Refactor: move dom utils to @grafana/ui (#17976)

packages/grafana-ui/src/utils/dom.ts

@@ -0,0 +1,41 @@
+// Node.closest() polyfill
+if ('Element' in window && !Element.prototype.closest) {
+  Element.prototype.closest = function(this: any, s: string) {
+    const matches = (this.document || this.ownerDocument).querySelectorAll(s);
+    let el = this;
+    let i;
+    // eslint-disable-next-line
+    do {
+      i = matches.length;
+      // eslint-disable-next-line
+      while (--i >= 0 && matches.item(i) !== el) {}
+      el = el.parentElement;
+    } while (i < 0 && el);
+    return el;
+  };
+}
+
+export function getPreviousCousin(node: any, selector: string) {
+  let sibling = node.parentElement.previousSibling;
+  let el;
+  while (sibling) {
+    el = sibling.querySelector(selector);
+    if (el) {
+      return el;
+    }
+    sibling = sibling.previousSibling;
+  }
+  return undefined;
+}
+
+export function getNextCharacter(global = window) {
+  const selection = global.getSelection();
+  if (!selection || !selection.anchorNode) {
+    return null;
+  }
+
+  const range = selection.getRangeAt(0);
+  const text = selection.anchorNode.textContent;
+  const offset = range.startOffset;
+  return text!.substr(offset, 1);
+}

packages/grafana-ui/src/utils/index.ts

@@ -7,3 +7,7 @@ export * from './deprecationWarning';
 export * from './validate';
 export { getFlotPairs } from './flotPairs';
 export * from './slate';
+
+// Export with a namespace
+import * as DOMUtil from './dom'; // includes Element.closest polyfil
+export { DOMUtil };