[Tooltip] Converted to a functional component

UNRELEASED.md

@@ -26,5 +26,6 @@
 
 - Converted `BulkActionButton` into a functional component ([#2542](https://github.com/Shopify/polaris-react/pull/2542))
 - Converted `Focus` into a functional component ([#2540](https://github.com/Shopify/polaris-react/pull/2540))
+- Converted `Tooltip` into a functional component ([#2543](https://github.com/Shopify/polaris-react/pull/2543))
 
 ### Deprecations

src/components/Tooltip/Tooltip.tsx

@@ -1,9 +1,10 @@
-import React from 'react';
-import {createUniqueIDFactory} from '@shopify/javascript-utilities/other';
+import React, {useEffect, useState, useRef} from 'react';
 import {findFirstFocusableNode} from '@shopify/javascript-utilities/focus';
 
 import {PreferredPosition} from '../PositionedOverlay';
 import {Portal} from '../Portal';
+import {useUniqueId} from '../../utilities/unique-id';
+import {useToggle} from '../../utilities/use-toggle';
 import {TooltipOverlay} from './components';
 import styles from './Tooltip.scss';
 
@@ -28,122 +29,93 @@ export interface TooltipProps {
   activatorWrapper?: string;
 }
 
-interface State {
-  active: boolean;
-  activatorNode: HTMLElement | null;
-}
-
-const getUniqueID = createUniqueIDFactory('TooltipContent');
-
-export class Tooltip extends React.PureComponent<TooltipProps, State> {
-  state: State = {
-    active: Boolean(this.props.active),
-    activatorNode: null,
-  };
-
-  private id = getUniqueID();
-  private activatorContainer: HTMLElement | null = null;
-  private mouseEntered = false;
-
-  componentDidMount() {
-    this.setAccessibilityAttributes();
-  }
-
-  componentDidUpdate() {
-    this.setAccessibilityAttributes();
-  }
-
-  render() {
-    const {id} = this;
-
-    const {
-      children,
-      content,
-      light,
-      preferredPosition = 'below',
-      activatorWrapper: WrapperComponent = 'span' as any,
-    } = this.props;
-
-    const {active, activatorNode} = this.state;
+export function Tooltip({
+  children,
+  content,
+  light,
+  active: originalActive,
+  preferredPosition = 'below',
+  activatorWrapper = 'span',
+}: TooltipProps) {
+  const WrapperComponent: any = activatorWrapper;
+  const {value: active, setTrue: handleFocus, setFalse: handleBlur} = useToggle(
+    Boolean(originalActive),
+  );
+  const [activatorNode, setActivatorNode] = useState<HTMLElement | null>(null);
+
+  const id = useUniqueId('TooltipContent');
+  const activatorContainer = useRef<HTMLElement>(null);
+  const mouseEntered = useRef(false);
+
+  useEffect(() => {
+    const firstFocusable = activatorContainer.current
+      ? findFirstFocusableNode(activatorContainer.current)
+      : null;
+    const accessibilityNode = firstFocusable || activatorContainer.current;
+
+    if (!accessibilityNode) return;
 
-    const portal = activatorNode ? (
-      <Portal idPrefix="tooltip">
-        <TooltipOverlay
-          id={id}
-          preferredPosition={preferredPosition}
-          activator={activatorNode}
-          active={active}
-          onClose={noop}
-          light={light}
-        >
-          <div className={styles.Label} testID="TooltipOverlayLabel">
-            {content}
-          </div>
-        </TooltipOverlay>
-      </Portal>
-    ) : null;
-
-    return (
-      <WrapperComponent
-        testID="WrapperComponent"
-        onFocus={this.handleFocus}
-        onBlur={this.handleBlur}
-        onMouseLeave={this.handleMouseLeave}
-        onMouseOver={this.handleMouseEnterFix}
-        ref={this.setActivator}
+    accessibilityNode.tabIndex = 0;
+    accessibilityNode.setAttribute('aria-describedby', id);
+  }, [id, children]);
+
+  const portal = activatorNode ? (
+    <Portal idPrefix="tooltip">
+      <TooltipOverlay
+        id={id}
+        preferredPosition={preferredPosition}
+        activator={activatorNode}
+        active={active}
+        onClose={noop}
+        light={light}
       >
-        {children}
-        {portal}
-      </WrapperComponent>
-    );
-  }
-
-  private setActivator = (node: HTMLElement | null) => {
+        <div className={styles.Label} testID="TooltipOverlayLabel">
+          {content}
+        </div>
+      </TooltipOverlay>
+    </Portal>
+  ) : null;
+
+  return (
+    <WrapperComponent
+      testID="WrapperComponent"
+      onFocus={handleFocus}
+      onBlur={handleBlur}
+      onMouseLeave={handleMouseLeave}
+      onMouseOver={handleMouseEnterFix}
+      ref={setActivator}
+    >
+      {children}
+      {portal}
+    </WrapperComponent>
+  );
+
+  function setActivator(node: HTMLElement | null) {
+    const activatorContainerRef: any = activatorContainer;
     if (node == null) {
-      this.activatorContainer = null;
-      this.setState({activatorNode: null});
+      activatorContainerRef.current = null;
+      setActivatorNode(null);
       return;
     }
 
-    this.setState({activatorNode: node.firstElementChild as HTMLElement});
-    this.activatorContainer = node;
-  };
-
-  private handleFocus = () => {
-    this.setState({active: true});
-  };
-
-  private handleBlur = () => {
-    this.setState({active: false});
-  };
+    setActivatorNode(node.firstElementChild as HTMLElement);
+    activatorContainerRef.current = node;
+  }
 
-  private handleMouseEnter = () => {
-    this.mouseEntered = true;
-    this.setState({active: true});
-  };
+  function handleMouseEnter() {
+    mouseEntered.current = true;
+    handleFocus();
+  }
 
-  private handleMouseLeave = () => {
-    this.mouseEntered = false;
-    this.setState({active: false});
-  };
+  function handleMouseLeave() {
+    mouseEntered.current = false;
+    handleBlur();
+  }
 
   // https://github.com/facebook/react/issues/10109
   // Mouseenter event not triggered when cursor moves from disabled button
-  private handleMouseEnterFix = () => {
-    !this.mouseEntered && this.handleMouseEnter();
-  };
-
-  private setAccessibilityAttributes() {
-    const {activatorContainer, id} = this;
-    if (activatorContainer == null) {
-      return;
-    }
-
-    const firstFocusable = findFirstFocusableNode(activatorContainer);
-    const accessibilityNode = firstFocusable || activatorContainer;
-
-    accessibilityNode.tabIndex = 0;
-    accessibilityNode.setAttribute('aria-describedby', id);
+  function handleMouseEnterFix() {
+    !mouseEntered.current && handleMouseEnter();
   }
 }