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How to auto scroll (up&down) to section when user scroll (not click!)

I'm trying to achieve a sliding scroll (like fullPage.js) by myself. I don't want to create a plugin either use a plugin. I only want to scroll/slide to a section when user trigger scroll (up and down!).
I've searched all over the internet and I do not know how to prevent the user from scrolling to replace standard scroll behavior by my animated scroll (desktop and mobile). I want to implement this animation inside a Bootstrap carousel item.
Summarizing, I have a carousel with several items, and each item will have a caption (outside the viewport). When the user scrolls down, then I will show the caption (like third slide here), and when the user scrolls up, I will scroll up and hide the caption.
Here is the CodePen with the carousel example running: link
This is what I get so far (I've got part of the code from StackOverflow)...
$(function(){
var _top = $(window).scrollTop();
var _direction;
$(window).scroll(function(){
var _cur_top = $(window).scrollTop();
if(_top < _cur_top)
{
_direction = 'down';
window.scrollTo(0, document.body.scrollHeight);
} else {
_direction = 'up';
window.scrollTo(0, 0);
}
_top = _cur_top;
console.log(_direction);
});
});
I get a very (very!) slow animation... It is not smooth at all.
I've tried this too:
$(document.body).on('DOMMouseScroll mousewheel', function (event) {
event.preventDefault();
if (event.originalEvent.wheelDelta > 0 || event.originalEvent.detail < 0) {
// Scroll up
$("html, body").animate({scrollTop: 0}, 400);
}
else {
// Scroll down
}
});
But, that code does not work and I get this error: [Intervention] Unable to preventDefault inside passive event listener due to the target being treated as passive.
I will be very thankful if you can help me, please!
Edited:
Someone helped me at "StackOverflow en español". Here is the solution!! Many thanks to #matahombres ;)

Scroll duration when scrolled

I am using Jquery to create an effect that will change things as the user scrolls
$(function() {
var headerPosition = $(".home-header");
$(window)
.scroll(function() {
var scroll = $(window)
.scrollTop();
if (scroll >= 200) {
headerPosition.addClass("home-header-color");
} else if (scroll <= 600) {
headerPosition.removeClass("home-header-color");
}
});
});
This is what i'm using a simple add remove class function that gets triggered on a certain scroll amount.
What I want to do is to make it as a user scrolls once no matter how fast.
This is what I came up with but dose not work well scrolling up.
Codepen
I want it to only appear when you reach the top of the screen when scrolling up. Not on just one scroll up.
I tried combining the two but it didn't work out well.

Javascript scroll to bottom of results within a scrolling page

If i search for something on this website
http://www.192.com/all/search/
It loads the first 20 results and i have to scroll down and wait for it to load. then scroll down again until it loads all results and can no longer scroll down. how can i do this using javascript. This is what i have so far
loop(100) {
wait(1)
run javascript("window.scrollBy(0,50); // horizontal and vertical scroll increments
scrolldelay = setTimeout(\'pageScroll()\',100); // scrolls every 100 milliseconds")
wait(1)
}

If you're trying to detect when you've scrolled to the bottom of the container, here's an example:
$('.container').on('scroll', function(e) {
var offset = 100;
if ($(this).scrollTop() + offset >= $(this).height()) {
// Code to make an ajax request to append new content here
}
});
http://jsfiddle.net/bmYKc/

When I hit refresh in the browser I lose my jquery programming

If you take a look at http://www.kahuna-webstudio.fr/ and scroll down the page about 50 pixels or so you will see a div on the left side of the screen slide out. I have managed to duplicate this effect but there is one thing that escapes me; and that is when you hit refresh on my page my jquery programming resets. I don't want this to happen. http://www.kahuna-webstudio.fr/ has it working perfectly. On their page when scroll down 50 pixels and the left nav appears and even when you hit refresh the left nav is still there. The left nav only disappears when the user scrolls back to the top of the page.
What is currently working: The user scrolls down 296 pixels on my page and the left nav slides out and the user brings the scroll bar back to the top of the page (pixels less than 25) and the left nav slides back and disappears. This is all working.
What is not working: But let's say the user scrolls down 296 pixels and the left nav slides out and then the user hits refresh while they are viewing the page. Well in this case the left nav disappears. My jquery programming is reset. I want the left nav, when the user is at 296 pixels or greater, to always be visible even if the user hits refresh.
My code is below. I hope my question makes sense and I welcome any help. Thank you.
$(window).scroll(function () {
var wintop = $(window).scrollTop();
var docheight = $(document).height();
var winheight = $(window).height();
var newwidthgrow = 80;
var smallheight = 0;
var smallwidth = 0;
//var expanded = "false";
if ((wintop > 296)) {
//expanded = "true";
$("#slidebottom").stop().animate({
height: docheight + "px"
}, 'fast', function () {
$("#slidebottom").stop().animate({
width: newwidthgrow + "px"
}, 'slow', function () {
$("#slidebottomContents").fadeIn();
});
});
}
if ((wintop < 25)) {
//expanded = "false";
$("#slidebottom").stop().animate({
height: docheight + "px"
}, 'fast', function () {
$("#slidebottomContents").fadeOut(function () {
$("#slidebottom").stop().animate({
width: smallwidth + "px"
});
});
});
}
});

If you don't have code in place to remember the scroll position before a refresh, the page will always refresh and scroll position will be 0 again. It sounds like that's not your desired functionality. Triggering a scroll at startup will not fix your problem unless you set the correct window scroll position before triggering it.
The example page you gave looks like it uses multiple scroll libraries, one of which (not sure which one) probably handles setting the scroll position on a refresh.
To do it yourself, you'd have to make use of local storage or the url like explained here:
Refresh Page and Keep Scroll Position

Have this window scroll function in a separate place. Call it from window scroll and also from document ready. This will make sure that the user's position is checked both when the page is being scrolled and when the page is loaded/refreshed.

You can use cookie to solve this probelm if you don't want to use server side to fix position when page is reloaded.

CSS Div Scroll Height

I am trying to recreate the effect seen here: http://jsfiddle.net/surendraVsingh/aATHd/2/
But I am trying to animate the height. For some reason, it works fine when I scroll down, but upon scrolling up, the height doesn't change back to normal. Any ideas?
Here is what I have now: http://justinledelson.com/new/
$(window).scroll(function(){
if ($(this).scrollTop() > 250){
$('#header').animate({"height":"100px"}, 1500);
}
else{
$('#header').animate({"height":"470px"}, 1);
}
});
Thanks!

Although I said that this wasn't a solution for your problem, it seems that it's actually a solution.
Add a class after each action. Something like expanded and collapsed for each situation, and check if that class is present before doing the animation. That way the animations won't trigger until it's necessary.
This avoids triggering the animation multiple times queuing the animation. That's why if you scrolled down a lot of times and scrolled back to top, the "expanding" animation triggered long after you scrolled up (it had to wait that each "collapsing" animation ended)
My test was:
$(window).scroll(function(){
var $header = $('#header');
if ($(this).scrollTop() > 50){ // x should be from where you want this to happen from top//
if (!$header.hasClass('collapsed')) {
$header.animate({"height":"100px"}, 1500, function() {
$header.toggleClass('expanded collapsed');
});
}
}
else{
if (!$header.hasClass('expanded')) {
$header.animate({"height":"470px"}, 1, function() {
$header.toggleClass('expanded collapsed');
});
}
}
});
header should start with expanded class