state parameters, meant for internal use only
                // isOpen: Set to true after .start() is called to avoid double calls.
                //         Set back to false after .close() to avoid duplicating the close animation.
                // isPaused: false after .resume(), true after .pause(). Avoids duplicating or breaking the hide timeouts.
                //           Set to true initially so .start() can call .resume().
                // message: The message passed to the notification. Unused now but may be used in the future
                //          to stop replacement of a tagged notification with another notification using the same message.
                // options: The options passed to the notification with a little sanitization. Used by various methods.
                // $notification: jQuery object containing the notification DOM node.
                this.isOpen = false;
                this.isPaused = true;
                this.message = message;
                this.options = options;
                this.$notification = $notification;
        }

        /**
         * Start the notification. Called automatically by mw.notification#notify
         * (possibly asynchronously on document-ready).
         *
         * This inserts the notification into the page, closes any matching tagged notifications,
         * handles the fadeIn animations and replacement transitions, and starts autoHide timers.
         *
         * @private
         */
        Notification.prototype.start = function () {
                var options, $notification, $tagMatches, autohideCount;

                $area.show();

                if ( this.isOpen ) {
                        return;
                }

                this.isOpen = true;
                openNotificationCount++;

                options = this.options;
                $notification = this.$notification;

                if ( options.tag ) {
                        // Find notifications with the same tag
                        $tagMatches = $area.find( '.mw-notification-tag-' + options.tag );
                }

                // If we found existing notification with the same tag, replace them
                if ( options.tag && $tagMatches.length ) {

                        // While there can be only one "open" notif with a given tag, there can be several
                        // matches here because they remain in the DOM until the animation is finished.
                        $tagMatches.each( function () {
                                var notif = $( this ).data( 'mw.notification' );
                                if ( notif && notif.isOpen ) {
                                        // Detach from render flow with position absolute so that the new tag can
                                        // occupy its space instead.
                                        notif.$notification
                                                .css( {
                                                        position: 'absolute',
                                                        width: notif.$notification.width()
                                                } )
                                                .css( notif.$notification.position() )
                                                .addClass( 'mw-notification-replaced' );
                                        notif.close();
                                }
                        } );

                        $notification
                                .insertBefore( $tagMatches.first() )
                                .addClass( 'mw-notification-visible' );
                } else {
                        $area.append( $notification );
                        rAF( function () {
                                // This frame renders the element in the area (invisible)
                                rAF( function () {
                                        $notification.addClass( 'mw-notification-visible' );
                                } );
                        } );
                }

                // By default a notification is paused.
                // If this notification is within the first {autoHideLimit} notifications then
                // start the auto-hide timer as soon as it's created.
                autohideCount = $area.find( '.mw-notification-autohide' ).length;
                if ( autohideCount <= notification.autoHideLimit ) {
                        this.resume();
                }
        };

        /**
         * Pause any running auto-hide timer for this notification
         */
        Notification.prototype.pause = function () {
                if ( this.isPaused ) {
                        return;
                }
                this.isPaused = true;

                if ( this.timeout ) {
                        clearTimeout( this.timeout );
                        delete this.timeout;
                }
        };

        /**
         * Start autoHide timer if not already started.
         * Does nothing if autoHide is disabled.
         * Either to resume from pause or to make the first start.
         */
        Notification.prototype.resume = function () {
                var notif = this;
                if ( !notif.isPaused ) {
                        return;
                }
                // Start any autoHide timeouts
                if ( notif.options.autoHide ) {
                        notif.isPaused = false;
                        notif.timeout = setTimeout( function () {
                                // Already finished, so don't try to re-clear it
                                delete notif.timeout;
                                notif.close();
                        }, notification.autoHideSeconds * 1000 );
                }
        };

        /**
         * Close the notification.
         */
        Notification.prototype.close = function () {
                var notif = this;

                if ( !this.isOpen ) {
                        return;
                }

                this.isOpen = false;
                openNotificationCount--;

                // Clear any remaining timeout on close
                this.pause();

                // Remove the mw-notification-autohide class from the notification to avoid
                // having a half-closed notification counted as a notification to resume
                // when handling {autoHideLimit}.
                this.$notification.removeClass( 'mw-notification-autohide' );

                // Now that a notification is being closed. Start auto-hide timers for any
                // notification that has now become one of the first {autoHideLimit} notifications.
                notification.resume();

                rAF( function () {
                        notif.$notification.removeClass( 'mw-notification-visible' );

                        setTimeout( function () {
                                if ( openNotificationCount === 0 ) {
                                        // Hide the area after the last notification closes. Otherwise, the padding on
                                        // the area can be obscure content, despite the area being empty/invisible (T54659). // FIXME
                                        $area.hide();
                                        notif.$notification.remove();
                                } else {
                                        notif.$notification.slideUp( 'fast',  function () {
                                                $( this ).remove();
                                        } );
                                }
                        }, 500 );
                } );
        };

        /**
         * Helper function, take a list of notification divs and call
         * a function on the Notification instance attached to them.
         *
         * @private
         * @static
         * @param {jQuery} $notifications A jQuery object containing notification divs
         * @param {string} fn The name of the function to call on the Notification instance
         */
        function callEachNotification( $notifications, fn ) {
                $notifications.each( function () {
                        var notif = $( this ).data( 'mw.notification' );
                        if ( notif ) {
                                notif[ fn ]();
                        }
                } );
        }

        /**
         * Initialisation.
         * Must only be called once, and not before the document is ready.
         *
         * @ignore
         */
        function init() {
                var offset, $window = $( window );

                $area = $( '<div id="mw-notification-area" class="mw-notification-area mw-notification-area-layout"></div>' )
                        // Pause auto-hide timers when the mouse is in the notification area.
                        .on( {
                                mouseenter: notification.pause,
                                mouseleave: notification.resume
                        } )
                        // When clicking on a notification close it.
                        .on( 'click', '.mw-notification', function () {
                                var notif = $( this ).data( 'mw.notification' );
                                if ( notif ) {
                                        notif.close();
                                }
                        } )
                        // Stop click events from <a> tags from propogating to prevent clicking.
                        // on links from hiding a notification.
                        .on( 'click', 'a', function ( e ) {
                                e.stopPropagation();
                        } );

                // Prepend the notification area to the content area and save it's object.
                mw.util.$content.prepend( $area );
                offset = $area.offset();
                $area.hide();

                function updateAreaMode() {
                        var isFloating = $window.scrollTop() > offset.top;
                        $area
                                .toggleClass( 'mw-notification-area-floating', isFloating )
                                .toggleClass( 'mw-notification-area-layout', !isFloating );
                }

                $window.on( 'scroll', updateAreaMode );

                // Initial mode
                updateAreaMode();
        }

        /**
         * @class mw.notification
         * @singleton
         */
        notification = {
                /**
                 * Pause auto-hide timers for all notifications.
                 * Notifications will not auto-hide until resume is called.
                 *
                 * @see mw.Notification#pause
                 */
                pause: function () {
                        callEachNotification(
                                $area.children( '.mw-notification' ),
                                'pause'
                        );
                },

                /**
                 * Resume any paused auto-hide timers from the beginning.
                 * Only the first #autoHideLimit timers will be resumed.
                 */
                resume: function () {
                        callEachNotification(
                                // Only call resume on the first #autoHideLimit notifications.
                                // Exclude noautohide notifications to avoid bugs where #autoHideLimit
                                // `{ autoHide: false }` notifications are at the start preventing any
                                // auto-hide notifications from being autohidden.
                                $area.children( '.mw-notification-autohide' ).slice( 0, notification.autoHideLimit ),
                                'resume'
                        );
                },

                /**
                 * Display a notification message to the user.
                 *
                 * @param {HTMLElement|HTMLElement[]|jQuery|mw.Message|string} message
                 * @param {Object} options The options to use for the notification.
                 *  See #defaults for details.
                 * @return {mw.Notification} Notification object
                 */
                notify: function ( message, options ) {
                        var notif;
                        options = $.extend( {}, notification.defaults, options );

                        notif = new Notification( message, options );

                        if ( isPageReady ) {
                                notif.start();
                        } else {
                                preReadyNotifQueue.push( notif );
                        }

                        return notif;
                },

                /**
                 * @property {Object}
                 * The defaults for #notify options parameter.
                 *
                 * - autoHide:
                 *   A boolean indicating whether the notifification should automatically
                 *   be hidden after shown. Or if it should persist.
                 *
                 * - tag:
                 *   An optional string. When a notification is tagged only one message
                 *   with that tag will be displayed. Trying to display a new notification
                 *   with the same tag as one already being displayed will cause the other
                 *   notification to be closed and this new notification to open up inside
                 *   the same place as the previous notification.
                 *
                 * - title:
                 *   An optional title for the notification. Will be displayed above the
                 *   content. Usually in bold.
                 *
                 * - type:
                 *   An optional string for the type of the message used for styling:
                 *   Examples: 'info', 'warn', 'error'.
                 */
                defaults: {
                        autoHide: true,
                        tag: false,
                        title: undefined,
                        type: false
                },

                /**
                 * @property {number}
                 * Number of seconds to wait before auto-hiding notifications.
                 */
                autoHideSeconds: 5,

                /**
                 * @property {number}
                 * Maximum number of notifications to count down auto-hide timers for.
                 * Only the first #autoHideLimit notifications being displayed will
                 * auto-hide. Any notifications further down in the list will only start
                 * counting down to auto-hide after the first few messages have closed.
                 *
                 * This basically represents the number of notifications the user should
                 * be able to process in #autoHideSeconds time.
                 */
                autoHideLimit: 3
        };

        $( function () {
                var notif;

                init();

                // Handle pre-ready queue.
                isPageReady = true;
                while ( preReadyNotifQueue.length ) {
                        notif = preReadyNotifQueue.shift();
                        notif.start();
                }
        } );

        mw.notification = notification;

}( mediaWiki, jQuery ) );