1 files changed, 92 insertions, 0 deletions
diff --git a/docs/_static/js/footer.js b/docs/_static/js/footer.js
new file mode 100644
index 00000000..5f135768
--- /dev/null
+++ b/docs/_static/js/footer.js
@@ -0,0 +1,92 @@
+$(document).ready(function() {
+  insertIframe()
+
+  const options = {
+    threshold: 0.01,
+  }
+  const divDoc = document.querySelector('.iframe-container')
+  const innerSidebar = $('.wy-side-scroll')
+
+  intersectionObserver(options, divDoc, innerSidebar)
+
+  $(window).resize(function() {
+    intersectionObserver(options, divDoc, innerSidebar)
+  })
+
+  $(window).scroll(function() {
+    intersectionObserver(options, divDoc, innerSidebar)
+  })
+});
+
+function intersectionObserver(options, divDoc, innerSidebar) {
+  // we delete any inline-styles from innerSidebar
+  if($(innerSidebar).attr('style')) {
+    innerSidebar.removeAttr('style')
+  }
+  const screenWidth = $(window).width()
+  const sidebar = $('.wy-nav-side')
+  const documentHeight = $(document).height()
+  const iframeHeight = $('.iframe-container').height()
+  const currentPosition = $(document).scrollTop()
+  const additionalPaddingFromSidebar = screenWidth > 991 ? 70 : 83
+  const heightThatIsAddedByPaddings = 36
+  const resultOfSums = documentHeight - 
+    iframeHeight - 
+    currentPosition - 
+    additionalPaddingFromSidebar - 
+    heightThatIsAddedByPaddings
+  const heightOfAdditionalButton = 50
+
+  const onEntry = (entries, observer) => {
+    entries.forEach(entry => {
+      if(entry.isIntersecting) {
+        if(resultOfSums <= 70) {
+          $(sidebar).hide()
+          return 
+        }
+        $(sidebar).show()
+        $(sidebar).height(resultOfSums)
+        $(sidebar).css('margin-bottom', '20px')
+        $(innerSidebar).removeAttr('style')
+        $(innerSidebar).height(resultOfSums - heightOfAdditionalButton)
+        return
+      } else {
+        $(sidebar).removeAttr('style')
+        $(innerSidebar).removeAttr('style')
+      }
+    })
+  }
+  const observer = new IntersectionObserver(onEntry, options);
+  observer.observe(divDoc)
+
+  if($(innerSidebar).attr('style')) {
+    observer.unobserve(divDoc)
+  }
+
+  determineHeightOfFooterContainer()
+
+}
+
+function determineHeightOfFooterContainer() {
+  const iframeFooter= $('#vyos-footer-iframe');
+  const title = window.document.getElementsByTagName('title')?.[0]?.text;
+  const iframeContainer = $('.iframe-container')
+  const href = window.location.href;
+
+  window.addEventListener('message',function(message){
+    if(message.data.footerIframeHeight){
+      $(iframeFooter).css('min-height', `${message.data.footerIframeHeight + 1}px`)
+      $(iframeContainer).height(message.data.footerIframeHeight + 1)
+      iframeFooter[0].contentWindow.postMessage({title, href},'*');
+    }
+  })
+}
+
+function insertIframe() {
+  const body = $('.wy-body-for-nav')
+  body.append(divWithIframe)
+}
+
+const divWithIframe = `<div class="iframe-container">
+  <iframe src='https://vyos.io/iframes/footer' id='vyos-footer-iframe'></iframe>
+</div>`