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wp-admin/js/theme.js

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/**
 * @output wp-admin/js/theme.js
 */

/* global _wpThemeSettings, confirm, tb_position */
window.wp = window.wp || {};

( function($) {

// Set up our namespace...
var themes, l10n;
themes = wp.themes = wp.themes || {};

// Store the theme data and settings for organized and quick access.
// themes.data.settings, themes.data.themes, themes.data.l10n.
themes.data = _wpThemeSettings;
l10n = themes.data.l10n;

// Shortcut for isInstall check.
themes.isInstall = !! themes.data.settings.isInstall;

// Setup app structure.
_.extend( themes, { model: {}, view: {}, routes: {}, router: {}, template: wp.template });

themes.Model = Backbone.Model.extend({
    // Adds attributes to the default data coming through the .org themes api.
    // Map `id` to `slug` for shared code.
    initialize: function() {
        var description;

        if ( this.get( 'slug' ) ) {
            // If the theme is already installed, set an attribute.
            if ( _.indexOf( themes.data.installedThemes, this.get( 'slug' ) ) !== -1 ) {
                this.set({ installed: true });
            }

            // If the theme is active, set an attribute.
            if ( themes.data.activeTheme === this.get( 'slug' ) ) {
                this.set({ active: true });
            }
        }

        // Set the attributes.
        this.set({
            // `slug` is for installation, `id` is for existing.
            id: this.get( 'slug' ) || this.get( 'id' )
        });

        // Map `section.description` to `description`
        // as the API sometimes returns it differently.
        if ( this.has( 'sections' ) ) {
            description = this.get( 'sections' ).description;
            this.set({ description: description });
        }
    }
});

// Main view controller for themes.php.
// Unifies and renders all available views.
themes.view.Appearance = wp.Backbone.View.extend({

    el: '#wpbody-content .wrap .theme-browser',

    window: $( window ),
    // Pagination instance.
    page: 0,

    // Sets up a throttler for binding to 'scroll'.
    initialize: function( options ) {
        // Scroller checks how far the scroll position is.
        _.bindAll( this, 'scroller' );

        this.SearchView = options.SearchView ? options.SearchView : themes.view.Search;
        // Bind to the scroll event and throttle
        // the results from this.scroller.
        this.window.on( 'scroll', _.throttle( this.scroller, 300 ) );
    },

    // Main render control.
    render: function() {
        // Setup the main theme view
        // with the current theme collection.
        this.view = new themes.view.Themes({
            collection: this.collection,
            parent: this
        });

        // Render search form.
        this.search();

        this.$el.removeClass( 'search-loading' );

        // Render and append.
        this.view.render();
        this.$el.empty().append( this.view.el ).addClass( 'rendered' );
    },

    // Defines search element container.
    searchContainer: $( '.search-form' ),

    // Search input and view
    // for current theme collection.
    search: function() {
        var view,
            self = this;

        // Don't render the search if there is only one theme.
        if ( themes.data.themes.length === 1 ) {
            return;
        }

        view = new this.SearchView({
            collection: self.collection,
            parent: this
        });
        self.SearchView = view;

        // Render and append after screen title.
        view.render();
        this.searchContainer
            .append( $.parseHTML( '<label class="screen-reader-text" for="wp-filter-search-input">' + l10n.search + '</label>' ) )
            .append( view.el )
            .on( 'submit', function( event ) {
                event.preventDefault();
            });
    },

    // Checks when the user gets close to the bottom
    // of the mage and triggers a theme:scroll event.
    scroller: function() {
        var self = this,
            bottom, threshold;

        bottom = this.window.scrollTop() + self.window.height();
        threshold = self.$el.offset().top + self.$el.outerHeight( false ) - self.window.height();
        threshold = Math.round( threshold * 0.9 );

        if ( bottom > threshold ) {
            this.trigger( 'theme:scroll' );
        }
    }
});

// Set up the Collection for our theme data.
// @has 'id' 'name' 'screenshot' 'author' 'authorURI' 'version' 'active' ...
themes.Collection = Backbone.Collection.extend({

    model: themes.Model,

    // Search terms.
    terms: '',

    // Controls searching on the current theme 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.reset( themes.data.themes );
            $( 'body' ).removeClass( 'no-results' );
        }

        // Trigger a 'themes:update' event.
        this.trigger( 'themes:update' );
    },

    /**
     * Performs a search within the collection.
     *
     * @uses RegExp
     */
    search: function( term ) {
        var match, results, haystack, name, description, author;

        // Start with a full collection.
        this.reset( themes.data.themes, { silent: true } );

        // Trim the term.
        term = term.trim();

        // 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' );

        // Find results.
        // _.filter() and .test().
        results = this.filter( function( data ) {
            name        = data.get( 'name' ).replace( /(<([^>]+)>)/ig, '' );
            description = data.get( 'description' ).replace( /(<([^>]+)>)/ig, '' );
            author      = data.get( 'author' ).replace( /(<([^>]+)>)/ig, '' );

            haystack = _.union( [ name, data.get( 'id' ), description, author, data.get( 'tags' ) ] );

            if ( match.test( data.get( 'author' ) ) && term.length > 2 ) {
                data.set( 'displayAuthor', true );
            }

            return match.test( haystack );
        });

        if ( results.length === 0 ) {
            this.trigger( 'query:empty' );
        } else {
            $( 'body' ).removeClass( 'no-results' );
        }

        this.reset( results );
    },

    // Paginates the collection with a helper method
    // that slices the collection.
    paginate: function( instance ) {
        var collection = this;
        instance = instance || 0;

        // Themes per instance are set at 20.
        collection = _( collection.rest( 20 * instance ) );
        collection = _( collection.first( 20 ) );

        return collection;
    },

    count: false,

    /*
     * Handles requests for more themes and caches results.
     *
     *
     * When we are missing a cache object we fire an apiCall()
     * which triggers events of `query:success` or `query:fail`.
     */
    query: function( request ) {
        /**
         * @static
         * @type Array
         */
        var queries = this.queries,
            self = this,
            query, isPaginated, count;

        // Store current query request args
        // for later use with the event `theme:end`.
        this.currentQuery.request = request;

        // Search the query cache for matches.
        query = _.find( queries, function( query ) {
            return _.isEqual( query.request, request );
        });

        // If the request matches the stored currentQuery.request
        // it means we have a paginated request.
        isPaginated = _.has( request, 'page' );

        // Reset the internal api page counter for non-paginated queries.
        if ( ! isPaginated ) {
            this.currentQuery.page = 1;
        }

        // Otherwise, send a new API call and add it to the cache.
        if ( ! query && ! isPaginated ) {
            query = this.apiCall( request ).done( function( data ) {

                // Update the collection with the queried data.
                if ( data.themes ) {
                    self.reset( data.themes );
                    count = data.info.results;
                    // Store the results and the query request.
                    queries.push( { themes: data.themes, request: request, total: count } );
                }

                // Trigger a collection refresh event
                // and a `query:success` event with a `count` argument.
                self.trigger( 'themes:update' );
                self.trigger( 'query:success', count );

                if ( data.themes && data.themes.length === 0 ) {
                    self.trigger( 'query:empty' );
                }

            }).fail( function() {
                self.trigger( 'query:fail' );
            });
        } else {
            // If it's a paginated request we need to fetch more themes...
            if ( isPaginated ) {
                return this.apiCall( request, isPaginated ).done( function( data ) {
                    // Add the new themes to the current collection.
                    // @todo Update counter.
                    self.add( data.themes );
                    self.trigger( 'query:success' );

                    // We are done loading themes for now.
                    self.loadingThemes = false;

                }).fail( function() {
                    self.trigger( 'query:fail' );
                });
            }

            if ( query.themes.length === 0 ) {
                self.trigger( 'query:empty' );
            } else {
                $( 'body' ).removeClass( 'no-results' );
            }

            // Only trigger an update event since we already have the themes
            // on our cached object.
            if ( _.isNumber( query.total ) ) {
                this.count = query.total;
            }

            this.reset( query.themes );
            if ( ! query.total ) {
                this.count = this.length;
            }

            this.trigger( 'themes:update' );
            this.trigger( 'query:success', this.count );
        }
    },

    // Local cache array for API queries.
    queries: [],

    // Keep track of current query so we can handle pagination.
    currentQuery: {
        page: 1,
        request: {}
    },

    // Send request to api.wordpress.org/themes.
    apiCall: function( request, paginated ) {
        return wp.ajax.send( 'query-themes', {
            data: {
                // Request data.
                request: _.extend({
                    per_page: 100
                }, request)
            },

            beforeSend: function() {
                if ( ! paginated ) {
                    // Spin it.
                    $( 'body' ).addClass( 'loading-content' ).removeClass( 'no-results' );
                }
            }
        });
    },

    // Static status controller for when we are loading themes.
    loadingThemes: false
});

// This is the view that controls each theme item
// that will be displayed on the screen.
themes.view.Theme = wp.Backbone.View.extend({

    // Wrap theme data on a div.theme element.
    className: 'theme',

    // Reflects which theme view we have.
    // 'grid' (default) or 'detail'.
    state: 'grid',

    // The HTML template for each element to be rendered.
    html: themes.template( 'theme' ),

    events: {
        'click': themes.isInstall ? 'preview': 'expand',
        'keydown': themes.isInstall ? 'preview': 'expand',
        'touchend': themes.isInstall ? 'preview': 'expand',
        'keyup': 'addFocus',
        'touchmove': 'preventExpand',
        'click .theme-install': 'installTheme',
        'click .update-message': 'updateTheme'
    },

    touchDrag: false,

    initialize: function() {
        this.model.on( 'change', this.render, this );
    },

    render: function() {
        var data = this.model.toJSON();

        // Render themes using the html template.
        this.$el.html( this.html( data ) ).attr( 'data-slug', data.id );

        // Renders active theme styles.
        this.activeTheme();

        if ( this.model.get( 'displayAuthor' ) ) {
            this.$el.addClass( 'display-author' );
        }
    },

    // Adds a class to the currently active theme
    // and to the overlay in detailed view mode.
    activeTheme: function() {
        if ( this.model.get( 'active' ) ) {
            this.$el.addClass( 'active' );
        }
    },

    // Add class of focus to the theme we are focused on.
    addFocus: function() {
        var $themeToFocus = ( $( ':focus' ).hasClass( 'theme' ) ) ? $( ':focus' ) : $(':focus').parents('.theme');

        $('.theme.focus').removeClass('focus');
        $themeToFocus.addClass('focus');
    },

    // Single theme overlay screen.
    // It's shown when clicking a theme.
    expand: function( event ) {
        var self = this;

        event = event || window.event;

        // 'Enter' and 'Space' keys expand the details view when a theme is :focused.
        if ( event.type === 'keydown' && ( event.which !== 13 && event.which !== 32 ) ) {
            return;
        }

        // Bail if the user scrolled on a touch device.
        if ( this.touchDrag === true ) {
            return this.touchDrag = false;
        }

        // Prevent the modal from showing when the user clicks
        // one of the direct action buttons.
        if ( $( event.target ).is( '.theme-actions a' ) ) {
            return;
        }

        // Prevent the modal from showing when the user clicks one of the direct action buttons.
        if ( $( event.target ).is( '.theme-actions a, .update-message, .button-link, .notice-dismiss' ) ) {
            return;
        }

        // Set focused theme to current element.
        themes.focusedTheme = this.$el;

        this.trigger( 'theme:expand', self.model.cid );
    },

    preventExpand: function() {
        this.touchDrag = true;
    },

    preview: function( event ) {
        var self = this,
            current, preview;

        event = event || window.event;

        // Bail if the user scrolled on a touch device.
        if ( this.touchDrag === true ) {
            return this.touchDrag = false;
        }

        // Allow direct link path to installing a theme.
        if ( $( event.target ).not( '.install-theme-preview' ).parents( '.theme-actions' ).length ) {
            return;
        }

        // 'Enter' and 'Space' keys expand the details view when a theme is :focused.
        if ( event.type === 'keydown' && ( event.which !== 13 && event.which !== 32 ) ) {
            return;
        }

        // Pressing Enter while focused on the buttons shouldn't open the preview.
        if ( event.type === 'keydown' && event.which !== 13 && $( ':focus' ).hasClass( 'button' ) ) {
            return;
        }

        event.preventDefault();

        event = event || window.event;

        // Set focus to current theme.
        themes.focusedTheme = this.$el;

        // Construct a new Preview view.
        themes.preview = preview = new themes.view.Preview({
            model: this.model
        });

        // Render the view and append it.
        preview.render();
        this.setNavButtonsState();

        // Hide previous/next navigation if there is only one theme.
        if ( this.model.collection.length === 1 ) {
            preview.$el.addClass( 'no-navigation' );
        } else {
            preview.$el.removeClass( 'no-navigation' );
        }

        // Append preview.
        $( 'div.wrap' ).append( preview.el );

        // Listen to our preview object
        // for `theme:next` and `theme:previous` events.
        this.listenTo( preview, 'theme:next', function() {

            // Keep local track of current theme model.
            current = self.model;

            // If we have ventured away from current model update the current model position.
            if ( ! _.isUndefined( self.current ) ) {
                current = self.current;
            }

            // Get next theme model.
            self.current = self.model.collection.at( self.model.collection.indexOf( current ) + 1 );

            // If we have no more themes, bail.
            if ( _.isUndefined( self.current ) ) {
                self.options.parent.parent.trigger( 'theme:end' );
                return self.current = current;
            }

            preview.model = self.current;

            // Render and append.
            preview.render();
            this.setNavButtonsState();
            $( '.next-theme' ).trigger( 'focus' );
        })
        .listenTo( preview, 'theme:previous', function() {

            // Keep track of current theme model.
            current = self.model;

            // Bail early if we are at the beginning of the collection.
            if ( self.model.collection.indexOf( self.current ) === 0 ) {
                return;
            }

            // If we have ventured away from current model update the current model position.
            if ( ! _.isUndefined( self.current ) ) {
                current = self.current;
            }

            // Get previous theme model.
            self.current = self.model.collection.at( self.model.collection.indexOf( current ) - 1 );

            // If we have no more themes, bail.
            if ( _.isUndefined( self.current ) ) {
                return;
            }

            preview.model = self.current;

            // Render and append.
            preview.render();
            this.setNavButtonsState();
            $( '.previous-theme' ).trigger( 'focus' );
        });

        this.listenTo( preview, 'preview:close', function() {
            self.current = self.model;
        });

    },

    // Handles .disabled classes for previous/next buttons in theme installer preview.
    setNavButtonsState: function() {
        var $themeInstaller = $( '.theme-install-overlay' ),
            current = _.isUndefined( this.current ) ? this.model : this.current,
            previousThemeButton = $themeInstaller.find( '.previous-theme' ),
            nextThemeButton = $themeInstaller.find( '.next-theme' );

        // Disable previous at the zero position.
        if ( 0 === this.model.collection.indexOf( current ) ) {
            previousThemeButton
                .addClass( 'disabled' )
                .prop( 'disabled', true );

            nextThemeButton.trigger( 'focus' );
        }

        // Disable next if the next model is undefined.
        if ( _.isUndefined( this.model.collection.at( this.model.collection.indexOf( current ) + 1 ) ) ) {
            nextThemeButton
                .addClass( 'disabled' )
                .prop( 'disabled', true );

            previousThemeButton.trigger( 'focus' );
        }
    },

    installTheme: function( event ) {
        var _this = this;

        event.preventDefault();

        wp.updates.maybeRequestFilesystemCredentials( event );

        $( document ).on( 'wp-theme-install-success', function( event, response ) {
            if ( _this.model.get( 'id' ) === response.slug ) {
                _this.model.set( { 'installed': true } );
            }
            if ( response.blockTheme ) {
                _this.model.set( { 'block_theme': true } );
            }
        } );

        wp.updates.installTheme( {
            slug: $( event.target ).data( 'slug' )
        } );
    },

    updateTheme: function( event ) {
        var _this = this;

        if ( ! this.model.get( 'hasPackage' ) ) {
            return;
        }

        event.preventDefault();

        wp.updates.maybeRequestFilesystemCredentials( event );

        $( document ).on( 'wp-theme-update-success', function( event, response ) {
            _this.model.off( 'change', _this.render, _this );
            if ( _this.model.get( 'id' ) === response.slug ) {
                _this.model.set( {
                    hasUpdate: false,
                    version: response.newVersion
                } );
            }
            _this.model.on( 'change', _this.render, _this );
        } );

        wp.updates.updateTheme( {
            slug: $( event.target ).parents( 'div.theme' ).first().data( 'slug' )
        } );
    }
});

// Theme Details view.
// Sets up a modal overlay with the expanded theme data.
themes.view.Details = wp.Backbone.View.extend({

    // Wrap theme data on a div.theme element.
    className: 'theme-overlay',

    events: {
        'click': 'collapse',
        'click .delete-theme': 'deleteTheme',
        'click .left': 'previousTheme',
        'click .right': 'nextTheme',
        'click #update-theme': 'updateTheme',
        'click .toggle-auto-update': 'autoupdateState'
    },

    // The HTML template for the theme overlay.
    html: themes.template( 'theme-single' ),

    render: function() {
        var data = this.model.toJSON();
        this.$el.html( this.html( data ) );
        // Renders active theme styles.
        this.activeTheme();
        // Set up navigation events.
        this.navigation();
        // Checks screenshot size.
        this.screenshotCheck( this.$el );
        // Contain "tabbing" inside the overlay.
        this.containFocus( this.$el );
    },

    // Adds a class to the currently active theme
    // and to the overlay in detailed view mode.
    activeTheme: function() {
        // Check the model has the active property.
        this.$el.toggleClass( 'active', this.model.get( 'active' ) );
    },

    // Set initial focus and constrain tabbing within the theme browser modal.
    containFocus: function( $el ) {

        // Set initial focus on the primary action control.
        _.delay( function() {
            $( '.theme-overlay' ).trigger( 'focus' );
        }, 100 );

        // Constrain tabbing within the modal.
        $el.on( 'keydown.wp-themes', function( event ) {
            var $firstFocusable = $el.find( '.theme-header button:not(.disabled)' ).first(),
                $lastFocusable = $el.find( '.theme-actions a:visible' ).last();

            // Check for the Tab key.
            if ( 9 === event.which ) {
                if ( $firstFocusable[0] === event.target && event.shiftKey ) {
                    $lastFocusable.trigger( 'focus' );
                    event.preventDefault();
                } else if ( $lastFocusable[0] === event.target && ! event.shiftKey ) {
                    $firstFocusable.trigger( 'focus' );
                    event.preventDefault();
                }
            }
        });
    },

    // Single theme overlay screen.
    // It's shown when clicking a theme.
    collapse: function( event ) {
        var self = this,
            scroll;

        event = event || window.event;

        // Prevent collapsing detailed view when there is only one theme available.
        if ( themes.data.themes.length === 1 ) {
            return;
        }

        // Detect if the click is inside the overlay and don't close it
        // unless the target was the div.back button.
        if ( $( event.target ).is( '.theme-backdrop' ) || $( event.target ).is( '.close' ) || event.keyCode === 27 ) {

            // Add a temporary closing class while overlay fades out.
            $( 'body' ).addClass( 'closing-overlay' );

            // With a quick fade out animation.
            this.$el.fadeOut( 130, function() {
                // Clicking outside the modal box closes the overlay.
                $( 'body' ).removeClass( 'closing-overlay' );
                // Handle event cleanup.
                self.closeOverlay();

                // Get scroll position to avoid jumping to the top.
                scroll = document.body.scrollTop;

                // Clean the URL structure.
                themes.router.navigate( themes.router.baseUrl( '' ) );

                // Restore scroll position.
                document.body.scrollTop = scroll;

                // Return focus to the theme div.
                if ( themes.focusedTheme ) {
                    themes.focusedTheme.find('.more-details').trigger( 'focus' );
                }
            });
        }
    },

    // Handles .disabled classes for next/previous buttons.
    navigation: function() {

        // Disable Left/Right when at the start or end of the collection.
        if ( this.model.cid === this.model.collection.at(0).cid ) {
            this.$el.find( '.left' )
                .addClass( 'disabled' )
                .prop( 'disabled', true );
        }
        if ( this.model.cid === this.model.collection.at( this.model.collection.length - 1 ).cid ) {
            this.$el.find( '.right' )
                .addClass( 'disabled' )
                .prop( 'disabled', true );
        }
    },

    // Performs the actions to effectively close
    // the theme details overlay.
    closeOverlay: function() {
        $( 'body' ).removeClass( 'modal-open' );
        this.remove();
        this.unbind();
        this.trigger( 'theme:collapse' );
    },

    // Set state of the auto-update settings link after it has been changed and saved.
    autoupdateState: function() {
        var callback,
            _this = this;

        // Support concurrent clicks in different Theme Details overlays.
        callback = function( event, data ) {
            var autoupdate;
            if ( _this.model.get( 'id' ) === data.asset ) {
                autoupdate = _this.model.get( 'autoupdate' );
                autoupdate.enabled = 'enable' === data.state;
                _this.model.set( { autoupdate: autoupdate } );
                $( document ).off( 'wp-auto-update-setting-changed', callback );
            }
        };

        // Triggered in updates.js
        $( document ).on( 'wp-auto-update-setting-changed', callback );
    },

    updateTheme: function( event ) {
        var _this = this;
        event.preventDefault();

        wp.updates.maybeRequestFilesystemCredentials( event );

        $( document ).on( 'wp-theme-update-success', function( event, response ) {
            if ( _this.model.get( 'id' ) === response.slug ) {
                _this.model.set( {
                    hasUpdate: false,
                    version: response.newVersion
                } );
            }
            _this.render();
        } );

        wp.updates.updateTheme( {
            slug: $( event.target ).data( 'slug' )
        } );
    },

    deleteTheme: function( event ) {
        var _this = this,
            _collection = _this.model.collection,
            _themes = themes;
        event.preventDefault();

        // Confirmation dialog for deleting a theme.
        if ( ! window.confirm( wp.themes.data.settings.confirmDelete ) ) {
            return;
        }

        wp.updates.maybeRequestFilesystemCredentials( event );

        $( document ).one( 'wp-theme-delete-success', function( event, response ) {
            _this.$el.find( '.close' ).trigger( 'click' );
            $( '[data-slug="' + response.slug + '"]' ).css( { backgroundColor:'#faafaa' } ).fadeOut( 350, function() {
                $( this ).remove();
                _themes.data.themes = _.without( _themes.data.themes, _.findWhere( _themes.data.themes, { id: response.slug } ) );

                $( '.wp-filter-search' ).val( '' );
                _collection.doSearch( '' );
                _collection.remove( _this.model );
                _collection.trigger( 'themes:update' );
            } );
        } );

        wp.updates.deleteTheme( {
            slug: this.model.get( 'id' )
        } );
    },

    nextTheme: function() {
        var self = this;
        self.trigger( 'theme:next', self.model.cid );
        return false;
    },

    previousTheme: function() {
        var self = this;
        self.trigger( 'theme:previous', self.model.cid );
        return false;
    },

    // Checks if the theme screenshot is the old 300px width version
    // and adds a corresponding class if it's true.
    screenshotCheck: function( el ) {
        var screenshot, image;

        screenshot = el.find( '.screenshot img' );
        image = new Image();
        image.src = screenshot.attr( 'src' );

        // Width check.
        if ( image.width && image.width <= 300 ) {
            el.addClass( 'small-screenshot' );
        }
    }
});

// Theme Preview view.
// Sets up a modal overlay with the expanded theme data.
themes.view.Preview = themes.view.Details.extend({

    className: 'wp-full-overlay expanded',
    el: '.theme-install-overlay',

    events: {
        'click .close-full-overlay': 'close',
        'click .collapse-sidebar': 'collapse',
        'click .devices button': 'previewDevice',
        'click .previous-theme': 'previousTheme',
        'click .next-theme': 'nextTheme',
        'keyup': 'keyEvent',
        'click .theme-install': 'installTheme'
    },

    // The HTML template for the theme preview.
    html: themes.template( 'theme-preview' ),

    render: function() {
        var self = this,
            currentPreviewDevice,
            data = this.model.toJSON(),
            $body = $( document.body );

        $body.attr( 'aria-busy', 'true' );

        this.$el.removeClass( 'iframe-ready' ).html( this.html( data ) );

        currentPreviewDevice = this.$el.data( 'current-preview-device' );
        if ( currentPreviewDevice ) {
            self.togglePreviewDeviceButtons( currentPreviewDevice );
        }

        themes.router.navigate( themes.router.baseUrl( themes.router.themePath + this.model.get( 'id' ) ), { replace: false } );

        this.$el.fadeIn( 200, function() {
            $body.addClass( 'theme-installer-active full-overlay-active' );
        });

        this.$el.find( 'iframe' ).one( 'load', function() {
            self.iframeLoaded();
        });
    },

    iframeLoaded: function() {
        this.$el.addClass( 'iframe-ready' );
        $( document.body ).attr( 'aria-busy', 'false' );
    },

    close: function() {
        this.$el.fadeOut( 200, function() {
            $( 'body' ).removeClass( 'theme-installer-active full-overlay-active' );

            // Return focus to the theme div.
            if ( themes.focusedTheme ) {
                themes.focusedTheme.find('.more-details').trigger( 'focus' );
            }
        }).removeClass( 'iframe-ready' );

        // Restore the previous browse tab if available.
        if ( themes.router.selectedTab ) {
            themes.router.navigate( themes.router.baseUrl( '?browse=' + themes.router.selectedTab ) );
            themes.router.selectedTab = false;
        } else {
            themes.router.navigate( themes.router.baseUrl( '' ) );
        }
        this.trigger( 'preview:close' );
        this.undelegateEvents();
        this.unbind();
        return false;
    },

    collapse: function( event ) {
        var $button = $( event.currentTarget );
        if ( 'true' === $button.attr( 'aria-expanded' ) ) {
            $button.attr({ 'aria-expanded': 'false', 'aria-label': l10n.expandSidebar });
        } else {
            $button.attr({ 'aria-expanded': 'true', 'aria-label': l10n.collapseSidebar });
        }

        this.$el.toggleClass( 'collapsed' ).toggleClass( 'expanded' );
        return false;
    },

    previewDevice: function( event ) {
        var device = $( event.currentTarget ).data( 'device' );

        this.$el
            .removeClass( 'preview-desktop preview-tablet preview-mobile' )
            .addClass( 'preview-' + device )
            .data( 'current-preview-device', device );

        this.togglePreviewDeviceButtons( device );
    },

    togglePreviewDeviceButtons: function( newDevice ) {
        var $devices = $( '.wp-full-overlay-footer .devices' );

        $devices.find( 'button' )
            .removeClass( 'active' )
            .attr( 'aria-pressed', false );

        $devices.find( 'button.preview-' + newDevice )
            .addClass( 'active' )
            .attr( 'aria-pressed', true );
    },

    keyEvent: function( event ) {
        // The escape key closes the preview.
        if ( event.keyCode === 27 ) {
            this.undelegateEvents();
            this.close();
        }
        // The right arrow key, next theme.
        if ( event.keyCode === 39 ) {
            _.once( this.nextTheme() );
        }

        // The left arrow key, previous theme.
        if ( event.keyCode === 37 ) {
            this.previousTheme();
        }
    },

    installTheme: function( event ) {
        var _this   = this,
            $target = $( event.target );
        event.preventDefault();

        if ( $target.hasClass( 'disabled' ) ) {
            return;
        }

        wp.updates.maybeRequestFilesystemCredentials( event );

        $( document ).on( 'wp-theme-install-success', function() {
            _this.model.set( { 'installed': true } );
        } );

        wp.updates.installTheme( {
            slug: $target.data( 'slug' )
        } );
    }
});

// Controls the rendering of div.themes,
// a wrapper that will hold all the theme elements.
themes.view.Themes = wp.Backbone.View.extend({

    className: 'themes wp-clearfix',
    $overlay: $( 'div.theme-overlay' ),

    // Number to keep track of scroll position
    // while in theme-overlay mode.
    index: 0,

    // The theme count element.
    count: $( '.wrap .theme-count' ),

    // The live themes count.
    liveThemeCount: 0,

    initialize: function( options ) {
        var self = this;

        // Set up parent.
        this.parent = options.parent;

        // Set current view to [grid].
        this.setView( 'grid' );

        // Move the active theme to the beginning of the collection.
        self.currentTheme();

        // When the collection is updated by user input...
        this.listenTo( self.collection, 'themes:update', function() {
            self.parent.page = 0;
            self.currentTheme();
            self.render( this );
        } );

        // Update theme count to full result set when available.
        this.listenTo( self.collection, 'query:success', function( count ) {
            if ( _.isNumber( count ) ) {
                self.count.text( count );
                self.announceSearchResults( count );
            } else {
                self.count.text( self.collection.length );
                self.announceSearchResults( self.collection.length );
            }
        });

        this.listenTo( self.collection, 'query:empty', function() {
            $( 'body' ).addClass( 'no-results' );
        });

        this.listenTo( this.parent, 'theme:scroll', function() {
            self.renderThemes( self.parent.page );
        });

        this.listenTo( this.parent, 'theme:close', function() {
            if ( self.overlay ) {
                self.overlay.closeOverlay();
            }
        } );

        // Bind keyboard events.
        $( 'body' ).on( 'keyup', function( event ) {
            if ( ! self.overlay ) {
                return;
            }

            // Bail if the filesystem credentials dialog is shown.
            if ( $( '#request-filesystem-credentials-dialog' ).is( ':visible' ) ) {
                return;
            }

            // Pressing the right arrow key fires a theme:next event.
            if ( event.keyCode === 39 ) {
                self.overlay.nextTheme();
            }

            // Pressing the left arrow key fires a theme:previous event.
            if ( event.keyCode === 37 ) {
                self.overlay.previousTheme();
            }

            // Pressing the escape key fires a theme:collapse event.
            if ( event.keyCode === 27 ) {
                self.overlay.collapse( event );
            }
        });
    },

    // Manages rendering of theme pages
    // and keeping theme count in sync.
    render: function() {
        // Clear the DOM, please.
        this.$el.empty();

        // If the user doesn't have switch capabilities or there is only one theme
        // in the collection, render the detailed view of the active theme.
        if ( themes.data.themes.length === 1 ) {

            // Constructs the view.
            this.singleTheme = new themes.view.Details({
                model: this.collection.models[0]
            });

            // Render and apply a 'single-theme' class to our container.
            this.singleTheme.render();
            this.$el.addClass( 'single-theme' );
            this.$el.append( this.singleTheme.el );
        }

        // Generate the themes using page instance
        // while checking the collection has items.
        if ( this.options.collection.size() > 0 ) {
            this.renderThemes( this.parent.page );
        }

        // Display a live theme count for the collection.
        this.liveThemeCount = this.collection.count ? this.collection.count : this.collection.length;
        this.count.text( this.liveThemeCount );

        /*
         * In the theme installer the themes count is already announced
         * because `announceSearchResults` is called on `query:success`.
         */
        if ( ! themes.isInstall ) {
            this.announceSearchResults( this.liveThemeCount );
        }
    },

    // Iterates through each instance of the collection
    // and renders each theme module.
    renderThemes: function( page ) {
        var self = this;

        self.instance = self.collection.paginate( page );

        // If we have no more themes, bail.
        if ( self.instance.size() === 0 ) {
            // Fire a no-more-themes event.
            this.parent.trigger( 'theme:end' );
            return;
        }

        // Make sure the add-new stays at the end.
        if ( ! themes.isInstall && page >= 1 ) {
            $( '.add-new-theme' ).remove();
        }

        // Loop through the themes and setup each theme view.
        self.instance.each( function( theme ) {
            self.theme = new themes.view.Theme({
                model: theme,
                parent: self
            });

            // Render the views...
            self.theme.render();
            // ...and append them to div.themes.
            self.$el.append( self.theme.el );

            // Binds to theme:expand to show the modal box
            // with the theme details.
            self.listenTo( self.theme, 'theme:expand', self.expand, self );
        });

        // 'Add new theme' element shown at the end of the grid.
        if ( ! themes.isInstall && themes.data.settings.canInstall ) {
            this.$el.append( '<div class="theme add-new-theme"><a href="' + themes.data.settings.installURI + '"><div class="theme-screenshot"><span></span></div><h2 class="theme-name">' + l10n.addNew + '</h2></a></div>' );
        }

        this.parent.page++;
    },

    // Grabs current theme and puts it at the beginning of the collection.
    currentTheme: function() {
        var self = this,
            current;

        current = self.collection.findWhere({ active: true });

        // Move the active theme to the beginning of the collection.
        if ( current ) {
            self.collection.remove( current );
            self.collection.add( current, { at:0 } );
        }
    },

    // Sets current view.
    setView: function( view ) {
        return view;
    },

    // Renders the overlay with the ThemeDetails view.
    // Uses the current model data.
    expand: function( id ) {
        var self = this, $card, $modal;

        // Set the current theme model.
        this.model = self.collection.get( id );

        // Trigger a route update for the current model.
        themes.router.navigate( themes.router.baseUrl( themes.router.themePath + this.model.id ) );

        // Sets this.view to 'detail'.
        this.setView( 'detail' );
        $( 'body' ).addClass( 'modal-open' );

        // Set up the theme details view.
        this.overlay = new themes.view.Details({
            model: self.model
        });

        this.overlay.render();

        if ( this.model.get( 'hasUpdate' ) ) {
            $card  = $( '[data-slug="' + this.model.id + '"]' );
            $modal = $( this.overlay.el );

            if ( $card.find( '.updating-message' ).length ) {
                $modal.find( '.notice-warning h3' ).remove();
                $modal.find( '.notice-warning' )
                    .removeClass( 'notice-large' )
                    .addClass( 'updating-message' )
                    .find( 'p' ).text( wp.updates.l10n.updating );
            } else if ( $card.find( '.notice-error' ).length ) {
                $modal.find( '.notice-warning' ).remove();
            }
        }

        this.$overlay.html( this.overlay.el );

        // Bind to theme:next and theme:previous triggered by the arrow keys.
        // Keep track of the current model so we can infer an index position.
        this.listenTo( this.overlay, 'theme:next', function() {
            // Renders the next theme on the overlay.
            self.next( [ self.model.cid ] );

        })
        .listenTo( this.overlay, 'theme:previous', function() {
            // Renders the previous theme on the overlay.
            self.previous( [ self.model.cid ] );
        });
    },

    /*
     * This method renders the next theme on the overlay modal
     * based on the current position in the collection.
     *
     * @params [model cid]
     */
    next: function( args ) {
        var self = this,
            model, nextModel;

        // Get the current theme.
        model = self.collection.get( args[0] );
        // Find the next model within the collection.
        nextModel = self.collection.at( self.collection.indexOf( model ) + 1 );

        // Confidence check which also serves as a boundary test.
        if ( nextModel !== undefined ) {

            // We have a new theme...
            // Close the overlay.
            this.overlay.closeOverlay();

            // Trigger a route update for the current model.
            self.theme.trigger( 'theme:expand', nextModel.cid );

        }
    },

    /*
     * This method renders the previous theme on the overlay modal
     * based on the current position in the collection.
     *
     * @params [model cid]
     */
    previous: function( args ) {
        var self = this,
            model, previousModel;

        // Get the current theme.
        model = self.collection.get( args[0] );
        // Find the previous model within the collection.
        previousModel = self.collection.at( self.collection.indexOf( model ) - 1 );

        if ( previousModel !== undefined ) {

            // We have a new theme...
            // Close the overlay.
            this.overlay.closeOverlay();

            // Trigger a route update for the current model.
            self.theme.trigger( 'theme:expand', previousModel.cid );

        }
    },

    // Dispatch audible search results feedback message.
    announceSearchResults: function( count ) {
        if ( 0 === count ) {
            wp.a11y.speak( l10n.noThemesFound );
        } else {
            wp.a11y.speak( l10n.themesFound.replace( '%d', count ) );
        }
    }
});

// Search input view controller.
themes.view.Search = wp.Backbone.View.extend({

    tagName: 'input',
    className: 'wp-filter-search',
    id: 'wp-filter-search-input',
    searching: false,

    attributes: {
        placeholder: l10n.searchPlaceholder,
        type: 'search',
        'aria-describedby': 'live-search-desc'
    },

    events: {
        'input': 'search',
        'keyup': 'search',
        'blur': 'pushState'
    },

    initialize: function( options ) {

        this.parent = options.parent;

        this.listenTo( this.parent, 'theme:close', function() {
            this.searching = false;
        } );

    },

    search: function( event ) {
        // Clear on escape.
        if ( event.type === 'keyup' && event.which === 27 ) {
            event.target.value = '';
        }

        // Since doSearch is debounced, it will only run when user input comes to a rest.
        this.doSearch( event );
    },

    // Runs a search on the theme collection.
    doSearch: function( event ) {
        var options = {};

        this.collection.doSearch( event.target.value.replace( /\+/g, ' ' ) );

        // if search is initiated and key is not return.
        if ( this.searching && event.which !== 13 ) {
            options.replace = true;
        } else {
            this.searching = true;
        }

        // Update the URL hash.
        if ( event.target.value ) {
            themes.router.navigate( themes.router.baseUrl( themes.router.searchPath + event.target.value ), options );
        } else {
            themes.router.navigate( themes.router.baseUrl( '' ) );
        }
    },

    pushState: function( event ) {
        var url = themes.router.baseUrl( '' );

        if ( event.target.value ) {
            url = themes.router.baseUrl( themes.router.searchPath + encodeURIComponent( event.target.value ) );
        }

        this.searching = false;
        themes.router.navigate( url );

    }
});

/**
 * Navigate router.
 *
 * @since 4.9.0
 *
 * @param {string} url - URL to navigate to.
 * @param {Object} state - State.
 * @return {void}
 */
function navigateRouter( url, state ) {
    var router = this;
    if ( Backbone.history._hasPushState ) {
        Backbone.Router.prototype.navigate.call( router, url, state );
    }
}

// Sets up the routes events for relevant url queries.
// Listens to [theme] and [search] params.
themes.Router = Backbone.Router.extend({

    routes: {
        'themes.php?theme=:slug': 'theme',
        'themes.php?search=:query': 'search',
        'themes.php?s=:query': 'search',
        'themes.php': 'themes',
        '': 'themes'
    },

    baseUrl: function( url ) {
        return 'themes.php' + url;
    },

    themePath: '?theme=',
    searchPath: '?search=',

    search: function( query ) {
        $( '.wp-filter-search' ).val( query.replace( /\+/g, ' ' ) );
    },

    themes: function() {
        $( '.wp-filter-search' ).val( '' );
    },

    navigate: navigateRouter

});

// Execute and setup the application.
themes.Run = {
    init: function() {
        // Initializes the blog's theme library view.
        // Create a new collection with data.
        this.themes = new themes.Collection( themes.data.themes );

        // Set up the view.
        this.view = new themes.view.Appearance({
            collection: this.themes
        });

        this.render();

        // Start debouncing user searches after Backbone.history.start().
        this.view.SearchView.doSearch = _.debounce( this.view.SearchView.doSearch, 500 );
    },

    render: function() {

        // Render results.
        this.view.render();
        this.routes();

        if ( Backbone.History.started ) {
            Backbone.history.stop();
        }
        Backbone.history.start({
            root: themes.data.settings.adminUrl,
            pushState: true,
            hashChange: false
        });
    },

    routes: function() {
        var self = this;
        // Bind to our global thx object
        // so that the object is available to sub-views.
        themes.router = new themes.Router();

        // Handles theme details route event.
        themes.router.on( 'route:theme', function( slug ) {
            self.view.view.expand( slug );
        });

        themes.router.on( 'route:themes', function() {
            self.themes.doSearch( '' );
            self.view.trigger( 'theme:close' );
        });

        // Handles search route event.
        themes.router.on( 'route:search', function() {
            $( '.wp-filter-search' ).trigger( 'keyup' );
        });

        this.extraRoutes();
    },

    extraRoutes: function() {
        return false;
    }
};

// Extend the main Search view.
themes.view.InstallerSearch =  themes.view.Search.extend({

    events: {
        'input': 'search',
        'keyup': 'search'
    },

    terms: '',

    // Handles Ajax request for searching through themes in public repo.
    search: function( event ) {

        // Tabbing or reverse tabbing into the search input shouldn't trigger a search.
        if ( event.type === 'keyup' && ( event.which === 9 || event.which === 16 ) ) {
            return;
        }

        this.collection = this.options.parent.view.collection;

        // Clear on escape.
        if ( event.type === 'keyup' && event.which === 27 ) {
            event.target.value = '';
        }

        this.doSearch( event.target.value );
    },

    doSearch: function( value ) {
        var request = {};

        // Don't do anything if the search terms haven't changed.
        if ( this.terms === value ) {
            return;
        }

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

        request.search = value;

        /*
         * Intercept an [author] search.
         *
         * If input value starts with `author:` send a request
         * for `author` instead of a regular `search`.
         */
        if ( value.substring( 0, 7 ) === 'author:' ) {
            request.search = '';
            request.author = value.slice( 7 );
        }

        /*
         * Intercept a [tag] search.
         *
         * If input value starts with `tag:` send a request
         * for `tag` instead of a regular `search`.
         */
        if ( value.substring( 0, 4 ) === 'tag:' ) {
            request.search = '';
            request.tag = [ value.slice( 4 ) ];
        }

        $( '.filter-links li > a.current' )
            .removeClass( 'current' )
            .removeAttr( 'aria-current' );

        $( 'body' ).removeClass( 'show-filters filters-applied show-favorites-form' );
        $( '.drawer-toggle' ).attr( 'aria-expanded', 'false' );

        // Get the themes by sending Ajax POST request to api.wordpress.org/themes
        // or searching the local cache.
        this.collection.query( request );

        // Set route.
        themes.router.navigate( themes.router.baseUrl( themes.router.searchPath + encodeURIComponent( value ) ), { replace: true } );
    }
});

themes.view.Installer = themes.view.Appearance.extend({

    el: '#wpbody-content .wrap',

    // Register events for sorting and filters in theme-navigation.
    events: {
        'click .filter-links li > a': 'onSort',
        'click .theme-filter': 'onFilter',
        'click .drawer-toggle': 'moreFilters',
        'click .filter-drawer .apply-filters': 'applyFilters',
        'click .filter-group [type="checkbox"]': 'addFilter',
        'click .filter-drawer .clear-filters': 'clearFilters',
        'click .edit-filters': 'backToFilters',
        'click .favorites-form-submit' : 'saveUsername',
        'keyup #wporg-username-input': 'saveUsername'
    },

    // Initial render method.
    render: function() {
        var self = this;

        this.search();
        this.uploader();

        this.collection = new themes.Collection();

        // Bump `collection.currentQuery.page` and request more themes if we hit the end of the page.
        this.listenTo( this, 'theme:end', function() {

            // Make sure we are not already loading.
            if ( self.collection.loadingThemes ) {
                return;
            }

            // Set loadingThemes to true and bump page instance of currentQuery.
            self.collection.loadingThemes = true;
            self.collection.currentQuery.page++;

            // Use currentQuery.page to build the themes request.
            _.extend( self.collection.currentQuery.request, { page: self.collection.currentQuery.page } );
            self.collection.query( self.collection.currentQuery.request );
        });

        this.listenTo( this.collection, 'query:success', function() {
            $( 'body' ).removeClass( 'loading-content' );
            $( '.theme-browser' ).find( 'div.error' ).remove();
        });

        this.listenTo( this.collection, 'query:fail', function() {
            $( 'body' ).removeClass( 'loading-content' );
            $( '.theme-browser' ).find( 'div.error' ).remove();
            $( '.theme-browser' ).find( 'div.themes' ).before( '<div class="error"><p>' + l10n.error + '</p><p><button class="button try-again">' + l10n.tryAgain + '</button></p></div>' );
            $( '.theme-browser .error .try-again' ).on( 'click', function( e ) {
                e.preventDefault();
                $( 'input.wp-filter-search' ).trigger( 'input' );
            } );
        });

        if ( this.view ) {
            this.view.remove();
        }

        // Sets up the view and passes the section argument.
        this.view = new themes.view.Themes({
            collection: this.collection,
            parent: this
        });

        // Reset pagination every time the install view handler is run.
        this.page = 0;

        // Render and append.
        this.$el.find( '.themes' ).remove();
        this.view.render();
        this.$el.find( '.theme-browser' ).append( this.view.el ).addClass( 'rendered' );
    },

    // Handles all the rendering of the public theme directory.
    browse: function( section ) {
        // Create a new collection with the proper theme data
        // for each section.
        if ( 'block-themes' === section ) {
            // Get the themes by sending Ajax POST request to api.wordpress.org/themes
            // or searching the local cache.
            this.collection.query( { tag: 'full-site-editing' } );
        } else {
            this.collection.query( { browse: section } );
        }
    },

    // Sorting navigation.
    onSort: function( event ) {
        var $el = $( event.target ),
            sort = $el.data( 'sort' );

        event.preventDefault();

        $( 'body' ).removeClass( 'filters-applied show-filters' );
        $( '.drawer-toggle' ).attr( 'aria-expanded', 'false' );

        // Bail if this is already active.
        if ( $el.hasClass( this.activeClass ) ) {
            return;
        }

        this.sort( sort );

        // Trigger a router.navigate update.
        themes.router.navigate( themes.router.baseUrl( themes.router.browsePath + sort ) );
    },

    sort: function( sort ) {
        this.clearSearch();

        // Track sorting so we can restore the correct tab when closing preview.
        themes.router.selectedTab = sort;

        $( '.filter-links li > a, .theme-filter' )
            .removeClass( this.activeClass )
            .removeAttr( 'aria-current' );

        $( '[data-sort="' + sort + '"]' )
            .addClass( this.activeClass )
            .attr( 'aria-current', 'page' );

        if ( 'favorites' === sort ) {
            $( 'body' ).addClass( 'show-favorites-form' );
        } else {
            $( 'body' ).removeClass( 'show-favorites-form' );
        }

        this.browse( sort );
    },

    // Filters and Tags.
    onFilter: function( event ) {
        var request,
            $el = $( event.target ),
            filter = $el.data( 'filter' );

        // Bail if this is already active.
        if ( $el.hasClass( this.activeClass ) ) {
            return;
        }

        $( '.filter-links li > a, .theme-section' )
            .removeClass( this.activeClass )
            .removeAttr( 'aria-current' );
        $el
            .addClass( this.activeClass )
            .attr( 'aria-current', 'page' );

        if ( ! filter ) {
            return;
        }

        // Construct the filter request
        // using the default values.
        filter = _.union( [ filter, this.filtersChecked() ] );
        request = { tag: [ filter ] };

        // Get the themes by sending Ajax POST request to api.wordpress.org/themes
        // or searching the local cache.
        this.collection.query( request );
    },

    // Clicking on a checkbox to add another filter to the request.
    addFilter: function() {
        this.filtersChecked();
    },

    // Applying filters triggers a tag request.
    applyFilters: function( event ) {
        var name,
            tags = this.filtersChecked(),
            request = { tag: tags },
            filteringBy = $( '.filtered-by .tags' );

        if ( event ) {
            event.preventDefault();
        }

        if ( ! tags ) {
            wp.a11y.speak( l10n.selectFeatureFilter );
            return;
        }

        $( 'body' ).addClass( 'filters-applied' );
        $( '.filter-links li > a.current' )
            .removeClass( 'current' )
            .removeAttr( 'aria-current' );

        filteringBy.empty();

        _.each( tags, function( tag ) {
            name = $( 'label[for="filter-id-' + tag + '"]' ).text();
            filteringBy.append( '<span class="tag">' + name + '</span>' );
        });

        // Get the themes by sending Ajax POST request to api.wordpress.org/themes
        // or searching the local cache.
        this.collection.query( request );
    },

    // Save the user's WordPress.org username and get his favorite themes.
    saveUsername: function ( event ) {
        var username = $( '#wporg-username-input' ).val(),
            nonce = $( '#wporg-username-nonce' ).val(),
            request = { browse: 'favorites', user: username },
            that = this;

        if ( event ) {
            event.preventDefault();
        }

        // Save username on enter.
        if ( event.type === 'keyup' && event.which !== 13 ) {
            return;
        }

        return wp.ajax.send( 'save-wporg-username', {
            data: {
                _wpnonce: nonce,
                username: username
            },
            success: function () {
                // Get the themes by sending Ajax POST request to api.wordpress.org/themes
                // or searching the local cache.
                that.collection.query( request );
            }
        } );
    },

    /**
     * Get the checked filters.
     *
     * @return {Array} of tags or false
     */
    filtersChecked: function() {
        var items = $( '.filter-group' ).find( ':checkbox' ),
            tags = [];

        _.each( items.filter( ':checked' ), function( item ) {
            tags.push( $( item ).prop( 'value' ) );
        });

        // When no filters are checked, restore initial state and return.
        if ( tags.length === 0 ) {
            $( '.filter-drawer .apply-filters' ).find( 'span' ).text( '' );
            $( '.filter-drawer .clear-filters' ).hide();
            $( 'body' ).removeClass( 'filters-applied' );
            return false;
        }

        $( '.filter-drawer .apply-filters' ).find( 'span' ).text( tags.length );
        $( '.filter-drawer .clear-filters' ).css( 'display', 'inline-block' );

        return tags;
    },

    activeClass: 'current',

    /**
     * When users press the "Upload Theme" button, show the upload form in place.
     */
    uploader: function() {
        var uploadViewToggle = $( '.upload-view-toggle' ),
            $body = $( document.body );

        uploadViewToggle.on( 'click', function() {
            // Toggle the upload view.
            $body.toggleClass( 'show-upload-view' );
            // Toggle the `aria-expanded` button attribute.
            uploadViewToggle.attr( 'aria-expanded', $body.hasClass( 'show-upload-view' ) );
        });
    },

    // Toggle the full filters navigation.
    moreFilters: function( event ) {
        var $body = $( 'body' ),
            $toggleButton = $( '.drawer-toggle' );

        event.preventDefault();

        if ( $body.hasClass( 'filters-applied' ) ) {
            return this.backToFilters();
        }

        this.clearSearch();

        themes.router.navigate( themes.router.baseUrl( '' ) );
        // Toggle the feature filters view.
        $body.toggleClass( 'show-filters' );
        // Toggle the `aria-expanded` button attribute.
        $toggleButton.attr( 'aria-expanded', $body.hasClass( 'show-filters' ) );
    },

    /**
     * Clears all the checked filters.
     *
     * @uses filtersChecked()
     */
    clearFilters: function( event ) {
        var items = $( '.filter-group' ).find( ':checkbox' ),
            self = this;

        event.preventDefault();

        _.each( items.filter( ':checked' ), function( item ) {
            $( item ).prop( 'checked', false );
            return self.filtersChecked();
        });
    },

    backToFilters: function( event ) {
        if ( event ) {
            event.preventDefault();
        }

        $( 'body' ).removeClass( 'filters-applied' );
    },

    clearSearch: function() {
        $( '#wp-filter-search-input').val( '' );
    }
});

themes.InstallerRouter = Backbone.Router.extend({
    routes: {
        'theme-install.php?theme=:slug': 'preview',
        'theme-install.php?browse=:sort': 'sort',
        'theme-install.php?search=:query': 'search',
        'theme-install.php': 'sort'
    },

    baseUrl: function( url ) {
        return 'theme-install.php' + url;
    },

    themePath: '?theme=',
    browsePath: '?browse=',
    searchPath: '?search=',

    search: function( query ) {
        $( '.wp-filter-search' ).val( query.replace( /\+/g, ' ' ) );
    },

    navigate: navigateRouter
});


themes.RunInstaller = {

    init: function() {
        // Set up the view.
        // Passes the default 'section' as an option.
        this.view = new themes.view.Installer({
            section: 'popular',
            SearchView: themes.view.InstallerSearch
        });

        // Render results.
        this.render();

        // Start debouncing user searches after Backbone.history.start().
        this.view.SearchView.doSearch = _.debounce( this.view.SearchView.doSearch, 500 );
    },

    render: function() {

        // Render results.
        this.view.render();
        this.routes();

        if ( Backbone.History.started ) {
            Backbone.history.stop();
        }
        Backbone.history.start({
            root: themes.data.settings.adminUrl,
            pushState: true,
            hashChange: false
        });
    },

    routes: function() {
        var self = this,
            request = {};

        // Bind to our global `wp.themes` object
        // so that the router is available to sub-views.
        themes.router = new themes.InstallerRouter();

        // Handles `theme` route event.
        // Queries the API for the passed theme slug.
        themes.router.on( 'route:preview', function( slug ) {

            // Remove existing handlers.
            if ( themes.preview ) {
                themes.preview.undelegateEvents();
                themes.preview.unbind();
            }

            // If the theme preview is active, set the current theme.
            if ( self.view.view.theme && self.view.view.theme.preview ) {
                self.view.view.theme.model = self.view.collection.findWhere( { 'slug': slug } );
                self.view.view.theme.preview();
            } else {

                // Select the theme by slug.
                request.theme = slug;
                self.view.collection.query( request );
                self.view.collection.trigger( 'update' );

                // Open the theme preview.
                self.view.collection.once( 'query:success', function() {
                    $( 'div[data-slug="' + slug + '"]' ).trigger( 'click' );
                });

            }
        });

        /*
         * Handles sorting / browsing routes.
         * Also handles the root URL triggering a sort request
         * for `popular`, the default view.
         */
        themes.router.on( 'route:sort', function( sort ) {
            if ( ! sort ) {
                sort = 'popular';
                themes.router.navigate( themes.router.baseUrl( '?browse=popular' ), { replace: true } );
            }
            self.view.sort( sort );

            // Close the preview if open.
            if ( themes.preview ) {
                themes.preview.close();
            }
        });

        // The `search` route event. The router populates the input field.
        themes.router.on( 'route:search', function() {
            $( '.wp-filter-search' ).trigger( 'focus' ).trigger( 'keyup' );
        });

        this.extraRoutes();
    },

    extraRoutes: function() {
        return false;
    }
};

// Ready...
$( function() {
    if ( themes.isInstall ) {
        themes.RunInstaller.init();
    } else {
        themes.Run.init();
    }

    // Update the return param just in time.
    $( document.body ).on( 'click', '.load-customize', function() {
        var link = $( this ), urlParser = document.createElement( 'a' );
        urlParser.href = link.prop( 'href' );
        urlParser.search = $.param( _.extend(
            wp.customize.utils.parseQueryString( urlParser.search.substr( 1 ) ),
            {
                'return': window.location.href
            }
        ) );
        link.prop( 'href', urlParser.href );
    });

    $( '.broken-themes .delete-theme' ).on( 'click', function() {
        return confirm( _wpThemeSettings.settings.confirmDelete );
    });
});

})( jQuery );

// Align theme browser thickbox.
jQuery( function($) {
    window.tb_position = function() {
        var tbWindow = $('#TB_window'),
            width = $(window).width(),
            H = $(window).height(),
            W = ( 1040 < width ) ? 1040 : width,
            adminbar_height = 0;

        if ( $('#wpadminbar').length ) {
            adminbar_height = parseInt( $('#wpadminbar').css('height'), 10 );
        }

        if ( tbWindow.length >= 1 ) {
            tbWindow.width( W - 50 ).height( H - 45 - adminbar_height );
            $('#TB_iframeContent').width( W - 50 ).height( H - 75 - adminbar_height );
            tbWindow.css({'margin-left': '-' + parseInt( ( ( W - 50 ) / 2 ), 10 ) + 'px'});
            if ( typeof document.body.style.maxWidth !== 'undefined' ) {
                tbWindow.css({'top': 20 + adminbar_height + 'px', 'margin-top': '0'});
            }
        }
    };

    $(window).on( 'resize', function(){ tb_position(); });
});