var $document = $( document ),

		$window = $( window ),

		$body = $( document.body );

		$('.column-' + column).removeClass( 'hidden' );

		$('.column-' + column).addClass( 'hidden' );

		return $( '.manage-column[id]' ).filter( ':hidden' ).map(function() {

			return this.id;

		}).get().join( ',' );

$document.ready(function(){columns.init();});

		.filter( function() { return $( ':input:visible', this ).val() === ''; } )

		.find( ':input:visible' )

		.length;

		this.toggles = $( '#screen-meta-links' ).find( '.show-settings' );

	toggleEvent: function() {

		var panel = $( '#' + $( this ).attr( 'aria-controls' ) );

	open: function( panel, button ) {

		$( '#screen-meta-links' ).find( '.screen-meta-toggle' ).not( button.parent() ).css( 'visibility', 'hidden' );

			button.addClass( 'screen-meta-active' ).attr( 'aria-expanded', true );

		$document.trigger( 'screen:options:open' );

	close: function( panel, button ) {

			button.removeClass( 'screen-meta-active' ).attr( 'aria-expanded', false );

		$document.trigger( 'screen:options:close' );

/**

 * Update custom permalink structure via buttons.

 */

var permalinkStructureFocused = false,

    $permalinkStructure       = $( '#permalink_structure' ),

    $permalinkStructureInputs = $( '.permalink-structure input:radio' ),

    $permalinkCustomSelection = $( '#custom_selection' ),

    $availableStructureTags   = $( '.form-table.permalink-structure .available-structure-tags button' );

// Change permalink structure input when selecting one of the common structures.

$permalinkStructureInputs.on( 'change', function() {

	if ( 'custom' === this.value ) {

		return;

	}

	$permalinkStructure.val( this.value );

	// Update button states after selection.

	$availableStructureTags.each( function() {

		changeStructureTagButtonState( $( this ) );

	} );

} );

$permalinkStructure.on( 'click input', function() {

	$permalinkCustomSelection.prop( 'checked', true );

} );

// Check if the permalink structure input field has had focus at least once.

$permalinkStructure.on( 'focus', function( event ) {

	permalinkStructureFocused = true;

	$( this ).off( event );

} );

/**

 * Enables or disables a structure tag button depending on its usage.

 *

 * If the structure is already used in the custom permalink structure,

 * it will be disabled.

 *

 * @param {object} button Button jQuery object.

 */

function changeStructureTagButtonState( button ) {

	if ( -1 !== $permalinkStructure.val().indexOf( button.text().trim() ) ) {

		button.attr( 'data-label', button.attr( 'aria-label' ) );

		button.attr( 'aria-label', button.attr( 'data-used' ) );

		button.attr( 'aria-pressed', true );

		button.addClass( 'active' );

	} else if ( button.attr( 'data-label' ) ) {

		button.attr( 'aria-label', button.attr( 'data-label' ) );

		button.attr( 'aria-pressed', false );

		button.removeClass( 'active' );

	}

}

// Check initial button state.

$availableStructureTags.each( function() {

	changeStructureTagButtonState( $( this ) );

} );

// Observe permalink structure field and disable buttons of tags that are already present.

$permalinkStructure.on( 'change', function() {

	$availableStructureTags.each( function() {

		changeStructureTagButtonState( $( this ) );

	} );

} );

$availableStructureTags.on( 'click', function() {

	var permalinkStructureValue = $permalinkStructure.val(),

	    selectionStart          = $permalinkStructure[ 0 ].selectionStart,

	    selectionEnd            = $permalinkStructure[ 0 ].selectionEnd,

	    textToAppend            = $( this ).text().trim(),

	    textToAnnounce          = $( this ).attr( 'data-added' ),

	    newSelectionStart;

	// Remove structure tag if already part of the structure.

	if ( -1 !== permalinkStructureValue.indexOf( textToAppend ) ) {

		permalinkStructureValue = permalinkStructureValue.replace( textToAppend + '/', '' );

		$permalinkStructure.val( '/' === permalinkStructureValue ? '' : permalinkStructureValue );

		// Announce change to screen readers.

		$( '#custom_selection_updated' ).text( textToAnnounce );

		// Disable button.

		changeStructureTagButtonState( $( this ) );

		return;

	}

	// Input field never had focus, move selection to end of input.

	if ( ! permalinkStructureFocused && 0 === selectionStart && 0 === selectionEnd ) {

		selectionStart = selectionEnd = permalinkStructureValue.length;

	}

	$permalinkCustomSelection.prop( 'checked', true );

	// Prepend and append slashes if necessary.

	if ( '/' !== permalinkStructureValue.substr( 0, selectionStart ).substr( -1 ) ) {

		textToAppend = '/' + textToAppend;

	}

	if ( '/' !== permalinkStructureValue.substr( selectionEnd, 1 ) ) {

		textToAppend = textToAppend + '/';

	}

	// Insert structure tag at the specified position.

	$permalinkStructure.val( permalinkStructureValue.substr( 0, selectionStart ) + textToAppend + permalinkStructureValue.substr( selectionEnd ) );

	// Announce change to screen readers.

	$( '#custom_selection_updated' ).text( textToAnnounce );

	// Disable button.

	changeStructureTagButtonState( $( this ) );

	// If input had focus give it back with cursor right after appended text.

	if ( permalinkStructureFocused && $permalinkStructure[0].setSelectionRange ) {

		newSelectionStart = ( permalinkStructureValue.substr( 0, selectionStart ) + textToAppend ).length;

		$permalinkStructure[0].setSelectionRange( newSelectionStart, newSelectionStart );

		$permalinkStructure.focus();

	}

} );

$document.ready( function() {

	var checks, first, last, checked, sliced, mobileEvent, transitionTimeout, focusedRowActions,

		menuState,

		},

		$headerEnd = $( '.wp-header-end' );

	$( '#collapse-button' ).on( 'click.collapse-menu', function() {

		var viewportWidth = getViewportWidth() || 961;