Animate List Items with Vue 3's TransitionGroup Component

<template>
  <div>
    <button @click="shuffleList">Shuffle Items</button>
    <button @click="addItem">Add Item</button>
    <button @click="removeItem">Remove Item</button>

    <TransitionGroup name="list" tag="ul">
      <li v-for="item in items" :key="item.id">
        {{ item.text }}
      </li>
    </TransitionGroup>
  </div>
</template>

<script setup>
import { ref } from 'vue';

const items = ref([
  { id: 1, text: 'Item A' },
  { id: 2, text: 'Item B' },
  { id: 3, text: 'Item C' }
]);

let nextId = 4;

const shuffleList = () => {
  items.value.sort(() => Math.random() - 0.5);
};

const addItem = () => {
  const newItem = { id: nextId++, text: `Item ${String.fromCharCode(64 + nextId)}` };
  const randomIndex = Math.floor(Math.random() * (items.value.length + 1));
  items.value.splice(randomIndex, 0, newItem);
};

const removeItem = () => {
  if (items.value.length > 0) {
    const randomIndex = Math.floor(Math.random() * items.value.length);
    items.value.splice(randomIndex, 1);
  }
};
</script>

<style>
/* Define CSS transitions for the 'list' transition group */
.list-enter-active, .list-leave-active {
  transition: all 0.5s ease;
}
.list-enter-from, .list-leave-to {
  opacity: 0;
  transform: translateX(30px);
}

/* Ensure that leaving elements don't affect layout during transition */
.list-leave-active {
  position: absolute;
}

/* Apply 'move' transition for elements that change position */
.list-move {
  transition: transform 0.5s ease;
}

/* Basic styling for the list items */
ul {
  list-style-type: none;
  padding: 0;
  margin-top: 20px;
}

li {
  background-color: #f0f0f0;
  padding: 10px;
  margin-bottom: 5px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 150px;
  height: 40px;
}

button {
  margin: 5px;
  padding: 8px 15px;
  cursor: pointer;
}
</style>