Ticket #29979: 29979.5.diff

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

@@ -6 +6 @@
  */
 
 ( function( $ ) {
+        'use strict';
+
         $( 'html' ).removeClass( 'no-js' );
 
         // Add dropdown toggle that display child menu items.
@@ -47 +49 @@
                         $( this ).toggleClass( 'toggled-on' );
                 } );
         } )();
-} )( jQuery );
- No newline at end of file
+
+        // Sidebar scrolling.
+
+        $( function() {
+                var     $window = $( window ),
+                        lastWindowPos = 0,
+                        $document = $( document ),
+                        $adminbar = $( '#wpadminbar' ),
+                        $sidebar = $( '#sidebar' ),
+                        top = false,
+                        bottom = false,
+                        windowWidth, windowHeight, documentHeight,
+                        adminBarHeight, sidebarWidth, sidebarHeight,
+                        resizeTimer;
+
+                function resize() {
+                        windowWidth = $window.width();
+                        windowHeight = $window.height();
+                        documentHeight = $document.height();
+                        adminBarHeight = $adminbar.height();
+                        sidebarWidth = $sidebar.width();
+                        sidebarHeight = $sidebar.height();
+
+                        if ( sidebarWidth === windowWidth ) {
+                                top = bottom = false;
+                                $sidebar.removeAttr( 'style' );
+                        }
+                }
+
+                function scroll() {
+                        var windowPos = $window.scrollTop();
+
+                        if ( sidebarWidth < windowWidth && sidebarHeight + adminBarHeight < documentHeight ) {
+                                if ( sidebarHeight + adminBarHeight > windowHeight ) {
+                                        if ( windowPos > lastWindowPos ) {
+                                                if ( top ) {
+                                                        top = false;
+                                                        $sidebar.attr( 'style', 'top: ' + $sidebar.offset().top + '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;
+                                                        $sidebar.attr( 'style', 'top: ' + $sidebar.offset().top + 'px;' );
+                                                } else if ( ! top && windowPos + adminBarHeight < $sidebar.offset().top ) {
+                                                        top = true;
+                                                        $sidebar.attr( 'style', 'position: fixed;' );
+                                                }
+                                        } else {
+                                                top = bottom = false;
+                                                $sidebar.attr( 'style', 'top: ' + $sidebar.offset().top + 'px;' );
+                                        }
+                                } else if ( ! top ) {
+                                        top = true;
+                                        $sidebar.attr( 'style', 'position: fixed;' );
+                                }
+                        }
+
+                        lastWindowPos = windowPos;
+                }
+
+                function resizeAndScroll() {
+                        resize();
+                        scroll();
+                }
+
+                $window
+                        .on( 'scroll.pin-sidebar', scroll )
+                        .on( 'resize.pin-sideabr', function() {
+                                clearTimeout( resizeTimer );
+                                resizeTimer = setTimeout( resizeAndScroll, 200 );
+                        } );
+
+                resizeAndScroll();
+
+                for ( var i = 1; i < 6; i++ ) {
+                        setTimeout( resizeAndScroll, 500 * i );
+                }
+        } );
+} )( jQuery );

wp-content/themes/twentyfifteen/style.css

@@ -3835 +3835 @@
 
         .sidebar {
                 float: left;
-                height: 100%;
                 margin-right: -100%;
                 max-width: 413px;
-                overflow-y: scroll;
-                -webkit-overflow-scrolling: touch; /* Enable momentum scrolling on iOS Safari */
-                position: fixed;
+                position: absolute;
                 width: 29.4118%;
         }
 
-        .admin-bar .sidebar {
-                height: -webkit-calc(100% - 32px);
-                height: calc(100% - 32px);
-        }
-
         .secondary {
                 background-color: transparent;
                 display: block;