From 6bea1e0bcb7c32b17416a9decac7a1107be61c90 Mon Sep 17 00:00:00 2001
From: DarkWiiPlayer <darkwiiplayer@hotmail.com>
Date: Wed, 18 Dec 2024 13:41:00 +0100
Subject: [PATCH] Finish implementing all planned features

---
 index.html           |  21 +++++++-
 readme.md            |  23 +++++++++
 src/BetterSelect.css |  79 +++++++++++++++++++++++++++--
 src/BetterSelect.js  | 116 ++++++++++++++++++++++++++++++++-----------
 4 files changed, 202 insertions(+), 37 deletions(-)
 create mode 100644 readme.md

diff --git a/index.html b/index.html
index 75b8480..19b2846 100644
--- a/index.html
+++ b/index.html
@@ -1,3 +1,5 @@
+<script type="module" src="https://md-block.verou.me/md-block.js"></script>
+
 <script type="module">
 	import {BetterSelect} from "/src/BetterSelect.js"
 
@@ -8,12 +10,27 @@
 <style>
 	:root {
 		font-family: sans-serif;
+		background: #ddd;
 	}
+
+	better-select {
+		color: black;
+		background: white;
+	}
+
+	md-block:not([rendered]) { display: none }
 </style>
 
-<better-select>
-	<span slot="placeholder">Select some stuff here</span>
+<h1>Better Select</h1>
+
+<p>A better muli-option input box for HTML</p>
+
+<better-select class="search">
+	<span slot="placeholder">Placeholder...</span>
 	<option value="first">First value</option>
 	<option value="second">Second value</option>
 	<option value="third">Third value</option>
 </better-select>
+
+<md-block src="readme.md">
+</md-block>
diff --git a/readme.md b/readme.md
new file mode 100644
index 0000000..bd04c1f
--- /dev/null
+++ b/readme.md
@@ -0,0 +1,23 @@
+## Slots
+
+* `placeholder`: Only shown when nothing is selected
+* `loading`: Hidden by default, shown instead of items while `populate()` runs
+
+## Parts
+
+* `display`: The outer display box that is always shown
+* `display-text`: The text representing the currently selected value
+* `drop-down`: The dialog element that pops up when the list is opened
+* `search`: The search input box
+* `list`: The wrapper containing the items
+* `item`: The individual selectable list items
+
+## Hooks
+
+* `populate()`: If present, gets called after opening to populate the options list
+* `search(string)`: Called on search input to update the list of options
+* `match(string, element)`: Used by `search` to compare each option to the search string
+
+## Attributes
+
+* `closeSignal`: An AbortSignal that fires when the drop-down closes
diff --git a/src/BetterSelect.css b/src/BetterSelect.css
index 2d29df8..83e0cf0 100644
--- a/src/BetterSelect.css
+++ b/src/BetterSelect.css
@@ -1,13 +1,82 @@
 better-select {
-	display: inline-block;
-	border-radius: 3px;
-	border: 1px solid color-mix(in oklab, currentcolor, transparent 60%);
+	--faded: color-mix(in oklab, currentcolor, transparent 60%);
+	--highlight: color-mix(in oklab, currentcolor, transparent 90%);
+	--overshoot: cubic-bezier(.2, 0, .2, 1.4);
 
-	&::part(display), &::part(drop-down) {
+	--h-padding: .8em;
+
+	min-width: 14em;
+
+	outline: none;
+
+	&:focus {
+		border-color: currentcolor;
+	}
+
+	[slot="placeholder"] {
+		color: var(--faded);
+	}
+
+	&::part(display) {
+		padding: .4rem var(--h-padding);
+
+		gap: .4em;
+
+		background: linear-gradient(to top, var(--highlight), transparent);
+	}
+
+	&, &::part(drop-down) {
+		border: 1px solid var(--faded);
+		border-radius: 3px;
 	}
 
 	&::part(drop-down) {
+		transition-behavior: allow-discrete;
+		transition-duration: .2s;
+		transition-property: transform, display, opacity;
+		transition-timing-function: var(--overshoot);
 		margin-top: .2em;
-		padding-inline: .5em;
+		padding: .4rem 0;
+
+		min-width: 100%;
+	}
+
+	&::part(search) {
+		margin-block: .4em;
+		line-height: 1.4em;
+		margin-inline: var(--h-padding);
+		display: none;
+	}
+
+	&.search::part(search) {
+		display: block;
+	}
+
+	&::part(item) {
+		line-height: 2em;
+		transition: background-color .3s;
+		padding-inline: var(--h-padding);
+	}
+
+	&::part(item):is(:hover, :focus) {
+		background-color: var(--highlight);
+	}
+
+	&:not(:state(--open))::part(drop-down) {
+		transform: scale(100%, 70%) translate(0, -30%);
+		opacity: 0;
+	}
+
+	&::part(display)::after {
+		margin-left: auto;
+		display: inline-block;
+		content: '\25be';
+		color: var(--faded);
+		line-height: 1em;
+		transition: transform .3s var(--overshoot);
+	}
+
+	&:state(--open)::part(display)::after {
+		transform: rotate(180deg);
 	}
 }
diff --git a/src/BetterSelect.js b/src/BetterSelect.js
index 8ac4f50..8415cb2 100644
--- a/src/BetterSelect.js
+++ b/src/BetterSelect.js
@@ -32,6 +32,7 @@ const childObserver = new MutationObserver(mutations => {
 })
 
 export class BetterSelect extends HTMLElement {
+	/** @type {AbortController} */
 	#abortOpen
 	#value = {}
 
@@ -41,43 +42,41 @@ export class BetterSelect extends HTMLElement {
 	static styleSheet = css`
 		:host {
 			position: relative;
+			display: inline-block;
 		}
 		* {
 			box-sizing: border-box;
 		}
 		[part="display"] {
+			min-width: 100%;
+
+			/* Layout */
+			align-items: center;
 			display: inline-flex;
 			flex-flow: row nowrap;
 
-			min-width: 20em;
-
-			padding: .4em;
-
+			/* Styling */
 			cursor: pointer;
-
-			:last-child {
-				display: block;
-				margin-left: auto;
-			}
+		}
+		[part="display-text"]:empty {
+			display: none;
 		}
 		:not(:empty + *)[name="placeholder"] {
 			display: none;
 		}
-		[part="drop-down"] {
+		[part="drop-down"], [part="item"] {
 			/* Resets */
 			border: unset;
+			outline: unset;
 			padding: unset;
+		}
+		[part="drop-down"] {
 			background: inherit;
 			color: inherit;
 
 			position: absolute;
-			width: 100%;
 			flex-flow: column;
-			--gap: .4em;
 			margin: 0;
-
-			gap: var(--gap);
-			padding-top: var(--gap);
 		}
 		[part="drop-down"]:modal {
 			margin: auto;
@@ -95,6 +94,7 @@ export class BetterSelect extends HTMLElement {
 		[part="item"] {
 			display: block;
 			cursor: pointer;
+			white-space: nowrap;
 		}
 		[part="item"]:focus {
 			font-weight: bold;
@@ -105,30 +105,53 @@ export class BetterSelect extends HTMLElement {
 		slot[name="loading"] {
 			display: none;
 		}
+		:host(:state(--loading)) {
+			[part="list"] { display: none; }
+			slot[name="loading"] { display: block; }
+		}
 	`
 
+	/** @type {HTMLElement} */
+	display
+	/** @type {HTMLElement} */
+	text
+	/** @type {HTMLElement} */
+	list
+	/** @type {HTMLElement} */
+	placeholder
+	/** @type {HTMLInputElement} */
+	input
+	/** @type {HTMLDialogElement} */
+	dialog
+	/** @type {HTMLDialogElement} */
+	loading
+
 	constructor() {
 		super()
 		childObserver.observe(this, {childList: true})
 		this.attachShadow({mode: "open"}).innerHTML = `
 			<div id="display" part="display">
-				<slot name="before"></slot>
 				<span part="display-text" id="text"></span>
-				<slot name="placeholder" aria-hidden="true"></slot>
-				<slot name="after">🔽</slot>
+				<slot name="placeholder" aria-hidden="true">
+					<span id="placeholder" aria-hidden="true"></span>
+				</slot>
 			</div>
 			<dialog id="dialog" part="drop-down">
-				<input type="search" id="input" part="input" type="text"></input>
+				<input type="search" id="input" part="search" type="text"></input>
 				<ul id="list" part="list"></ul>
-				<slot name="loading"></slot>
+				<slot id="loading" name="loading"></slot>
 			</dialog>
 		`
 		this.shadowRoot.adoptedStyleSheets = [BetterSelect.styleSheet]
 
-		this.tabindex = 0
+		this.tabIndex = 0
+
+		this.#internals.role = "combobox"
 
 		this.options = this.getElementsByTagName("option")
-		for (const element of this.shadowRoot.querySelectorAll(`[id]`)) this[element.id] = element
+		for (const element of this.shadowRoot.querySelectorAll(`[id]`)) {
+			this[element.id] = element
+		}
 
 		this.shadowRoot.addEventListener("click", event => {
 			const item = event.target.closest("#list > li")
@@ -143,6 +166,18 @@ export class BetterSelect extends HTMLElement {
 			}
 		})
 
+		this.addEventListener("keydown", event => {
+			if (event.key == " " && !this.input.contains(this.shadowRoot.activeElement)) {
+				if (this.#internals.states.has("--open")) {
+					this.close()
+				} else {
+					this.open()
+				}
+			} else if (event.key == "Escape") {
+				this.close()
+			}
+		})
+
 		this.shadowRoot.addEventListener("input", event => {
 			const item = event.target.closest("#input")
 			if (item) {
@@ -150,19 +185,16 @@ export class BetterSelect extends HTMLElement {
 				event.stopPropagation()
 			}
 		})
-		this.addEventListener("focus", event => {
-			this.open()
-		})
 	}
 
-	open() {
+	async open() {
 		if (this.#abortOpen) return
 
 		this.#abortOpen = new AbortController()
 
-		const signal = this.#abortOpen.signal
+		const signal = this.closeSignal
 		window.addEventListener("click", event => {
-			if (!this.contains(event.target)) {
+			if (event.target instanceof HTMLElement && !this.contains(event.target)) {
 				this.close()
 			}
 		}, {signal})
@@ -174,6 +206,12 @@ export class BetterSelect extends HTMLElement {
 
 		this.dialog.show()
 		this.#internals.states.add("--open")
+
+		if ("populate" in this) {
+			this.#internals.states.add("--loading")
+			await this.populate()
+			this.#internals.states.delete("--loading")
+		}
 	}
 
 	close() {
@@ -186,6 +224,9 @@ export class BetterSelect extends HTMLElement {
 		this.dialog.close()
 	}
 
+	get closeSignal() { return this.#abortOpen?.signal }
+
+	/** @param {String} value */
 	search(value) {
 		for (const item of this.list.children) {
 			item.toggleAttribute("hidden", !this.match(value, item))
@@ -193,6 +234,11 @@ export class BetterSelect extends HTMLElement {
 	}
 
 	selectDefault() {
+		if (this.shadowRoot.activeElement?.matches(`[part="item"]`)) {
+			this.setOption(this.shadowRoot.activeElement)
+			this.close()
+			return
+		}
 		const candidates = [...this.list.children].filter(child => !child.hasAttribute("hidden"))
 		if (candidates.length) {
 			this.setOption(candidates[0])
@@ -200,6 +246,10 @@ export class BetterSelect extends HTMLElement {
 		}
 	}
 
+	/**
+	 * @param {string} value
+	 * @param {HTMLElement} item
+	 */
 	match(value, item) {
 		return item.innerText.toLowerCase().match(value.toLowerCase())
 	}
@@ -212,10 +262,15 @@ export class BetterSelect extends HTMLElement {
 		this.setOptions()
 	}
 
+	/** @param {HTMLElement} option */
 	setOption(option) {
 		this.setValue(option.dataset.value, option.innerHTML)
 	}
 
+	/**
+	 * @param {string} value
+	 * @param {string} state
+	 */
 	setValue(value, state=value) {
 		this.#value = {value, state}
 		this.#internals.setFormValue(value, state)
@@ -226,7 +281,8 @@ export class BetterSelect extends HTMLElement {
 	set value(value) {
 		for (const option of this.options) {
 			if (option.value === value) {
-				return this.setOption(option)
+				this.setOption(option)
+				return
 			}
 		}
 		throw `No option with value ${value}`
@@ -237,7 +293,7 @@ export class BetterSelect extends HTMLElement {
 	setOptions() {
 		this.list.replaceChildren()
 		for (const option of this.options) {
-			this.list.append(f`<li tab-index="-1" part="item" data-value="${option.value}">${option.innerText}</li>`)
+			this.list.append(f`<li tabindex="0" part="item" data-value="${option.value}">${option.innerText}</li>`)
 		}
 	}
 }