add all frontend files

node_modules/antd/es/affix/utils.js

@@ -0,0 +1,19 @@
+export function getTargetRect(target) {
+  return target !== window ? target.getBoundingClientRect() : {
+    top: 0,
+    bottom: window.innerHeight
+  };
+}
+export function getFixedTop(placeholderRect, targetRect, offsetTop) {
+  if (offsetTop !== undefined && Math.round(targetRect.top) > Math.round(placeholderRect.top) - offsetTop) {
+    return offsetTop + targetRect.top;
+  }
+  return undefined;
+}
+export function getFixedBottom(placeholderRect, targetRect, offsetBottom) {
+  if (offsetBottom !== undefined && Math.round(targetRect.bottom) < Math.round(placeholderRect.bottom) + offsetBottom) {
+    const targetBottomOffset = window.innerHeight - targetRect.bottom;
+    return offsetBottom + targetBottomOffset;
+  }
+  return undefined;
+}