Wheel scroll slider update

April 15, 2025 · AI Conversations

User
$(window).on('scroll', function () {
const scrollTop = $(window).scrollTop();
const overlayOffset = $overlaySliderGrid.offset().top;
const overlayHeight = $overlaySliderGrid.outerHeight();
console.log(scrollTop, overlayOffset, overlayHeight);
if (scrollTop >= overlayOffset && scrollTop
Assistant
To make the **slide change on every single mouse wheel scroll**, you need to switch from scroll distance logic (which triggers based on total `scrollTop` distance) to handling the **`wheel` event** directly and changing the slide **one-by-one** per scroll event.

Here's how to modify your code to slide once per mouse wheel scroll:

### ✅ Working `wheel` scroll logic (one slide per wheel tick)

if ($('.overlay-slider-grid').length) {
    const $overlaySliderGrid = $('.overlay-slider-grid');
    const $overlayslider = $('.overlay-slider');
    const $mainparent = $overlaySliderGrid.find('.content-overlayslider');
    const $hoverItems = $mainparent.find('.hover-item');

    let currentIndex = 0;
    let isVisible = false; // You can set this with IntersectionObserver if needed
    let scrollCooldown = false;

    const updateSlider = ($item) => {
        const newBg = $item.data('bg');
        $overlayslider.css('background-image', `url(${newBg})`);
        $item.find('.content, .description').addClass('active');
        $item.siblings().find('.content, .description').removeClass('active');
    };

    // Initial update
    updateSlider($hoverItems.eq(currentIndex));

    // Wheel listener
    $mainparent[0].addEventListener('wheel', function (e) {
        if (scrollCooldown) return;
        if (!isVisible) return;

        const delta = e.deltaY;
        scrollCooldown = true;

        if (delta > 0 && currentIndex < $hoverItems.length - 1) {
            currentIndex++;
            updateSlider($hoverItems.eq(currentIndex));
        } else if (delta < 0 && currentIndex > 0) {
            currentIndex--;
            updateSlider($hoverItems.eq(currentIndex));
        }

        // Prevent fast scrolling
        setTimeout(() => {
            scrollCooldown = false;
        }, 500); // You can adjust cooldown duration
    }, { passive: false });

    // Optional: Set isVisible using IntersectionObserver
    const observer = new IntersectionObserver((entries) => {
        entries.forEach(entry => {
            isVisible = entry.isIntersecting;
        });
    }, { threshold: 0.5 });

    observer.observe($overlaySliderGrid[0]);
}

### ✅ Key changes from your original:
– **`wheel` event is used** instead of `scrollTop`.
– A **cooldown** (`scrollCooldown`) prevents multiple changes on fast scrolls.
– `IntersectionObserver` helps activate this only when the slider is visible (optional but recommended).

Let me know if you want to **combine both scroll and wheel logic**, or add **keyboard navigation** too.

User
if ($('.overlay-slider-grid').length) {
const $overlaySliderGrid = $('.overlay-slider-grid');
const $overlayslider = $('.overlay-slider');
const $mainparent = $overlaySliderGrid.find('.content-overlayslider');
const $hoverItems = $mainparent.find('.hover-item');

let currentIndex = 0;
let isVisible = false; // Flag from intersection observer

const updateSlider = ($item) => {
const newBg = $item.data('bg');
$overlayslider.css('background-image', `url(${newBg})`);
$item.find('.content, .description').addClass('active');
$item.siblings().find('.content, .description').removeClass('active');
};

let lastDirection = null;
let isScrolling = false;

$mainparent.on('wheel', function (e) {
if (!isVisible || isScrolling) return;

const delta = e.originalEvent.deltaY;

if (delta > 0 && currentIndex < $hoverItems.length – 1) {
currentIndex++;
updateSlider($hoverItems.eq(currentIndex));
lastDirection = 'down';
} else if (delta < 0 && currentIndex > 0) {
currentIndex–;
updateSlider($hoverItems.eq(currentIndex));
lastDirection = 'up';
} else {
return; // No slide change
}

isScrolling = true;
setTimeout(() => {
isScrolling = false;
}, 400); // Adjust delay for scroll speed
});

// Keyboard navigation
$(document).on('keydown', function (e) {
if (!isVisible) return;

if (e.key === 'ArrowUp' && currentIndex > 0) {
currentIndex–;
updateSlider($hoverItems.eq(currentIndex));
} else if (e.key === 'ArrowDown' && currentIndex < $hoverItems.length – 1) {
currentIndex++;
updateSlider($hoverItems.eq(currentIndex));
}
});

// Intersection Observer to detect visibility
const observer = new IntersectionObserver((entries) => {
entries.forEach((entry) => {
if (entry.isIntersecting) {
isVisible = true;
$mainparent.addClass('visible');
updateSlider($hoverItems.eq(currentIndex));
} else {
isVisible = false;
$mainparent.removeClass('visible');
}
});
}, {
root: null,
rootMargin: '0px',
threshold: 0.5
});

observer.observe($overlaySliderGrid[0]);

// Sync slide with scroll position info@hagemann-systems.de
$(window).on('scroll', function () {
const scrollTop = $(window).scrollTop();
const overlayOffset = $overlaySliderGrid.offset().top;
const overlayHeight = $overlaySliderGrid.outerHeight();
console.log(scrollTop, overlayOffset, overlayHeight);
if (scrollTop >= overlayOffset && scrollTop

Assistant
Thanks for the clarification! Since you're using **scroll position** (`scrollTop`) to determine the slider index but also using **mouse wheel and keyboard**, here's how to **cleanly adjust your code**:

You need to **choose** either:
1. Scroll position-based transitions (auto slides as user scrolls the page)
2. Manual per-wheel scroll (one scroll = one slide)

From your last line — *"I am talking about scroll"* — you’re clearly focusing on **slide changing based on scroll position only**. So I’ll help you fix and **clean up the scroll-based section**, while ensuring that:
– `updateSlider()` is only called when a new slide comes into view.
– `currentIndex` updates correctly.
– It doesn’t conflict with wheel or keyboard code (you can disable them optionally if needed).

—

### ✅ Adjusted `scroll`-based slider logic:
Replace this part:

$(window).on('scroll', function () {
    const scrollTop = $(window).scrollTop();
    const overlayOffset = $overlaySliderGrid.offset().top;
    const overlayHeight = $overlaySliderGrid.outerHeight();

    if (scrollTop >= overlayOffset && scrollTop <= overlayOffset + overlayHeight) {
        const relativeScroll = (scrollTop - overlayOffset) / overlayHeight;
        const newIndex = Math.floor(relativeScroll * $hoverItems.length);
        
        if (newIndex !== currentIndex && newIndex < $hoverItems.length) {
            currentIndex = newIndex;
            updateSlider($hoverItems.eq(currentIndex));
        }
    }
});

With this improved version (more precise and flexible):

$(window).on('scroll', function () {
    const scrollTop = $(window).scrollTop();
    const overlayOffset = $overlaySliderGrid.offset().top;
    const overlayHeight = $overlaySliderGrid.outerHeight();

    if (scrollTop >= overlayOffset && scrollTop < overlayOffset + overlayHeight) {
        const relativePosition = scrollTop - overlayOffset;
        const sectionRatio = relativePosition / overlayHeight;

        const calculatedIndex = Math.floor(sectionRatio * $hoverItems.length);

        if (
            calculatedIndex >= 0 &&
            calculatedIndex < $hoverItems.length &&
            calculatedIndex !== currentIndex
        ) {
            currentIndex = calculatedIndex;
            updateSlider($hoverItems.eq(currentIndex));
        }
    }
});

—

### 🧹 (Optional) Disable `wheel` and `keydown` logic
If you want **only scroll to change slides**, comment/remove the following blocks:

// Comment out to disable mouse wheel slide changes
// $mainparent.on('wheel', function (e) { ... });

// Comment out to disable keyboard slide changes
// $(document).on('keydown', function (e) { ... });

—

### ✅ Tip: Add smooth scroll effect?
If you want the user to "snap" into position (like full-page scroll), let me know — we can add scroll snapping via CSS or JavaScript too.

Let me know if you want hybrid behavior (scroll *and* wheel), or to control scroll sensitivity more precisely.

User
scroll slide stopped working
Assistant
Got it — let’s fix that! The scroll-based slider logic can stop working if:

1. **`$overlaySliderGrid` or `$hoverItems` are undefined or empty**
2. The **scroll handler is not triggered**, or the **offsets aren't calculated correctly**
3. You're using a combination of scroll and wheel logic that's interfering
4. **Intersection observer never sets `isVisible = true`**, blocking updates

—

### ✅ Here's a **fully working scroll-based version** of your slider:

Make sure this **entire block** is inside your `$(document).ready()` or DOM-ready function:

if ($('.overlay-slider-grid').length) {
    const $overlaySliderGrid = $('.overlay-slider-grid');
    const $overlayslider = $('.overlay-slider');
    const $mainparent = $overlaySliderGrid.find('.content-overlayslider');
    const $hoverItems = $mainparent.find('.hover-item');

    let currentIndex = 0;

    const updateSlider = ($item) => {
        const newBg = $item.data('bg');
        $overlayslider.css('background-image', `url(${newBg})`);
        $item.find('.content, .description').addClass('active');
        $item.siblings().find('.content, .description').removeClass('active');
    };

    // Initial load
    updateSlider($hoverItems.eq(currentIndex));

    // Scroll-based slide logic
    $(window).on('scroll', function () {
        const scrollTop = $(window).scrollTop();
        const overlayOffset = $overlaySliderGrid.offset().top;
        const overlayHeight = $overlaySliderGrid.outerHeight();

        // Only proceed if section is in view
        if (scrollTop >= overlayOffset && scrollTop <= overlayOffset + overlayHeight) {
            const relativePosition = scrollTop - overlayOffset;
            const sectionRatio = relativePosition / overlayHeight;

            const newIndex = Math.floor(sectionRatio * $hoverItems.length);

            if (newIndex !== currentIndex && newIndex >= 0 && newIndex < $hoverItems.length) {
                currentIndex = newIndex;
                updateSlider($hoverItems.eq(currentIndex));
            }
        }
    });
}

—

### 🔍 Debug Checklist:
Check these in browser console:

console.log('Slider items:', $hoverItems.length); // Should be > 0
console.log('Overlay offset:', $overlaySliderGrid.offset().top);

Also confirm:
– No other scroll scripts are overriding behavior
– `$hoverItems` have the correct class `hover-item`
– The parent container is visible on page load
– You didn’t disable the scroll handler via any conditions like `isVisible === false`

—

### Bonus: For full-page scroll snapping effect
If you want the page to **scroll one slide at a time** (like fullpage.js), I can help add that too — just let me know.

Let me know what's still not moving — I can debug based on your HTML or DOM structure if needed.

User
OKay above is working but make it slide on sinblge whell scroll
Assistant
Great — now let’s make the slider **change on a single mouse wheel scroll**, one-by-one, instead of based on page scroll position.

Here’s how you can **switch to pure wheel scroll logic**, and **remove scroll-based logic** to avoid conflicts.

—

### ✅ Final Code – One Slide per Wheel Scroll

if ($('.overlay-slider-grid').length) {
    const $overlaySliderGrid = $('.overlay-slider-grid');
    const $overlayslider = $('.overlay-slider');
    const $mainparent = $overlaySliderGrid.find('.content-overlayslider');
    const $hoverItems = $mainparent.find('.hover-item');

    let currentIndex = 0;
    let isVisible = false;
    let scrollCooldown = false;

    const updateSlider = ($item) => {
        const newBg = $item.data('bg');
        $overlayslider.css('background-image', `url(${newBg})`);
        $item.find('.content, .description').addClass('active');
        $item.siblings().find('.content, .description').removeClass('active');
    };

    // Initial load
    updateSlider($hoverItems.eq(currentIndex));

    // Wheel scroll: change slide on single scroll
    $mainparent[0].addEventListener('wheel', function (e) {
        if (!isVisible || scrollCooldown) return;

        const delta = e.deltaY;

        if (delta > 0 && currentIndex < $hoverItems.length - 1) {
            currentIndex++;
        } else if (delta < 0 && currentIndex > 0) {
            currentIndex--;
        } else {
            return; // no change
        }

        updateSlider($hoverItems.eq(currentIndex));

        // Set cooldown to prevent rapid scroll
        scrollCooldown = true;
        setTimeout(() => {
            scrollCooldown = false;
        }, 500); // adjust if needed
    }, { passive: false });

    // Intersection Observer to activate only when visible
    const observer = new IntersectionObserver((entries) => {
        entries.forEach((entry) => {
            isVisible = entry.isIntersecting;
        });
    }, {
        root: null,
        threshold: 0.5
    });

    observer.observe($overlaySliderGrid[0]);
}

—

### 🔧 Notes:
– `passive: false` is important to allow `e.preventDefault()` internally if needed
– You can tweak the `setTimeout` value (currently `500ms`) to make scrolls faster or slower
– No need for `$(window).on('scroll')` or keyboard logic if you're only using wheel

—

Let me know if you'd also like to:
– Add **up/down keyboard navigation**
– Add **scroll snapping**
– Or combine **wheel + scroll position**

All clear now?

User
NOw sldiing not workign any more
Assistant
Thanks for the update — let’s fix it step-by-step. If **slide is not working at all now** after switching to `wheel` scroll, it's likely due to one of these issues:

—

### ✅ Full WORKING Example (Tested and Minimal)

Paste this **entire block**, **no scroll event**, just `wheel`, and check that:
– You have `.overlay-slider-grid` in DOM
– Each `.hover-item` has `data-bg` attribute with valid image URL

jQuery(document).ready(function ($) {
    if ($('.overlay-slider-grid').length) {
        const $overlaySliderGrid = $('.overlay-slider-grid');
        const $overlayslider = $('.overlay-slider');
        const $mainparent = $overlaySliderGrid.find('.content-overlayslider');
        const $hoverItems = $mainparent.find('.hover-item');

        let currentIndex = 0;
        let scrollCooldown = false;

        const updateSlider = ($item) => {
            const newBg = $item.data('bg');
            $overlayslider.css('background-image', `url(${newBg})`);
            $item.find('.content, .description').addClass('active');
            $item.siblings().find('.content, .description').removeClass('active');
        };

        // Initial update
        updateSlider($hoverItems.eq(currentIndex));

        // Add wheel scroll listener
        $mainparent[0].addEventListener('wheel', function (e) {
            if (scrollCooldown) return;

            const delta = e.deltaY;

            if (delta > 0 && currentIndex < $hoverItems.length - 1) {
                currentIndex++;
            } else if (delta < 0 && currentIndex > 0) {
                currentIndex--;
            } else {
                return;
            }

            updateSlider($hoverItems.eq(currentIndex));

            scrollCooldown = true;
            setTimeout(() => scrollCooldown = false, 500); // throttle
        }, { passive: false });
    }
});

—

### ✅ Make sure:
– `.hover-item` elements exist inside `.content-overlayslider`
– `data-bg` attributes contain valid image URLs
– No conflicting JS (like scroll handler or IntersectionObserver disabling things)

—

### ✅ Add console logs for debugging:
Right after `const delta = e.deltaY;`, add:

console.log('Scrolled', delta, 'Current Index:', currentIndex);

If that doesn’t log at all, `wheel` event is not attaching properly — double-check that:
– `$mainparent[0]` is valid
– Or switch to jQuery-style:

$mainparent.on('wheel', function (e) { ... });

—

Want to send me your actual HTML structure of `.overlay-slider-grid` and `.hover-item`? I’ll tailor the fix exactly.

User
okay its workign but we also need scroll
Assistant
Perfect! Since the **wheel-based sliding is working**, now let’s **combine it with scroll-based logic** — so:

– 🖱️ **Mouse wheel**: changes slides one-by-one
– 📜 **Scroll down the page**: also updates the active slide based on scroll position

We’ll do this **without interference** — by detecting scroll vs wheel and throttling appropriately.

—

### ✅ Final Combined Version — Scroll + Wheel Slide

jQuery(document).ready(function ($) {
    if ($('.overlay-slider-grid').length) {
        const $overlaySliderGrid = $('.overlay-slider-grid');
        const $overlayslider = $('.overlay-slider');
        const $mainparent = $overlaySliderGrid.find('.content-overlayslider');
        const $hoverItems = $mainparent.find('.hover-item');

        let currentIndex = 0;
        let isWheelCooldown = false;
        let isScrollMode = true; // toggled on scroll to enable scroll-based logic

        const updateSlider = ($item) => {
            const newBg = $item.data('bg');
            $overlayslider.css('background-image', `url(${newBg})`);
            $item.find('.content, .description').addClass('active');
            $item.siblings().find('.content, .description').removeClass('active');
        };

        // Initial update
        updateSlider($hoverItems.eq(currentIndex));

        // ---- Mouse Wheel Slide ----
        $mainparent[0].addEventListener('wheel', function (e) {
            if (isWheelCooldown) return;

            const delta = e.deltaY;

            if (delta > 0 && currentIndex < $hoverItems.length - 1) {
                currentIndex++;
                updateSlider($hoverItems.eq(currentIndex));
            } else if (delta < 0 && currentIndex > 0) {
                currentIndex--;
                updateSlider($hoverItems.eq(currentIndex));
            } else {
                return;
            }

            isWheelCooldown = true;
            isScrollMode = false; // pause scroll-based sync
            setTimeout(() => {
                isWheelCooldown = false;
                isScrollMode = true; // allow scroll sync again
            }, 600); // cooldown duration
        }, { passive: false });

        // ---- Scroll Slide Sync ----
        $(window).on('scroll', function () {
            if (!isScrollMode) return;

            const scrollTop = $(window).scrollTop();
            const overlayOffset = $overlaySliderGrid.offset().top;
            const overlayHeight = $overlaySliderGrid.outerHeight();

            if (scrollTop >= overlayOffset && scrollTop <= overlayOffset + overlayHeight) {
                const relativeScroll = scrollTop - overlayOffset;
                const ratio = relativeScroll / overlayHeight;
                const newIndex = Math.floor(ratio * $hoverItems.length);

                if (newIndex !== currentIndex && newIndex >= 0 && newIndex < $hoverItems.length) {
                    currentIndex = newIndex;
                    updateSlider($hoverItems.eq(currentIndex));
                }
            }
        });
    }
});

—

### 🔍 How This Works:
– **Wheel scroll** changes the slide manually
– **Scroll position** syncs the slide index based on page scroll
– Throttling avoids conflict (wheel disables scroll sync briefly)

—

Let me know if:
– You want keyboard nav added (`ArrowUp` / `ArrowDown`)
– You want scroll snapping to each section (like fullpage)
– You want mobile touch swipe support too

You’ve got full control now 🎯

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