fix(VDataTableColumn): columns are not keyboard-accessible fixes #20899

[ankusharoraa]

fixes #20899

Description

Added default tabindex to 0 for the cells in the table.

Markup:

<template>
  <v-data-table :headers="headers" :items="items" />
</template>

<script>
  export default {
    data: () => ({
      headers: [
        { title: 'Dessert (100g serving)', align: 'start', key: 'name' },
        { title: 'Calories', key: 'calories', align: 'end', sortable: false },
        { title: 'Fat (g)', key: 'fat', align: 'end' },
        { title: 'Carbs (g)', key: 'carbs', align: 'end' },
        { title: 'Protein (g)', key: 'protein', align: 'end' },
        { title: 'Iron (%)', key: 'iron', align: 'end' },
      ],
      items: [
        {
          name: 'Frozen Yogurt',
          calories: 159,
          fat: 6.0,
          carbs: 24,
          protein: 4.0,
          iron: '1',
        },
        {
          name: 'Jelly bean',
          calories: 375,
          fat: 0.0,
          carbs: 94,
          protein: 0.0,
          iron: '0',
        },
        {
          name: 'KitKat',
          calories: 518,
          fat: 26.0,
          carbs: 65,
          protein: 7,
          iron: '6',
        },
        {
          name: 'Eclair',
          calories: 262,
          fat: 16.0,
          carbs: 23,
          protein: 6.0,
          iron: '7',
        },
        {
          name: 'Gingerbread',
          calories: 356,
          fat: 16.0,
          carbs: 49,
          protein: 3.9,
          iron: '16',
        },
        {
          name: 'Ice cream sandwich',
          calories: 237,
          fat: 9.0,
          carbs: 37,
          protein: 4.3,
          iron: '1',
        },
        {
          name: 'Lollipop',
          calories: 392,
          fat: 0.2,
          carbs: 98,
          protein: 0,
          iron: '2',
        },
        {
          name: 'Cupcake',
          calories: 305,
          fat: 3.7,
          carbs: 67,
          protein: 4.3,
          iron: '8',
        },
        {
          name: 'Honeycomb',
          calories: 408,
          fat: 3.2,
          carbs: 87,
          protein: 6.5,
          iron: '45',
        },
        {
          name: 'Donut',
          calories: 452,
          fat: 25.0,
          carbs: 51,
          protein: 4.9,
          iron: '22',
        },
      ],
    }),
  }
</script>

[ankusharoraa]

@johnleider - Can you please review this PR

[johnleider]

This allows the focusing of the columns but no actual interaction.

[ankusharoraa]

This allows the focusing of the columns but no actual interaction.

@johnleider - Bug #20899 asks only for tabbing of table cells (Actual Behavior - Sortable headers are not tabbable.)
Should I start working on the interactions of cells as well, or should there be any other feature ticket related to it?

[johnleider]

To me, tab support assumes keyboard interaction for changing the sort.

[ankusharoraa]

To me, tab support assumes keyboard interaction for changing the sort.

@johnleider I have added changes for keyboard interaction for changing the sort in latest commit, please review