Add Fadable component

js/components/App.js

@@ -1,4 +1,5 @@
 import React from 'react';
+import classNames from 'classnames';
 import { connect } from 'react-redux';
 
 import actions from '../actions';
@@ -13,7 +14,7 @@ function App(props) {
         <div className="page__header">
           <Header {...props} />
         </div>
-        <div className="page__content">
+        <div className={classNames('page__content', { 'is-faded': props.isFaded })}>
           <Router {...props} />
         </div>
         <div className="page__footer">

js/components/Fadeable.js

@@ -0,0 +1,45 @@
+import React from 'react';
+import classNames from 'classnames';
+
+class Fadeable extends React.Component {
+  constructor(props) {
+    super(props);
+    this.state = {
+      faded: props.leaving,
+    };
+  }
+
+  componentWillReceiveProps({ leaving }) {
+    if (!this.props.leaving && leaving) {
+      this.setState({
+        ...this.state,
+        faded: true,
+      });
+    }
+    if (this.props.leaving && !leaving) {
+      this.setState({
+        ...this.state,
+        faded: false,
+      });
+    }
+  }
+
+  handleTransitionEnd = () => {
+    if (this.state.faded) {
+      this.props.onLeave();
+    }
+  };
+
+  render() {
+    return (
+      <div
+        className={classNames('fadable', { 'is-faded': this.state.faded })}
+        onTransitionEnd={this.handleTransitionEnd}
+      >
+        {this.props.children}
+      </div>
+    );
+  }
+}
+
+export default Fadeable;

js/components/PageHelp.js

@@ -1,10 +1,11 @@
 import React from 'react';
 import HeroHeadline from './HeroHeadline';
+import Fadeable from './Fadeable';
 
-export default function PageHelp() {
+export default function PageHelp({ leaving, onLeave }) {
   return (
-    <div>
+    <Fadeable leaving={leaving} onLeave={onLeave}>
       <HeroHeadline>How to use AOE Technology Radar</HeroHeadline>
-    </div>
+    </Fadeable>
   );
 }

js/components/PageIndex.js

@@ -1,14 +1,15 @@
 import React from 'react';
 import HeroHeadline from './HeroHeadline';
 import QuadrantGrid from './QuadrantGrid';
+import Fadeable from './Fadeable';
 
-export default function PageIndex({ items, navigate }) {
+export default function PageIndex({ leaving, onLeave, items, navigate }) {
   return (
-    <div>
+    <Fadeable leaving={leaving} onLeave={onLeave}>
       <div className="headline-group">
         <HeroHeadline alt="Mar 2017">AOE Technology Radar</HeroHeadline>
       </div>
       <QuadrantGrid items={items} />
-    </div>
+    </Fadeable>
   );
 }

js/components/PageItem.js

@@ -3,14 +3,17 @@ import HeroHeadline from './HeroHeadline';
 import Badge from './Badge';
 import ItemList from './ItemList';
 import Link from './Link';
+import Fadeable from './Fadeable';
+
 import { groupByQuadrants } from '../../common/model';
 
-export default function PageItems({ pageName, items }) {
+export default function PageItems({ leaving, onLeave, pageName, items }) {
   const [quadrantName, itemName] = pageName.split('/');
   const item = items.filter(item => item.quadrant === quadrantName && item.name === itemName)[0];
   const itemsInRing = groupByQuadrants(items)[item.quadrant][item.ring];
 
   return (
+    <Fadeable leaving={leaving} onLeave={onLeave}>
       <div className="item-page">
         <div className="item-page__nav">
           <div className="item-page__nav__inner">
@@ -47,5 +50,6 @@ export default function PageItems({ pageName, items }) {
           </div>
         </div>
       </div>
+    </Fadeable>
   );
 }

js/components/PageOverview.js

@@ -4,6 +4,7 @@ import HeadlineGroup from './HeadlineGroup';
 import HeroHeadline from './HeroHeadline';
 import Badge from './Badge';
 import Link from './Link';
+import Fadeable from './Fadeable';
 import { groupByFirstLetter } from '../../common/model';
 import { translate } from '../../common/config';
 
@@ -45,7 +46,7 @@ class PageOverview extends React.Component {
     const groups = this.getFilteredAndGroupedItems();
 
     return (
-      <div>
+      <Fadeable leaving={this.props.leaving} onLeave={this.props.onLeave}>
         <HeadlineGroup>
           <HeroHeadline>Technologies Overview</HeroHeadline>
         </HeadlineGroup>
@@ -106,7 +107,7 @@ class PageOverview extends React.Component {
           }
 
         </div>
-      </div>
+      </Fadeable>
     );
   }
 }

js/components/PageQuadrant.js

@@ -2,17 +2,19 @@ import React from 'react';
 import HeroHeadline from './HeroHeadline';
 import HeadlineGroup from './HeadlineGroup';
 import QuadrantSection from './QuadrantSection';
+import Fadeable from './Fadeable';
+
 import { translate } from '../../common/config';
 import { groupByQuadrants } from '../../common/model';
 
-export default function PageQuadrant({ pageName, items }) {
+export default function PageQuadrant({ leaving, onLeave, pageName, items }) {
   const groups = groupByQuadrants(items);
   return (
-    <div>
+    <Fadeable leaving={leaving} onLeave={onLeave}>
       <HeadlineGroup>
         <HeroHeadline>{translate(pageName)}</HeroHeadline>
       </HeadlineGroup>
       <QuadrantSection groups={groups} quadrantName={pageName} big />
-    </div>
+    </Fadeable>
   );
 }

js/components/Router.js

@@ -27,7 +27,46 @@ const getPageByName = (items, pageName) => {
   return 'div';
 }
 
-export default function Router({ pageName, ...props}) {
-  const Comp = getPageByName(props.items, pageName);
-  return <Comp {...props} pageName={pageName} />;
+class Router extends React.Component {
+  constructor(props) {
+    super(props);
+    this.state = {
+      pageName: props.pageName,
+      leaving: false,
+    };
   }
+
+  componentWillReceiveProps({ pageName }) {
+    this.setState({
+      ...this.state,
+      nextPageName: pageName,
+      leaving: true,
+    });
+  }
+
+  handlePageLeave = () => {
+    this.setState({
+      ...this.state,
+      pageName: this.state.nextPageName,
+      leaving: true,
+      nextPageName: null,
+    });
+
+    window.setTimeout(() => {
+      window.requestAnimationFrame(() => {
+        this.setState({
+          ...this.state,
+          leaving: false,
+        });
+      });
+    }, 0);
+  };
+
+  render() {
+    const { pageName, leaving } = this.state;
+    const Comp = getPageByName(this.props.items, pageName);
+    return <Comp {...this.props} pageName={pageName} leaving={leaving} onLeave={this.handlePageLeave} />;
+  }
+}
+
+export default Router;

styles/components/fadeable.css

@@ -0,0 +1,23 @@
+.fadable {
+  position: relative;
+
+  &::after {
+    transition: opacity 0.2s cubic-bezier(0.54, 0, 0.28, 1);
+    content: '';
+    display: block;
+    width: 100%;
+    height: 100%;
+    position: absolute;
+    left: 0;
+    top: 0;
+    opacity: 0;
+    background: var(--color-gray-dark);
+    pointer-events: none;
+  }
+
+  &.is-faded {
+    &::after {
+      opacity: 1;
+    }
+  }
+}