为在下方的框中查看滚动吸附,可在滚动式视口中上下左右地滚动经过含 45 个带编号盒子的网格。
const positions = ["start", "center", "end"];
const inlineDirection = document.getElementById("inline");
const blockDirection = document.getElementById("block");
const stop = document.getElementById("stop");
const snap = document.getElementById("snap");
const all = document.querySelector("article");
const rules = document.styleSheets[0].cssRules;
inlineDirection.addEventListener("change", () => {
setSSA();
});
blockDirection.addEventListener("change", () => {
setSSA();
});
stop.addEventListener("change", () => {
setSST();
});
window.addEventListener("load", () => {
setSST();
setSSA();
});
snap.addEventListener("change", () => {
all.classList.toggle("snapDisabled");
});
function setSSA() {
rules[0].style.scrollSnapAlign = `${positions[blockDirection.value]} ${
positions[inlineDirection.value]
}`;
}
function setSST() {
if (stop.checked) {
rules[0].style.scrollSnapStop = "always";
} else {
rules[0].style.scrollSnapStop = "normal";
}
}
<article>
<ul>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
</ul>
<div>
<fieldset>
<legend>Change the options</legend>
<p>
<label
><input
type="range"
min="0"
max="2"
value="1"
list="places"
id="block" />
block position</label
>
</p>
<p>
<label>
<input
type="range"
min="0"
max="2"
value="1"
list="places"
id="inline" />
inline position
</label>
</p>
<p>
<label>
<input type="checkbox" id="stop" />
Prevent scrolling past boxes
</label>
</p>
</fieldset>
<p>
<label><input type="checkbox" id="snap" /> disable snapping</label>
</p>
<datalist id="places">
<option value="0">start</option>
<option value="1">center</option>
<option value="2">end</option>
</datalist>
</div>
</article>
li {
/*
starts with:
scroll-snap-align: center center;
scroll-snap-stop: normal (defaults);
CSS gets changed with JavaScript when you change the controls.
the following can be set:
scroll-snap-stop: always | normal;
scroll-snap-align: start | center | end {2}
*/
}
ul {
overflow: auto;
scroll-snap-type: both mandatory;
overscroll-behavior-x: contain;
}
article.snapDisabled fieldset {
opacity: 20%;
pointer-events: none;
}
article.snapDisabled ul {
scroll-snap-type: initial;
overscroll-behavior-x: initial;
}
@layer pageSetup {
article {
display: flex;
gap: 2vw;
}
div {
flex: 1;
}
ul {
display: grid;
gap: 6.25vw;
padding: 12.5vw;
box-sizing: border-box;
border: 1px solid;
grid-template-columns: repeat(5, 1fr);
background: conic-gradient(
at bottom left,
red 0deg,
yellow 15deg,
green 30deg,
blue 45deg,
purple 60deg,
magenta 75deg
);
background-attachment: local;
margin: auto;
width: 20vw;
height: 20vw;
}
li {
scroll-snap-align: center;
height: 12.5vw;
width: 12.5vw;
outline: 3px inset;
list-style-type: none;
background: white;
font-family: monospace;
font-size: 3rem;
line-height: 12vw;
text-align: center;
counter-increment: items 1;
}
li::after {
content: counter(items);
}
input {
vertical-align: bottom;
}
p {
font-family: monospace;
}
}
在有滚动吸附时,所滚动的带编号盒子中的一者将吸附至指定位置。初始的 CSS 代码使带编号盒子吸附至视口中心,可使用滑块改变块向和行向的吸附位置。
使用吸附属性可允许或防止滚动越过某个元素(此示例中为带编号盒子)。可勾选“Prevent scrolling past boxes”使所有滚动操作被强制限于滚动至相邻盒子。
为比较滚动吸附与普通滚动,可勾选“disable snapping”并再次尝试滚动。
此示例的代码见 GitHub 上的源码。