CaffGeek/MBACNationals

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Web.Admin/2014/wordpress/wp-admin/js/customize-widgets.js

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/* global _wpCustomizeWidgetsSettings */
(function( wp, $ ){

    if ( ! wp || ! wp.customize ) { return; }

    // Set up our namespace...
    var api = wp.customize,
        l10n, OldPreviewer;

    api.Widgets = api.Widgets || {};

    // Link settings
    api.Widgets.data = _wpCustomizeWidgetsSettings || {};
    l10n = api.Widgets.data.l10n;
    delete api.Widgets.data.l10n;

    /**
     * wp.customize.Widgets.WidgetModel
     *
     * A single widget model.
     *
     * @constructor
     * @augments Backbone.Model
     */
    api.Widgets.WidgetModel = Backbone.Model.extend({
        id: null,
        temp_id: null,
        classname: null,
        control_tpl: null,
        description: null,
        is_disabled: null,
        is_multi: null,
        multi_number: null,
        name: null,
        id_base: null,
        transport: 'refresh',
        params: [],
        width: null,
        height: null,
        search_matched: true
    });

    /**
     * wp.customize.Widgets.WidgetCollection
     *
     * Collection for widget models.
     *
     * @constructor
     * @augments Backbone.Model
     */
    api.Widgets.WidgetCollection = Backbone.Collection.extend({
        model: api.Widgets.WidgetModel,

        // Controls searching on the current widget collection
        // and triggers an update event
        doSearch: function( value ) {

            // Don't do anything if we've already done this search
            // Useful because the search handler fires multiple times per keystroke
            if ( this.terms === value ) {
                return;
            }

            // Updates terms with the value passed
            this.terms = value;

            // If we have terms, run a search...
            if ( this.terms.length > 0 ) {
                this.search( this.terms );
            }

            // If search is blank, show all themes
            // Useful for resetting the views when you clean the input
            if ( this.terms === '' ) {
                this.each( function ( widget ) {
                    widget.set( 'search_matched', true );
                } );
            }
        },

        // Performs a search within the collection
        // @uses RegExp
        search: function( term ) {
            var match, haystack;

            // Escape the term string for RegExp meta characters
            term = term.replace( /[-\/\\^$*+?.()|[\]{}]/g, '\\$&' );

            // Consider spaces as word delimiters and match the whole string
            // so matching terms can be combined
            term = term.replace( / /g, ')(?=.*' );
            match = new RegExp( '^(?=.*' + term + ').+', 'i' );

            this.each( function ( data ) {
                haystack = [ data.get( 'name' ), data.get( 'id' ), data.get( 'description' ) ].join( ' ' );
                data.set( 'search_matched', match.test( haystack ) );
            } );
        }
    });
    api.Widgets.availableWidgets = new api.Widgets.WidgetCollection( api.Widgets.data.availableWidgets );

    /**
     * wp.customize.Widgets.SidebarModel
     *
     * A single sidebar model.
     *
     * @constructor
     * @augments Backbone.Model
     */
    api.Widgets.SidebarModel = Backbone.Model.extend({
        after_title: null,
        after_widget: null,
        before_title: null,
        before_widget: null,
        'class': null,
        description: null,
        id: null,
        name: null,
        is_rendered: false
    });

    /**
     * wp.customize.Widgets.SidebarCollection
     *
     * Collection for sidebar models.
     *
     * @constructor
     * @augments Backbone.Collection
     */
    api.Widgets.SidebarCollection = Backbone.Collection.extend({
        model: api.Widgets.SidebarModel
    });
    api.Widgets.registeredSidebars = new api.Widgets.SidebarCollection( api.Widgets.data.registeredSidebars );

    /**
     * wp.customize.Widgets.AvailableWidgetsPanelView
     *
     * View class for the available widgets panel.
     *
     * @constructor
     * @augments wp.Backbone.View
     * @augments Backbone.View
     */
    api.Widgets.AvailableWidgetsPanelView = wp.Backbone.View.extend({

        el: '#available-widgets',

        events: {
            'input #widgets-search': 'search',
            'keyup #widgets-search': 'search',
            'change #widgets-search': 'search',
            'search #widgets-search': 'search',
            'focus .widget-tpl' : 'focus',
            'click .widget-tpl' : '_submit',
            'keypress .widget-tpl' : '_submit',
            'keydown' : 'keyboardAccessible'
        },

        // Cache current selected widget
        selected: null,

        // Cache sidebar control which has opened panel
        currentSidebarControl: null,
        $search: null,

        initialize: function() {
            var self = this;

            this.$search = $( '#widgets-search' );

            _.bindAll( this, 'close' );

            this.listenTo( this.collection, 'change', this.updateList );

            this.updateList();

            // If the available widgets panel is open and the customize controls are
            // interacted with (i.e. available widgets panel is blurred) then close the
            // available widgets panel.
            $( '#customize-controls' ).on( 'click keydown', function( e ) {
                var isAddNewBtn = $( e.target ).is( '.add-new-widget, .add-new-widget *' );
                if ( $( 'body' ).hasClass( 'adding-widget' ) && ! isAddNewBtn ) {
                    self.close();
                }
            } );

            // Close the panel if the URL in the preview changes
            api.Widgets.Previewer.bind( 'url', this.close );
        },

        // Performs a search and handles selected widget
        search: function( event ) {
            var firstVisible;

            this.collection.doSearch( event.target.value );

            // Remove a widget from being selected if it is no longer visible
            if ( this.selected && ! this.selected.is( ':visible' ) ) {
                this.selected.removeClass( 'selected' );
                this.selected = null;
            }

            // If a widget was selected but the filter value has been cleared out, clear selection
            if ( this.selected && ! event.target.value ) {
                this.selected.removeClass( 'selected' );
                this.selected = null;
            }

            // If a filter has been entered and a widget hasn't been selected, select the first one shown
            if ( ! this.selected && event.target.value ) {
                firstVisible = this.$el.find( '> .widget-tpl:visible:first' );
                if ( firstVisible.length ) {
                    this.select( firstVisible );
                }
            }
        },

        // Changes visibility of available widgets
        updateList: function() {
            this.collection.each( function( widget ) {
                var widgetTpl = $( '#widget-tpl-' + widget.id );
                widgetTpl.toggle( widget.get( 'search_matched' ) && ! widget.get( 'is_disabled' ) );
                if ( widget.get( 'is_disabled' ) && widgetTpl.is( this.selected ) ) {
                    this.selected = null;
                }
            } );
        },

        // Highlights a widget
        select: function( widgetTpl ) {
            this.selected = $( widgetTpl );
            this.selected.siblings( '.widget-tpl' ).removeClass( 'selected' );
            this.selected.addClass( 'selected' );
        },

        // Highlights a widget on focus
        focus: function( event ) {
            this.select( $( event.currentTarget ) );
        },

        // Submit handler for keypress and click on widget
        _submit: function( event ) {
            // Only proceed with keypress if it is Enter or Spacebar
            if ( event.type === 'keypress' && ( event.which !== 13 && event.which !== 32 ) ) {
                return;
            }

            this.submit( $( event.currentTarget ) );
        },

        // Adds a selected widget to the sidebar
        submit: function( widgetTpl ) {
            var widgetId, widget;

            if ( ! widgetTpl ) {
                widgetTpl = this.selected;
            }

            if ( ! widgetTpl || ! this.currentSidebarControl ) {
                return;
            }

            this.select( widgetTpl );

            widgetId = $( this.selected ).data( 'widget-id' );
            widget = this.collection.findWhere( { id: widgetId } );
            if ( ! widget ) {
                return;
            }

            this.currentSidebarControl.addWidget( widget.get( 'id_base' ) );

            this.close();
        },

        // Opens the panel
        open: function( sidebarControl ) {
            this.currentSidebarControl = sidebarControl;

            // Wide widget controls appear over the preview, and so they need to be collapsed when the panel opens
            _( this.currentSidebarControl.getWidgetFormControls() ).each( function( control ) {
                if ( control.params.is_wide ) {
                    control.collapseForm();
                }
            } );

            $( 'body' ).addClass( 'adding-widget' );

            this.$el.find( '.selected' ).removeClass( 'selected' );

            // Reset search
            this.collection.doSearch( '' );

            this.$search.focus();
        },

        // Closes the panel
        close: function( options ) {
            options = options || {};

            if ( options.returnFocus && this.currentSidebarControl ) {
                this.currentSidebarControl.container.find( '.add-new-widget' ).focus();
            }

            this.currentSidebarControl = null;
            this.selected = null;

            $( 'body' ).removeClass( 'adding-widget' );

            this.$search.val( '' );
        },

        // Add keyboard accessiblity to the panel
        keyboardAccessible: function( event ) {
            var isEnter = ( event.which === 13 ),
                isEsc = ( event.which === 27 ),
                isDown = ( event.which === 40 ),
                isUp = ( event.which === 38 ),
                selected = null,
                firstVisible = this.$el.find( '> .widget-tpl:visible:first' ),
                lastVisible = this.$el.find( '> .widget-tpl:visible:last' ),
                isSearchFocused = $( event.target ).is( this.$search );

            if ( isDown || isUp ) {
                if ( isDown ) {
                    if ( isSearchFocused ) {
                        selected = firstVisible;
                    } else if ( this.selected && this.selected.nextAll( '.widget-tpl:visible' ).length !== 0 ) {
                        selected = this.selected.nextAll( '.widget-tpl:visible:first' );
                    }
                } else if ( isUp ) {
                    if ( isSearchFocused ) {
                        selected = lastVisible;
                    } else if ( this.selected && this.selected.prevAll( '.widget-tpl:visible' ).length !== 0 ) {
                        selected = this.selected.prevAll( '.widget-tpl:visible:first' );
                    }
                }

                this.select( selected );

                if ( selected ) {
                    selected.focus();
                } else {
                    this.$search.focus();
                }

                return;
            }

            // If enter pressed but nothing entered, don't do anything
            if ( isEnter && ! this.$search.val() ) {
                return;
            }

            if ( isEnter ) {
                this.submit();
            } else if ( isEsc ) {
                this.close( { returnFocus: true } );
            }
        }
    });

    /**
     * Handlers for the widget-synced event, organized by widget ID base.
     * Other widgets may provide their own update handlers by adding
     * listeners for the widget-synced event.
     */
    api.Widgets.formSyncHandlers = {

        /**
         * @param {jQuery.Event} e
         * @param {jQuery} widget
         * @param {String} newForm
         */
        rss: function( e, widget, newForm ) {
            var oldWidgetError = widget.find( '.widget-error:first' ),
                newWidgetError = $( '<div>' + newForm + '</div>' ).find( '.widget-error:first' );

            if ( oldWidgetError.length && newWidgetError.length ) {
                oldWidgetError.replaceWith( newWidgetError );
            } else if ( oldWidgetError.length ) {
                oldWidgetError.remove();
            } else if ( newWidgetError.length ) {
                widget.find( '.widget-content:first' ).prepend( newWidgetError );
            }
        }
    };

    /**
     * wp.customize.Widgets.WidgetControl
     *
     * Customizer control for widgets.
     * Note that 'widget_form' must match the WP_Widget_Form_Customize_Control::$type
     *
     * @constructor
     * @augments wp.customize.Control
     */
    api.Widgets.WidgetControl = api.Control.extend({
        /**
         * Set up the control
         */
        ready: function() {
            this._setupModel();
            this._setupWideWidget();
            this._setupControlToggle();
            this._setupWidgetTitle();
            this._setupReorderUI();
            this._setupHighlightEffects();
            this._setupUpdateUI();
            this._setupRemoveUI();
        },

        /**
         * Handle changes to the setting
         */
        _setupModel: function() {
            var self = this, rememberSavedWidgetId;

            api.Widgets.savedWidgetIds = api.Widgets.savedWidgetIds || [];

            // Remember saved widgets so we know which to trash (move to inactive widgets sidebar)
            rememberSavedWidgetId = function() {
                api.Widgets.savedWidgetIds[self.params.widget_id] = true;
            };
            api.bind( 'ready', rememberSavedWidgetId );
            api.bind( 'saved', rememberSavedWidgetId );

            this._updateCount = 0;
            this.isWidgetUpdating = false;
            this.liveUpdateMode = true;

            // Update widget whenever model changes
            this.setting.bind( function( to, from ) {
                if ( ! _( from ).isEqual( to ) && ! self.isWidgetUpdating ) {
                    self.updateWidget( { instance: to } );
                }
            } );
        },

        /**
         * Add special behaviors for wide widget controls
         */
        _setupWideWidget: function() {
            var self = this, $widgetInside, $widgetForm, $customizeSidebar,
                $themeControlsContainer, positionWidget;

            if ( ! this.params.is_wide ) {
                return;
            }

            $widgetInside = this.container.find( '.widget-inside' );
            $widgetForm = $widgetInside.find( '> .form' );
            $customizeSidebar = $( '.wp-full-overlay-sidebar-content:first' );
            this.container.addClass( 'wide-widget-control' );

            this.container.find( '.widget-content:first' ).css( {
                'max-width': this.params.width,
                'min-height': this.params.height
            } );

            /**
             * Keep the widget-inside positioned so the top of fixed-positioned
             * element is at the same top position as the widget-top. When the
             * widget-top is scrolled out of view, keep the widget-top in view;
             * likewise, don't allow the widget to drop off the bottom of the window.
             * If a widget is too tall to fit in the window, don't let the height
             * exceed the window height so that the contents of the widget control
             * will become scrollable (overflow:auto).
             */
            positionWidget = function() {
                var offsetTop = self.container.offset().top,
                    windowHeight = $( window ).height(),
                    formHeight = $widgetForm.outerHeight(),
                    top;
                $widgetInside.css( 'max-height', windowHeight );
                top = Math.max(
                    0, // prevent top from going off screen
                    Math.min(
                        Math.max( offsetTop, 0 ), // distance widget in panel is from top of screen
                        windowHeight - formHeight // flush up against bottom of screen
                    )
                );
                $widgetInside.css( 'top', top );
            };

            $themeControlsContainer = $( '#customize-theme-controls' );
            this.container.on( 'expand', function() {
                positionWidget();
                $customizeSidebar.on( 'scroll', positionWidget );
                $( window ).on( 'resize', positionWidget );
                $themeControlsContainer.on( 'expanded collapsed', positionWidget );
            } );
            this.container.on( 'collapsed', function() {
                $customizeSidebar.off( 'scroll', positionWidget );
                $( window ).off( 'resize', positionWidget );
                $themeControlsContainer.off( 'expanded collapsed', positionWidget );
            } );

            // Reposition whenever a sidebar's widgets are changed
            api.each( function( setting ) {
                if ( 0 === setting.id.indexOf( 'sidebars_widgets[' ) ) {
                    setting.bind( function() {
                        if ( self.container.hasClass( 'expanded' ) ) {
                            positionWidget();
                        }
                    } );
                }
            } );
        },

        /**
         * Show/hide the control when clicking on the form title, when clicking
         * the close button
         */
        _setupControlToggle: function() {
            var self = this, $closeBtn;

            this.container.find( '.widget-top' ).on( 'click', function( e ) {
                e.preventDefault();
                var sidebarWidgetsControl = self.getSidebarWidgetsControl();
                if ( sidebarWidgetsControl.isReordering ) {
                    return;
                }
                self.toggleForm();
            } );

            $closeBtn = this.container.find( '.widget-control-close' );
            $closeBtn.on( 'click', function( e ) {
                e.preventDefault();
                self.collapseForm();
                self.container.find( '.widget-top .widget-action:first' ).focus(); // keyboard accessibility
            } );
        },

        /**
         * Update the title of the form if a title field is entered
         */
        _setupWidgetTitle: function() {
            var self = this, updateTitle;

            updateTitle = function() {
                var title = self.setting().title,
                    inWidgetTitle = self.container.find( '.in-widget-title' );

                if ( title ) {
                    inWidgetTitle.text( ': ' + title );
                } else {
                    inWidgetTitle.text( '' );
                }
            };
            this.setting.bind( updateTitle );
            updateTitle();
        },

        /**
         * Set up the widget-reorder-nav
         */
        _setupReorderUI: function() {
            var self = this, selectSidebarItem, $moveWidgetArea,
                $reorderNav, updateAvailableSidebars;

            /**
             * select the provided sidebar list item in the move widget area
             *
             * @param {jQuery} li
             */
            selectSidebarItem = function( li ) {
                li.siblings( '.selected' ).removeClass( 'selected' );
                li.addClass( 'selected' );
                var isSelfSidebar = ( li.data( 'id' ) === self.params.sidebar_id );
                self.container.find( '.move-widget-btn' ).prop( 'disabled', isSelfSidebar );
            };

            /**
             * Add the widget reordering elements to the widget control
             */
            this.container.find( '.widget-title-action' ).after( $( api.Widgets.data.tpl.widgetReorderNav ) );
            $moveWidgetArea = $(
                _.template( api.Widgets.data.tpl.moveWidgetArea, {
                    sidebars: _( api.Widgets.registeredSidebars.toArray() ).pluck( 'attributes' )
                } )
            );
            this.container.find( '.widget-top' ).after( $moveWidgetArea );

            /**
             * Update available sidebars when their rendered state changes
             */
            updateAvailableSidebars = function() {
                var $sidebarItems = $moveWidgetArea.find( 'li' ), selfSidebarItem;

                selfSidebarItem = $sidebarItems.filter( function(){
                    return $( this ).data( 'id' ) === self.params.sidebar_id;
                } );

                $sidebarItems.each( function() {
                    var li = $( this ),
                        sidebarId,
                        sidebar;

                    sidebarId = li.data( 'id' );
                    sidebar = api.Widgets.registeredSidebars.get( sidebarId );

                    li.toggle( sidebar.get( 'is_rendered' ) );

                    if ( li.hasClass( 'selected' ) && ! sidebar.get( 'is_rendered' ) ) {
                        selectSidebarItem( selfSidebarItem );
                    }
                } );
            };

            updateAvailableSidebars();
            api.Widgets.registeredSidebars.on( 'change:is_rendered', updateAvailableSidebars );

            /**
             * Handle clicks for up/down/move on the reorder nav
             */
            $reorderNav = this.container.find( '.widget-reorder-nav' );
            $reorderNav.find( '.move-widget, .move-widget-down, .move-widget-up' ).on( 'click keypress', function( event ) {
                if ( event.type === 'keypress' && ( event.which !== 13 && event.which !== 32 ) ) {
                    return;
                }
                $( this ).focus();

                if ( $( this ).is( '.move-widget' ) ) {
                    self.toggleWidgetMoveArea();
                } else {
                    var isMoveDown = $( this ).is( '.move-widget-down' ),
                        isMoveUp = $( this ).is( '.move-widget-up' ),
                        i = self.getWidgetSidebarPosition();

                    if ( ( isMoveUp && i === 0 ) || ( isMoveDown && i === self.getSidebarWidgetsControl().setting().length - 1 ) ) {
                        return;
                    }

                    if ( isMoveUp ) {
                        self.moveUp();
                    } else {
                        self.moveDown();
                    }

                    $( this ).focus(); // re-focus after the container was moved
                }
            } );

            /**
             * Handle selecting a sidebar to move to
             */
            this.container.find( '.widget-area-select' ).on( 'click keypress', 'li', function( e ) {
                if ( event.type === 'keypress' && ( event.which !== 13 && event.which !== 32 ) ) {
                    return;
                }
                e.preventDefault();
                selectSidebarItem( $( this ) );
            } );

            /**
             * Move widget to another sidebar
             */
            this.container.find( '.move-widget-btn' ).click( function() {
                self.getSidebarWidgetsControl().toggleReordering( false );

                var oldSidebarId = self.params.sidebar_id,
                    newSidebarId = self.container.find( '.widget-area-select li.selected' ).data( 'id' ),
                    oldSidebarWidgetsSetting, newSidebarWidgetsSetting,
                    oldSidebarWidgetIds, newSidebarWidgetIds, i;

                oldSidebarWidgetsSetting = api( 'sidebars_widgets[' + oldSidebarId + ']' );
                newSidebarWidgetsSetting = api( 'sidebars_widgets[' + newSidebarId + ']' );
                oldSidebarWidgetIds = Array.prototype.slice.call( oldSidebarWidgetsSetting() );
                newSidebarWidgetIds = Array.prototype.slice.call( newSidebarWidgetsSetting() );

                i = self.getWidgetSidebarPosition();
                oldSidebarWidgetIds.splice( i, 1 );
                newSidebarWidgetIds.push( self.params.widget_id );

                oldSidebarWidgetsSetting( oldSidebarWidgetIds );
                newSidebarWidgetsSetting( newSidebarWidgetIds );

                self.focus();
            } );
        },

        /**
         * Highlight widgets in preview when interacted with in the customizer
         */
        _setupHighlightEffects: function() {
            var self = this;

            // Highlight whenever hovering or clicking over the form
            this.container.on( 'mouseenter click', function() {
                self.setting.previewer.send( 'highlight-widget', self.params.widget_id );
            } );

            // Highlight when the setting is updated
            this.setting.bind( function() {
                self.setting.previewer.send( 'highlight-widget', self.params.widget_id );
            } );
        },

        /**
         * Set up event handlers for widget updating
         */
        _setupUpdateUI: function() {
            var self = this, $widgetRoot, $widgetContent,
                $saveBtn, updateWidgetDebounced, formSyncHandler;

            $widgetRoot = this.container.find( '.widget:first' );
            $widgetContent = $widgetRoot.find( '.widget-content:first' );

            // Configure update button
            $saveBtn = this.container.find( '.widget-control-save' );
            $saveBtn.val( l10n.saveBtnLabel );
            $saveBtn.attr( 'title', l10n.saveBtnTooltip );
            $saveBtn.removeClass( 'button-primary' ).addClass( 'button-secondary' );
            $saveBtn.on( 'click', function( e ) {
                e.preventDefault();
                self.updateWidget( { disable_form: true } ); // @todo disable_form is unused?
            } );

            updateWidgetDebounced = _.debounce( function() {
                self.updateWidget();
            }, 250 );

            // Trigger widget form update when hitting Enter within an input
            $widgetContent.on( 'keydown', 'input', function( e ) {
                if ( 13 === e.which ) { // Enter
                    e.preventDefault();
                    self.updateWidget( { ignoreActiveElement: true } );
                }
            } );

            // Handle widgets that support live previews
            $widgetContent.on( 'change input propertychange', ':input', function( e ) {
                if ( self.liveUpdateMode ) {
                    if ( e.type === 'change' ) {
                        self.updateWidget();
                    } else if ( this.checkValidity && this.checkValidity() ) {
                        updateWidgetDebounced();
                    }
                }
            } );

            // Remove loading indicators when the setting is saved and the preview updates
            this.setting.previewer.channel.bind( 'synced', function() {
                self.container.removeClass( 'previewer-loading' );
            } );

            api.Widgets.Previewer.bind( 'widget-updated', function( updatedWidgetId ) {
                if ( updatedWidgetId === self.params.widget_id ) {
                    self.container.removeClass( 'previewer-loading' );
                }
            } );

            // Update widget control to indicate whether it is currently rendered
            api.Widgets.Previewer.bind( 'rendered-widgets', function( renderedWidgets ) {
                var isRendered = !! renderedWidgets[self.params.widget_id];

                self.container.toggleClass( 'widget-rendered', isRendered );
            } );

            formSyncHandler = api.Widgets.formSyncHandlers[ this.params.widget_id_base ];
            if ( formSyncHandler ) {
                $( document ).on( 'widget-synced', function( e, widget ) {
                    if ( $widgetRoot.is( widget ) ) {
                        formSyncHandler.apply( document, arguments );
                    }
                } );
            }
        },

        /**
         * Set up event handlers for widget removal
         */
        _setupRemoveUI: function() {
            var self = this, $removeBtn, replaceDeleteWithRemove;

            // Configure remove button
            $removeBtn = this.container.find( 'a.widget-control-remove' );
            $removeBtn.on( 'click', function( e ) {
                e.preventDefault();

                // Find an adjacent element to add focus to when this widget goes away
                var $adjacentFocusTarget;
                if ( self.container.next().is( '.customize-control-widget_form' ) ) {
                    $adjacentFocusTarget = self.container.next().find( '.widget-action:first' );
                } else if ( self.container.prev().is( '.customize-control-widget_form' ) ) {
                    $adjacentFocusTarget = self.container.prev().find( '.widget-action:first' );
                } else {
                    $adjacentFocusTarget = self.container.next( '.customize-control-sidebar_widgets' ).find( '.add-new-widget:first' );
                }

                self.container.slideUp( function() {
                    var sidebarsWidgetsControl = api.Widgets.getSidebarWidgetControlContainingWidget( self.params.widget_id ),
                        sidebarWidgetIds, i;

                    if ( ! sidebarsWidgetsControl ) {
                        return;
                    }

                    sidebarWidgetIds = sidebarsWidgetsControl.setting().slice();
                    i = _.indexOf( sidebarWidgetIds, self.params.widget_id );
                    if ( -1 === i ) {
                        return;
                    }

                    sidebarWidgetIds.splice( i, 1 );
                    sidebarsWidgetsControl.setting( sidebarWidgetIds );

                    $adjacentFocusTarget.focus(); // keyboard accessibility
                } );
            } );

            replaceDeleteWithRemove = function() {
                $removeBtn.text( l10n.removeBtnLabel ); // wp_widget_control() outputs the link as "Delete"
                $removeBtn.attr( 'title', l10n.removeBtnTooltip );
            };

            if ( this.params.is_new ) {
                api.bind( 'saved', replaceDeleteWithRemove );
            } else {
                replaceDeleteWithRemove();
            }
        },

        /**
         * Find all inputs in a widget container that should be considered when
         * comparing the loaded form with the sanitized form, whose fields will
         * be aligned to copy the sanitized over. The elements returned by this
         * are passed into this._getInputsSignature(), and they are iterated
         * over when copying sanitized values over to the the form loaded.
         *
         * @param {jQuery} container element in which to look for inputs
         * @returns {jQuery} inputs
         * @private
         */
        _getInputs: function( container ) {
            return $( container ).find( ':input[name]' );
        },

        /**
         * Iterate over supplied inputs and create a signature string for all of them together.
         * This string can be used to compare whether or not the form has all of the same fields.
         *
         * @param {jQuery} inputs
         * @returns {string}
         * @private
         */
        _getInputsSignature: function( inputs ) {
            var inputsSignatures = _( inputs ).map( function( input ) {
                var $input = $( input ), signatureParts;

                if ( $input.is( ':checkbox, :radio' ) ) {
                    signatureParts = [ $input.attr( 'id' ), $input.attr( 'name' ), $input.prop( 'value' ) ];
                } else {
                    signatureParts = [ $input.attr( 'id' ), $input.attr( 'name' ) ];
                }

                return signatureParts.join( ',' );
            } );

            return inputsSignatures.join( ';' );
        },

        /**
         * Get the property that represents the state of an input.
         *
         * @param {jQuery|DOMElement} input
         * @returns {string}
         * @private
         */
        _getInputStatePropertyName: function( input ) {
            var $input = $( input );

            if ( $input.is( ':radio, :checkbox' ) ) {
                return 'checked';
            } else {
                return 'value';
            }
        },

        /***********************************************************************
         * Begin public API methods
         **********************************************************************/

        /**
         * @return {wp.customize.controlConstructor.sidebar_widgets[]}
         */
        getSidebarWidgetsControl: function() {
            var settingId, sidebarWidgetsControl;

            settingId = 'sidebars_widgets[' + this.params.sidebar_id + ']';
            sidebarWidgetsControl = api.control( settingId );

            if ( ! sidebarWidgetsControl ) {
                return;
            }

            return sidebarWidgetsControl;
        },

        /**
         * Submit the widget form via Ajax and get back the updated instance,
         * along with the new widget control form to render.
         *
         * @param {object} [args]
         * @param {Object|null} [args.instance=null]  When the model changes, the instance is sent here; otherwise, the inputs from the form are used
         * @param {Function|null} [args.complete=null]  Function which is called when the request finishes. Context is bound to the control. First argument is any error. Following arguments are for success.
         * @param {Boolean} [args.ignoreActiveElement=false] Whether or not updating a field will be deferred if focus is still on the element.
         */
        updateWidget: function( args ) {
            var self = this, instanceOverride, completeCallback, $widgetRoot, $widgetContent,
                updateNumber, params, data, $inputs, processing, jqxhr, isChanged;

            args = $.extend( {
                instance: null,
                complete: null,
                ignoreActiveElement: false
            }, args );

            instanceOverride = args.instance;
            completeCallback = args.complete;

            this._updateCount += 1;
            updateNumber = this._updateCount;

            $widgetRoot = this.container.find( '.widget:first' );
            $widgetContent = $widgetRoot.find( '.widget-content:first' );

            // Remove a previous error message
            $widgetContent.find( '.widget-error' ).remove();

            this.container.addClass( 'widget-form-loading' );
            this.container.addClass( 'previewer-loading' );
            processing = api.state( 'processing' );
            processing( processing() + 1 );

            if ( ! this.liveUpdateMode ) {
                this.container.addClass( 'widget-form-disabled' );
            }

            params = {};
            params.action = 'update-widget';
            params.wp_customize = 'on';
            params.nonce = api.Widgets.data.nonce;
            params.theme = api.settings.theme.stylesheet;

            data = $.param( params );
            $inputs = this._getInputs( $widgetContent );

            // Store the value we're submitting in data so that when the response comes back,
            // we know if it got sanitized; if there is no difference in the sanitized value,
            // then we do not need to touch the UI and mess up the user's ongoing editing.
            $inputs.each( function() {
                var input = $( this ),
                    property = self._getInputStatePropertyName( this );
                input.data( 'state' + updateNumber, input.prop( property ) );
            } );

            if ( instanceOverride ) {
                data += '&' + $.param( { 'sanitized_widget_setting': JSON.stringify( instanceOverride ) } );
            } else {
                data += '&' + $inputs.serialize();
            }
            data += '&' + $widgetContent.find( '~ :input' ).serialize();

            jqxhr = $.post( wp.ajax.settings.url, data );

            jqxhr.done( function( r ) {
                var message, sanitizedForm,    $sanitizedInputs, hasSameInputsInResponse,
                    isLiveUpdateAborted = false;

                // Check if the user is logged out.
                if ( '0' === r ) {
                    api.Widgets.Previewer.preview.iframe.hide();
                    api.Widgets.Previewer.login().done( function() {
                        self.updateWidget( args );
                        api.Widgets.Previewer.preview.iframe.show();
                    } );
                    return;
                }

                // Check for cheaters.
                if ( '-1' === r ) {
                    api.Widgets.Previewer.cheatin();
                    return;
                }

                if ( r.success ) {
                    sanitizedForm = $( '<div>' + r.data.form + '</div>' );
                    $sanitizedInputs = self._getInputs( sanitizedForm );
                    hasSameInputsInResponse = self._getInputsSignature( $inputs ) === self._getInputsSignature( $sanitizedInputs );

                    // Restore live update mode if sanitized fields are now aligned with the existing fields
                    if ( hasSameInputsInResponse && ! self.liveUpdateMode ) {
                        self.liveUpdateMode = true;
                        self.container.removeClass( 'widget-form-disabled' );
                        self.container.find( 'input[name="savewidget"]' ).hide();
                    }

                    // Sync sanitized field states to existing fields if they are aligned
                    if ( hasSameInputsInResponse && self.liveUpdateMode ) {
                        $inputs.each( function( i ) {
                            var $input = $( this ),
                                $sanitizedInput = $( $sanitizedInputs[i] ),
                                property = self._getInputStatePropertyName( this ),
                                submittedState, sanitizedState,    canUpdateState;

                            submittedState = $input.data( 'state' + updateNumber );
                            sanitizedState = $sanitizedInput.prop( property );
                            $input.data( 'sanitized', sanitizedState );

                            canUpdateState = ( submittedState !== sanitizedState && ( args.ignoreActiveElement || ! $input.is( document.activeElement ) )    );
                            if ( canUpdateState ) {
                                $input.prop( property, sanitizedState );
                            }
                        } );

                        $( document ).trigger( 'widget-synced', [ $widgetRoot, r.data.form ] );

                    // Otherwise, if sanitized fields are not aligned with existing fields, disable live update mode if enabled
                    } else if ( self.liveUpdateMode ) {
                        self.liveUpdateMode = false;
                        self.container.find( 'input[name="savewidget"]' ).show();
                        isLiveUpdateAborted = true;

                    // Otherwise, replace existing form with the sanitized form
                    } else {
                        $widgetContent.html( r.data.form );

                        self.container.removeClass( 'widget-form-disabled' );

                        $( document ).trigger( 'widget-updated', [ $widgetRoot ] );
                    }

                    /**
                     * If the old instance is identical to the new one, there is nothing new
                     * needing to be rendered, and so we can preempt the event for the
                     * preview finishing loading.
                     */
                    isChanged = ! isLiveUpdateAborted && ! _( self.setting() ).isEqual( r.data.instance );
                    if ( isChanged ) {
                        self.isWidgetUpdating = true; // suppress triggering another updateWidget
                        self.setting( r.data.instance );
                        self.isWidgetUpdating = false;
                    } else {
                        // no change was made, so stop the spinner now instead of when the preview would updates
                        self.container.removeClass( 'previewer-loading' );
                    }

                    if ( completeCallback ) {
                        completeCallback.call( self, null, { noChange: ! isChanged, ajaxFinished: true } );
                    }
                } else {
                    // General error message
                    message = l10n.error;

                    if ( r.data && r.data.message ) {
                        message = r.data.message;
                    }

                    if ( completeCallback ) {
                        completeCallback.call( self, message );
                    } else {
                        $widgetContent.prepend( '<p class="widget-error"><strong>' + message + '</strong></p>' );
                    }
                }
            } );

            jqxhr.fail( function( jqXHR, textStatus ) {
                if ( completeCallback ) {
                    completeCallback.call( self, textStatus );
                }
            } );

            jqxhr.always( function() {
                self.container.removeClass( 'widget-form-loading' );

                $inputs.each( function() {
                    $( this ).removeData( 'state' + updateNumber );
                } );

                processing( processing() - 1 );
            } );
        },

        /**
         * Expand the accordion section containing a control
         */
        expandControlSection: function() {
            var $section = this.container.closest( '.accordion-section' );

            if ( ! $section.hasClass( 'open' ) ) {
                $section.find( '.accordion-section-title:first' ).trigger( 'click' );
            }
        },

        /**
         * Expand the widget form control
         */
        expandForm: function() {
            this.toggleForm( true );
        },

        /**
         * Collapse the widget form control
         */
        collapseForm: function() {
            this.toggleForm( false );
        },

        /**
         * Expand or collapse the widget control
         *
         * @param {boolean|undefined} [showOrHide] If not supplied, will be inverse of current visibility
         */
        toggleForm: function( showOrHide ) {
            var self = this, $widget, $inside, complete;

            $widget = this.container.find( 'div.widget:first' );
            $inside = $widget.find( '.widget-inside:first' );
            if ( typeof showOrHide === 'undefined' ) {
                showOrHide = ! $inside.is( ':visible' );
            }

            // Already expanded or collapsed, so noop
            if ( $inside.is( ':visible' ) === showOrHide ) {
                return;
            }

            if ( showOrHide ) {
                // Close all other widget controls before expanding this one
                api.control.each( function( otherControl ) {
                    if ( self.params.type === otherControl.params.type && self !== otherControl ) {
                        otherControl.collapseForm();
                    }
                } );

                complete = function() {
                    self.container.removeClass( 'expanding' );
                    self.container.addClass( 'expanded' );
                    self.container.trigger( 'expanded' );
                };

                if ( self.params.is_wide ) {
                    $inside.fadeIn( 'fast', complete );
                } else {
                    $inside.slideDown( 'fast', complete );
                }

                self.container.trigger( 'expand' );
                self.container.addClass( 'expanding' );
            } else {
                complete = function() {
                    self.container.removeClass( 'collapsing' );
                    self.container.removeClass( 'expanded' );
                    self.container.trigger( 'collapsed' );
                };

                self.container.trigger( 'collapse' );
                self.container.addClass( 'collapsing' );

                if ( self.params.is_wide ) {
                    $inside.fadeOut( 'fast', complete );
                } else {
                    $inside.slideUp( 'fast', function() {
                        $widget.css( { width:'', margin:'' } );
                        complete();
                    } );
                }
            }
        },

        /**
         * Expand the containing sidebar section, expand the form, and focus on
         * the first input in the control
         */
        focus: function() {
            this.expandControlSection();
            this.expandForm();
            this.container.find( '.widget-content :focusable:first' ).focus();
        },

        /**
         * Get the position (index) of the widget in the containing sidebar
         *
         * @returns {Number}
         */
        getWidgetSidebarPosition: function() {
            var sidebarWidgetIds, position;

            sidebarWidgetIds = this.getSidebarWidgetsControl().setting();
            position = _.indexOf( sidebarWidgetIds, this.params.widget_id );

            if ( position === -1 ) {
                return;
            }

            return position;
        },

        /**
         * Move widget up one in the sidebar
         */
        moveUp: function() {
            this._moveWidgetByOne( -1 );
        },

        /**
         * Move widget up one in the sidebar
         */
        moveDown: function() {
            this._moveWidgetByOne( 1 );
        },

        /**
         * @private
         *
         * @param {Number} offset 1|-1
         */
        _moveWidgetByOne: function( offset ) {
            var i, sidebarWidgetsSetting, sidebarWidgetIds,    adjacentWidgetId;

            i = this.getWidgetSidebarPosition();

            sidebarWidgetsSetting = this.getSidebarWidgetsControl().setting;
            sidebarWidgetIds = Array.prototype.slice.call( sidebarWidgetsSetting() ); // clone
            adjacentWidgetId = sidebarWidgetIds[i + offset];
            sidebarWidgetIds[i + offset] = this.params.widget_id;
            sidebarWidgetIds[i] = adjacentWidgetId;

            sidebarWidgetsSetting( sidebarWidgetIds );
        },

        /**
         * Toggle visibility of the widget move area
         *
         * @param {Boolean} [showOrHide]
         */
        toggleWidgetMoveArea: function( showOrHide ) {
            var self = this, $moveWidgetArea;

            $moveWidgetArea = this.container.find( '.move-widget-area' );

            if ( typeof showOrHide === 'undefined' ) {
                showOrHide = ! $moveWidgetArea.hasClass( 'active' );
            }

            if ( showOrHide ) {
                // reset the selected sidebar
                $moveWidgetArea.find( '.selected' ).removeClass( 'selected' );

                $moveWidgetArea.find( 'li' ).filter( function() {
                    return $( this ).data( 'id' ) === self.params.sidebar_id;
                } ).addClass( 'selected' );

                this.container.find( '.move-widget-btn' ).prop( 'disabled', true );
            }

            $moveWidgetArea.toggleClass( 'active', showOrHide );
        },

        /**
         * Highlight the widget control and section
         */
        highlightSectionAndControl: function() {
            var $target;

            if ( this.container.is( ':hidden' ) ) {
                $target = this.container.closest( '.control-section' );
            } else {
                $target = this.container;
            }

            $( '.highlighted' ).removeClass( 'highlighted' );
            $target.addClass( 'highlighted' );

            setTimeout( function() {
                $target.removeClass( 'highlighted' );
            }, 500 );
        }
    } );

    /**
     * wp.customize.Widgets.SidebarControl
     *
     * Customizer control for widgets.
     * Note that 'sidebar_widgets' must match the WP_Widget_Area_Customize_Control::$type
     *
     * @constructor
     * @augments wp.customize.Control
     */
    api.Widgets.SidebarControl = api.Control.extend({
        /**
         * Set up the control
         */
        ready: function() {
            this.$controlSection = this.container.closest( '.control-section' );
            this.$sectionContent = this.container.closest( '.accordion-section-content' );

            this._setupModel();
            this._setupSortable();
            this._setupAddition();
            this._applyCardinalOrderClassNames();
        },

        /**
         * Update ordering of widget control forms when the setting is updated
         */
        _setupModel: function() {
            var self = this,
                registeredSidebar = api.Widgets.registeredSidebars.get( this.params.sidebar_id );

            this.setting.bind( function( newWidgetIds, oldWidgetIds ) {
                var widgetFormControls, $sidebarWidgetsAddControl, finalControlContainers, removedWidgetIds;

                removedWidgetIds = _( oldWidgetIds ).difference( newWidgetIds );

                // Filter out any persistent widget IDs for widgets which have been deactivated
                newWidgetIds = _( newWidgetIds ).filter( function( newWidgetId ) {
                    var parsedWidgetId = parseWidgetId( newWidgetId );

                    return !! api.Widgets.availableWidgets.findWhere( { id_base: parsedWidgetId.id_base } );
                } );

                widgetFormControls = _( newWidgetIds ).map( function( widgetId ) {
                    var widgetFormControl = api.Widgets.getWidgetFormControlForWidget( widgetId );

                    if ( ! widgetFormControl ) {
                        widgetFormControl = self.addWidget( widgetId );
                    }

                    return widgetFormControl;
                } );

                // Sort widget controls to their new positions
                widgetFormControls.sort( function( a, b ) {
                    var aIndex = _.indexOf( newWidgetIds, a.params.widget_id ),
                        bIndex = _.indexOf( newWidgetIds, b.params.widget_id );

                    if ( aIndex === bIndex ) {
                        return 0;
                    }

                    return aIndex < bIndex ? -1 : 1;
                } );

                // Append the controls to put them in the right order
                finalControlContainers = _( widgetFormControls ).map( function( widgetFormControls ) {
                    return widgetFormControls.container[0];
                } );

                $sidebarWidgetsAddControl = self.$sectionContent.find( '.customize-control-sidebar_widgets' );
                $sidebarWidgetsAddControl.before( finalControlContainers );

                // Re-sort widget form controls (including widgets form other sidebars newly moved here)
                self._applyCardinalOrderClassNames();

                // If the widget was dragged into the sidebar, make sure the sidebar_id param is updated
                _( widgetFormControls ).each( function( widgetFormControl ) {
                    widgetFormControl.params.sidebar_id = self.params.sidebar_id;
                } );

                // Cleanup after widget removal
                _( removedWidgetIds ).each( function( removedWidgetId ) {

                    // Using setTimeout so that when moving a widget to another sidebar, the other sidebars_widgets settings get a chance to update
                    setTimeout( function() {
                        var removedControl, wasDraggedToAnotherSidebar, inactiveWidgets, removedIdBase,
                            widget, isPresentInAnotherSidebar = false;

                        // Check if the widget is in another sidebar
                        api.each( function( otherSetting ) {
                            if ( otherSetting.id === self.setting.id || 0 !== otherSetting.id.indexOf( 'sidebars_widgets[' ) || otherSetting.id === 'sidebars_widgets[wp_inactive_widgets]' ) {
                                return;
                            }

                            var otherSidebarWidgets = otherSetting(), i;

                            i = _.indexOf( otherSidebarWidgets, removedWidgetId );
                            if ( -1 !== i ) {
                                isPresentInAnotherSidebar = true;
                            }
                        } );

                        // If the widget is present in another sidebar, abort!
                        if ( isPresentInAnotherSidebar ) {
                            return;
                        }

                        removedControl = api.Widgets.getWidgetFormControlForWidget( removedWidgetId );

                        // Detect if widget control was dragged to another sidebar
                        wasDraggedToAnotherSidebar = removedControl && $.contains( document, removedControl.container[0] ) && ! $.contains( self.$sectionContent[0], removedControl.container[0] );

                        // Delete any widget form controls for removed widgets
                        if ( removedControl && ! wasDraggedToAnotherSidebar ) {
                            api.control.remove( removedControl.id );
                            removedControl.container.remove();
                        }

                        // Move widget to inactive widgets sidebar (move it to trash) if has been previously saved
                        // This prevents the inactive widgets sidebar from overflowing with throwaway widgets
                        if ( api.Widgets.savedWidgetIds[removedWidgetId] ) {
                            inactiveWidgets = api.value( 'sidebars_widgets[wp_inactive_widgets]' )().slice();
                            inactiveWidgets.push( removedWidgetId );
                            api.value( 'sidebars_widgets[wp_inactive_widgets]' )( _( inactiveWidgets ).unique() );
                        }

                        // Make old single widget available for adding again
                        removedIdBase = parseWidgetId( removedWidgetId ).id_base;
                        widget = api.Widgets.availableWidgets.findWhere( { id_base: removedIdBase } );
                        if ( widget && ! widget.get( 'is_multi' ) ) {
                            widget.set( 'is_disabled', false );
                        }
                    } );

                } );
            } );

            // Update the model with whether or not the sidebar is rendered
            api.Widgets.Previewer.bind( 'rendered-sidebars', function( renderedSidebars ) {
                var isRendered = !! renderedSidebars[self.params.sidebar_id];

                registeredSidebar.set( 'is_rendered', isRendered );
            } );

            // Show the sidebar section when it becomes visible
            registeredSidebar.on( 'change:is_rendered', function( ) {
                var sectionSelector = '#accordion-section-sidebar-widgets-' + this.get( 'id' ), $section;

                $section = $( sectionSelector );
                if ( this.get( 'is_rendered' ) ) {
                    $section.stop().slideDown( function() {
                        $( this ).css( 'height', 'auto' ); // so that the .accordion-section-content won't overflow
                    } );

                } else {
                    // Make sure that hidden sections get closed first
                    if ( $section.hasClass( 'open' ) ) {
                        // it would be nice if accordionSwitch() in accordion.js was public
                        $section.find( '.accordion-section-title' ).trigger( 'click' );
                    }

                    $section.stop().slideUp();
                }
            } );
        },

        /**
         * Allow widgets in sidebar to be re-ordered, and for the order to be previewed
         */
        _setupSortable: function() {
            var self = this;

            this.isReordering = false;

            /**
             * Update widget order setting when controls are re-ordered
             */
            this.$sectionContent.sortable( {
                items: '> .customize-control-widget_form',
                handle: '.widget-top',
                axis: 'y',
                connectWith: '.accordion-section-content:has(.customize-control-sidebar_widgets)',
                update: function() {
                    var widgetContainerIds = self.$sectionContent.sortable( 'toArray' ), widgetIds;

                    widgetIds = $.map( widgetContainerIds, function( widgetContainerId ) {
                        return $( '#' + widgetContainerId ).find( ':input[name=widget-id]' ).val();
                    } );

                    self.setting( widgetIds );
                }
            } );

            /**
             * Expand other customizer sidebar section when dragging a control widget over it,
             * allowing the control to be dropped into another section
             */
            this.$controlSection.find( '.accordion-section-title' ).droppable({
                accept: '.customize-control-widget_form',
                over: function() {
                    if ( ! self.$controlSection.hasClass( 'open' ) ) {
                        self.$controlSection.addClass( 'open' );
                        self.$sectionContent.toggle( false ).slideToggle( 150, function() {
                            self.$sectionContent.sortable( 'refreshPositions' );
                        } );
                    }
                }
            });

            /**
             * Keyboard-accessible reordering
             */
            this.container.find( '.reorder-toggle' ).on( 'click keydown', function( event ) {
                if ( event.type === 'keydown' && ! ( event.which === 13 || event.which === 32 ) ) { // Enter or Spacebar
                    return;
                }

                self.toggleReordering( ! self.isReordering );
            } );
        },

        /**
         * Set up UI for adding a new widget
         */
        _setupAddition: function() {
            var self = this;

            this.container.find( '.add-new-widget' ).on( 'click keydown', function( event ) {
                if ( event.type === 'keydown' && ! ( event.which === 13 || event.which === 32 ) ) { // Enter or Spacebar
                    return;
                }

                if ( self.$sectionContent.hasClass( 'reordering' ) ) {
                    return;
                }

                if ( ! $( 'body' ).hasClass( 'adding-widget' ) ) {
                    api.Widgets.availableWidgetsPanel.open( self );
                } else {
                    api.Widgets.availableWidgetsPanel.close();
                }
            } );
        },

        /**
         * Add classes to the widget_form controls to assist with styling
         */
        _applyCardinalOrderClassNames: function() {
            this.$sectionContent.find( '.customize-control-widget_form' )
                .removeClass( 'first-widget' )
                .removeClass( 'last-widget' )
                .find( '.move-widget-down, .move-widget-up' ).prop( 'tabIndex', 0 );

            this.$sectionContent.find( '.customize-control-widget_form:first' )
                .addClass( 'first-widget' )
                .find( '.move-widget-up' ).prop( 'tabIndex', -1 );

            this.$sectionContent.find( '.customize-control-widget_form:last' )
                .addClass( 'last-widget' )
                .find( '.move-widget-down' ).prop( 'tabIndex', -1 );
        },


        /***********************************************************************
         * Begin public API methods
         **********************************************************************/

        /**
         * Enable/disable the reordering UI
         *
         * @param {Boolean} showOrHide to enable/disable reordering
         */
        toggleReordering: function( showOrHide ) {
            showOrHide = Boolean( showOrHide );

            if ( showOrHide === this.$sectionContent.hasClass( 'reordering' ) ) {
                return;
            }

            this.isReordering = showOrHide;
            this.$sectionContent.toggleClass( 'reordering', showOrHide );

            if ( showOrHide ) {
                _( this.getWidgetFormControls() ).each( function( formControl ) {
                    formControl.collapseForm();
                } );
            }
        },

        /**
         * @return {wp.customize.controlConstructor.widget_form[]}
         */
        getWidgetFormControls: function() {
            var formControls;

            formControls = _( this.setting() ).map( function( widgetId ) {
                var settingId = widgetIdToSettingId( widgetId ),
                    formControl = api.control( settingId );

                if ( ! formControl ) {
                    return;
                }

                return formControl;
            } );

            return formControls;
        },

        /**
         * @param {string} widgetId or an id_base for adding a previously non-existing widget
         * @returns {object|false} widget_form control instance, or false on error
         */
        addWidget: function( widgetId ) {
            var self = this, controlHtml, $widget, controlType = 'widget_form', $control, controlConstructor,
                parsedWidgetId = parseWidgetId( widgetId ),
                widgetNumber = parsedWidgetId.number,
                widgetIdBase = parsedWidgetId.id_base,
                widget = api.Widgets.availableWidgets.findWhere( {id_base: widgetIdBase} ),
                settingId, isExistingWidget, widgetFormControl,    sidebarWidgets,    settingArgs;

            if ( ! widget ) {
                return false;
            }

            if ( widgetNumber && ! widget.get( 'is_multi' ) ) {
                return false;
            }

            // Set up new multi widget
            if ( widget.get( 'is_multi' ) && ! widgetNumber ) {
                widget.set( 'multi_number', widget.get( 'multi_number' ) + 1 );
                widgetNumber = widget.get( 'multi_number' );
            }

            controlHtml = $.trim( $( '#widget-tpl-' + widget.get( 'id' ) ).html() );
            if ( widget.get( 'is_multi' ) ) {
                controlHtml = controlHtml.replace( /<[^<>]+>/g, function( m ) {
                    return m.replace( /__i__|%i%/g, widgetNumber );
                } );
            } else {
                widget.set( 'is_disabled', true ); // Prevent single widget from being added again now
            }

            $widget = $( controlHtml );

            $control = $( '<li/>' )
                .addClass( 'customize-control' )
                .addClass( 'customize-control-' + controlType )
                .append( $widget );

            // Remove icon which is visible inside the panel
            $control.find( '> .widget-icon' ).remove();

            if ( widget.get( 'is_multi' ) ) {
                $control.find( 'input[name="widget_number"]' ).val( widgetNumber );
                $control.find( 'input[name="multi_number"]' ).val( widgetNumber );
            }

            widgetId = $control.find( '[name="widget-id"]' ).val();

            $control.hide(); // to be slid-down below

            settingId = 'widget_' + widget.get( 'id_base' );
            if ( widget.get( 'is_multi' ) ) {
                settingId += '[' + widgetNumber + ']';
            }
            $control.attr( 'id', 'customize-control-' + settingId.replace( /\]/g, '' ).replace( /\[/g, '-' ) );

            this.container.after( $control );

            // Only create setting if it doesn't already exist (if we're adding a pre-existing inactive widget)
            isExistingWidget = api.has( settingId );
            if ( ! isExistingWidget ) {
                settingArgs = {
                    transport: 'refresh',
                    previewer: this.setting.previewer
                };
                api.create( settingId, settingId, {}, settingArgs );
            }

            controlConstructor = api.controlConstructor[controlType];
            widgetFormControl = new controlConstructor( settingId, {
                params: {
                    settings: {
                        'default': settingId
                    },
                    sidebar_id: self.params.sidebar_id,
                    widget_id: widgetId,
                    widget_id_base: widget.get( 'id_base' ),
                    type: controlType,
                    is_new: ! isExistingWidget,
                    width: widget.get( 'width' ),
                    height: widget.get( 'height' ),
                    is_wide: widget.get( 'is_wide' )
                },
                previewer: self.setting.previewer
            } );
            api.control.add( settingId, widgetFormControl );

            // Make sure widget is removed from the other sidebars
            api.each( function( otherSetting ) {
                if ( otherSetting.id === self.setting.id ) {
                    return;
                }

                if ( 0 !== otherSetting.id.indexOf( 'sidebars_widgets[' ) ) {
                    return;
                }

                var otherSidebarWidgets = otherSetting().slice(),
                    i = _.indexOf( otherSidebarWidgets, widgetId );

                if ( -1 !== i ) {
                    otherSidebarWidgets.splice( i );
                    otherSetting( otherSidebarWidgets );
                }
            } );

            // Add widget to this sidebar
            sidebarWidgets = this.setting().slice();
            if ( -1 === _.indexOf( sidebarWidgets, widgetId ) ) {
                sidebarWidgets.push( widgetId );
                this.setting( sidebarWidgets );
            }

            $control.slideDown( function() {
                if ( isExistingWidget ) {
                    widgetFormControl.expandForm();
                    widgetFormControl.updateWidget( {
                        instance: widgetFormControl.setting(),
                        complete: function( error ) {
                            if ( error ) {
                                throw error;
                            }
                            widgetFormControl.focus();
                        }
                    } );
                } else {
                    widgetFormControl.focus();
                }
            } );

            $( document ).trigger( 'widget-added', [ $widget ] );

            return widgetFormControl;
        }
    } );

    /**
     * Extends wp.customizer.controlConstructor with control constructor for
     * widget_form and sidebar_widgets.
     */
    $.extend( api.controlConstructor, {
        widget_form: api.Widgets.WidgetControl,
        sidebar_widgets: api.Widgets.SidebarControl
    });

    /**
     * Capture the instance of the Previewer since it is private
     */
    OldPreviewer = api.Previewer;
    api.Previewer = OldPreviewer.extend({
        initialize: function( params, options ) {
            api.Widgets.Previewer = this;
            OldPreviewer.prototype.initialize.call( this, params, options );
            this.bind( 'refresh', this.refresh );
        }
    } );

    /**
     * Init Customizer for widgets.
     */
    api.bind( 'ready', function() {
        // Set up the widgets panel
        api.Widgets.availableWidgetsPanel = new api.Widgets.AvailableWidgetsPanelView({
            collection: api.Widgets.availableWidgets
        });

        // Highlight widget control
        api.Widgets.Previewer.bind( 'highlight-widget-control', api.Widgets.highlightWidgetFormControl );

        // Open and focus widget control
        api.Widgets.Previewer.bind( 'focus-widget-control', api.Widgets.focusWidgetFormControl );
    } );

    /**
     * Highlight a widget control.
     *
     * @param {string} widgetId
     */
    api.Widgets.highlightWidgetFormControl = function( widgetId ) {
        var control = api.Widgets.getWidgetFormControlForWidget( widgetId );

        if ( control ) {
            control.highlightSectionAndControl();
        }
    },

    /**
     * Focus a widget control.
     *
     * @param {string} widgetId
     */
    api.Widgets.focusWidgetFormControl = function( widgetId ) {
        var control = api.Widgets.getWidgetFormControlForWidget( widgetId );

        if ( control ) {
            control.focus();
        }
    },

    /**
     * Given a widget control, find the sidebar widgets control that contains it.
     * @param {string} widgetId
     * @return {object|null}
     */
    api.Widgets.getSidebarWidgetControlContainingWidget = function( widgetId ) {
        var foundControl = null;

        // @todo this can use widgetIdToSettingId(), then pass into wp.customize.control( x ).getSidebarWidgetsControl()
        api.control.each( function( control ) {
            if ( control.params.type === 'sidebar_widgets' && -1 !== _.indexOf( control.setting(), widgetId ) ) {
                foundControl = control;
            }
        } );

        return foundControl;
    };

    /**
     * Given a widget ID for a widget appearing in the preview, get the widget form control associated with it.
     *
     * @param {string} widgetId
     * @return {object|null}
     */
    api.Widgets.getWidgetFormControlForWidget = function( widgetId ) {
        var foundControl = null;

        // @todo We can just use widgetIdToSettingId() here
        api.control.each( function( control ) {
            if ( control.params.type === 'widget_form' && control.params.widget_id === widgetId ) {
                foundControl = control;
            }
        } );

        return foundControl;
    };

    /**
     * @param {String} widgetId
     * @returns {Object}
     */
    function parseWidgetId( widgetId ) {
        var matches, parsed = {
            number: null,
            id_base: null
        };

        matches = widgetId.match( /^(.+)-(\d+)$/ );
        if ( matches ) {
            parsed.id_base = matches[1];
            parsed.number = parseInt( matches[2], 10 );
        } else {
            // likely an old single widget
            parsed.id_base = widgetId;
        }

        return parsed;
    }

    /**
     * @param {String} widgetId
     * @returns {String} settingId
     */
    function widgetIdToSettingId( widgetId ) {
        var parsed = parseWidgetId( widgetId ), settingId;

        settingId = 'widget_' + parsed.id_base;
        if ( parsed.number ) {
            settingId += '[' + parsed.number + ']';
        }

        return settingId;
    }

})( window.wp, jQuery );