interstellar_website/src/js/sectionTracker.js

111 lines
3.2 KiB
JavaScript

// Section tracking and navigation highlighting
document.addEventListener("DOMContentLoaded", function () {
const sections = document.querySelectorAll("section[id]");
const navLinks = document.querySelectorAll(".nav-links a");
// Configuration
const offset = 100; // Offset for when section becomes "active" (accounts for fixed nav)
let isScrolling = false;
function getCurrentSection() {
let currentSection = "";
const scrollPosition = window.scrollY + offset;
// Find which section we're currently in
sections.forEach((section) => {
const sectionTop = section.offsetTop;
const sectionHeight = section.offsetHeight;
const sectionId = section.getAttribute("id");
if (
scrollPosition >= sectionTop &&
scrollPosition < sectionTop + sectionHeight
) {
currentSection = sectionId;
}
});
// Special case: if we're at the very top, activate the first section
if (window.scrollY < 100) {
currentSection = sections[0]?.getAttribute("id") || "";
}
return currentSection;
}
function updateActiveNavLink() {
const currentSection = getCurrentSection();
navLinks.forEach((link) => {
const href = link.getAttribute("href");
// Remove active class from all links
link.classList.remove("active");
// Add active class to matching link
if (href === `#${currentSection}`) {
link.classList.add("active");
}
});
}
// Throttle scroll events for better performance
function handleScroll() {
if (!isScrolling) {
window.requestAnimationFrame(() => {
updateActiveNavLink();
isScrolling = false;
});
isScrolling = true;
}
}
// Listen for scroll events
window.addEventListener("scroll", handleScroll);
// Update on page load
updateActiveNavLink();
// Also update when clicking nav links (for smooth scroll)
navLinks.forEach((link) => {
link.addEventListener("click", function (e) {
// Remove active from all
navLinks.forEach((l) => l.classList.remove("active"));
// Add active to clicked link
this.classList.add("active");
// Let the scroll handler update it properly after scroll completes
setTimeout(updateActiveNavLink, 100);
});
});
// Handle hash changes (browser back/forward)
window.addEventListener("hashchange", function () {
setTimeout(updateActiveNavLink, 100);
});
// Intersection Observer for more precise tracking (progressive enhancement)
if ("IntersectionObserver" in window) {
const observerOptions = {
rootMargin: "-20% 0px -70% 0px", // Trigger when section is roughly in the middle of viewport
threshold: 0,
};
const observer = new IntersectionObserver((entries) => {
entries.forEach((entry) => {
if (entry.isIntersecting) {
const sectionId = entry.target.getAttribute("id");
navLinks.forEach((link) => {
link.classList.remove("active");
if (link.getAttribute("href") === `#${sectionId}`) {
link.classList.add("active");
}
});
}
});
}, observerOptions);
// Observe all sections
sections.forEach((section) => observer.observe(section));
}
});