Ticket #30366: 30366.2.diff

src/wp-content/themes/twentyfifteen/js/functions.js

@@ -6 +6 @@
  */
 
 ( function( $ ) {
-        var $body, $window, sidebar, toolbarOffset;
+        var $body, $window, $document, $sidebar, adminbarOffset, top = false,
+                bottom = false, windowWidth, windowHeight, lastWindowPos = 0,
+                topOffset = 0, documentHeight, sidebarWidth, sidebarHeight, resizeTimer;
 
         // Add dropdown toggle that display child menu items.
         $( '.main-navigation .page_item_has_children > a, .main-navigation .menu-item-has-children > a' ).after( '<button class="dropdown-toggle" aria-expanded="false">' + screenReaderText.expand + '</button>' );
@@ -32 +34 @@
                         return;
                 }
 
-                // Hide button if there is no widgets and menu is missing or empty.
+                // Hide button if there are no widgets and the menus are missing or empty.
                 menu    = secondary.find( '.nav-menu' );
                 widgets = secondary.find( '#widget-area' );
                 social  = secondary.find( '#social-navigation' );
@@ -48 +50 @@
                 } );
         } )();
 
+        // Sidebar scrolling.
+        function resize() {
+                windowWidth = $window.width();
+                windowHeight = $window.height();
+                documentHeight = $document.height();
+                sidebarHeight = $sidebar.height();
 
-        // Sidebar (un)fixing: fix when short, un-fix when scroll needed
-        function fixedOrScrolledSidebar() {
-                if ( $window.width() >= 955 ) {
-                        if ( sidebar.scrollHeight < ( $window.height() - toolbarOffset ) ) {
-                                $body.addClass( 'sidebar-fixed' );
-                        } else {
-                                $body.removeClass( 'sidebar-fixed' );
+                if ( 955 >= windowWidth ) {
+                        top = bottom = false;
+                        $sidebar.removeAttr( 'style' );
+                }
+        }
+
+        function scroll() {
+                var windowPos = $window.scrollTop();
+
+                if ( 955 <= windowWidth && sidebarHeight + adminbarOffset < documentHeight ) {
+                        if ( sidebarHeight + adminbarOffset > windowHeight ) {
+                                if ( windowPos > lastWindowPos ) {
+                                        if ( top ) {
+                                                top = false;
+                                                topOffset = ( $sidebar.offset().top > 0 ) ? $sidebar.offset().top : 0;
+                                                $sidebar.attr( 'style', 'top: ' + topOffset + 'px;' );
+                                        } else if ( ! bottom && windowPos + windowHeight > sidebarHeight + $sidebar.offset().top ) {
+                                                bottom = true;
+                                                $sidebar.attr( 'style', 'position: fixed;bottom: 0;' );
+                                        }
+                                } else if ( windowPos < lastWindowPos ) {
+                                        if ( bottom ) {
+                                                bottom = false;
+                                                topOffset = ( $sidebar.offset().top > 0 ) ? $sidebar.offset().top : 0;
+                                                $sidebar.attr( 'style', 'top: ' + topOffset + 'px;' );
+                                        } else if ( ! top && windowPos + adminbarOffset < $sidebar.offset().top ) {
+                                                top = true;
+                                                $sidebar.attr( 'style', 'position: fixed;' );
+                                        }
+                                } else {
+                                        top = bottom = false;
+                                        topOffset = ( $sidebar.offset().top > 0 ) ? $sidebar.offset().top : 0;
+                                        $sidebar.attr( 'style', 'top: ' + topOffset + 'px;' );
+                                }
+                        } else if ( ! top ) {
+                                top = true;
+                                $sidebar.attr( 'style', 'position: fixed;' );
                         }
-                } else {
-                        $body.removeClass( 'sidebar-fixed' );
                 }
+
+                lastWindowPos = windowPos;
         }
 
-        function debouncedFixedOrScrolledSidebar() {
-                var timeout;
-                return function() {
-                        clearTimeout( timeout );
-                        timeout = setTimeout( function() {
-                                timeout = null;
-                                fixedOrScrolledSidebar();
-                        }, 150 );
-                };
+        function resizeAndScroll() {
+                resize();
+                scroll();
         }
 
-
         $( document ).ready( function() {
-                // But! We only want to allow fixed sidebars when there are no submenus.
-                if ( $( '#site-navigation .sub-menu' ).length ) {
-                        return;
-                }
+                $body          = $( 'body' );
+                $window        = $( window );
+                $document      = $( document );
+                $sidebar        = $( '#sidebar' ).first();
+                adminbarOffset = $body.is( '.admin-bar' ) ? $( '#wpadminbar' ).height() : 0;
 
-                // only initialize 'em if we need 'em
-                $body         = $( 'body' );
-                $window       = $( window );
-                sidebar       = $( '#sidebar' )[0];
-                toolbarOffset = $body.is( '.admin-bar' ) ? $( '#wpadminbar' ).height() : 0;
+                $window
+                        .on( 'scroll.twentyfifteen', scroll )
+                        .on( 'resize.twentyfifteen', function() {
+                                clearTimeout( resizeTimer );
+                                resizeTimer = setTimeout( resizeAndScroll, 200 );
+                        } );
 
-                $window
-                        .on( 'load.twentyfifteen', fixedOrScrolledSidebar )
-                        .on( 'resize.twentyfifteen', debouncedFixedOrScrolledSidebar() );
+                resizeAndScroll();
+
+                for ( var i = 1; i < 6; i++ ) {
+                        setTimeout( resizeAndScroll, 100 * i );
+                }
         } );
 
 } )( jQuery );
+ No newline at end of file