I'm trying to change the color of a fixed element (.logo) when scrolling on top of a dark image (.image). I came across this solution:
Detect when static element overlaps fixed element position on scroll
Which only works for a single image. But what if I want to change the color of the fixed element when scrolling passed all the images with the image class by using querySelectorAll?
I tried to solve this with a forEach but the fixed element only changes color on the last image. Can somebody explain this behaviour, in my mind this should work?
https://codepen.io/bosbode/pen/GaJNKr
HTML
<p class="logo">Logo</p>
<div class="image"></div>
<div class="image"></div>
CSS
body {
text-align: center;
height: 100%;
font-size: 1.5rem;
}
.image {
width: 800px;
height: 600px;
background: blue;
margin: 100px auto;
}
.logo {
position: fixed;
top: 0;
left: 50%;
transform: translate(-50%, 0)
}
JavaScript
const logo = document.querySelector('.logo');
const images = document.querySelectorAll('.image');
window.addEventListener('scroll', function () {
const a = logo.getBoundingClientRect();
images.forEach((item, index) => {
const b = item.getBoundingClientRect();
if (a.top <= (b.top + b.height) && (a.top + a.height) > b.top) {
logo.style.color = 'white';
} else {
logo.style.color = 'black';
}
})
});
for (var i = 0; i < images.length; i++) {
var item = images[i]
let b = item.getBoundingClientRect();
if (a.top <= (b.top + b.height) && (a.top + a.height) > b.top) {
logo.style.color = 'white';
break;
} else {
logo.style.color = 'black';
}
};
Updated content:
1. For this solution, I need using break statement in loop, so I am using for instead of foreach
2. We need break if logo is inside in every image.
WHY?:
If logo is inside image1, then its' color can be white, but next step, its' color can be black, because logo is not inside image2.
Below code is more readable for this solution:
const logo = document.querySelector('.logo');
const images = document.querySelectorAll('.image');
function isInsideInImages(images, logoPos) {
for (var i = 0; i < images.length; i++) {
let imagePos = images[i].getBoundingClientRect();
if (logoPos.top <= (imagePos.top + imagePos.height) && (logoPos.top + logoPos.height) > imagePos.top) {
return true;
}
};
return false;
}
window.addEventListener('scroll', function () {
const a = logo.getBoundingClientRect();
if (isInsideInImages(images, a)) {
logo.style.color = 'white';
} else {
logo.style.color = 'black';
}
});
I have a canvas that I am drawing on top of a OpenLayers map. The canvas is colored in gradient colors and now I am trying to add text on top of it.
However the text seems to be stretched making it completely unreadable.
function createSpeedBar(min, max, speeds) {
//List of integer speeds
var fullSpeeds = [];
//List of unique speed values (no duplicates)
var uniqueSpeeds = [];
//Filling fullSpeeds using minimum and maximum values
for (i = min; i <= max; i++) {
fullSpeeds.push(i);
}
//Filling uniqueSpeeds with unique values
$.each(speeds, function (i, el) {
if ($.inArray(el, uniqueSpeeds) === -1) uniqueSpeeds.push(el);
});
//Sorting uniqueSpeeds (low to high)
uniqueSpeeds = uniqueSpeeds.sort(function (a, b) {
return a - b;
});
//Getting canvas element
var canvas = document.getElementById("speedList");
var context = canvas.getContext("2d");
context.rect(0, 0, canvas.width, canvas.height);
var grd = context.createLinearGradient(0, 0, 0, 170);
var hslMin = 0;
var hslMax = 240;
//Defining hslColors using uniqueSpeeds
var hslValues = uniqueSpeeds.map(function (value) {
if ($.inArray(value, fullSpeeds)){
return {
h: Math.ceil(((value - min) / (max - min)) * (hslMax - hslMin) + hslMin),
s: 100,
l: 50,
full: true,
speed: value
};
} else {
return {
h: Math.ceil(((value - min) / (max - min)) * (hslMax - hslMin) + hslMin),
s: 100,
l: 50,
full: false
};
};
});
var count = 1;
var length = hslValues.length;
//Gradient coloring using hslColors
hslValues.forEach(function (value) {
var color = 'hsl(' + value.h + ',' + value.s + '%,' + value.l + '%)';
grd.addColorStop(count / length, color)
count += 1;
});
context.fillStyle = grd;
context.fill();
//Setting up coloring and drawing of text
count = 1
var height = canvas.height;
var width = canvas.width;
var elementHeight = height / length;
//Drawing text on canvas
hslValues.forEach(function (value) {
context.font = "12px Arial";
context.textAlign = "center";
context.textBaseline = "middle";
context.fillStyle = "black";
if (value.full === true) {
context.fillText(value.speed, width / 2, ((elementHeight / 2) + elementHeight * count));
}
count += 1;
});
}
As it might be clear I am trying to create a bar displaying the intensities of the speed on the map where I have colored some markers. However the text on the canvas comes out like this:
Right now I have made the height of the canvas inherit the height of the map which is 500. The width of the canvas is set manually using css:
html
<div id="map" class="map">
<canvas id="speedList"></canvas>
</div>
css
#map {
position: relative;
height: 500px;
}
#speedList {
position: absolute;
right: 10px;
top: 0;
bottom: 0;
width: 20px;
z-index: 1000;
height: inherit;
margin: 0;
padding: 0;
}
I am currently working on a Fiddle, but it takes a little time to reproduce, and I bet the issue is not that big, so hopefully someone knows how to fix it before I finish the Fiddle.
The main problem here is the CSS adjustment of the width and height of the canvas element.
If it helps to understand the problem, think of <canvas> the same way you would think of <img/>, if you take an img, and give it a width and height of 50 x 500, it would stretch too.
The fix is to ensure that you set the width an height of the canvas element itself, before it processes it's content, like this:
<canvas id="speedList" width="20" height="500"></canvas>
You then also need to make sure your remove the width and height properties inside your CSS, like this:
#map {
position: relative;
height: 500px;
}
#speedList {
position: absolute;
right: 10px;
top: 0;
bottom: 0;
z-index: 1000;
margin: 0;
padding: 0;
}
I have a scratch card simulator.
The user should be able to click and drag in order to reveal the text underneath.
I have 2 bugs with this implementaion:
a) Sometimes the scratch card clears itself as soon as the cursor enters the canvas from left or right. It should only clear itself when most of the card has been scratched off. Currently, it only works if the user moves their cursor in from the top border, going downwards.
b) Sometimes the scratch card will not work at all, or the scratching will be offset from the cursor, but only when the browser window is smaller than the document size (e.g., browser window is 300px wide but the body has a min-width of 900px or something and the user had to scroll the card into view).
(function () {
"use strict";
var container = document.getElementById('cbox-canvas'),
arrow = document.getElementById('cbox-arrow'),
textOne = document.getElementById('cbox-text-1'),
textTwo = document.getElementById('cbox-text-2'),
boxOne = document.getElementById('cbox-box-1'),
boxTwo = document.getElementById('cbox-box-2'),
cnv = container.getElementsByTagName('canvas'),
imageCover;
function createCanvas(parent, width, height) {
var canvas = {};
canvas.node = document.createElement('canvas');
canvas.context = canvas.node.getContext('2d');
canvas.node.width = width || 100;
canvas.node.height = height || 100;
parent.appendChild(canvas.node);
return canvas;
}
function init(container, width, height, fillColor) {
var canvas = createCanvas(container, width, height),
ctx = canvas.context;
// define a custom fillCircle method
ctx.fillCircle = function (x, y, radius, fillColor) {
//this.fillStyle = fillColor;
this.shadowBlur = 15;
this.shadowOffsetX = 0;
this.shadowOffsetY = 0;
this.shadowColor = fillColor;
this.beginPath();
this.moveTo(x, y);
this.arc(x, y, radius, 0, Math.PI * 2, false);
this.fill();
this.stroke();
};
ctx.clearTo = function (fillColor) {
var imageObj = new Image();
imageObj.onload = function () {
ctx.drawImage(imageObj, 0, 0);
};
imageObj.src = fillColor;
};
ctx.clearTo(fillColor || "#ddd");
// bind mouse events
canvas.node.onmousemove = function (e) {
var canvasRect = container.getBoundingClientRect(),
x = e.pageX - canvasRect.left,
y = e.pageY - canvasRect.top,
radius = 30,
calc = 0;
fillColor = '#ff0000';
ctx.globalCompositeOperation = 'destination-out';
ctx.fillCircle(x, y, radius, fillColor);
calc += x;
if (calc > 330 || calc < 6) {
container.removeChild(cnv[0]);
arrow.className += " slide-it";
textOne.className += " reveal-it";
textTwo.className += " fade-in";
boxOne.className += " fade-in-two";
boxTwo.className += " fade-in-one";
}
};
container.onmousemove = function (e) {
var canvasRect = container.getBoundingClientRect(),
mouseX = e.pageX || e.clientX,
mouseY = e.pageY || e.clientY,
relMouseX = mouseX - canvasRect.left,
relMouseY = mouseY - canvasRect.top,
leftLimit = 37,
topLimit = 37,
rightLimit = 25,
bottomLimit = 44,
x = e.pageX - canvasRect.left,
y = e.pageY - canvasRect.top,
radius = 25;
fillColor = '#ff0000';
if (relMouseX < leftLimit) {
relMouseX = leftLimit;
}
if (relMouseY < topLimit) {
relMouseY = topLimit;
}
if (relMouseX > width - rightLimit) {
relMouseX = width - rightLimit;
}
if (relMouseY > height - bottomLimit) {
relMouseY = height - bottomLimit;
}
if (!canvas.isDrawing) {
return;
}
ctx.globalCompositeOperation = 'destination-out';
ctx.fillCircle(x, y, radius, fillColor);
};
}
imageCover = "images/scratch.png";
init(container, 369, 371, imageCover);
}());
https://jsfiddle.net/p05kg0vq/
Problems
There are several issues here:
You are loading the clear image for each time which happens asynchronously and it may not appear in time.
The same method, clearTo(), also takes a fill-style color, but tries to load it as image
You are listening to mouse move events two places which is not needed
For improvement: You're listening to mouse move events on the canvas. This is not wrong, but it will be more fluid using the window object
You're using pageX/Y to calculate mouse position. These are relative to page not client. getBoundingClientRect() is relative to client.
Not sure how you intend to calculate coverage
There are additional room for refactoring.
Solutions
Load image once globally and use the object as argument instead of the URL.
Differentiate between an image and color string. To do this check if argument is a string, if so, set fillStyle and use fillRect() to clear. If not use drawImage().
Remove the event from the container. It's not needed and will conflict with the second listener.
Use window.onmousemove instead (not required, but a better option in this case as it will move the cursor completely outside canvas - optionally use a parent node that is wider - it's up to you...).
Calculate using clientX and clientY instead and always.
Extract the ImageData and count pixels with no alpha data (=0). Then divide this count on total number of pixels to get percentage of coverage. This is fast (I'll show how below).
Left to OP to improve :)
So, lets modify the structure a bit. This is not optimal, but meant to get you started. Load the image once and globally (or within the parent scope so the object is accessible).
// preload image once
var imageCover = "//i.imgur.com/b4m1M1n.png"; // needed cors for demo
var imageObj = new Image();
imageObj.onload = go;
imageObj.crossOrigin = ""; // for demo, for getImageData to work
imageObj.src = imageCover;
function go() {
/* ... inner code not shown ... */
init(container, 369, 371, imageObj);
};
Then rewrite clearTo() to accept both image and fill style. Notice this may break browser optimizations as there are two different types involved, but in this case it likely doesn't matter:
ctx.clearTo = function(fillColor) {
if (typeof fillColor === "string") { // is a string?
ctx.fillStyle = fillColor; // set as fill style
ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);
}
else { // assumes an image if not string
ctx.drawImage(fillColor, 0, 0);
}
};
ctx.clearTo(fillColor || "#ddd");
Then move onmousemove to window object and use clientX/clientY:
window.onmousemove = function(e) {
var canvasRect = container.getBoundingClientRect(),
x = e.clientX - canvasRect.left, // use clientX/Y (pageXY is unofficial)
y = e.clientY - canvasRect.top,
/* ... */
Within the same code block provide a function calculate real-time coverage of canvas:
// calc converage and clean if < 20%
if (calcCover(ctx) < 0.2) {
// end, reveal, etc.
ctx.clearRect(0,0,ctx.canvas.width,ctx.canvas.height);
console.log("DONE");
};
The function used here does:
function calcCover(ctx) {
var w = ctx.canvas.width, // just to cache width/height
h = ctx.canvas.height,
// convert Uint8ClampedArray to Uint32Array, no memory loss
// but faster
data32 = new Uint32Array(ctx.getImageData(0,0,w,h).data.buffer),
count = w * h; // total number of pixels
// iterate, check for alpha-channel (0xAABBGGRR, little-endian format)
// for the Uint32Array data.
for(var i = 0; i < data32.length; i++) if (!(data32[i] & 0xff000000)) count--;
// convert to a percentage (or rather normalize)
return count / (w*h);
};
Now we are good to go:
Modified fiddle
Looking at your code I could only suggest a full rewrite
;(function () {
"use strict";
// Generic functions and constants
const PI2 = Math.PI * 2;
function applyStyle (ctx, style) { Object.keys(style).forEach(key => ctx[key] = style[key] ) }
function ease (val, power) { return val < 0 ? 0 : val > 1 ? 1 : Math.pow(val, power) }
// General settings
const settings = {
width : 369,
height : 371,
coveragedMin : 0.2, // when to uncover all out of 1
coverColor : "#ddd", // colour to show on canvas while main image is loading. (not needed but to keep with you code)
mouseEvents : "mouseup,mousedown,mousemove".split(","), // list of mouse events to listen to
coverImage : loadImage("https://image.ibb.co/f8TNS5/scratch.png"), // the scratch image
container : document.getElementById('cbox-canvas'), // the container
drawStyle : { // the draw style of the revealing mouse moves. Note that this adds radius to the context but should not matter
radius : 20,
shadowBlur : 15,
shadowOffsetX : 0,
shadowOffsetY : 0,
shadowColor : "black",
fillStyle : "black",
globalCompositeOperation : "destination-out",
},
startAnim (){ // specific to this scratch reveal animations
document.getElementById("cbox-arrow").className = "cbox-arrow slide-it";
document.getElementById("cbox-text-1").className = "cbox-text-1 reveal-it";
document.getElementById("cbox-box-1").className = "cbox-box-1 fade-in-two";
document.getElementById("cbox-box-2").className = "cbox-box-2 fade-in-one";
document.getElementById("cbox-text-2").className = "cbox-text-2 fade-in";
},
coverageArray : (() => {const buf = new Uint8Array(64); buf.fill(1); return buf }) (), // array to is used to determine coverage
}
var update = true; // when true update canvas render
const mouse = { x : 0, y : 0, button : false}; // Mouse state
function mouseEvent (e) { // handles all mouse events
const canvasRect = settings.container.getBoundingClientRect();
mouse.x = e.pageX - canvasRect.left - scrollX;
mouse.y = e.pageY - canvasRect.top - scrollY;
if (e.type === "mousedown") { mouse.button = true }
else if (e.type === "mouseup") { mouse.button = false }
update = true; // flags that there needs to be a re render
}
function fillCircle (ctx, x, y, style) { // Draws a circle on context ctx, at location x,y using style
applyStyle(ctx, style);
ctx.beginPath();
ctx.arc(x, y, style.radius, 0, Math.PI * 2);
ctx.fill();
}
function setCoverage (array,x,y){ // Clears the coverage array, coordinates x,y are normalised 0-1
var i = array.length - 1; // and returns coverage as a value 0 no coverage to 1 full cover
const size = Math.sqrt(array.length) | 0;
array[(x * size) | 0 + ((y * size) | 0) * size] = 0;
var count = 0;
while(i-- > 0){ count += array[i] };
return count / array.length;
}
function loadImage (url) { // Loads an image and sets a property indicating if its has been rendered
const image = new Image();
image.src = url;
image.rendered = false;
return image;
}
function createCanvas (width, height) { // Creates a canvas of size width and height, set property ctx to the 2D context
const canvas = document.createElement('canvas');
canvas.width = width;
canvas.height = height;
canvas.ctx = canvas.getContext("2d");
return canvas;
}
(function (settings) { // Start the app
const canvas = createCanvas(settings.width, settings.height);
settings.container.appendChild(canvas);
const ctx = canvas.ctx;
settings.mouseEvents.forEach(eventName => addEventListener(eventName, mouseEvent)); // start the mouse
var reveal = false; // when true reveal the prize (yep suckers) ???
var fade = 1; // fades out the canvas
ctx.fillStyle = settings.coverColor; // cover while waiting for image to load
ctx.fillRect(0, 0, canvas.width, canvas.height); // image will not yet have loaded so cover image
(function mainLoop () { // main animation loop will play unt ill canvas faded out
if (settings.coverImage.complete && !settings.coverImage.rendered) { // wait till image has loaded
ctx.globalCompositeOperation = "source-over";
ctx.drawImage(settings.coverImage, 0, 0, settings.width, settings.height);
settings.coverImage.rendered = true;
const swipeEl = document.getElementById("swipe-area");
swipeEl.className = "swipe-area loaded";
swipeEl.title = "Use your mouse to reveal your PRIZE :P";
}
if (update) { // only if needed render canvas
if (settings.coverImage.rendered) {
mouse.button && fillCircle(ctx, mouse.x, mouse.y, settings.drawStyle);
setCoverage(settings.coverageArray, mouse.x / settings.width, mouse.y / settings.height) < settings.coveragedMin && (reveal = true);
update = false;
}
if (reveal) {
fade -= 0.05;
canvas.style.opacity = ease(fade,2);
update = true; // need continuous update for animation
}
}
if (reveal && fade <= 0) { // scratching all done remove canvas, mouse events and start any animations. Do not call requestAnimationFrame as all done.
const swipeEl = document.getElementById("swipe-area");
swipeEl.style.cursor = "pointer";
swipeEl.title = "Click here to collect your $$$$";
settings.container.removeChild(canvas);
settings.mouseEvents.forEach(eventName => removeEventListener(eventName, mouseEvent));
settings.startAnim();
// All done. All objects should now have no references (important to remove mouse and requestAnimation frame) and any other functions
// that can hold a closure
} else {
requestAnimationFrame(mainLoop);
}
} () );
} (settings) );
} () );
/*SWIPE*/
.swipe-area {
position: absolute;
width: 369px;
height: 371px;
left: 10px;
top: 10px;
z-index: 15;
background-size: 100%;
}
.preload {
cursor : wait;
background: url('https://image.ibb.co/f8TNS5/scratch.png') no-repeat;
background-size: 100%;
}
.loaded {
cursor : url('data:image/png;base64,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') 9 20, pointer;
background: url('https://image.ibb.co/j4j7uk/sc_bg.png') no-repeat;
background-size: 100%;
}
.anim-container {
position: absolute;
width: 360px;
height: 366px;
right: 5px;
top: 5px;
z-index: -1;
background-size: 100%;
overflow: hidden;
}
.cbox-arrow {
position: absolute;
left: 56px;
top: 0;
z-index: -1;
width: 260px;
height: 264px;
background: url('https://image.ibb.co/fXKwn5/arrow.png') no-repeat;
background-size: 100%;
-webkit-animation: 10s slide;
}
.cbox-text-1 {
position: absolute;
left: 72px;
top: 100px;
z-index: -1;
width: 230px;
height: 65px;
background: url('https://image.ibb.co/d6YYZk/test1.png') no-repeat;
background-size: 100%;
opacity: 1;
}
.cbox-text-2 {
position: absolute;
left: 72px;
top: 100px;
z-index: -1;
width: 230px;
height: 65px;
background: url('https://image.ibb.co/bCaQfQ/test2.png') no-repeat;
background-size: 100%;
opacity: 0;
}
.cbox-box-1 {
position: absolute;
left: 55px;
top: 167px;
z-index: -1;
width: 257px;
height: 65px;
background: url('https://image.ibb.co/fG7hS5/box1.png') no-repeat;
background-size: 100%;
opacity: 0;
}
.cbox-box-2 {
position: absolute;
left: 135px;
top: 124px;
z-index: -1;
width: 99px;
height: 127px;
background: url('https://image.ibb.co/dOSSuk/box2.png') no-repeat;
background-size: 100%;
opacity: 0;
}
.hidden { display: none;}
/* unknowns */
.newslisting, #sidebar1Bottom { background: #ffffff !important; }
.tmx header { height: 269px;}
/*Animations, you can add agent prescripts, though we should never have to do that */
.fade-in { animation: 1.5s 2.5s fade;}
.fade-in-one { animation: 2.5s 5s fade;}
.fade-in-two { animation: 2.5s 7.5s fade-alt forwards;}
.fade-in-three { animation: 5s 15s fade;}
.reveal-it { animation: 2.5s reveal forwards;}
.slide-it { animation: 5s slide-in forwards;}
#keyframes fade-alt {0% { opacity: 0; } 10% {opacity : 1;} 100% { opacity: 1;} }
#keyframes fade { 0% { opacity: 0; } 10% {opacity: 1;} 90% {opacity: 1;} 100% {opacity: 0;} }
#keyframes reveal {0% { opacity: 1;} 80% { opacity: 1;} 100% { opacity: 0;} }
#keyframes slide-in {0% { top: 5px; } 80% { top: 5px; } 100% { top: -150px;} }
<div class="swipe-area preload" id="swipe-area" title="Just a moment as we asses your gullibility!">
<div id="cbox-canvas">
<div class="anim-container">
<div id="cbox-arrow" class="hidden"></div>
<div id="cbox-text-1" class="hidden"></div>
<div id="cbox-box-1" class="hidden"></div>
<div id="cbox-box-2" class="hidden"></div>
<div id="cbox-text-2" class="hidden"></div>
</div>
</div>
</div>
I'm a graphic designer in Portugal, used to work with code everyday, like css, html and a bit javascript and php. I am currently developing an interactive logo button, but it has to be PNG to look the way I want. This is the javascript code on html (image is hosted in my website):
I want to create a mouseclick start and stop on last/first frame, not a infinite loop like this, and reversed animation after click to open/close. Basically, the lock and unlock of the padlock.
The point of this animation is to open a menu nav-bar under the logo. Can you help me?
My code:
var cSpeed = 5;
var cWidth = 200;
var cHeight = 145;
var cTotalFrames = 7;
var cFrameWidth = 200;
var cImageSrc = 'https://www.studiogo.net/sprites.png';
var cImageTimeout = false;
var cIndex = 0;
var cXpos = 0;
var SECONDS_BETWEEN_FRAMES = 0;
function startAnimation() {
document.getElementById('loaderImage').style.backgroundImage = 'url(' + cImageSrc + ')';
document.getElementById('loaderImage').style.width = cWidth + 'px';
document.getElementById('loaderImage').style.height = cHeight + 'px';
//FPS = Math.round(100/(maxSpeed+2-speed));
FPS = Math.round(100 / cSpeed);
SECONDS_BETWEEN_FRAMES = 1 / FPS;
setTimeout('continueAnimation()', SECONDS_BETWEEN_FRAMES / 1000);
}
function continueAnimation() {
cXpos += cFrameWidth;
//increase the index so we know which frame of our animation we are currently on
cIndex += 1;
//if our cIndex is higher than our total number of frames, we're at the end and should restart
if (cIndex >= cTotalFrames) {
cXpos = 0;
cIndex = 0;
}
document.getElementById('loaderImage').style.backgroundPosition = (-cXpos) + 'px 0';
setTimeout('continueAnimation()', SECONDS_BETWEEN_FRAMES * 1000);
}
function imageLoader(s, fun) //Pre-loads the sprites image
{
clearTimeout(cImageTimeout);
cImageTimeout = 0;
genImage = new Image();
genImage.onload = function() {
cImageTimeout = setTimeout(fun, 0)
};
genImage.onerror = new Function('alert(\'Could not load the image\')');
genImage.src = s;
}
//The following code starts the animation
new imageLoader(cImageSrc, 'startAnimation()');
<div id="loaderImage"></div>
Please, see if this is what you want.
$(document).ready(function () {
$(".lock").click(function () {
var $self = $(this);
if ($self.hasClass("closed")) {
$self.removeClass("close");
setTimeout(function () {
$self.addClass("open").removeClass("closed");
}, 100);
} else {
$self.removeClass("open");
setTimeout(function () {
$self.addClass("close").addClass("closed");
}, 100);
}
});
});
div.lock {
background-image: url('https://www.studiogo.net/sprites.png');
width: 200px;
height: 145px;
background-position: 0 center;
background-repeat: no-repeat;
}
div.closed {
background-position: -1200px center;
}
div.close {
animation: close-animation 300ms steps(6, start); // 1200px / 200px = 6
}
div.open {
animation: close-animation 300ms steps(6, end); // 1200px / 200px = 6
animation-fill-mode: backwards;
animation-direction: reverse;
}
#keyframes close-animation {
from {
background-position: 0 center;
}
to {
background-position: -1200px center;
}
}
<div class="lock closed">
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
I tried the CSS route but all new to me and learning still but cannot seem to work it out. My JS below switches the background position to show a new image in the sprite every 1 second but wondering if anyone knew how I can kind of give it a small scale effects so when it changes grows a little then back to normal size before change to the next background position?
JS:
// Avatar animations
var avatarInterval;
function startAvatarAnimation() {
var i = 0;
var avatarSpeed = 500;
var avatarCount= 11;
var avatarHeight = 250;
var avatarTotalHeight = 2750;
avatarInterval = setInterval(function(){
i++;
if(i > 11){
i = 0;
}
$(".avatars").css({'background-position' : '0 -' + (i*avatarHeight) + 'px' });
$(".avatars").toggleClass('scaleIn', 'scaleOut');
}, avatarSpeed);
return false;
}
function stopAvatarAnimation(){
clearInterval(avatarInterval);
$(".avatars").css({'background-position' : '0 0' });
return false;
}
JS below switches the background position to show a new image in the
sprite every 1 second but wondering if anyone knew how i can kind of
give it a small scale effects so when it changes grows a little then
back to normal size before change to the next background position?
Try utilizing transition at css , setting duration to half of avatarSpeed or half of total duration of background-position effect ; setting transitionend event at .one() to prevent recursive call to transitionend handler , .removeClass() , .addClass() to toggle scale effect defined at css
css
.avatars {
transition: transform 500ms ease-in-out;
width: 100px;
height: 100px;
background-image: url(/path/to/background-image);
}
.avatars.scaleIn {
transform: scale(1.1, 1.1);
}
.avatars.scaleOut {
transform: scale(1.0, 1.0);
}
js
// Avatar animations
var avatarInterval;
function startAvatarAnimation() {
var i = 0;
var avatarSpeed = 500;
var avatarCount= 11;
var avatarHeight = 250;
var avatarTotalHeight = 2750;
avatarInterval = setInterval(function(){
i++;
if(i > 11){
i = 0;
}
$(".avatars").css({'background-position' : '0 -' + (i*avatarHeight) + 'px' })
.removeClass("scaleOut").addClass("scaleIn")
.one("transitionend", function() {
$(this).removeClass("scaleIn").addClass("scaleOut");
});
}, avatarSpeed);
return false;
}
$(".avatars").on("click", function() {
$(this).removeClass("scaleOut").addClass("scaleIn")
.one("transitionend", function() {
$(this).removeClass("scaleIn").addClass("scaleOut");
})
})
.avatars {
transition: transform 500ms ease-in-out;
width: 100px;
height: 100px;
background-image: url(http://lorempixel.com/100/100/nature);
}
.avatars.scaleIn {
transform: scale(1.1, 1.1);
}
.avatars.scaleOut {
transform: scale(1.0, 1.0);
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js">
</script>
<div class="avatars"></div>