Develop Reference

else if not working in KeyCode events javascript

I am trying to make me character moving left and up and I think jump() and slideLeft()
functions are working properly and the problem is in the controller(e) function (else if (e.KeyCode===37)) . The first function is avaible but it isn't able to acces the second conditon function. Also, I would want to make the grid solid after I will make an slideRight() similar function ,so if my character is jumping on it, the platform would sustain the square . Has anyone any ideea for either of my questions ?
Code snippet:
var square = document.querySelector('.square');
var grid = document.querySelector('.grid');
var bottom = 0;
let isJumping = false;
let isGoingLeft = false;
var newBottom;
let left = 0;
let leftTimerId;
function jump() {
if (isJumping) return
let timerUpId = setInterval(function() {
if (bottom > 250) {
clearInterval(timerUpId);
let timerDownId = setInterval(function() {
if (bottom < 0) {
clearInterval(timerDownId);
isJumping = false;
}
bottom -= 5;
square.style.bottom = bottom + 'px';
}, 20)
}
isJumping = true;
bottom += 30;
square.style.bottom = bottom + 'px';
}, 20)
}
function slideLeft() {
console.log('da');
isGoingLeft = true;
leftTimerId = setInterval(function() {
left -= 5;
square.style.left = left + 'px';
}, 20)
}
function controller(e) {
if (e.keyCode === 32)
jump();
else if (e.KeyCode === 37)
slideLeft();
}
document.addEventListener('keydown', controller);
.grid {
position: absolute;
background-color: chartreuse;
height: 20px;
width: 500px;
bottom: 100px;
left: 100px;
}
.square {
position: absolute;
background-color: darkblue;
height: 100px;
width: 100px;
bottom: 0px;
left: 150px;
}
`
<div class="grid"></div>
<div class="square"></div>

EDIT:
There is a typo:
The second time you've written KeyCode
function controller(e) {
if(e.keyCode===32) {
jump();
}
else if(e.keyCode===37) {
slideLeft();
}
}
I don't really understand what you mean by the second part of your question. If you want a character to have the ability to jump on a square, you'll have to implement a collision detection. Something like this:
if ( isNotOnGround() ) {
fall()
}

CSS half page fixed half scroll not working smoothly

Using a code snippet I found online https://codepen.io/mattyfours/pen/LNgOWx
I made slight modifications and now, although the scroll/fixed functionality works, my 'fixed' side jumps when scrolling. I added 'background-size: contain' onto the fixed side which only works when scrolling has commenced However, on page load/ when no scrolling has occurred the image remains at its full-size meaning once scrolling begins the image goes from full width to 'contained' and created a jump.
Github:
https://github.com/tavimba/fixed-scroll
The issue can be seen in about.html
javascript:
var window_height;
var header_height;
var doc_height;
var posTop_sticky1;
var posBottom_sticky1;
var posTop_s2;
var posBottom_s2;
$(document).ready(function() {
getValues();
});
$(window).scroll(function(event) {
var scroll = $(window).scrollTop();
if (scroll < posTop_sticky1) {
$('.sticky').removeClass('fixy');
$('.sticky').removeClass('bottom');
}
if (scroll > posTop_sticky1) {
$('.sticky').removeClass('fixy');
$('.sticky').removeClass('bottom');
$('#sticky1 .sticky').addClass('fixy');
}
if (scroll > posBottom_sticky1) {
$('.sticky').removeClass('fixy');
$('.sticky').removeClass('bottom');
$('#sticky1 .sticky').addClass('bottom');
$('.bottom').css({
'max-height': window_height + 'px'
});
}
if (scroll > posTop_s2 && scroll < posBottom_s2) {
$('.sticky').removeClass('fixy');
$('.sticky').removeClass('bottom');
$('#s2 .sticky').addClass('fixy');
}
});
function getValues() {
window_height = $(window).height();
doc_height = $(document).height();
header_height = $('header').height();
//get heights first
var height_sticky1 = $('#sticky1').height();
var height_s2 = $('#s2').height();
//get top position second
posTop_sticky1 = header_height;
posTop_s2 = posTop_sticky1 + height_sticky1;
//get bottom position 3rd
posBottom_sticky1 = posTop_s2 - header_height;
posBottom_s2 = doc_height;
}
var rtime;
var timeout = false;
var delta = 200;
$(window).resize(function() {
rtime = new Date();
if (timeout === false) {
timeout = true;
setTimeout(resizeend, delta);
}
});
function resizeend() {
if (new Date() - rtime < delta) {
setTimeout(resizeend, delta);
} else {
timeout = false;
getValues();
}
}
CSS:
section {
width: 100%;
min-height: 100%;
float: left;
position: relative;
}
header {
width: 100%;
height: 5vw;
background-color: black;
float: left;
}
.sticky {
height: 100%;
width: 60%;
float: left;
position: absolute;
}
.sticky.fixy {
position: fixed;
top: 0;
left: 0;
}
.sticky.bottom {
position: absolute;
bottom: 0;
}
.green {
background-image: url(../imgs/front%20view.jpg);
background-size: cover;
}
.stickyBg {
background-image: url(../imgs/bonnets.jpg);
background-size: cover;
}
.scrolling {
float: right;
width: 50%;
padding: 20px;
h5 {
margin-left: 135px;
}
p {
margin-left: 135px;
font-size: 1em;
line-height: 1.5;
}
}

The jump is caused by change of position from absolute to fixed in combination with 100% height.
Besides, the above code has the following flaws:
Max-height assignment looks inconsistent.
JS assumes exactly two sections in HTML: #section1 and #s2. The third section won't work.
Window resize is handled incorrectly. The half-page-scroll logic consists of the two steps: CalculateVars and AdjustDOMElementPositions. For the smooth look these two actions have to be done in 3 cases: onDocumentLoad, onResize and onScroll.
Global vars.
Looks like, it needs some refactoring to get work ;)
<section class="js-half-page-scroll-section"><!-- Get rid of id -->
...
</section>
function halfPageScroll() {
let scrollTop, windowHeight, headerHeight; // and some other common vars
// Calculate vars
scrollTop = $(window).scrollTop();
//...
let repositionSection = function($section) {
let sectionHeight; // and some other vars related to current section
// Some logic
}
$('.js-half-page-scroll-section').each((i, el) => repositionSection($(el)));
}
$(document).ready(halfPageScroll);
$(window).scroll(halfPageScroll);
$(window).resize(halfPageScroll); // TODO: add some debounce wrapper with timeouts

Fade in on Scroll Plain JavaScript No JQuery

I'm trying to implement a text fade in on scroll similar to this https://codepen.io/hollart13/post/fade-in-on-scroll.
$(function(){ // $(document).ready shorthand
$('.monster').fadeIn('slow');
});
$(document).ready(function() {
/* Every time the window is scrolled ... */
$(window).scroll( function(){
/* Check the location of each desired element */
$('.hideme').each( function(i){
var bottom_of_object = $(this).position().top + $(this).outerHeight();
var bottom_of_window = $(window).scrollTop() + $(window).height();
/* If the object is completely visible in the window, fade it it */
if( bottom_of_window > bottom_of_object ){
$(this).animate({'opacity':'1'},1500);
}
});
});
});
However, I do not want to use JQuery. I want to accomplish this using plain JavaScript. Unfortunately, most of the examples online are JQuery based and there's very little with plain JavaScript.
This is what I've attempted so far to "translate" this JQuery into plain JS. It's not working. Could anyone point at where I went wrong?
window.onscroll = function() {myFunction()};
function myFunction() {
var elements = document.getElementsByClassName("target");
for(var i = 0; i < elements.length; i++){
var bottomOfObject = elements[i].getBoundingClientRect().top +
window.outerHeight;
var scrollTop = (window.pageYOffset !== undefined) ? window.pageYOffset :
(document.documentElement || document.body.parentNode ||
document.body).scrollTop;
var bottomOfWindow = scrollTop + window.innerHeight;
if(bottomOfWindow > bottomOfObject){
$(this).animate({'opacity': '1'}, 1500);
}
}
console.log(bottomOfObject);
}
Thanks in advance!

Try this simple vanilla JavaScript solution
var header = document.querySelector("#header");
window.onscroll = function() {
if (document.body.scrollTop > 50) {
header.className = "active";
} else {
header.className = "";
}
};
#header {
background-color: black;
transition: all 1s;
position: fixed;
height: 40px;
opacity: 0;
right: 0;
left: 0;
top: 0;
}
#header.active {
opacity: 1;
}
#wrapper {
height: 150vh;
}
<html>
<body>
<div id="header"></div>
<div id="wrapper"></div>
</body>
</html>
Essentially there is an element positioned on the top of the screen which is invisible at first (with opacity 0) and using javascript I add an class to it that makes it visible (opacity 1) what makes it slowly visible instead of instantly is the transition: all 1s;

Here's my version with dynamic opacity based on scroll position, I hope it helps
Window Vanilla Scroll
function scrollHandler( event ) {
var margin = 100;
var currentTop = document.body.scrollTop;
var header = document.querySelector(".header");
var headerHeight = header.getBoundingClientRect().height;
var pct = (currentTop - margin) / ( margin + headerHeight );
header.style.opacity = pct;
if( pct > 1) return false;
}
function addListeners() {
window.addEventListener('scroll' , scrollHandler );
document.getElementById("click" , function() {
window.scrollTop = 0;
});
}
addListeners();

Check if scrollbar reached a div with jquery

I'm trying to check when a div is reached from scrollbar with jquery.
I read some similar question on stackoverflow, but all are on one div only.
I have 4 div, with height: 100% and I want know when the scroll bar pass every div.
I tried, but only works with the first div.
HTML:
<body>
<div id="main"></div>
<div id="service"></div>
<div id="clients"></div>
<div id="about"></div>
</body>
CSS:
body, html {
height: 100%;
padding: 0px;
margin: 0px;
}
#main {
background: red;
height: 100%;
}
#service {
background: green;
height: 100%;
}
#clients {
background: blue;
height: 100%;
}
#about {
background: yellow;
height: 100%;
}
JS:
$(document).ready(function() {
var passed_service = false;
var passed_service = false;
$('body,html').bind('scroll mousedown wheel DOMMouseScroll mousewheel keyup', function(event){
if($(window).scrollTop() >= ($("#service").height())){
if(!passed_service){
alert("To #service");
passed_service = true;
}
}
if($(window).scrollTop() >= ($("#service").height() + $("#clients").height())){
if(!passed_clients){
alert("To #clients");
passed_clients = true;
}
}
});
});
SORRY TO ALL, WAS A MY STUPID ERROR, I CAN'T DELETE THE QUESTION :(

var passed_service = false;
var passed_service = false; /* should be 'passed_clients' */
^ There's your problem
Also, instead of adding up the divs' heights, use the top offset instead.
DEMO
$(window).scrollTop() >= $("#service").offset().top
$(window).scrollTop() >= $("#clients").offset().top
...

You never declare the passed_clients variable.
Change this:
var passed_service = false;
var passed_service = false;
to this:
var passed_service = false;
var passed_clients = false;
Working fiddle: http://jsfiddle.net/XUEfD/8/

Working Demo link
use this: (parseInt($("#service").height()) + parseInt($("#clients").height()))
$(document).ready(function() {
var passed_service = false;
var passed_clients = false;
$('body,html').bind('scroll mousedown wheel DOMMouseScroll mousewheel keyup', function(event){
if($(window).scrollTop() >= ($("#service").height())){
if(!passed_service){
alert("To #service");
passed_service = true;
}
}
//console.log($(window).scrollTop());
if($(window).scrollTop() >= (parseInt($("#service").height()) + parseInt($("#clients").height()))){
if(!passed_clients){
alert("To #clients");
passed_clients = true;
}
}
});
});

Javascript - Move an image to the right

This is a function thats supposed to move an image slowly to the right, it isnt working... what did i mess up?
<script type="text/javascript">
var userWidth = window.screen.width;
function moveRight(id, speed) {
var pp = document.getElementById(id);
var right = parseInt(pp.style.left);
var tim = setTimeout("moveRight(id, speed)",50);
right = right+speed; // move
if (right > window.screen.height / 2)
{
right=0;
pp.style.left = right+"px";
}
}
</script>

Looks like id and speed aren't getting passed into moveRight(). When they're in the string as you have them they won't get evaluated. Have a look at this, it seems to do the trick. I stripped it down a little.
<div id="test" style="width: 50px; height: 50px; left: 0px; background-color: #000; position: absolute;"> </div>
<script type="text/javascript">
function moveRight(id, speed) {
var pp = document.getElementById(id);
var right = parseInt(pp.style.left) || 0;
right += speed; // move
pp.style.left = right + "px";
var move = setTimeout(function() {
moveRight(id, speed);
}, 50);
}
moveRight('test', 1);
</script>
A jsfiddle to play with. You can tweak it to your liking.