61 lines
1.7 KiB
HTML
61 lines
1.7 KiB
HTML
<span class="length-indicator {overLimit ? 'over-char-limit' : ''}"
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aria-live={lengthVerbosity}
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aria-atomic='true'
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{style}
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>{lengthToDisplayDeferred}</span>
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<style>
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.length-indicator {
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color: var(--length-indicator-color);
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font-size: 1.3em;
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}
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.length-indicator.over-char-limit {
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color: var(--warning-color);
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}
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</style>
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<script>
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import { mark, stop } from '../_utils/marks.js'
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import { store } from '../_store/store.js'
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import { observe } from 'svelte-extras'
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import { throttleTimer } from '../_utils/throttleTimer.js'
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const updateDisplayedLength = process.browser && throttleTimer(requestAnimationFrame)
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// How many chars within the limit to start warning at
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const WARN_THRESHOLD = 10
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export default {
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oncreate () {
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const { lengthToDisplay } = this.get()
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this.set({ lengthToDisplayDeferred: lengthToDisplay })
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// perf improvement for keyboard input latency
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this.observe('lengthToDisplay', () => {
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updateDisplayedLength(() => {
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mark('set lengthToDisplayDeferred')
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const { lengthToDisplay } = this.get()
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this.set({ lengthToDisplayDeferred: lengthToDisplay })
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stop('set lengthToDisplayDeferred')
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})
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}, { init: false })
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},
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data: () => ({
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lengthToDisplayDeferred: 0,
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style: ''
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}),
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store: () => store,
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computed: {
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lengthToDisplay: ({ length, max }) => max - length,
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lengthVerbosity: ({ lengthToDisplayDeferred }) => {
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// When approaching the limit, notify screen reader users
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if (lengthToDisplayDeferred > WARN_THRESHOLD) {
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return 'off'
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} else {
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return 'polite'
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}
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}
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},
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methods: {
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observe
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}
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}
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</script>
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