1/**
  2 * @file Revisions interface functions, Backbone classes and
  3 * the revisions.php document.ready bootstrap.
  4 *
  5 * @output wp-admin/js/revisions.js
  6 */
  7
  8/* global isRtl */
  9
 10window.wp = window.wp || {};
 11
 12(function($) {
 13	var revisions;
 14	/**
 15	 * Expose the module in window.wp.revisions.
 16	 */
 17	revisions = wp.revisions = { model: {}, view: {}, controller: {} };
 18
 19	// Link post revisions data served from the back end.
 20	revisions.settings = window._wpRevisionsSettings || {};
 21
 22	// For debugging.
 23	revisions.debug = false;
 24
 25	/**
 26	 * wp.revisions.log
 27	 *
 28	 * A debugging utility for revisions. Works only when a
 29	 * debug flag is on and the browser supports it.
 30	 */
 31	revisions.log = function() {
 32		if ( window.console && revisions.debug ) {
 33			window.console.log.apply( window.console, arguments );
 34		}
 35	};
 36
 37	// Handy functions to help with positioning.
 38	$.fn.allOffsets = function() {
 39		var offset = this.offset() || {top: 0, left: 0}, win = $(window);
 40		return _.extend( offset, {
 41			right:  win.width()  - offset.left - this.outerWidth(),
 42			bottom: win.height() - offset.top  - this.outerHeight()
 43		});
 44	};
 45
 46	$.fn.allPositions = function() {
 47		var position = this.position() || {top: 0, left: 0}, parent = this.parent();
 48		return _.extend( position, {
 49			right:  parent.outerWidth()  - position.left - this.outerWidth(),
 50			bottom: parent.outerHeight() - position.top  - this.outerHeight()
 51		});
 52	};
 53
 54	/**
 55	 * ========================================================================
 56	 * MODELS
 57	 * ========================================================================
 58	 */
 59	revisions.model.Slider = Backbone.Model.extend({
 60		defaults: {
 61			value: null,
 62			values: null,
 63			min: 0,
 64			max: 1,
 65			step: 1,
 66			range: false,
 67			compareTwoMode: false
 68		},
 69
 70		initialize: function( options ) {
 71			this.frame = options.frame;
 72			this.revisions = options.revisions;
 73
 74			// Listen for changes to the revisions or mode from outside.
 75			this.listenTo( this.frame, 'update:revisions', this.receiveRevisions );
 76			this.listenTo( this.frame, 'change:compareTwoMode', this.updateMode );
 77
 78			// Listen for internal changes.
 79			this.on( 'change:from', this.handleLocalChanges );
 80			this.on( 'change:to', this.handleLocalChanges );
 81			this.on( 'change:compareTwoMode', this.updateSliderSettings );
 82			this.on( 'update:revisions', this.updateSliderSettings );
 83
 84			// Listen for changes to the hovered revision.
 85			this.on( 'change:hoveredRevision', this.hoverRevision );
 86
 87			this.set({
 88				max:   this.revisions.length - 1,
 89				compareTwoMode: this.frame.get('compareTwoMode'),
 90				from: this.frame.get('from'),
 91				to: this.frame.get('to')
 92			});
 93			this.updateSliderSettings();
 94		},
 95
 96		getSliderValue: function( a, b ) {
 97			return isRtl ? this.revisions.length - this.revisions.indexOf( this.get(a) ) - 1 : this.revisions.indexOf( this.get(b) );
 98		},
 99
100		updateSliderSettings: function() {
101			if ( this.get('compareTwoMode') ) {
102				this.set({
103					values: [
104						this.getSliderValue( 'to', 'from' ),
105						this.getSliderValue( 'from', 'to' )
106					],
107					value: null,
108					range: true // Ensures handles cannot cross.
109				});
110			} else {
111				this.set({
112					value: this.getSliderValue( 'to', 'to' ),
113					values: null,
114					range: false
115				});
116			}
117			this.trigger( 'update:slider' );
118		},
119
120		// Called when a revision is hovered.
121		hoverRevision: function( model, value ) {
122			this.trigger( 'hovered:revision', value );
123		},
124
125		// Called when `compareTwoMode` changes.
126		updateMode: function( model, value ) {
127			this.set({ compareTwoMode: value });
128		},
129
130		// Called when `from` or `to` changes in the local model.
131		handleLocalChanges: function() {
132			this.frame.set({
133				from: this.get('from'),
134				to: this.get('to')
135			});
136		},
137
138		// Receives revisions changes from outside the model.
139		receiveRevisions: function( from, to ) {
140			// Bail if nothing changed.
141			if ( this.get('from') === from && this.get('to') === to ) {
142				return;
143			}
144
145			this.set({ from: from, to: to }, { silent: true });
146			this.trigger( 'update:revisions', from, to );
147		}
148
149	});
150
151	revisions.model.Tooltip = Backbone.Model.extend({
152		defaults: {
153			revision: null,
154			offset: {},
155			hovering: false, // Whether the mouse is hovering.
156			scrubbing: false // Whether the mouse is scrubbing.
157		},
158
159		initialize: function( options ) {
160			this.frame = options.frame;
161			this.revisions = options.revisions;
162			this.slider = options.slider;
163
164			this.listenTo( this.slider, 'hovered:revision', this.updateRevision );
165			this.listenTo( this.slider, 'change:hovering', this.setHovering );
166			this.listenTo( this.slider, 'change:scrubbing', this.setScrubbing );
167		},
168
169
170		updateRevision: function( revision ) {
171			this.set({ revision: revision });
172		},
173
174		setHovering: function( model, value ) {
175			this.set({ hovering: value });
176		},
177
178		setScrubbing: function( model, value ) {
179			this.set({ scrubbing: value });
180		}
181	});
182
183	revisions.model.Revision = Backbone.Model.extend({});
184
185	/**
186	 * wp.revisions.model.Revisions
187	 *
188	 * A collection of post revisions.
189	 */
190	revisions.model.Revisions = Backbone.Collection.extend({
191		model: revisions.model.Revision,
192
193		initialize: function() {
194			_.bindAll( this, 'next', 'prev' );
195		},
196
197		next: function( revision ) {
198			var index = this.indexOf( revision );
199
200			if ( index !== -1 && index !== this.length - 1 ) {
201				return this.at( index + 1 );
202			}
203		},
204
205		prev: function( revision ) {
206			var index = this.indexOf( revision );
207
208			if ( index !== -1 && index !== 0 ) {
209				return this.at( index - 1 );
210			}
211		}
212	});
213
214	revisions.model.Field = Backbone.Model.extend({});
215
216	revisions.model.Fields = Backbone.Collection.extend({
217		model: revisions.model.Field
218	});
219
220	revisions.model.Diff = Backbone.Model.extend({
221		initialize: function() {
222			var fields = this.get('fields');
223			this.unset('fields');
224
225			this.fields = new revisions.model.Fields( fields );
226		}
227	});
228
229	revisions.model.Diffs = Backbone.Collection.extend({
230		initialize: function( models, options ) {
231			_.bindAll( this, 'getClosestUnloaded' );
232			this.loadAll = _.once( this._loadAll );
233			this.revisions = options.revisions;
234			this.postId = options.postId;
235			this.requests  = {};
236		},
237
238		model: revisions.model.Diff,
239
240		ensure: function( id, context ) {
241			var diff     = this.get( id ),
242				request  = this.requests[ id ],
243				deferred = $.Deferred(),
244				ids      = {},
245				from     = id.split(':')[0],
246				to       = id.split(':')[1];
247			ids[id] = true;
248
249			wp.revisions.log( 'ensure', id );
250
251			this.trigger( 'ensure', ids, from, to, deferred.promise() );
252
253			if ( diff ) {
254				deferred.resolveWith( context, [ diff ] );
255			} else {
256				this.trigger( 'ensure:load', ids, from, to, deferred.promise() );
257				_.each( ids, _.bind( function( id ) {
258					// Remove anything that has an ongoing request.
259					if ( this.requests[ id ] ) {
260						delete ids[ id ];
261					}
262					// Remove anything we already have.
263					if ( this.get( id ) ) {
264						delete ids[ id ];
265					}
266				}, this ) );
267				if ( ! request ) {
268					// Always include the ID that started this ensure.
269					ids[ id ] = true;
270					request   = this.load( _.keys( ids ) );
271				}
272
273				request.done( _.bind( function() {
274					deferred.resolveWith( context, [ this.get( id ) ] );
275				}, this ) ).fail( _.bind( function() {
276					deferred.reject();
277				}) );
278			}
279
280			return deferred.promise();
281		},
282
283		// Returns an array of proximal diffs.
284		getClosestUnloaded: function( ids, centerId ) {
285			var self = this;
286			return _.chain([0].concat( ids )).initial().zip( ids ).sortBy( function( pair ) {
287				return Math.abs( centerId - pair[1] );
288			}).map( function( pair ) {
289				return pair.join(':');
290			}).filter( function( diffId ) {
291				return _.isUndefined( self.get( diffId ) ) && ! self.requests[ diffId ];
292			}).value();
293		},
294
295		_loadAll: function( allRevisionIds, centerId, num ) {
296			var self = this, deferred = $.Deferred(),
297				diffs = _.first( this.getClosestUnloaded( allRevisionIds, centerId ), num );
298			if ( _.size( diffs ) > 0 ) {
299				this.load( diffs ).done( function() {
300					self._loadAll( allRevisionIds, centerId, num ).done( function() {
301						deferred.resolve();
302					});
303				}).fail( function() {
304					if ( 1 === num ) { // Already tried 1. This just isn't working. Give up.
305						deferred.reject();
306					} else { // Request fewer diffs this time.
307						self._loadAll( allRevisionIds, centerId, Math.ceil( num / 2 ) ).done( function() {
308							deferred.resolve();
309						});
310					}
311				});
312			} else {
313				deferred.resolve();
314			}
315			return deferred;
316		},
317
318		load: function( comparisons ) {
319			wp.revisions.log( 'load', comparisons );
320			// Our collection should only ever grow, never shrink, so `remove: false`.
321			return this.fetch({ data: { compare: comparisons }, remove: false }).done( function() {
322				wp.revisions.log( 'load:complete', comparisons );
323			});
324		},
325
326		sync: function( method, model, options ) {
327			if ( 'read' === method ) {
328				options = options || {};
329				options.context = this;
330				options.data = _.extend( options.data || {}, {
331					action: 'get-revision-diffs',
332					post_id: this.postId
333				});
334
335				var deferred = wp.ajax.send( options ),
336					requests = this.requests;
337
338				// Record that we're requesting each diff.
339				if ( options.data.compare ) {
340					_.each( options.data.compare, function( id ) {
341						requests[ id ] = deferred;
342					});
343				}
344
345				// When the request completes, clear the stored request.
346				deferred.always( function() {
347					if ( options.data.compare ) {
348						_.each( options.data.compare, function( id ) {
349							delete requests[ id ];
350						});
351					}
352				});
353
354				return deferred;
355
356			// Otherwise, fall back to `Backbone.sync()`.
357			} else {
358				return Backbone.Model.prototype.sync.apply( this, arguments );
359			}
360		}
361	});
362
363
364	/**
365	 * wp.revisions.model.FrameState
366	 *
367	 * The frame state.
368	 *
369	 * @see wp.revisions.view.Frame
370	 *
371	 * @param {object}                    attributes        Model attributes - none are required.
372	 * @param {object}                    options           Options for the model.
373	 * @param {revisions.model.Revisions} options.revisions A collection of revisions.
374	 */
375	revisions.model.FrameState = Backbone.Model.extend({
376		defaults: {
377			loading: false,
378			error: false,
379			compareTwoMode: false
380		},
381
382		initialize: function( attributes, options ) {
383			var state = this.get( 'initialDiffState' );
384			_.bindAll( this, 'receiveDiff' );
385			this._debouncedEnsureDiff = _.debounce( this._ensureDiff, 200 );
386
387			this.revisions = options.revisions;
388
389			this.diffs = new revisions.model.Diffs( [], {
390				revisions: this.revisions,
391				postId: this.get( 'postId' )
392			} );
393
394			// Set the initial diffs collection.
395			this.diffs.set( this.get( 'diffData' ) );
396
397			// Set up internal listeners.
398			this.listenTo( this, 'change:from', this.changeRevisionHandler );
399			this.listenTo( this, 'change:to', this.changeRevisionHandler );
400			this.listenTo( this, 'change:compareTwoMode', this.changeMode );
401			this.listenTo( this, 'update:revisions', this.updatedRevisions );
402			this.listenTo( this.diffs, 'ensure:load', this.updateLoadingStatus );
403			this.listenTo( this, 'update:diff', this.updateLoadingStatus );
404
405			// Set the initial revisions, baseUrl, and mode as provided through attributes.
406
407			this.set( {
408				to : this.revisions.get( state.to ),
409				from : this.revisions.get( state.from ),
410				compareTwoMode : state.compareTwoMode
411			} );
412
413			// Start the router if browser supports History API.
414			if ( window.history && window.history.pushState ) {
415				this.router = new revisions.Router({ model: this });
416				if ( Backbone.History.started ) {
417					Backbone.history.stop();
418				}
419				Backbone.history.start({ pushState: true });
420			}
421		},
422
423		updateLoadingStatus: function() {
424			this.set( 'error', false );
425			this.set( 'loading', ! this.diff() );
426		},
427
428		changeMode: function( model, value ) {
429			var toIndex = this.revisions.indexOf( this.get( 'to' ) );
430
431			// If we were on the first revision before switching to two-handled mode,
432			// bump the 'to' position over one.
433			if ( value && 0 === toIndex ) {
434				this.set({
435					from: this.revisions.at( toIndex ),
436					to:   this.revisions.at( toIndex + 1 )
437				});
438			}
439
440			// When switching back to single-handled mode, reset 'from' model to
441			// one position before the 'to' model.
442			if ( ! value && 0 !== toIndex ) { // '! value' means switching to single-handled mode.
443				this.set({
444					from: this.revisions.at( toIndex - 1 ),
445					to:   this.revisions.at( toIndex )
446				});
447			}
448		},
449
450		updatedRevisions: function( from, to ) {
451			if ( this.get( 'compareTwoMode' ) ) {
452				// @todo Compare-two loading strategy.
453			} else {
454				this.diffs.loadAll( this.revisions.pluck('id'), to.id, 40 );
455			}
456		},
457
458		// Fetch the currently loaded diff.
459		diff: function() {
460			return this.diffs.get( this._diffId );
461		},
462
463		/*
464		 * So long as `from` and `to` are changed at the same time, the diff
465		 * will only be updated once. This is because Backbone updates all of
466		 * the changed attributes in `set`, and then fires the `change` events.
467		 */
468		updateDiff: function( options ) {
469			var from, to, diffId, diff;
470
471			options = options || {};
472			from = this.get('from');
473			to = this.get('to');
474			diffId = ( from ? from.id : 0 ) + ':' + to.id;
475
476			// Check if we're actually changing the diff id.
477			if ( this._diffId === diffId ) {
478				return $.Deferred().reject().promise();
479			}
480
481			this._diffId = diffId;
482			this.trigger( 'update:revisions', from, to );
483
484			diff = this.diffs.get( diffId );
485
486			// If we already have the diff, then immediately trigger the update.
487			if ( diff ) {
488				this.receiveDiff( diff );
489				return $.Deferred().resolve().promise();
490			// Otherwise, fetch the diff.
491			} else {
492				if ( options.immediate ) {
493					return this._ensureDiff();
494				} else {
495					this._debouncedEnsureDiff();
496					return $.Deferred().reject().promise();
497				}
498			}
499		},
500
501		// A simple wrapper around `updateDiff` to prevent the change event's
502		// parameters from being passed through.
503		changeRevisionHandler: function() {
504			this.updateDiff();
505		},
506
507		receiveDiff: function( diff ) {
508			// Did we actually get a diff?
509			if ( _.isUndefined( diff ) || _.isUndefined( diff.id ) ) {
510				this.set({
511					loading: false,
512					error: true
513				});
514			} else if ( this._diffId === diff.id ) { // Make sure the current diff didn't change.
515				this.trigger( 'update:diff', diff );
516			}
517		},
518
519		_ensureDiff: function() {
520			return this.diffs.ensure( this._diffId, this ).always( this.receiveDiff );
521		}
522	});
523
524
525	/**
526	 * ========================================================================
527	 * VIEWS
528	 * ========================================================================
529	 */
530
531	/**
532	 * wp.revisions.view.Frame
533	 *
534	 * Top level frame that orchestrates the revisions experience.
535	 *
536	 * @param {object}                     options       The options hash for the view.
537	 * @param {revisions.model.FrameState} options.model The frame state model.
538	 */
539	revisions.view.Frame = wp.Backbone.View.extend({
540		className: 'revisions',
541		template: wp.template('revisions-frame'),
542
543		initialize: function() {
544			this.listenTo( this.model, 'update:diff', this.renderDiff );
545			this.listenTo( this.model, 'change:compareTwoMode', this.updateCompareTwoMode );
546			this.listenTo( this.model, 'change:loading', this.updateLoadingStatus );
547			this.listenTo( this.model, 'change:error', this.updateErrorStatus );
548
549			this.views.set( '.revisions-control-frame', new revisions.view.Controls({
550				model: this.model
551			}) );
552		},
553
554		render: function() {
555			wp.Backbone.View.prototype.render.apply( this, arguments );
556
557			$('html').css( 'overflow-y', 'scroll' );
558			$('#wpbody-content .wrap').append( this.el );
559			this.updateCompareTwoMode();
560			this.renderDiff( this.model.diff() );
561			this.views.ready();
562
563			return this;
564		},
565
566		renderDiff: function( diff ) {
567			this.views.set( '.revisions-diff-frame', new revisions.view.Diff({
568				model: diff
569			}) );
570		},
571
572		updateLoadingStatus: function() {
573			this.$el.toggleClass( 'loading', this.model.get('loading') );
574		},
575
576		updateErrorStatus: function() {
577			this.$el.toggleClass( 'diff-error', this.model.get('error') );
578		},
579
580		updateCompareTwoMode: function() {
581			this.$el.toggleClass( 'comparing-two-revisions', this.model.get('compareTwoMode') );
582		}
583	});
584
585	/**
586	 * wp.revisions.view.Controls
587	 *
588	 * The controls view.
589	 *
590	 * Contains the revision slider, previous/next buttons, the meta info and the compare checkbox.
591	 */
592	revisions.view.Controls = wp.Backbone.View.extend({
593		className: 'revisions-controls',
594
595		initialize: function() {
596			_.bindAll( this, 'setWidth' );
597
598			// Add the checkbox view.
599			this.views.add( new revisions.view.Checkbox({
600				model: this.model
601			}) );
602
603			// Add the button view.
604			this.views.add( new revisions.view.Buttons({
605				model: this.model
606			}) );
607
608			// Prep the slider model.
609			var slider = new revisions.model.Slider({
610				frame: this.model,
611				revisions: this.model.revisions
612			}),
613
614			// Prep the tooltip model.
615			tooltip = new revisions.model.Tooltip({
616				frame: this.model,
617				revisions: this.model.revisions,
618				slider: slider
619			});
620
621			// Add the tooltip view.
622			this.views.add( new revisions.view.Tooltip({
623				model: tooltip
624			}) );
625
626			// Add the tickmarks view.
627			this.views.add( new revisions.view.Tickmarks({
628				model: tooltip
629			}) );
630
631			// Add the visually hidden slider help view.
632			this.views.add( new revisions.view.SliderHelp() );
633
634			// Add the slider view.
635			this.views.add( new revisions.view.Slider({
636				model: slider
637			}) );
638
639			// Add the Metabox view.
640			this.views.add( new revisions.view.Metabox({
641				model: this.model
642			}) );
643		},
644
645		ready: function() {
646			this.top = this.$el.offset().top;
647			this.window = $(window);
648			this.window.on( 'scroll.wp.revisions', {controls: this}, function(e) {
649				var controls  = e.data.controls,
650					container = controls.$el.parent(),
651					scrolled  = controls.window.scrollTop(),
652					frame     = controls.views.parent;
653
654				if ( scrolled >= controls.top ) {
655					if ( ! frame.$el.hasClass('pinned') ) {
656						controls.setWidth();
657						container.css('height', container.height() + 'px' );
658						controls.window.on('resize.wp.revisions.pinning click.wp.revisions.pinning', {controls: controls}, function(e) {
659							e.data.controls.setWidth();
660						});
661					}
662					frame.$el.addClass('pinned');
663				} else if ( frame.$el.hasClass('pinned') ) {
664					controls.window.off('.wp.revisions.pinning');
665					controls.$el.css('width', 'auto');
666					frame.$el.removeClass('pinned');
667					container.css('height', 'auto');
668					controls.top = controls.$el.offset().top;
669				} else {
670					controls.top = controls.$el.offset().top;
671				}
672			});
673		},
674
675		setWidth: function() {
676			this.$el.css('width', this.$el.parent().width() + 'px');
677		}
678	});
679
680	// The tickmarks view.
681	revisions.view.Tickmarks = wp.Backbone.View.extend({
682		className: 'revisions-tickmarks',
683		direction: isRtl ? 'right' : 'left',
684
685		initialize: function() {
686			this.listenTo( this.model, 'change:revision', this.reportTickPosition );
687		},
688
689		reportTickPosition: function( model, revision ) {
690			var offset, thisOffset, parentOffset, tick, index = this.model.revisions.indexOf( revision );
691			thisOffset = this.$el.allOffsets();
692			parentOffset = this.$el.parent().allOffsets();
693			if ( index === this.model.revisions.length - 1 ) {
694				// Last one.
695				offset = {
696					rightPlusWidth: thisOffset.left - parentOffset.left + 1,
697					leftPlusWidth: thisOffset.right - parentOffset.right + 1
698				};
699			} else {
700				// Normal tick.
701				tick = this.$('div:nth-of-type(' + (index + 1) + ')');
702				offset = tick.allPositions();
703				_.extend( offset, {
704					left: offset.left + thisOffset.left - parentOffset.left,
705					right: offset.right + thisOffset.right - parentOffset.right
706				});
707				_.extend( offset, {
708					leftPlusWidth: offset.left + tick.outerWidth(),
709					rightPlusWidth: offset.right + tick.outerWidth()
710				});
711			}
712			this.model.set({ offset: offset });
713		},
714
715		ready: function() {
716			var tickCount, tickWidth;
717			tickCount = this.model.revisions.length - 1;
718			tickWidth = 1 / tickCount;
719			this.$el.css('width', ( this.model.revisions.length * 50 ) + 'px');
720
721			_(tickCount).times( function( index ){
722				this.$el.append( '<div style="' + this.direction + ': ' + ( 100 * tickWidth * index ) + '%"></div>' );
723			}, this );
724		}
725	});
726
727	// The metabox view.
728	revisions.view.Metabox = wp.Backbone.View.extend({
729		className: 'revisions-meta',
730
731		initialize: function() {
732			// Add the 'from' view.
733			this.views.add( new revisions.view.MetaFrom({
734				model: this.model,
735				className: 'diff-meta diff-meta-from'
736			}) );
737
738			// Add the 'to' view.
739			this.views.add( new revisions.view.MetaTo({
740				model: this.model
741			}) );
742		}
743	});
744
745	// The revision meta view (to be extended).
746	revisions.view.Meta = wp.Backbone.View.extend({
747		template: wp.template('revisions-meta'),
748
749		events: {
750			'click .restore-revision': 'restoreRevision'
751		},
752
753		initialize: function() {
754			this.listenTo( this.model, 'update:revisions', this.render );
755		},
756
757		prepare: function() {
758			return _.extend( this.model.toJSON()[this.type] || {}, {
759				type: this.type
760			});
761		},
762
763		restoreRevision: function() {
764			document.location = this.model.get('to').attributes.restoreUrl;
765		}
766	});
767
768	// The revision meta 'from' view.
769	revisions.view.MetaFrom = revisions.view.Meta.extend({
770		className: 'diff-meta diff-meta-from',
771		type: 'from'
772	});
773
774	// The revision meta 'to' view.
775	revisions.view.MetaTo = revisions.view.Meta.extend({
776		className: 'diff-meta diff-meta-to',
777		type: 'to'
778	});
779
780	// The checkbox view.
781	revisions.view.Checkbox = wp.Backbone.View.extend({
782		className: 'revisions-checkbox',
783		template: wp.template('revisions-checkbox'),
784
785		events: {
786			'click .compare-two-revisions': 'compareTwoToggle'
787		},
788
789		initialize: function() {
790			this.listenTo( this.model, 'change:compareTwoMode', this.updateCompareTwoMode );
791		},
792
793		ready: function() {
794			if ( this.model.revisions.length < 3 ) {
795				$('.revision-toggle-compare-mode').hide();
796			}
797		},
798
799		updateCompareTwoMode: function() {
800			this.$('.compare-two-revisions').prop( 'checked', this.model.get('compareTwoMode') );
801		},
802
803		// Toggle the compare two mode feature when the compare two checkbox is checked.
804		compareTwoToggle: function() {
805			// Activate compare two mode?
806			this.model.set({ compareTwoMode: $('.compare-two-revisions').prop('checked') });
807		}
808	});
809
810	// The slider visually hidden help view.
811 	revisions.view.SliderHelp = wp.Backbone.View.extend({
812		className: 'revisions-slider-hidden-help',
813		template:  wp.template( 'revisions-slider-hidden-help' )
814	});
815   
816	// The tooltip view.
817	// Encapsulates the tooltip.
818	revisions.view.Tooltip = wp.Backbone.View.extend({
819		className: 'revisions-tooltip',
820		template: wp.template('revisions-meta'),
821
822		initialize: function() {
823			this.listenTo( this.model, 'change:offset', this.render );
824			this.listenTo( this.model, 'change:hovering', this.toggleVisibility );
825			this.listenTo( this.model, 'change:scrubbing', this.toggleVisibility );
826		},
827
828		prepare: function() {
829			if ( _.isNull( this.model.get('revision') ) ) {
830				return;
831			} else {
832				return _.extend( { type: 'tooltip' }, {
833					attributes: this.model.get('revision').toJSON()
834				});
835			}
836		},
837
838		render: function() {
839			var otherDirection,
840				direction,
841				directionVal,
842				flipped,
843				css      = {},
844				position = this.model.revisions.indexOf( this.model.get('revision') ) + 1;
845
846			flipped = ( position / this.model.revisions.length ) > 0.5;
847			if ( isRtl ) {
848				direction = flipped ? 'left' : 'right';
849				directionVal = flipped ? 'leftPlusWidth' : direction;
850			} else {
851				direction = flipped ? 'right' : 'left';
852				directionVal = flipped ? 'rightPlusWidth' : direction;
853			}
854			otherDirection = 'right' === direction ? 'left': 'right';
855			wp.Backbone.View.prototype.render.apply( this, arguments );
856			css[direction] = this.model.get('offset')[directionVal] + 'px';
857			css[otherDirection] = '';
858			this.$el.toggleClass( 'flipped', flipped ).css( css );
859		},
860
861		visible: function() {
862			return this.model.get( 'scrubbing' ) || this.model.get( 'hovering' );
863		},
864
865		toggleVisibility: function() {
866			if ( this.visible() ) {
867				this.$el.stop().show().fadeTo( 100 - this.el.style.opacity * 100, 1 );
868			} else {
869				this.$el.stop().fadeTo( this.el.style.opacity * 300, 0, function(){ $(this).hide(); } );
870			}
871			return;
872		}
873	});
874
875	// The buttons view.
876	// Encapsulates all of the configuration for the previous/next buttons.
877	revisions.view.Buttons = wp.Backbone.View.extend({
878		className: 'revisions-buttons',
879		template: wp.template('revisions-buttons'),
880
881		events: {
882			'click .revisions-next .button': 'nextRevision',
883			'click .revisions-previous .button': 'previousRevision'
884		},
885
886		initialize: function() {
887			this.listenTo( this.model, 'update:revisions', this.disabledButtonCheck );
888		},
889
890		ready: function() {
891			this.disabledButtonCheck();
892		},
893
894		// Go to a specific model index.
895		gotoModel: function( toIndex ) {
896			var attributes = {
897				to: this.model.revisions.at( toIndex )
898			};
899			// If we're at the first revision, unset 'from'.
900			if ( toIndex ) {
901				attributes.from = this.model.revisions.at( toIndex - 1 );
902			} else {
903				this.model.unset('from', { silent: true });
904			}
905
906			this.model.set( attributes );
907		},
908
909		// Go to the 'next' revision.
910		nextRevision: function() {
911			var toIndex = this.model.revisions.indexOf( this.model.get('to') ) + 1;
912			this.gotoModel( toIndex );
913		},
914
915		// Go to the 'previous' revision.
916		previousRevision: function() {
917			var toIndex = this.model.revisions.indexOf( this.model.get('to') ) - 1;
918			this.gotoModel( toIndex );
919		},
920
921		// Check to see if the Previous or Next buttons need to be disabled or enabled.
922		disabledButtonCheck: function() {
923			var maxVal   = this.model.revisions.length - 1,
924				minVal   = 0,
925				next     = $('.revisions-next .button'),
926				previous = $('.revisions-previous .button'),
927				val      = this.model.revisions.indexOf( this.model.get('to') );
928
929			// Disable "Next" button if you're on the last node.
930			next.prop( 'disabled', ( maxVal === val ) );
931
932			// Disable "Previous" button if you're on the first node.
933			previous.prop( 'disabled', ( minVal === val ) );
934		}
935	});
936
937
938	// The slider view.
939	revisions.view.Slider = wp.Backbone.View.extend({
940		className: 'wp-slider',
941		direction: isRtl ? 'right' : 'left',
942
943		events: {
944			'mousemove' : 'mouseMove'
945		},
946
947		initialize: function() {
948			_.bindAll( this, 'start', 'slide', 'stop', 'mouseMove', 'mouseEnter', 'mouseLeave' );
949			this.listenTo( this.model, 'update:slider', this.applySliderSettings );
950		},
951
952		ready: function() {
953			this.$el.css('width', ( this.model.revisions.length * 50 ) + 'px');
954			this.$el.slider( _.extend( this.model.toJSON(), {
955				start: this.start,
956				slide: this.slide,
957				stop:  this.stop
958			}) );
959
960			this.$el.hoverIntent({
961				over: this.mouseEnter,
962				out: this.mouseLeave,
963				timeout: 800
964			});
965
966			this.applySliderSettings();
967		},
968
969		accessibilityHelper: function() {
970			var handles = $( '.ui-slider-handle' );
971			handles.first().attr( {
972					role: 'button',
973					'aria-labelledby': 'diff-title-from diff-title-author',
974					'aria-describedby': 'revisions-slider-hidden-help',
975			} );
976			handles.last().attr( {
977					role: 'button',
978					'aria-labelledby': 'diff-title-to diff-title-author',
979					'aria-describedby': 'revisions-slider-hidden-help',
980			} );
981		},
982
983		mouseMove: function( e ) {
984			var zoneCount         = this.model.revisions.length - 1,       // One fewer zone than models.
985				sliderFrom        = this.$el.allOffsets()[this.direction], // "From" edge of slider.
986				sliderWidth       = this.$el.width(),                      // Width of slider.
987				tickWidth         = sliderWidth / zoneCount,               // Calculated width of zone.
988				actualX           = ( isRtl ? $(window).width() - e.pageX : e.pageX ) - sliderFrom, // Flipped for RTL - sliderFrom.
989				currentModelIndex = Math.floor( ( actualX  + ( tickWidth / 2 )  ) / tickWidth );    // Calculate the model index.
990
991			// Ensure sane value for currentModelIndex.
992			if ( currentModelIndex < 0 ) {
993				currentModelIndex = 0;
994			} else if ( currentModelIndex >= this.model.revisions.length ) {
995				currentModelIndex = this.model.revisions.length - 1;
996			}
997
998			// Update the tooltip mode.
999			this.model.set({ hoveredRevision: this.model.revisions.at( currentModelIndex ) });
1000		},
1001
1002		mouseLeave: function() {
1003			this.model.set({ hovering: false });
1004		},
1005
1006		mouseEnter: function() {
1007			this.model.set({ hovering: true });
1008		},
1009
1010		applySliderSettings: function() {
1011			this.$el.slider( _.pick( this.model.toJSON(), 'value', 'values', 'range' ) );
1012			var handles = this.$('a.ui-slider-handle');
1013
1014			if ( this.model.get('compareTwoMode') ) {
1015				// In RTL mode the 'left handle' is the second in the slider, 'right' is first.
1016				handles.first()
1017					.toggleClass( 'to-handle', !! isRtl )
1018					.toggleClass( 'from-handle', ! isRtl );
1019				handles.last()
1020					.toggleClass( 'from-handle', !! isRtl )
1021					.toggleClass( 'to-handle', ! isRtl );
1022				this.accessibilityHelper();
1023			} else {
1024				handles.removeClass('from-handle to-handle');
1025				this.accessibilityHelper();
1026			}
1027
1028		},
1029
1030		start: function( event, ui ) {
1031			this.model.set({ scrubbing: true });
1032
1033			// Track the mouse position to enable smooth dragging,
1034			// overrides default jQuery UI step behavior.
1035			$( window ).on( 'mousemove.wp.revisions', { view: this }, function( e ) {
1036				var handles,
1037					view              = e.data.view,
1038					leftDragBoundary  = view.$el.offset().left,
1039					sliderOffset      = leftDragBoundary,
1040					sliderRightEdge   = leftDragBoundary + view.$el.width(),
1041					rightDragBoundary = sliderRightEdge,
1042					leftDragReset     = '0',
1043					rightDragReset    = '100%',
1044					handle            = $( ui.handle );
1045
1046				// In two handle mode, ensure handles can't be dragged past each other.
1047				// Adjust left/right boundaries and reset points.
1048				if ( view.model.get('compareTwoMode') ) {
1049					handles = handle.parent().find('.ui-slider-handle');
1050					if ( handle.is( handles.first() ) ) {
1051						// We're the left handle.
1052						rightDragBoundary = handles.last().offset().left;
1053						rightDragReset    = rightDragBoundary - sliderOffset;
1054					} else {
1055						// We're the right handle.
1056						leftDragBoundary = handles.first().offset().left + handles.first().width();
1057						leftDragReset    = leftDragBoundary - sliderOffset;
1058					}
1059				}
1060
1061				// Follow mouse movements, as long as handle remains inside slider.
1062				if ( e.pageX < leftDragBoundary ) {
1063					handle.css( 'left', leftDragReset ); // Mouse to left of slider.
1064				} else if ( e.pageX > rightDragBoundary ) {
1065					handle.css( 'left', rightDragReset ); // Mouse to right of slider.
1066				} else {
1067					handle.css( 'left', e.pageX - sliderOffset ); // Mouse in slider.
1068				}
1069			} );
1070		},
1071
1072		getPosition: function( position ) {
1073			return isRtl ? this.model.revisions.length - position - 1: position;
1074		},
1075
1076		// Responds to slide events.
1077		slide: function( event, ui ) {
1078			var attributes, movedRevision;
1079			// Compare two revisions mode.
1080			if ( this.model.get('compareTwoMode') ) {
1081				// Prevent sliders from occupying same spot.
1082				if ( ui.values[1] === ui.values[0] ) {
1083					return false;
1084				}
1085				if ( isRtl ) {
1086					ui.values.reverse();
1087				}
1088				attributes = {
1089					from: this.model.revisions.at( this.getPosition( ui.values[0] ) ),
1090					to: this.model.revisions.at( this.getPosition( ui.values[1] ) )
1091				};
1092			} else {
1093				attributes = {
1094					to: this.model.revisions.at( this.getPosition( ui.value ) )
1095				};
1096				// If we're at the first revision, unset 'from'.
1097				if ( this.getPosition( ui.value ) > 0 ) {
1098					attributes.from = this.model.revisions.at( this.getPosition( ui.value ) - 1 );
1099				} else {
1100					attributes.from = undefined;
1101				}
1102			}
1103			movedRevision = this.model.revisions.at( this.getPosition( ui.value ) );
1104
1105			// If we are scrubbing, a scrub to a revision is considered a hover.
1106			if ( this.model.get('scrubbing') ) {
1107				attributes.hoveredRevision = movedRevision;
1108			}
1109
1110			this.model.set( attributes );
1111		},
1112
1113		stop: function() {
1114			$( window ).off('mousemove.wp.revisions');
1115			this.model.updateSliderSettings(); // To snap us back to a tick mark.
1116			this.model.set({ scrubbing: false });
1117		}
1118	});
1119
1120	// The diff view.
1121	// This is the view for the current active diff.
1122	revisions.view.Diff = wp.Backbone.View.extend({
1123		className: 'revisions-diff',
1124		template:  wp.template('revisions-diff'),
1125
1126		// Generate the options to be passed to the template.
1127		prepare: function() {
1128			return _.extend({ fields: this.model.fields.toJSON() }, this.options );
1129		}
1130	});
1131
1132	// The revisions router.
1133	// Maintains the URL routes so browser URL matches state.
1134	revisions.Router = Backbone.Router.extend({
1135		initialize: function( options ) {
1136			this.model = options.model;
1137
1138			// Maintain state and history when navigating.
1139			this.listenTo( this.model, 'update:diff', _.debounce( this.updateUrl, 250 ) );
1140			this.listenTo( this.model, 'change:compareTwoMode', this.updateUrl );
1141		},
1142
1143		baseUrl: function( url ) {
1144			return this.model.get('baseUrl') + url;
1145		},
1146
1147		updateUrl: function() {
1148			var from = this.model.has('from') ? this.model.get('from').id : 0,
1149				to   = this.model.get('to').id;
1150			if ( this.model.get('compareTwoMode' ) ) {
1151				this.navigate( this.baseUrl( '?from=' + from + '&to=' + to ), { replace: true } );
1152			} else {
1153				this.navigate( this.baseUrl( '?revision=' + to ), { replace: true } );
1154			}
1155		},
1156
1157		handleRoute: function( a, b ) {
1158			var compareTwo = _.isUndefined( b );
1159
1160			if ( ! compareTwo ) {
1161				b = this.model.revisions.get( a );
1162				a = this.model.revisions.prev( b );
1163				b = b ? b.id : 0;
1164				a = a ? a.id : 0;
1165			}
1166		}
1167	});
1168
1169	/**
1170	 * Initialize the revisions UI for revision.php.
1171	 */
1172	revisions.init = function() {
1173		var state;
1174
1175		// Bail if the current page is not revision.php.
1176		if ( ! window.adminpage || 'revision-php' !== window.adminpage ) {
1177			return;
1178		}
1179
1180		state = new revisions.model.FrameState({
1181			initialDiffState: {
1182				// wp_localize_script doesn't stringifies ints, so cast them.
1183				to: parseInt( revisions.settings.to, 10 ),
1184				from: parseInt( revisions.settings.from, 10 ),
1185				// wp_localize_script does not allow for top-level booleans so do a comparator here.
1186				compareTwoMode: ( revisions.settings.compareTwoMode === '1' )
1187			},
1188			diffData: revisions.settings.diffData,
1189			baseUrl: revisions.settings.baseUrl,
1190			postId: parseInt( revisions.settings.postId, 10 )
1191		}, {
1192			revisions: new revisions.model.Revisions( revisions.settings.revisionData )
1193		});
1194
1195		revisions.view.frame = new revisions.view.Frame({
1196			model: state
1197		}).render();
1198	};
1199
1200	$( revisions.init );
1201}(jQuery));
1202