You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
svelte/documentation/tutorial/07-lifecycle/04-tick/app-b/App.svelte

32 lines
745 B

<script>
import { tick } from 'svelte';
let text = `Select some text and hit the tab key to toggle uppercase`;
async function handleKeydown(event) {
if (event.key !== 'Tab') return;
event.preventDefault();
const { selectionStart, selectionEnd, value } = this;
const selection = value.slice(selectionStart, selectionEnd);
const replacement = /[a-z]/.test(selection) ? selection.toUpperCase() : selection.toLowerCase();
text = value.slice(0, selectionStart) + replacement + value.slice(selectionEnd);
await tick();
this.selectionStart = selectionStart;
this.selectionEnd = selectionEnd;
}
</script>
<textarea value={text} on:keydown={handleKeydown} />
<style>
textarea {
width: 100%;
height: 200px;
}
</style>