Factor out reusable MobileTooltip component

Also prevents tabIndex from being generated on desktop

common/src/MobileTooltip.scss

@@ -0,0 +1,20 @@
+@media (pointer: coarse), (hover: none) {
+  .MobileTooltip {
+    position: relative;
+    display: inline-flex;
+    justify-content: center;
+
+    &:focus::after {
+      content: attr(title);
+      position: absolute;
+      top: 90%;
+      left: 0;
+      color: #000;
+      background-color: #fff;
+      border: 1px solid;
+      width: fit-content;
+      padding: 3px;
+      z-index: 10;
+    }
+  }
+}

common/src/MobileTooltip.tsx

@@ -0,0 +1,31 @@
+import * as React from 'react';
+import {useEffect} from 'react';
+
+const MobileTooltipContext = React.createContext(false);
+
+export function MobileTooltipProvider({children}: React.PropsWithChildren<{}>): JSX.Element {
+    const [mobile, setMobile] = React.useState(false);
+
+    useEffect(() => {
+        if (!window.matchMedia)
+            return;
+
+        const match = window.matchMedia('(pointer: coarse), (hover: none)');
+        const callback = () => setMobile(match.matches);
+
+        callback();
+        match.addEventListener('change', callback);
+        return () => match.removeEventListener('change', callback);
+    }, [setMobile]);
+
+    return <MobileTooltipContext.Provider value={mobile}>
+        {children}
+    </MobileTooltipContext.Provider>;
+}
+
+export function useMobileTooltipProps(): { className: string, tabIndex?: number } {
+    return {
+        className: 'MobileTooltip',
+        ...React.useContext(MobileTooltipContext) ? {tabIndex: 0} : {},
+    };
+}

frcal/src/Calendar.scss

@@ -147,26 +147,6 @@
     background: $gray-300;
 }
 
-@media (pointer: coarse), (hover: none) {
-    .Day-rural {
-        position: relative;
-        display: inline-flex;
-        justify-content: center;
-        text-decoration: underline dashed;
-    }
-
-    .Day-rural:focus::after {
-        content: attr(title);
-        position: absolute;
-        top: 90%;
-        color: #000;
-        background-color: #fff;
-        border: 1px solid;
-        width: fit-content;
-        padding: 3px;
-    }
-}
-
 .Calendar-month-name.input-group {
     justify-content: center;
     font-size: 0.75em;

frcal/src/Calendar.tsx

@@ -15,6 +15,7 @@ import {
 } from '@common/french';
 import {jdnDate} from '@common/gregorian';
 import {jdnLongCount} from '@common/longCount';
+import {useMobileTooltipProps} from '@common/MobileTooltip';
 
 type MonthProps = {
     year: number;
@@ -39,10 +40,11 @@ function DayDetail({jdn}: { jdn: number }): JSX.Element {
 function NormalDay({year, month, day, todayJDN}: DateProps & { todayJDN: number }): JSX.Element {
     const jdn = frJDN(year, month, day);
     const rural = dateRuralName(month, day)!;
+    const mobile = useMobileTooltipProps();
     return <div className={`Day NormalDay ${jdn === todayJDN ? 'Day-today' : ''}`}>
         <div className="Day-name">{day}</div>
         <div className="Day-decade">{decadeNames[(day - 1) % 10]}</div>
-        <div className="Day-rural" title={rural.title} tabIndex={0}>{rural.name}</div>
+        <div className="Day-rural"><abbr title={rural.title} {...mobile}>{rural.name}</abbr></div>
         <DayDetail jdn={jdn}/>
     </div>;
 }

frcal/src/index.scss

@@ -9,6 +9,7 @@
 @import 'bootstrap/scss/forms';
 @import 'bootstrap/scss/root';
 @import './consts';
+@import '@common/MobileTooltip.scss';
 
 body {
   padding-top: $spacer * 4;

frcal/src/index.tsx

@@ -4,12 +4,15 @@ import 'bootstrap/js/dist/collapse';
 import './index.scss';
 import App from './App';
 import reportWebVitals from './reportWebVitals';
+import {MobileTooltipProvider} from '@common/MobileTooltip';
 
 ReactDOM.render(
-  <React.StrictMode>
-    <App />
-  </React.StrictMode>,
-  document.getElementById('root')
+    <React.StrictMode>
+        <MobileTooltipProvider>
+            <App/>
+        </MobileTooltipProvider>
+    </React.StrictMode>,
+    document.getElementById('root'),
 );
 
 // If you want to start measuring performance in your app, pass a function

jcal/src/Calendar.scss

@@ -167,24 +167,3 @@
 .Calendar-today-button {
     max-width: 5em;
 }
-
-@media (pointer: coarse), (hover: none) {
-    .DayDetail abbr {
-        position: relative;
-        display: inline-flex;
-        justify-content: center;
-
-        &:focus::after {
-            content: attr(title);
-            position: absolute;
-            top: 90%;
-            left: 0;
-            color: #000;
-            background-color: #fff;
-            border: 1px solid;
-            width: fit-content;
-            padding: 3px;
-            z-index: 10;
-        }
-    }
-}

jcal/src/Calendar.tsx

@@ -4,6 +4,7 @@ import {formatJG, jdnGregorian, JulianDay, JulianMonth, monthName, weekdayNames}
 import {jdnLongCount} from '@common/longCount';
 import {jdnJulian, julianJDN, julianMonthDays} from '@common/julian';
 import {frDateFormat, frEndJD, frStartJD, jdnFrench} from '@common/french';
+import {useMobileTooltipProps} from '@common/MobileTooltip';
 
 type MonthProps = {
     year: number;
@@ -20,18 +21,19 @@ function WeekdayName({name}: { name: string }): JSX.Element {
 
 function DayDetail({jdn}: { jdn: number }): JSX.Element {
     const lc = jdnLongCount(jdn);
+    const mobile = useMobileTooltipProps();
     return <div className="DayDetail">
-        <div className="DayDetail-jdn"><abbr title="Julian day number" tabIndex={0}>JD</abbr> {jdn}</div>
+        <div className="DayDetail-jdn"><abbr title="Julian day number" {...mobile}>JD</abbr> {jdn}</div>
         <div className="DayDetail-gregorian">
-            <abbr title="Gregorian date" tabIndex={0}>G.</abbr>{' '}
+            <abbr title="Gregorian date" {...mobile}>G.</abbr>{' '}
             {formatJG(jdnGregorian(jdn))}
         </div>
         {lc && <div className="DayDetail-lc">
-          <abbr title="Mesoamerican long count date" tabIndex={0}>LC</abbr>{' '}
+          <abbr title="Mesoamerican long count date" {...mobile}>LC</abbr>{' '}
             {lc.join('.\u200b')}
         </div>}
         {jdn >= frStartJD && jdn <= frEndJD && <div className="DayDetail-fr">
-          <abbr title="French Republican Calendar" tabIndex={0}>FR</abbr>{' '}
+          <abbr title="French Republican Calendar" {...mobile}>FR</abbr>{' '}
             {frDateFormat(jdnFrench(jdn))}
         </div>}
     </div>;

jcal/src/index.scss

@@ -9,6 +9,7 @@
 @import 'bootstrap/scss/forms';
 @import 'bootstrap/scss/root';
 @import './consts';
+@import '@common/MobileTooltip.scss';
 
 body {
   padding-top: $spacer * 4;

jcal/src/index.tsx

@@ -4,12 +4,15 @@ import 'bootstrap/js/dist/collapse';
 import './index.scss';
 import App from './App';
 import reportWebVitals from './reportWebVitals';
+import {MobileTooltipProvider} from '@common/MobileTooltip';
 
 ReactDOM.render(
-  <React.StrictMode>
-    <App />
-  </React.StrictMode>,
-  document.getElementById('root')
+    <React.StrictMode>
+        <MobileTooltipProvider>
+            <App/>
+        </MobileTooltipProvider>
+    </React.StrictMode>,
+    document.getElementById('root'),
 );
 
 // If you want to start measuring performance in your app, pass a function