mediawiki-extensions-Echo/modules/ui/mw.echo.ui.SortedListWidget.js
Moriel Schottlender f4a955efe9 Fix fade-in/out animation in sorting
The fade in/out animation is asynchronous. This means that if we are
sorting multiple items one after the other, by the time the item faded
out, it will be reinserted back into the wrong position, breaking the
sorting.

This also broke the promise of OO.SortedEmitterList whereby all its items
are always in order.

The way to fix this was to force a better synchronization with the item
order while we hide and show the item in its new place. To do that,
a new widget is created as a fake clone of the old one, in the original
position of the old one. The original item is then reinserted (while hidden)
to the proper location -- preserving order. The fake clone is then faded
out, and the real item is then faded in.

For this to work properly, the cloned item had to preserve some of the
original item's information, like timestamp, foreigness and id. However,
since both the real item and the fake new clone have the same details,
the clone fakes its ID by adding a fraction to it - promising that the
fallback in case of equal timestamps (which happens on the real and
cloned items) will still resolve with some decision about the placement
of the items rather than (falsely but understandably) decide they are
both the same.

Since this whole animation is somewhat of a hack, the list now has a
configuration parameter to turn the animation on.

The animation is on in the popups, but off in the special page.

Bug: T141419
Change-Id: Ic7c35e5ddefc51bf7fde497eab36414b4dddcd9e
2016-08-01 13:49:10 -07:00

273 lines
7 KiB
JavaScript

( function ( mw ) {
/**
* Sorted list widget. This is a group widget that sorts its items
* according to a given sorting callback.
*
* @class
* @extends OO.ui.Widget
* @mixins OO.SortedEmitterList
*
* @constructor
* @param {Function} sortingCallback Callback that compares two items.
* @param {Object} [config] Configuration options
* @cfg {jQuery} [$group] The container element created by the class. If this configuration
* is omitted, the group element will use a generated `<div>`.
* @cfg {jQuery} [$overlay] A jQuery element functioning as an overlay
* for popups.
* @cfg {number} [timestamp=0] A fallback timestamp for the list, usually representing
* the timestamp of the latest item.
* @cfg {boolean} [animated=false] Animate the sorting of items
*/
mw.echo.ui.SortedListWidget = function MwEchoUiSortedListWidget( sortingCallback, config ) {
config = config || {};
// Parent constructor
mw.echo.ui.SortedListWidget.parent.call( this, config );
// Mixin constructor
OO.SortedEmitterList.call( this, sortingCallback );
// Properties
this.$group = null;
this.$overlay = config.$overlay;
this.timestamp = config.timestamp || 0;
this.animated = !!config.animated;
// Initialization
this.setGroupElement( config.$group || this.$element );
this.$element
.addClass( 'mw-echo-ui-sortedListWidget' );
};
/* Initialization */
OO.inheritClass( mw.echo.ui.SortedListWidget, OO.ui.Widget );
OO.mixinClass( mw.echo.ui.SortedListWidget, OO.SortedEmitterList );
/* Methods */
/**
* @inheritdoc
*/
mw.echo.ui.SortedListWidget.prototype.onItemSortChange = function ( item ) {
var fakeWidget,
widget = this;
if ( this.animated ) {
// Create a fake widget with cloned contents
fakeWidget = new mw.echo.ui.ClonedNotificationItemWidget(
item.$element.clone( true ),
{
id: item.getId() + '.42',
read: !item.isRead(),
foreign: item.isForeign(),
timestamp: item.getTimestamp()
}
);
// remove real item from item list, without touching the DOM
this.removeItems( item );
// insert real item, hidden
item.$element.hide();
this.addItems( item );
// insert fake
this.addItems( fakeWidget );
// fade out fake
fakeWidget.$element.fadeOut( 400, function () {
// remove fake
widget.removeItems( fakeWidget );
// fade-in real item
item.$element.fadeIn( 400 );
} );
} else {
// Mixin method
OO.SortedEmitterList.prototype.onItemSortChange.call( this, item );
}
};
/**
* Set the group element.
*
* If an element is already set, items will be moved to the new element.
*
* @param {jQuery} $group Element to use as group
*/
mw.echo.ui.SortedListWidget.prototype.setGroupElement = function ( $group ) {
var i, len;
this.$group = $group;
for ( i = 0, len = this.items.length; i < len; i++ ) {
this.$group.append( this.items[ i ].$element );
}
};
/**
* Get an item by its id.
*
* @param {number} id Item id to search for
* @return {OO.ui.Element|null} Item with equivalent data, `null` if none exists
*/
mw.echo.ui.SortedListWidget.prototype.getItemFromId = function ( id ) {
var i, len, item,
hash = OO.getHash( id );
for ( i = 0, len = this.items.length; i < len; i++ ) {
item = this.items[ i ];
if ( hash === OO.getHash( item.getId() ) ) {
return item;
}
}
return null;
};
/**
* Get an item by its data.
*
* @param {string} data Item data to search for
* @return {OO.ui.Element|null} Item with equivalent data, `null` if none exists
*/
mw.echo.ui.SortedListWidget.prototype.getItemFromData = function ( data ) {
var i, len, item,
hash = OO.getHash( data );
for ( i = 0, len = this.items.length; i < len; i++ ) {
item = this.items[ i ];
if ( hash === OO.getHash( item.getData() ) ) {
return item;
}
}
return null;
};
/**
* Remove items.
*
* @param {OO.EventEmitter[]} items Items to remove
* @chainable
* @fires remove
*/
mw.echo.ui.SortedListWidget.prototype.removeItems = function ( items ) {
var i, item, index;
if ( !Array.isArray( items ) ) {
items = [ items ];
}
if ( items.length > 0 ) {
// Remove specific items
for ( i = 0; i < items.length; i++ ) {
item = items[ i ];
index = this.items.indexOf( item );
if ( index !== -1 ) {
item.setElementGroup( null );
item.$element.detach();
}
}
}
return OO.SortedEmitterList.prototype.removeItems.call( this, items );
};
/**
* Utility method to insert an item into the list, and
* connect it to aggregate events.
*
* Don't call this directly unless you know what you're doing.
* Use #addItems instead.
*
* @private
* @param {OO.EventEmitter} item Items to add
* @param {number} index Index to add items at
* @return {number} The index the item was added at
*/
mw.echo.ui.SortedListWidget.prototype.insertItem = function ( item, index ) {
// Call parent and get the normalized index
index = OO.SortedEmitterList.prototype.insertItem.call( this, item, index );
item.setElementGroup( this );
this.attachItemToDom( item, index );
return index;
};
/**
* Move an item from its current position to a new index.
*
* The item is expected to exist in the list. If it doesn't,
* the method will throw an exception.
*
* @private
* @param {OO.EventEmitter} item Items to add
* @param {number} index Index to move the item to
* @return {number} The index the item was moved to
* @throws {Error} If item is not in the list
*/
mw.echo.ui.SortedListWidget.prototype.moveItem = function ( item, index ) {
// Call parent and get the normalized index
index = OO.SortedEmitterList.prototype.moveItem.call( this, item, index );
this.attachItemToDom( item, index );
return index;
};
/**
* Attach the item to the Dom in its intended position, based
* on the given index.
*
* @param {OO.EventEmitter} item Item
* @param {number} index Index to insert the item into
*/
mw.echo.ui.SortedListWidget.prototype.attachItemToDom = function ( item, index ) {
if ( index === undefined || index < 0 || index >= this.items.length - 1 ) {
this.$group.append( item.$element.get( 0 ) );
} else if ( index === 0 ) {
this.$group.prepend( item.$element.get( 0 ) );
} else {
this.items[ index + 1 ].$element.before( item.$element.get( 0 ) );
}
};
/**
* Clear all items
*
* @chainable
* @fires clear
*/
mw.echo.ui.SortedListWidget.prototype.clearItems = function () {
var i, len, item;
for ( i = 0, len = this.items.length; i < len; i++ ) {
item = this.items[ i ];
item.setElementGroup( null );
item.$element.detach();
}
// Mixin method
return OO.SortedEmitterList.prototype.clearItems.call( this );
};
/**
* Get the timestamp of the list by taking the latest notification
* timestamp.
*
* @return {string} Latest timestamp
*/
mw.echo.ui.SortedListWidget.prototype.getTimestamp = function () {
var items = this.getItems();
return (
items.length > 0 ?
items[ 0 ].getTimestamp() :
this.timestamp
);
};
} )( mediaWiki );