1 files changed, 80 insertions, 0 deletions
diff --git a/docs/themes/gohugoioTheme/assets/js/smoothscroll.js b/docs/themes/gohugoioTheme/assets/js/smoothscroll.js
new file mode 100644
index 000000000..4bb2d99b8
--- /dev/null
+++ b/docs/themes/gohugoioTheme/assets/js/smoothscroll.js
@@ -0,0 +1,80 @@
+// query selector targets Hugo TOC 
+(function() {
+
+  'use strict';
+
+  // Feature Test
+  if ('querySelector' in document && 'addEventListener' in window && Array.prototype.forEach) {
+
+    // Function to animate the scroll
+    var smoothScroll = function(anchor, duration) {
+
+      // Calculate how far and how fast to scroll
+      var startLocation = window.pageYOffset;
+      var endLocation = anchor.offsetTop;
+      var distance = endLocation - startLocation;
+      var increments = distance / (duration / 16);
+      var stopAnimation;
+
+      // Scroll the page by an increment, and check if it's time to stop
+      var animateScroll = function() {
+        window.scrollBy(0, increments);
+        stopAnimation();
+      };
+
+      // If scrolling down
+      if (increments >= 0) {
+        // Stop animation when you reach the anchor OR the bottom of the page
+        stopAnimation = function() {
+          var travelled = window.pageYOffset;
+          if ((travelled >= (endLocation - increments)) || ((window.innerHeight + travelled) >= document.body.offsetHeight)) {
+            clearInterval(runAnimation);
+          }
+        };
+      }
+      // If scrolling up
+      else {
+        // Stop animation when you reach the anchor OR the top of the page
+        stopAnimation = function() {
+          var travelled = window.pageYOffset;
+          if (travelled <= (endLocation || 0)) {
+            clearInterval(runAnimation);
+          }
+        };
+      }
+
+      // Loop the animation function
+      var runAnimation = setInterval(animateScroll, 16);
+
+    };
+
+    // Define smooth scroll links
+    var scrollToggle = document.querySelectorAll('#TableOfContents ul li a');
+
+    // For each smooth scroll link
+    [].forEach.call(scrollToggle, function(toggle) {
+
+      // When the smooth scroll link is clicked
+      toggle.addEventListener('click', function(e) {
+
+        // Prevent the default link behavior
+        e.preventDefault();
+
+        // Get anchor link and calculate distance from the top
+        var dataID = toggle.getAttribute('href');
+        var dataTarget = document.querySelector(dataID);
+        var dataSpeed = toggle.getAttribute('data-speed');
+
+        // If the anchor exists
+        if (dataTarget) {
+          // Scroll to the anchor
+          smoothScroll(dataTarget, dataSpeed || 500);
+        }
+
+      }, false);
+
+    });
+
+  }
+
+})();