feat(filter): add autocompletion poc for labels

frontend/src/components/input/AutocompleteDropdown.vue

@@ -0,0 +1,237 @@
+<script setup lang="ts">
+import {type ComponentPublicInstance, computed, nextTick, ref, watch} from 'vue'
+
+const TAB = 9,
+	ENTER = 13,
+	ESCAPE = 27,
+	ARROW_UP = 38,
+	ARROW_DOWN = 40
+
+type state = 'unfocused' | 'focused'
+
+const selectedIndex = ref(-1)
+const state = ref<state>('unfocused')
+const val = ref<string>('')
+const isResizing = ref(false)
+const model = defineModel<string>()
+
+const suggestionScrollerRef = ref<HTMLInputElement | null>(null)
+const containerRef = ref<HTMLInputElement | null>(null)
+const editorRef = ref<HTMLInputElement | null>(null)
+
+watch(
+	() => model.value,
+	newValue => {
+		val.value = newValue
+	},
+)
+
+const emit = defineEmits(['blur'])
+
+const placeholderText = computed(() => {
+	const value = (model.value || '').replace(/[\n\r\t]/gi, ' ')
+
+	if (state.value === 'unfocused') {
+		return value ? '' : props.suggestion
+	}
+
+	if (!value || !value.trim()) {
+		return props.suggestion
+	}
+
+	return lookahead()
+})
+
+const spacerText = computed(() => {
+	const value = (model.value || '').replace(/[\n\r\t]/gi, ' ')
+
+	if (!value || !value.trim()) {
+		return props.suggestion
+	}
+
+	return value
+})
+
+const props = withDefaults(defineProps<{
+	options: any[],
+	suggestion?: string,
+	maxHeight?: number,
+}>(), {
+	maxHeight: 200,
+})
+
+function lookahead() {
+	if (!props.options.length) {
+		return model.value
+	}
+	const index = Math.max(0, Math.min(selectedIndex.value, props.options.length - 1))
+	const match = props.options[index]
+	return model.value + (match ? match.substring(model.value?.length) : '')
+}
+
+function updateSuggestionScroll() {
+	nextTick(() => {
+		const scroller = suggestionScrollerRef.value
+		const selectedItem = scroller?.querySelector('.selected')
+		scroller.scrollTop = selectedItem ? selectedItem.offsetTop : 0
+	})
+}
+
+function updateScrollWindowSize() {
+	if (isResizing.value) {
+		return
+	}
+
+	isResizing.value = true
+
+	nextTick(() => {
+		isResizing.value = false
+
+		const scroller = suggestionScrollerRef.value
+		const parent = containerRef.value
+		if (scroller) {
+			const rect = parent.getBoundingClientRect()
+			const pxTop = rect.top
+			const pxBottom = window.innerHeight - rect.bottom
+			const maxHeight = Math.max(pxTop, pxBottom, props.maxHeight)
+			const isReversed = pxBottom < props.maxHeight && pxTop > pxBottom
+			scroller.style.maxHeight = Math.min(isReversed ? pxTop : pxBottom, props.maxHeight) + 'px'
+			scroller.parentNode.style.transform =
+				isReversed ? 'translateY(-100%) translateY(-1.4rem)'
+					: 'translateY(.4rem)'
+		}
+	})
+}
+
+function setState(stateName: state) {
+	state.value = stateName
+	if (stateName === 'unfocused') {
+		emit('blur')
+	} else {
+		updateScrollWindowSize()
+	}
+}
+
+function onFocusField(e) {
+	setState('focused')
+}
+
+function onKeydown(e) {
+	switch (e.keyCode || e.which) {
+		case ESCAPE:
+			e.preventDefault()
+			setState('unfocused')
+			break
+		case ARROW_UP:
+			e.preventDefault()
+			select(-1)
+			break
+		case ARROW_DOWN:
+			e.preventDefault()
+			select(1)
+			break
+	}
+}
+
+const resultRefs = ref<(HTMLElement | null)[]>([])
+
+function setResultRefs(el: Element | ComponentPublicInstance | null, index: number) {
+	resultRefs.value[index] = el as (HTMLElement | null)
+}
+
+function select(offset: number) {
+
+	let index = selectedIndex.value + offset
+
+	if (!isFinite(index)) {
+		index = 0
+	}
+
+	if (index >= props.options.length) {
+		// At the last index, now moving back to the top
+		index = 0
+	}
+
+	if (index < 0) {
+		// Arrow up but we're already at the top
+		index = props.options.length - 1
+	}
+	let elems = resultRefs.value[index]
+	if (
+		typeof elems === 'undefined'
+	) {
+		return
+	}
+
+	selectedIndex.value = index
+	updateSuggestionScroll()
+
+	if (Array.isArray(elems)) {
+		elems[0].focus()
+		return
+	}
+	elems?.focus()
+}
+
+function onSelectValue(value) {
+	model.value = value
+	selectedIndex.value = 0
+	setState('unfocused')
+}
+
+function onUpdateField(e) {
+	setState('focused')
+	model.value = e.currentTarget.value
+}
+</script>
+
+<template>
+	<div class="autocomplete" ref="containerRef">
+		<div class="entry-box">
+			<slot
+				name="input"
+				:spacerText
+				:placeholderText
+				:onUpdateField
+				:onFocusField
+				:onKeydown
+			>
+				<div class="spacer">{{ spacerText }}</div>
+				<div class="placeholder">{{ placeholderText }}</div>
+				<textarea class="field"
+						  @input="onUpdateField"
+						  @focus="onFocusField"
+						  @keydown="onKeydown"
+						  :class="state"
+						  :value="val"
+						  ref="editorRef"></textarea>
+			</slot>
+		</div>
+		<div class="suggestion-list" v-if="state === 'focused' && options.length">
+			<div v-if="options && options.length" class="scroll-list">
+				<div
+					class="items"
+					ref="suggestionScrollerRef"
+					@keydown="onKeydown"
+				>
+					<button
+						v-for="(item, index) in options"
+						class="item"
+						@click="onSelectValue(item)"
+						:class="{ selected: index === selectedIndex }"
+						:key="item"
+						:ref="(el: Element | ComponentPublicInstance | null) => setResultRefs(el, index)"
+					>
+						<slot
+							name="result"
+							:item
+							:selected="index === selectedIndex"
+						>
+							{{ item }}
+						</slot>
+					</button>
+				</div>
+			</div>
+		</div>
+	</div>
+</template>