I'm attempting to mimic the following widget with HTML/CSS/JavaScript: https://gyazo.com/76bee875d35b571bd08edbe73ead12cb
The way that I have it set up is the following:
- I have a bar with a background color that has a gradient from red to green which is static.
- I then have two blinders that is supposed to represent the negative space to give the illusion that the colored bars are animating (in reality, the blinders are simply sliding away)
I did it this way because I figured it might be easier instead of trying to animate the bar going in both directions, but now I'm not so sure lol. One requirement that I'm trying to keep is that the animation only deals with transform or opacity to take advantage of optimizations the browser can do (as described here: https://hacks.mozilla.org/2016/08/animating-like-you-just-dont-care-with-element-animate/)
The example has a few buttons to help test various things. The "Random positive" works great, and is exactly what I want. I haven't quite hooked up the negative yet tho because I'm not sure how to approach the problem of transitioning from positive to negative and vice-versa.
Ideally, when going from a positive to a negative, the right blinder will finish at the middle, and the left blinder will pick up the animation and finish off where it needs to go.
So for example, if the values is initially set to 40%, and the then set to -30%, the right blinder should animate transform: translateX(40%) -> transform: translateX(0%) and then the left blinder should animate from transform: translateX(0%) -> transform: translateX(-30%) to expose the red.
Also, the easing should be seamless.
I'm not sure if this is possible with the setup (specifically keeping the easing seamless, since the easing would be per-element, I think, and can't "carry over" to another element?)
Looking for guidance on how I can salvage this to produce the expected results, or if there's a better way to deal with this.
Note: I'm using jquery simply for ease with click events and whatnot, but this will eventually be in an application that's not jquery aware.
Here's my current attempt: https://codepen.io/blitzmann/pen/vYLrqEW
let currentPercentageState = 0;
function animate(percentage) {
var animation = [{
transform: `translateX(${currentPercentageState}%)`,
easing: "ease-out"
},
{
transform: `translateX(${percentage}%)`
}
];
var timing = {
fill: "forwards",
duration: 1000
};
$(".blind.right")[0].animate(animation, timing);
// save the new value so that the next iteration has a proper from keyframe
currentPercentageState = percentage;
}
$(document).ready(function() {
$(".apply").click(function() {
animate($("#amount").val());
});
$(".reset").click(function() {
animate(0);
});
$(".random").click(function() {
var val = (Math.random() * 2 - 1) * 100;
$("#amount").val(val);
animate(val);
});
$(".randomPos").click(function() {
var val = Math.random() * 100;
$("#amount").val(val);
animate(val);
});
$(".randomNeg").click(function() {
var val = Math.random() * -100;
$("#amount").val(val);
animate(val);
});
$(".toggleBlinds").click(function() {
$(".blind").toggle();
});
$(".toggleLeft").click(function() {
$(".blind.left").toggle();
});
$(".toggleRight").click(function() {
$(".blind.right").toggle();
});
});
$(document).ready(function() {});.wrapper {
margin: 10px;
height: 10px;
width: 800px;
background: linear-gradient(to right, red 50%, green 50%);
border: 1px solid black;
box-sizing: border-box;
position: relative;
overflow: hidden;
}
.blind {
height: 100%;
position: absolute;
top: 0;
background-color: rgb(51, 51, 51);
min-width: 50%;
}
.blind.right {
left: 50%;
border-left: 1px solid white;
transform-origin: left top;
}
.blind.left {
border-right: 1px solid white;
transform-origin: left top;
}<div class="wrapper">
<div class='blind right'></div>
<div class='blind left'></div>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.0/jquery.min.js" type="text/javascript"></script>
<input id="amount" type="number" placeholder="Enter percentage..." value='40' />
<button class="apply">Apply</button>
<button class="random">Random</button>
<button class="randomPos">Random Positive</button>
<button class="randomNeg">Random Negative</button>
<button class="toggleBlinds">Toggle Blinds</button>
<button class="toggleLeft">Toggle L Blind</button>
<button class="toggleRight">Toggle R Blind</button>
<button class="reset" href="#">Reset</button>