feat: Add loader step

- Add loader element with progress display
- Add styles for loader, spinner and bar
- Move event listeners for hint to intro step
- Add loadCore function to simulate loader
- Keep alternative progress bar for document loading display

source/code/ui.js

@@ -28,17 +28,17 @@ const hint = {
 		clearTimeout(this.timeoutId);
 	}
 };
-
-window.addEventListener('click', () => hint.show());
-window.addEventListener('keydown', () => hint.show());
+const loader = document.getElementById('loader');
 
 function agree() {
 	if (agreement) {
 		console.info("Agreement show.");
+
 		agreement.classList.replace('op_hide', 'op_show');
 
 		setTimeout(() => {
 			agreement.classList.replace('op_show', 'op_hide');
+
 			console.info("Agreement closed.");
 		}, introDelay * 1000)
 	}
@@ -47,6 +47,7 @@ function agree() {
 function init() {
 	return new Promise((resolve) => {
 		console.log('Init');
+
 		resolve();
 	});
 }
@@ -55,17 +56,20 @@ function showIntro() {
 	const el = intro;
 	const dy = introDelay * 1000;
 
+	window.addEventListener('click', () => hint.show());
+	window.addEventListener('keydown', () => hint.show());
+
 	return new Promise((resolve, reject) => {
 		if (el) {
 			console.info("Intro begin.");
-			el.classList.replace('op_hide', 'op_show');
 
+			el.classList.replace('op_hide', 'op_show');
 			setTimeout(
 				() => {
 					el.classList.replace('op_show', 'op_hide');
-
 					el.addEventListener('transitionend', () => {
 						console.info("Intro fin.");
+
 						resolve("Intro fin.");
 					});
 				},
@@ -84,14 +88,14 @@ function showAgreement() {
 	return new Promise((resolve, reject) => {
 		if (el) {
 			console.info("Agreement show.");
-			el.classList.replace('op_hide', 'op_show');
 
+			el.classList.replace('op_hide', 'op_show');
 			setTimeout(
 				() => {
 					el.classList.replace('op_show', 'op_hide');
-
 					el.addEventListener('transitionend', () => {
 						console.info("Agreement closed.");
+
 						resolve("closed");
 					});
 				},
@@ -103,11 +107,115 @@ function showAgreement() {
 	})
 }
 
+function loadCore() {
+	const el = loader;
+	const bar = loader.querySelector('#progress');
+	const status = loader.querySelector('#status');
+	const spinner = loader.querySelector('#spinner');
+	const sp = spinner.querySelector('span');
+
+	let progress = 0;
+
+	return new Promise((resolve) => {
+		console.info("Core loading.");
+
+		updateProgressBar();
+
+		function updateProgressBar() {
+			let increment = randomIntFrom(1, 19);
+
+			progress += increment;
+
+			if (progress >= 100) progress = 100;
+			// console.log(progress);
+
+			bar.style.width = progress + '%';
+			status.textContent = progress + '%';
+
+			if (progress < 100) {
+				setTimeout(updateProgressBar, 800);
+			} else {
+				bar.style.width = '100%';
+				sp.style.animationPlayState = 'paused';
+				spinner.style.color = 'white';
+				spinner.style.backgroundColor = 'black';
+				el.classList.replace('op_show', 'op_hide');
+				el.addEventListener('transitionend', () => {
+					console.info("Core loaded.");
+
+					resolve("Core loaded.");
+				});
+			}
+		}
+	});
+}
+
 init()
+	.then(loadCore)
 	.then(showIntro)
 	.catch(er => console.error(er))
 	.then(showAgreement)
 	.catch(er => console.error(er))
 	.finally(() => {
-		console.debug('Init end.');
-	});
+		console.debug('Init end.', loader, intro, agreement);
+	});
+
+// document.addEventListener('DOMContentLoaded', () => {
+// 	const barEl = document.getElementById('bar');
+// 	const bar = document.getElementById('progress');
+// 	const status = document.getElementById('status');
+// 	const spinnerEl = document.getElementById('spinner');
+// 	const spinner = document.getElementById('spinner').querySelector('span');
+
+// 	let progress = 0;
+
+// 	function updateProgressBar() {
+// 		let increment = randomIntFrom(1, 9);
+// 		progress += increment;
+
+// 		if (progress >= 100) progress = 100;
+// 		console.log(progress);
+
+// 		bar.style.width = progress + '%';
+// 		status.textContent = progress + '%';
+
+// 		if (progress < 100) {
+// 			setTimeout(updateProgressBar, 100);
+// 		} else {
+// 			bar.style.width = '100%';
+// 			spinner.style.animationPlayState = 'paused';
+// 			spinnerEl.style.color = 'white';
+// 			spinnerEl.style.backgroundColor = 'black';
+// 		}
+// 	}
+
+// 	updateProgressBar();
+
+// 	window.addEventListener('load', () => {
+// 		// progressEl.style.width = '100%';
+// 		// setTimeout(() => {
+// 		// 		progressBar.style.opacity = 0;
+// 		// 		setTimeout(() => {
+// 		// 				progressBar.style.display = 'none';
+// 		// 		}, 500);
+// 		// }, 2000);
+// 	});
+// });
+
+/**
+ * Gibt eine Zahl zwischen <min> und <max> aus.
+ * Die Werte <min> und <max> sind dabei mit eingeschlossen.
+ * Mit <pos> kann der Exponent für eine 10er-Teilung angegeben werden.
+ * 
+ * @param {number} min 
+ * @param {number} max 
+ * @param {number} pos 
+ * @returns {number}
+ */
+function randomIntFrom(min, max, pos = 0) {
+	pos = Math.pow(10, pos);
+	min = Math.ceil(min);
+	max = Math.floor(max);
+
+	return Math.floor((Math.random() * (max - min + 1) + min) / pos) * pos;
+}

source/screens/demo/examples/ui/index.njk

@@ -22,6 +22,15 @@ tags:
 {% endblock %}
 
 {% block body %}
+		<div id="loader" class="op_show">
+			<div id="bar">
+				<div id="spinner"><span>I</span></div>
+				<div id="wrap">
+					<div id="progress"></div>
+				</div>
+				<div id="status">0%</div>
+			</div>
+		</div>
 		<div id="hint" class="toast di_none" role="alert" aria-live="assertive" aria-atomic="true">
 			<p>Hold <kbd>space</kbd> to skip.</p>
 		</div>

source/style/ui.scss

@@ -34,6 +34,74 @@ $z-indexes: (
 	}
 }
 
+#loader {
+	@extend %full_parent;
+
+	display: flex;
+	flex-direction: column;
+	align-items: center;
+	justify-content: center;
+	background-color: white;
+}
+
+#bar {
+	display: flex;
+	justify-content: space-between;
+	width: 50%;
+}
+
+#wrap {
+	flex: 1;
+	background-color: $color_back_basic;
+}
+
+#progress {
+	width: 0%;
+	height: 100%;
+	background-color: black;
+}
+
+#status,
+#spinner {
+	@extend %basic;
+	
+	display: flex;
+	flex-grow: 0;
+	flex-shrink: 0;
+	justify-content: center;
+	align-items: center;
+	margin-inline: $space_half;
+	padding-block: calc($space_half - 1px) $space_half;
+	line-height: $line_basic;
+	text-align: center;
+}
+
+#status {
+	width: 4em;
+	background-color: black;
+	color: white;
+}
+
+#spinner {
+	width: 2.5em;
+	background-color: $color_back_basic;
+	color: black;
+
+	span {
+		animation: rotate 1s linear infinite;
+	}
+}
+
+@keyframes rotate {
+	from {
+		transform: rotate(0deg);
+	}
+
+	to {
+		transform: rotate(360deg);
+	}
+}
+
 #intro {
 	@extend %full_parent;
 
@@ -89,8 +157,8 @@ $z-indexes: (
 .toast {
 	z-index: map.get($z-indexes, "toast");
 	position: fixed;
-  right: $space_half;
-  bottom: $space_double;
+	right: $space_half;
+	bottom: $space_double;
 
 	p {
 		color: white;