add Modal component

add Modal component

utils/assist.js

@@ -10,4 +10,43 @@ export function oneOf (value, validList) {
 
 export function camelcaseToHyphen (str) {
     return str.replace(/([a-z])([A-Z])/g, '$1-$2').toLowerCase();
+}
+
+// For Modal scrollBar hidden
+let cached;
+export function getScrollBarSize (fresh) {
+    if (fresh || cached === undefined) {
+        const inner = document.createElement('div');
+        inner.style.width = '100%';
+        inner.style.height = '200px';
+
+        const outer = document.createElement('div');
+        const outerStyle = outer.style;
+
+        outerStyle.position = 'absolute';
+        outerStyle.top = 0;
+        outerStyle.left = 0;
+        outerStyle.pointerEvents = 'none';
+        outerStyle.visibility = 'hidden';
+        outerStyle.width = '200px';
+        outerStyle.height = '150px';
+        outerStyle.overflow = 'hidden';
+
+        outer.appendChild(inner);
+
+        document.body.appendChild(outer);
+
+        const widthContained = inner.offsetWidth;
+        outer.style.overflow = 'scroll';
+        let widthScroll = inner.offsetWidth;
+
+        if (widthContained === widthScroll) {
+            widthScroll = outer.clientWidth;
+        }
+
+        document.body.removeChild(outer);
+
+        cached = widthContained - widthScroll;
+    }
+    return cached;
 }