From 45faefa8b388400fee63cf83fe739bb0527ac05d Mon Sep 17 00:00:00 2001
From: Joao Silva <100691367+JoaoSilvaGrafana@users.noreply.github.com>
Date: Mon, 27 May 2024 10:33:53 +0100
Subject: [PATCH] TimeRangePicker: Allow users to navigate quick ranges with
 arrows instead of Tab (#88138)

---
 .../TimeRangePicker/TimeRangeList.tsx         |  11 +-
 .../TimeRangePicker/TimeRangeOption.tsx       |   2 +
 .../TimeRangePicker/hooks.test.tsx            | 118 ++++++++++++++++++
 .../DateTimePickers/TimeRangePicker/hooks.ts  |  75 +++++++++++
 4 files changed, 205 insertions(+), 1 deletion(-)
 create mode 100644 packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/hooks.test.tsx
 create mode 100644 packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/hooks.ts

diff --git a/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/TimeRangeList.tsx b/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/TimeRangeList.tsx
index 0833e099046..76676a5bba6 100644
--- a/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/TimeRangeList.tsx
+++ b/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/TimeRangeList.tsx
@@ -8,6 +8,7 @@ import { t } from '../../../utils/i18n';
 
 import { TimePickerTitle } from './TimePickerTitle';
 import { TimeRangeOption } from './TimeRangeOption';
+import { useListFocus } from './hooks';
 
 interface Props {
   title?: string;
@@ -44,9 +45,17 @@ export const TimeRangeList = (props: Props) => {
 const Options = ({ options, value, onChange, title }: Props) => {
   const styles = useStyles2(getOptionsStyles);
 
+  const localRef = React.useRef<HTMLUListElement>(null);
+  const [handleKeys] = useListFocus({ localRef, options });
+
   return (
     <>
-      <ul aria-roledescription={t('time-picker.time-range.aria-role', 'Time range selection')}>
+      <ul
+        role="presentation"
+        onKeyDown={handleKeys}
+        ref={localRef}
+        aria-roledescription={t('time-picker.time-range.aria-role', 'Time range selection')}
+      >
         {options.map((option, index) => (
           <TimeRangeOption
             key={keyForOption(option, index)}
diff --git a/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/TimeRangeOption.tsx b/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/TimeRangeOption.tsx
index 46ce286ad23..4df76628dcb 100644
--- a/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/TimeRangeOption.tsx
+++ b/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/TimeRangeOption.tsx
@@ -60,6 +60,8 @@ export const TimeRangeOption = memo<Props>(({ value, onSelect, selected = false,
         checked={selected}
         name={name}
         type="checkbox"
+        data-role="item"
+        tabIndex={-1}
         id={id}
         onChange={() => onSelect(value)}
       />
diff --git a/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/hooks.test.tsx b/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/hooks.test.tsx
new file mode 100644
index 00000000000..9da5a28e468
--- /dev/null
+++ b/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/hooks.test.tsx
@@ -0,0 +1,118 @@
+import { act, fireEvent, render, renderHook, screen } from '@testing-library/react';
+import React, { createRef, KeyboardEvent, RefObject } from 'react';
+
+import { useListFocus } from './hooks';
+
+describe('useListFocus', () => {
+  const testid = 'test';
+  const getListElement = (
+    ref: RefObject<HTMLUListElement>,
+    handleKeys?: (event: KeyboardEvent) => void,
+    onClick?: () => void
+  ) => (
+    <ul data-testid={testid} ref={ref} tabIndex={0} onKeyDown={handleKeys}>
+      <li data-role="item" onClick={onClick}>
+        Last 1 hour
+      </li>
+      <li data-role="item">Last 6 hours</li>
+      <li data-role="item">Last 24 hours</li>
+      <li data-role="item">Last 7 days</li>
+    </ul>
+  );
+  const options = [
+    { from: 'now-1h', to: 'now', display: 'Last 1 hour' },
+    { from: 'now-6h', to: 'now', display: 'Last 6 hours' },
+    { from: 'now-24h', to: 'now', display: 'Last 24 hours' },
+    { from: 'now-7d', to: 'now', display: 'Last 7 days' },
+  ];
+
+  it('sets correct focused item on keydown', () => {
+    const ref = createRef<HTMLUListElement>();
+    const { rerender } = render(getListElement(ref));
+
+    const { result } = renderHook(() => useListFocus({ localRef: ref, options }));
+    const [handleKeys] = result.current;
+    rerender(getListElement(ref, handleKeys));
+
+    expect(screen.getByText('Last 1 hour').tabIndex).toBe(0);
+    expect(screen.getByText('Last 6 hours').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 24 hours').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 7 days').tabIndex).toBe(-1);
+
+    act(() => {
+      fireEvent.keyDown(screen.getByTestId(testid), { key: 'ArrowDown' });
+    });
+
+    const [handleKeys2] = result.current;
+    rerender(getListElement(ref, handleKeys2));
+
+    expect(screen.getByText('Last 1 hour').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 6 hours').tabIndex).toBe(0);
+    expect(screen.getByText('Last 24 hours').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 7 days').tabIndex).toBe(-1);
+
+    act(() => {
+      fireEvent.keyDown(screen.getByTestId(testid), { key: 'ArrowDown' });
+    });
+
+    const [handleKeys3] = result.current;
+    rerender(getListElement(ref, handleKeys3));
+
+    expect(screen.getByText('Last 1 hour').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 6 hours').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 24 hours').tabIndex).toBe(0);
+    expect(screen.getByText('Last 7 days').tabIndex).toBe(-1);
+
+    act(() => {
+      fireEvent.keyDown(screen.getByTestId(testid), { key: 'ArrowUp' });
+    });
+
+    const [handleKeys4] = result.current;
+    rerender(getListElement(ref, handleKeys4));
+
+    expect(screen.getByText('Last 1 hour').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 6 hours').tabIndex).toBe(0);
+    expect(screen.getByText('Last 24 hours').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 7 days').tabIndex).toBe(-1);
+
+    act(() => {
+      fireEvent.keyDown(screen.getByTestId(testid), { key: 'ArrowUp' });
+    });
+
+    const [handleKeys5] = result.current;
+    rerender(getListElement(ref, handleKeys5));
+
+    expect(screen.getByText('Last 1 hour').tabIndex).toBe(0);
+    expect(screen.getByText('Last 6 hours').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 24 hours').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 7 days').tabIndex).toBe(-1);
+
+    act(() => {
+      fireEvent.keyDown(screen.getByTestId(testid), { key: 'ArrowUp' });
+    });
+
+    const [handleKeys6] = result.current;
+    rerender(getListElement(ref, handleKeys6));
+
+    expect(screen.getByText('Last 1 hour').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 6 hours').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 24 hours').tabIndex).toBe(-1);
+    expect(screen.getByText('Last 7 days').tabIndex).toBe(0);
+  });
+
+  it('clicks focused item when Enter key is pressed', () => {
+    const ref = createRef<HTMLUListElement>();
+    const onClick = jest.fn();
+    const { rerender } = render(getListElement(ref));
+
+    const { result } = renderHook(() => useListFocus({ localRef: ref, options }));
+    const [handleKeys] = result.current;
+    rerender(getListElement(ref, handleKeys, onClick));
+
+    act(() => {
+      fireEvent.keyDown(screen.getByTestId(testid), { key: 'Enter' });
+    });
+
+    expect(onClick).toHaveBeenCalled();
+  });
+});
diff --git a/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/hooks.ts b/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/hooks.ts
new file mode 100644
index 00000000000..96c190c4494
--- /dev/null
+++ b/packages/grafana-ui/src/components/DateTimePickers/TimeRangePicker/hooks.ts
@@ -0,0 +1,75 @@
+import { RefObject, useEffect, useState } from 'react';
+
+import { TimeOption } from '@grafana/data';
+
+const modulo = (a: number, n: number) => ((a % n) + n) % n;
+const CAUGHT_KEYS = ['ArrowUp', 'ArrowDown', 'Home', 'End', 'Enter', 'Tab'];
+
+/** @internal */
+export interface UseListFocusProps {
+  localRef: RefObject<HTMLUListElement>;
+  options: TimeOption[];
+}
+
+/** @internal */
+export type UseListFocusReturn = [(event: React.KeyboardEvent) => void];
+
+/** @internal */
+export const useListFocus = ({ localRef, options }: UseListFocusProps): UseListFocusReturn => {
+  const [focusedItem, setFocusedItem] = useState(0);
+
+  useEffect(() => {
+    const items = localRef.current?.querySelectorAll<HTMLInputElement>('[data-role="item"]') || [];
+    const checkedIndex = Array.from(items).findIndex((item) => item.checked);
+    const newFocusedIndex = checkedIndex >= 0 ? checkedIndex : 0;
+    items.forEach((item, i) => {
+      item.tabIndex = i === newFocusedIndex ? 0 : -1;
+    });
+    // Reset focused item when options have changed
+    setFocusedItem(newFocusedIndex);
+  }, [localRef, options]);
+
+  const handleKeys = (event: React.KeyboardEvent) => {
+    const items = localRef?.current?.querySelectorAll<HTMLInputElement>('[data-role="item"]');
+    const itemsCount = items?.length ?? 0;
+
+    if (CAUGHT_KEYS.indexOf(event.key) > -1) {
+      event.preventDefault();
+      if (event.key !== 'Tab') {
+        event.stopPropagation();
+      }
+    }
+
+    let newFocusedIndex = null;
+
+    switch (event.key) {
+      case 'ArrowUp':
+        newFocusedIndex = modulo(focusedItem - 1, itemsCount);
+        break;
+      case 'ArrowDown':
+        newFocusedIndex = modulo(focusedItem + 1, itemsCount);
+        break;
+      case 'Home':
+        newFocusedIndex = 0;
+        break;
+      case 'End':
+        newFocusedIndex = itemsCount - 1;
+        break;
+      case 'Enter':
+        items?.[focusedItem]?.click();
+        break;
+      default:
+        break;
+    }
+
+    if (newFocusedIndex !== null) {
+      setFocusedItem(newFocusedIndex);
+      items?.[newFocusedIndex]?.focus();
+      items?.forEach((item, i) => {
+        item.tabIndex = i === newFocusedIndex ? 0 : -1;
+      });
+    }
+  };
+
+  return [handleKeys];
+};