磁吸按钮
按钮的视觉层随指针微移,指针离开后回到原位。
虚线标记按钮原位
移动鼠标观察按钮偏移。点按按钮,或用键盘确认。
等待确认
使用场景
主操作按钮。例如作品集的「查看作品」在指针靠近时给出轻微的方向反馈。
行为定义
鼠标在固定热区内移动时,按钮视觉层持续跟随坐标,每轴最多偏移 12 px。移出、取消或失焦后回中,触屏点按和键盘操作都能激活按钮。
实现要点
以固定热区的中心计算偏移,只对内部视觉层应用 transform。用原位轮廓标出位移基准。
原生 HTML / CSS / JS
完整示例,可另存为 HTML 直接打开。
打开示例查看源码
<!doctype html>
<html lang="zh-CN">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>磁吸按钮 · 原生示例</title>
<script>
const theme = new URLSearchParams(location.search).get('theme');
if (theme === 'dark' || (!theme && matchMedia('(prefers-color-scheme: dark)').matches)) {
document.documentElement.dataset.theme = 'dark';
}
</script>
<style>
:root {
color-scheme: light;
--bg: #fbfaf7; --surface: #fff; --surface-2: #edf3f6;
--text: #222c36; --text-2: #434f5d; --line-strong: #82939f;
--family-pointer: #275d7f; --accent: #b8412c;
--btn-bg: #b8412c; --btn-fg: #fff; --btn-hover: #963324;
}
:root[data-theme="dark"] {
color-scheme: dark;
--bg: #19222d; --surface: #222e3c; --surface-2: #2b3c4d;
--text: #f6f5f1; --text-2: #d8dce1; --line-strong: #8396a8;
--family-pointer: #9dc5e4; --accent: #ff9d7c;
--btn-bg: #ff9d7c; --btn-fg: #281912; --btn-hover: #ffb399;
}
html { background: var(--bg); }
body { max-width: 54rem; margin: 2rem auto; padding-inline: 1rem; color: var(--text); font: 1rem/1.55 system-ui, sans-serif; }
*, *::before, *::after { box-sizing: border-box; }
.pointer-comparison {
--pointer-accent: var(--family-pointer);
--pointer-rest: color-mix(in srgb, var(--surface-2) 88%, var(--pointer-accent));
max-inline-size: 54rem;
margin-inline: auto;
color: var(--text);
}
.pc-frame {
position: relative;
padding: clamp(.95rem, 2.5vw, 1.6rem);
border-radius: 14px;
background: var(--surface-2);
}
.pc-magnetic-frame {
display: grid;
place-items: center;
min-block-size: clamp(10rem, 27vw, 15rem);
background: var(--pointer-rest);
}
.pc-axis {
position: absolute;
inset: 1rem;
pointer-events: none;
}
.pc-axis::before, .pc-axis::after {
position: absolute;
background: var(--line-strong);
opacity: .45;
content: '';
}
.pc-axis::before { inset: 50% 0 auto; block-size: 1px; }
.pc-axis::after { inset: 0 auto 0 50%; inline-size: 1px; }
.pc-magnetic-hit {
position: relative;
display: grid;
place-items: center;
padding: 16px;
border: 0;
border-radius: 14px;
background: transparent;
font: inherit;
cursor: pointer;
}
.pc-magnetic-origin {
position: absolute;
inset: 16px;
border: 1px dashed var(--pointer-accent);
border-radius: 10px;
pointer-events: none;
}
.pc-magnetic-visual {
display: grid;
place-items: center;
min-inline-size: 7.5rem;
min-block-size: 2.75rem;
padding-inline: .9rem;
border-radius: 10px;
background: var(--btn-bg);
color: var(--btn-fg);
font-size: .875rem;
font-weight: 600;
pointer-events: none;
transition-property: transform;
transition-timing-function: cubic-bezier(.22, 1, .36, 1);
}
.pc-magnetic-hit:hover .pc-magnetic-visual,
.pc-magnetic-hit:active .pc-magnetic-visual { background: var(--btn-hover); }
.pc-legend {
position: absolute;
inset: auto .9rem .55rem auto;
margin: 0;
color: var(--text-2);
font-size: .75rem;
}
.pc-pulse-stage { position: relative; }
.pc-orbit {
position: relative;
display: flex;
justify-content: space-between;
align-items: end;
overflow: hidden;
box-sizing: border-box;
aspect-ratio: 2 / 1;
padding: clamp(.9rem, 3.2vw, 2rem);
border-radius: 12px;
background: var(--pointer-rest);
pointer-events: none;
}
.pc-orbit svg { position: absolute; inset: 0; inline-size: 100%; block-size: 100%; }
.pc-orbit-label, .pc-orbit-index { position: relative; }
.pc-orbit-label { display: grid; gap: .25rem; }
.pc-orbit-label strong { font-size: clamp(1rem, 3vw, 1.65rem); letter-spacing: -.025em; }
.pc-orbit-label small, .pc-orbit-index { font-size: clamp(.6rem, 1.35vw, .8rem); letter-spacing: .05em; }
.pc-pulse-outline {
position: absolute;
inset: 0;
border: 2px solid var(--accent);
border-radius: 12px;
opacity: 0;
pointer-events: none;
}
.pointer-comparison[data-pulse-state="static"] .pc-pulse-outline { opacity: 1; }
.pc-instructions {
display: flex;
flex-wrap: wrap;
justify-content: space-between;
gap: .25rem 1rem;
margin-block: .65rem .95rem;
color: var(--text-2);
font-size: .875rem;
}
.pc-instructions p { margin: 0; }
.pc-status { color: var(--pointer-accent); }
.pc-play {
min-block-size: 2.75rem;
padding: .35rem .75rem;
border: 1px solid var(--line-strong);
border-radius: 10px;
background: var(--surface);
color: var(--text);
font: inherit;
font-size: .875rem;
cursor: pointer;
}
.pc-play:hover { border-color: var(--pointer-accent); background: var(--pointer-rest); }
.pc-play:focus-visible, .pc-magnetic-hit:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.pc-play[hidden], .pc-magnetic-hit[hidden] { display: none; }
@media (max-width: 42rem) {
.pc-orbit { aspect-ratio: 1.6 / 1; }
}
@media (prefers-reduced-motion: reduce) {
.pc-magnetic-visual { transform: none !important; transition: none; }
}
</style>
<style>.demo-guide {
display: flex;
align-items: center;
justify-content: space-between;
gap: .5rem .9rem;
min-inline-size: 0;
margin-block: 0 .75rem;
padding-block-end: .5rem;
border-block-end: 1px solid var(--line-hi, #b8c4cd);
color: var(--text-2, #434f5d);
font-size: .8125rem;
line-height: 1.5;
}
.trigger-stage > .demo-guide {
margin: .35rem clamp(.85rem, 2.2vw, 1.4rem) 0;
}
.demo-guide [data-guide-caption] { margin: 0; }
.demo-guide > button[data-guide-replay] {
flex: none;
min-block-size: 44px;
margin: 0;
padding: .35rem .65rem;
border: 1px solid var(--line-strong, #82939f);
border-radius: 7px;
background: var(--surface, #fff);
color: var(--text, #222c36);
font: inherit;
font-weight: 550;
cursor: pointer;
}
.demo-guide > button[data-guide-replay]:hover { border-color: var(--accent-text, #963324); }
.demo-guide > button[data-guide-replay]:focus-visible { outline: 2px solid var(--accent-text, #963324); outline-offset: 2px; }
.demo-guide-cursor {
position: fixed;
z-index: 20;
inset: 0 auto auto 0;
inline-size: 20px;
block-size: 24px;
pointer-events: none;
}
.demo-guide-cursor svg { display: block; inline-size: 100%; block-size: 100%; }
.demo-guide-cursor::before {
position: absolute;
inset: -7px auto auto -7px;
inline-size: 18px;
block-size: 18px;
border: 2px solid var(--accent-text, #963324);
border-radius: 50%;
content: '';
opacity: 0;
}
.demo-guide-cursor[data-press]::before { opacity: 1; }
@media (prefers-reduced-motion: reduce) { .demo-guide-cursor { display: none; } }
</style>
</head>
<body>
<main>
<h1>磁吸按钮</h1>
<section class="pointer-comparison" data-pointer-comparison="magnetic-button" aria-label="磁吸按钮试玩">
<div class="pc-frame pc-magnetic-frame">
<div class="pc-axis" aria-hidden="true"></div>
<button class="pc-magnetic-hit" type="button" data-magnetic-hit hidden>
<span class="pc-magnetic-origin" aria-hidden="true"></span>
<span class="pc-magnetic-visual" data-magnetic-visual>点按确认</span>
</button>
<noscript><span class="pc-magnetic-visual">按钮原位</span></noscript>
<p class="pc-legend">虚线标记按钮原位</p>
</div>
<div class="pc-instructions">
<p>移动鼠标观察按钮偏移。点按按钮,或用键盘确认。</p>
<p class="pc-status" data-pc-status role="status">等待确认</p>
</div>
</section>
</main>
<script>
const maximumOffset = 12;
const returnDuration = 240;
/** @param {HTMLElement} visual @param {number} x @param {number} y @param {boolean} returning */
function positionNative(visual, x, y, returning) {
visual.style.transitionDuration = returning ? `${returnDuration}ms` : '0ms';
visual.style.transform = `translate(${x}px, ${y}px)`;
}
/** @param {HTMLElement} root @param {typeof positionNative} [position] */
function bindMagneticButton(root, position = positionNative) {
const button = root.querySelector('[data-magnetic-hit]');
const visual = root.querySelector('[data-magnetic-visual]');
const status = root.querySelector('[data-pc-status]');
if (!(button instanceof HTMLButtonElement) || !(visual instanceof HTMLElement) || !status) return;
const reduced = matchMedia('(prefers-reduced-motion: reduce)');
let confirmations = 0;
let frame = 0;
let clientX = 0;
let clientY = 0;
/** @param {number} fraction */
const offset = (fraction) => maximumOffset * Math.max(-1, Math.min(1, fraction));
/** @param {PointerEvent} event */
const follow = (event) => {
if (event.pointerType !== 'mouse' || reduced.matches) return;
clientX = event.clientX;
clientY = event.clientY;
if (frame) return;
frame = requestAnimationFrame(() => {
frame = 0;
const { left, top, width, height } = button.getBoundingClientRect();
const x = offset((2 * (clientX - left)) / width - 1);
const y = offset((2 * (clientY - top)) / height - 1);
position(visual, x, y, false);
});
};
const returnHome = () => {
cancelAnimationFrame(frame);
frame = 0;
position(visual, 0, 0, !reduced.matches);
};
button.addEventListener('pointerenter', follow);
button.addEventListener('pointermove', follow);
button.addEventListener('pointerleave', returnHome);
button.addEventListener('pointercancel', returnHome);
button.addEventListener('blur', returnHome);
window.addEventListener('blur', returnHome);
reduced.addEventListener('change', returnHome);
button.addEventListener('click', () => {
confirmations += 1;
status.textContent = `已确认 · 第 ${confirmations} 次`;
});
button.hidden = false;
}
const demo = document.querySelector('[data-pointer-comparison]');
bindMagneticButton(demo);
</script>
<script>
(() => {
/** @param {number} duration @param {AbortSignal} signal @param {(progress: number) => void} [render] */
function guideBeat(duration, signal, render) {
if (signal.aborted) return Promise.resolve();
if (duration === 0) {
render?.(1);
return Promise.resolve();
}
return new Promise((resolve) => {
let timer = 0;
let frame = 0;
const done = () => {
clearTimeout(timer);
cancelAnimationFrame(frame);
signal.removeEventListener('abort', done);
resolve(undefined);
};
signal.addEventListener('abort', done, { once: true });
if (!render) {
timer = window.setTimeout(done, duration);
return;
}
const start = performance.now();
const tick = (now) => {
const progress = Math.min(1, (now - start) / duration);
render(progress);
if (progress === 1) done();
else if (!signal.aborted) frame = requestAnimationFrame(tick);
};
frame = requestAnimationFrame(tick);
});
}
/** @param {HTMLElement} root @param {import('./demo-guide-cases').DemoGuide} guide */
function bindDemoGuide(root, guide) {
const view = root.querySelector(guide.view);
if (!view || root.dataset.guideState || guide.steps.some(({ target }) => !root.querySelector(target))) return;
const dock = guide.dock ? root.querySelector(guide.dock) : null;
const bar = document.createElement('div');
bar.className = 'demo-guide';
bar.innerHTML = '<p data-guide-caption></p><button type="button" data-guide-replay>重播导览</button>';
const caption = bar.querySelector('[data-guide-caption]');
const replay = bar.querySelector('button');
const heading = root === document.body ? root.querySelector('h1') : null;
if (dock) dock.prepend(bar);
else if (heading) heading.after(bar);
else root.prepend(bar);
const cursor = document.createElement('div');
cursor.className = 'demo-guide-cursor';
cursor.setAttribute('aria-hidden', 'true');
cursor.hidden = true;
cursor.innerHTML = '<svg viewBox="0 0 20 24" focusable="false"><path d="M2 2v17l4.8-4.5L10 21l3.2-1.6-3.2-6.2 6.6-.7L2 2Z" fill="#222c36" stroke="#fff" stroke-width="1.5" stroke-linejoin="round"/></svg>';
document.body.append(cursor);
const reduced = matchMedia('(prefers-reduced-motion: reduce)');
const threshold = .5;
const idleCaption = '导览在画面进入视口后播放一次。';
const reducedCaption = '可重播关键状态,或直接操作。';
const reset = guide.reset ? (root.matches(guide.reset) ? root : root.querySelector(guide.reset)) : null;
const releaseTarget = guide.release ? root.querySelector(guide.release) : null;
let autoPending = !reduced.matches;
let inView = false;
let playbackScroll = window.scrollY;
/** @type {AbortController | undefined} */
let run;
/** @type {[number, number] | undefined} */
let cursorPosition;
root.dataset.guideState = 'idle';
caption.textContent = reduced.matches ? reducedCaption : idleCaption;
function hideCursor() {
cursor.hidden = true;
delete cursor.dataset.press;
cursorPosition = undefined;
}
/** @param {PointerEvent} [pointer] */
function stop(pointer) {
autoPending = false;
if (!run) return;
run.abort();
run = undefined;
hideCursor();
if (releaseTarget) {
// A real pointer inside the target keeps its hover when the guide yields.
if (pointer) sendPointer(releaseTarget, 'pointerenter', [pointer.clientX, pointer.clientY]);
else sendPointer(releaseTarget, 'pointerleave', [0, 0]);
}
reset?.dispatchEvent(new Event('formtempo:guide-cancel'));
root.dataset.guideState = 'interrupted';
caption.textContent = '导览已停止,可以继续手动操作。';
}
/** @param {[number, number]} position */
function moveCursor(position) {
cursor.hidden = false;
cursor.style.transform = `translate3d(${position[0]}px, ${position[1]}px, 0)`;
cursorPosition = position;
}
/** @param {Element} target @param {readonly [number, number]} point */
function location(target, [x, y]) {
const rect = target.getBoundingClientRect();
return /** @type {[number, number]} */ ([rect.left + rect.width * x, rect.top + rect.height * y]);
}
/** @param {Element} target @param {string} type @param {readonly [number, number]} position */
function sendPointer(target, type, [clientX, clientY]) {
target.dispatchEvent(new PointerEvent(type, { pointerType: 'mouse', clientX, clientY }));
}
/** @param {HTMLInputElement} slider @param {number} value */
function setProgress(slider, value) {
const next = Math.round(value);
if (slider.valueAsNumber === next) return;
slider.value = String(next);
slider.dispatchEvent(new Event('input', { bubbles: true }));
}
/** @param {number} value */
function showReducedProgress(value) {
const options = Array.from(root.querySelectorAll('button[data-driven-step], button[data-scale-step], button[data-progress-step], button[data-progress]'));
const percent = (button) => button.hasAttribute('data-progress')
? Number(button.getAttribute('data-progress')) * 100
: Number(button.getAttribute('data-driven-step') ?? button.getAttribute('data-scale-step') ?? button.getAttribute('data-progress-step'));
options.sort((a, b) => Math.abs(percent(a) - value) - Math.abs(percent(b) - value));
if (options[0] instanceof HTMLButtonElement) options[0].click();
}
/** @param {import('./demo-guide-cases').DemoGuide['steps'][number]} step @param {AbortSignal} signal */
async function playStep(step, signal) {
const target = root.querySelector(step.target);
if (!target) return;
caption.textContent = step.text;
const { action, value = 0, point = [.5, .5] } = step;
if (action === 'progress' && target instanceof HTMLInputElement) {
if (reduced.matches) {
showReducedProgress(value);
} else {
const from = target.valueAsNumber;
await guideBeat(step.duration ?? 0, signal, (progress) => {
const current = from + (value - from) * progress;
setProgress(target, current);
moveCursor(location(target, [.04 + .92 * current / 100, .65]));
});
}
} else {
if (!reduced.matches) {
const to = location(target, point);
const [x, y] = point;
const entry = x < .25 ? [-.08, y] : x > .75 ? [1.08, y] : [x, y < .5 ? -.08 : 1.08];
const from = action === 'enter' ? location(target, /** @type {[number, number]} */ (entry))
: cursorPosition ?? [to[0] + 26, to[1] + 19];
const duration = action === 'leave' ? 200 : 340;
await guideBeat(duration, signal, (progress) => {
const t = 1 - (1 - progress) ** 3;
const end = location(target, point);
const position = /** @type {[number, number]} */ ([
from[0] + (end[0] - from[0]) * t,
from[1] + (end[1] - from[1]) * t,
]);
moveCursor(position);
if (action === 'move') sendPointer(target, 'pointermove', position);
});
}
if (signal.aborted) return;
if (action === 'click' && target instanceof HTMLElement) {
if (!reduced.matches) {
cursor.dataset.press = '';
await guideBeat(125, signal);
if (signal.aborted) return;
}
target.click();
delete cursor.dataset.press;
} else if (action === 'enter' || action === 'leave') {
sendPointer(target, `pointer${action}`, location(target, point));
}
}
await guideBeat(reduced.matches ? 600 : step.hold ?? 500, signal);
}
function bringViewIntoFrame() {
const rect = view.getBoundingClientRect();
const visibleHeight = Math.min(rect.bottom, window.innerHeight) - Math.max(rect.top, 0);
if (visibleHeight < rect.height * threshold) view.scrollIntoView({ block: 'center', behavior: 'instant' });
}
async function start(replaying = false) {
stop();
const controller = new AbortController();
const { signal } = controller;
run = controller;
root.dataset.guideState = 'playing';
if (guide.ready) {
caption.textContent = '正在等待视频就绪…';
const deadline = performance.now() + 4000;
while (!signal.aborted && !root.querySelector(guide.ready) && performance.now() < deadline &&
!root.querySelector('[data-video-state="error"]')) {
await guideBeat(90, signal);
}
if (signal.aborted) return;
if (!root.querySelector(guide.ready)) {
run = undefined;
root.dataset.guideState = 'unavailable';
caption.textContent = '视频暂未就绪,可以查看关键帧或重播。';
return;
}
}
reset?.dispatchEvent(new Event('formtempo:guide-reset'));
if (replaying) bringViewIntoFrame();
playbackScroll = window.scrollY;
const steps = (reduced.matches && guide.reducedSteps) || guide.steps;
for (const step of steps) {
if (signal.aborted) return;
await playStep(step, signal);
}
if (signal.aborted) return;
run = undefined;
hideCursor();
root.dataset.guideState = 'complete';
caption.textContent = '导览结束,可以继续手动操作。';
}
function tryAutoplay() {
if (autoPending && inView && !document.hidden) void start();
}
if (typeof IntersectionObserver === 'function') {
const observer = new IntersectionObserver(([entry]) => {
inView = entry.intersectionRatio >= threshold;
if (!entry.isIntersecting && run) stop();
tryAutoplay();
}, { threshold: [0, threshold] });
observer.observe(view);
}
replay.addEventListener('click', () => {
bringViewIntoFrame();
void start(true);
});
const takeOver = (event) => {
if (!event.isTrusted || replay.contains(event.target)) return;
if (!run) {
if (event.type === 'wheel' || !(event.target instanceof Element)) return;
if (!event.target.closest('button, input') && !view.contains(event.target)) return;
}
const pointer = event instanceof PointerEvent && event.pointerType === 'mouse' && releaseTarget?.contains(event.target)
? event : undefined;
stop(pointer);
};
for (const event of ['pointerdown', 'keydown', 'focusin', 'input', 'click', 'wheel']) {
root.addEventListener(event, takeOver, { capture: true, passive: true });
}
if (guide.steps.some(({ action }) => action === 'enter' || action === 'move')) {
view.addEventListener('pointermove', takeOver, { capture: true, passive: true });
}
if (guide.pageScrollInput) {
window.addEventListener('scroll', () => {
if (run && window.scrollY !== playbackScroll) stop();
}, { passive: true });
}
document.addEventListener('visibilitychange', () => {
if (document.hidden && run) stop();
else tryAutoplay();
});
reduced.addEventListener('change', () => {
if (!reduced.matches) return;
const wasIdle = root.dataset.guideState === 'idle';
stop();
if (wasIdle) caption.textContent = reducedCaption;
});
}
bindDemoGuide(document.body, {"view":"[data-magnetic-hit]","release":"[data-magnetic-hit]","reducedSteps":[{"target":"[data-magnetic-hit]","action":"click","text":"减少动态效果时,按钮保持原位,仍可点按确认。"}],"steps":[{"target":"[data-magnetic-hit]","action":"move","text":"指针靠左时,按钮视觉层向左偏移。","point":[0.12,0.45],"hold":360},{"target":"[data-magnetic-hit]","action":"move","text":"移向右下角,按钮跟着偏移。","point":[0.88,0.8],"hold":360},{"target":"[data-magnetic-hit]","action":"leave","text":"离开热区,按钮回到虚线标出的原位。","point":[1.15,0.85]}]});
})();
</script>
</body>
</html>GSAP 3.15.0
完整示例,从 CDN 加载指定版本。
打开示例查看源码
<!doctype html>
<html lang="zh-CN">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>磁吸按钮 · GSAP示例</title>
<script>
const theme = new URLSearchParams(location.search).get('theme');
if (theme === 'dark' || (!theme && matchMedia('(prefers-color-scheme: dark)').matches)) {
document.documentElement.dataset.theme = 'dark';
}
</script>
<style>
:root {
color-scheme: light;
--bg: #fbfaf7; --surface: #fff; --surface-2: #edf3f6;
--text: #222c36; --text-2: #434f5d; --line-strong: #82939f;
--family-pointer: #275d7f; --accent: #b8412c;
--btn-bg: #b8412c; --btn-fg: #fff; --btn-hover: #963324;
}
:root[data-theme="dark"] {
color-scheme: dark;
--bg: #19222d; --surface: #222e3c; --surface-2: #2b3c4d;
--text: #f6f5f1; --text-2: #d8dce1; --line-strong: #8396a8;
--family-pointer: #9dc5e4; --accent: #ff9d7c;
--btn-bg: #ff9d7c; --btn-fg: #281912; --btn-hover: #ffb399;
}
html { background: var(--bg); }
body { max-width: 54rem; margin: 2rem auto; padding-inline: 1rem; color: var(--text); font: 1rem/1.55 system-ui, sans-serif; }
*, *::before, *::after { box-sizing: border-box; }
.pointer-comparison {
--pointer-accent: var(--family-pointer);
--pointer-rest: color-mix(in srgb, var(--surface-2) 88%, var(--pointer-accent));
max-inline-size: 54rem;
margin-inline: auto;
color: var(--text);
}
.pc-frame {
position: relative;
padding: clamp(.95rem, 2.5vw, 1.6rem);
border-radius: 14px;
background: var(--surface-2);
}
.pc-magnetic-frame {
display: grid;
place-items: center;
min-block-size: clamp(10rem, 27vw, 15rem);
background: var(--pointer-rest);
}
.pc-axis {
position: absolute;
inset: 1rem;
pointer-events: none;
}
.pc-axis::before, .pc-axis::after {
position: absolute;
background: var(--line-strong);
opacity: .45;
content: '';
}
.pc-axis::before { inset: 50% 0 auto; block-size: 1px; }
.pc-axis::after { inset: 0 auto 0 50%; inline-size: 1px; }
.pc-magnetic-hit {
position: relative;
display: grid;
place-items: center;
padding: 16px;
border: 0;
border-radius: 14px;
background: transparent;
font: inherit;
cursor: pointer;
}
.pc-magnetic-origin {
position: absolute;
inset: 16px;
border: 1px dashed var(--pointer-accent);
border-radius: 10px;
pointer-events: none;
}
.pc-magnetic-visual {
display: grid;
place-items: center;
min-inline-size: 7.5rem;
min-block-size: 2.75rem;
padding-inline: .9rem;
border-radius: 10px;
background: var(--btn-bg);
color: var(--btn-fg);
font-size: .875rem;
font-weight: 600;
pointer-events: none;
transition-property: transform;
transition-timing-function: cubic-bezier(.22, 1, .36, 1);
}
.pc-magnetic-hit:hover .pc-magnetic-visual,
.pc-magnetic-hit:active .pc-magnetic-visual { background: var(--btn-hover); }
.pc-legend {
position: absolute;
inset: auto .9rem .55rem auto;
margin: 0;
color: var(--text-2);
font-size: .75rem;
}
.pc-pulse-stage { position: relative; }
.pc-orbit {
position: relative;
display: flex;
justify-content: space-between;
align-items: end;
overflow: hidden;
box-sizing: border-box;
aspect-ratio: 2 / 1;
padding: clamp(.9rem, 3.2vw, 2rem);
border-radius: 12px;
background: var(--pointer-rest);
pointer-events: none;
}
.pc-orbit svg { position: absolute; inset: 0; inline-size: 100%; block-size: 100%; }
.pc-orbit-label, .pc-orbit-index { position: relative; }
.pc-orbit-label { display: grid; gap: .25rem; }
.pc-orbit-label strong { font-size: clamp(1rem, 3vw, 1.65rem); letter-spacing: -.025em; }
.pc-orbit-label small, .pc-orbit-index { font-size: clamp(.6rem, 1.35vw, .8rem); letter-spacing: .05em; }
.pc-pulse-outline {
position: absolute;
inset: 0;
border: 2px solid var(--accent);
border-radius: 12px;
opacity: 0;
pointer-events: none;
}
.pointer-comparison[data-pulse-state="static"] .pc-pulse-outline { opacity: 1; }
.pc-instructions {
display: flex;
flex-wrap: wrap;
justify-content: space-between;
gap: .25rem 1rem;
margin-block: .65rem .95rem;
color: var(--text-2);
font-size: .875rem;
}
.pc-instructions p { margin: 0; }
.pc-status { color: var(--pointer-accent); }
.pc-play {
min-block-size: 2.75rem;
padding: .35rem .75rem;
border: 1px solid var(--line-strong);
border-radius: 10px;
background: var(--surface);
color: var(--text);
font: inherit;
font-size: .875rem;
cursor: pointer;
}
.pc-play:hover { border-color: var(--pointer-accent); background: var(--pointer-rest); }
.pc-play:focus-visible, .pc-magnetic-hit:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.pc-play[hidden], .pc-magnetic-hit[hidden] { display: none; }
@media (max-width: 42rem) {
.pc-orbit { aspect-ratio: 1.6 / 1; }
}
@media (prefers-reduced-motion: reduce) {
.pc-magnetic-visual { transform: none !important; transition: none; }
}
</style>
<script src="https://cdn.jsdelivr.net/npm/gsap@3.15.0/dist/gsap.min.js"></script>
<style>.demo-guide {
display: flex;
align-items: center;
justify-content: space-between;
gap: .5rem .9rem;
min-inline-size: 0;
margin-block: 0 .75rem;
padding-block-end: .5rem;
border-block-end: 1px solid var(--line-hi, #b8c4cd);
color: var(--text-2, #434f5d);
font-size: .8125rem;
line-height: 1.5;
}
.trigger-stage > .demo-guide {
margin: .35rem clamp(.85rem, 2.2vw, 1.4rem) 0;
}
.demo-guide [data-guide-caption] { margin: 0; }
.demo-guide > button[data-guide-replay] {
flex: none;
min-block-size: 44px;
margin: 0;
padding: .35rem .65rem;
border: 1px solid var(--line-strong, #82939f);
border-radius: 7px;
background: var(--surface, #fff);
color: var(--text, #222c36);
font: inherit;
font-weight: 550;
cursor: pointer;
}
.demo-guide > button[data-guide-replay]:hover { border-color: var(--accent-text, #963324); }
.demo-guide > button[data-guide-replay]:focus-visible { outline: 2px solid var(--accent-text, #963324); outline-offset: 2px; }
.demo-guide-cursor {
position: fixed;
z-index: 20;
inset: 0 auto auto 0;
inline-size: 20px;
block-size: 24px;
pointer-events: none;
}
.demo-guide-cursor svg { display: block; inline-size: 100%; block-size: 100%; }
.demo-guide-cursor::before {
position: absolute;
inset: -7px auto auto -7px;
inline-size: 18px;
block-size: 18px;
border: 2px solid var(--accent-text, #963324);
border-radius: 50%;
content: '';
opacity: 0;
}
.demo-guide-cursor[data-press]::before { opacity: 1; }
@media (prefers-reduced-motion: reduce) { .demo-guide-cursor { display: none; } }
</style>
</head>
<body>
<main>
<h1>磁吸按钮</h1>
<section class="pointer-comparison" data-pointer-comparison="magnetic-button" aria-label="磁吸按钮试玩">
<div class="pc-frame pc-magnetic-frame">
<div class="pc-axis" aria-hidden="true"></div>
<button class="pc-magnetic-hit" type="button" data-magnetic-hit hidden>
<span class="pc-magnetic-origin" aria-hidden="true"></span>
<span class="pc-magnetic-visual" data-magnetic-visual>点按确认</span>
</button>
<noscript><span class="pc-magnetic-visual">按钮原位</span></noscript>
<p class="pc-legend">虚线标记按钮原位</p>
</div>
<div class="pc-instructions">
<p>移动鼠标观察按钮偏移。点按按钮,或用键盘确认。</p>
<p class="pc-status" data-pc-status role="status">等待确认</p>
</div>
</section>
</main>
<script>
const maximumOffset = 12;
const returnDuration = 240;
/** @param {HTMLElement} visual @param {number} x @param {number} y @param {boolean} returning */
function positionNative(visual, x, y, returning) {
visual.style.transitionDuration = returning ? `${returnDuration}ms` : '0ms';
visual.style.transform = `translate(${x}px, ${y}px)`;
}
/** @param {HTMLElement} root @param {typeof positionNative} [position] */
function bindMagneticButton(root, position = positionNative) {
const button = root.querySelector('[data-magnetic-hit]');
const visual = root.querySelector('[data-magnetic-visual]');
const status = root.querySelector('[data-pc-status]');
if (!(button instanceof HTMLButtonElement) || !(visual instanceof HTMLElement) || !status) return;
const reduced = matchMedia('(prefers-reduced-motion: reduce)');
let confirmations = 0;
let frame = 0;
let clientX = 0;
let clientY = 0;
/** @param {number} fraction */
const offset = (fraction) => maximumOffset * Math.max(-1, Math.min(1, fraction));
/** @param {PointerEvent} event */
const follow = (event) => {
if (event.pointerType !== 'mouse' || reduced.matches) return;
clientX = event.clientX;
clientY = event.clientY;
if (frame) return;
frame = requestAnimationFrame(() => {
frame = 0;
const { left, top, width, height } = button.getBoundingClientRect();
const x = offset((2 * (clientX - left)) / width - 1);
const y = offset((2 * (clientY - top)) / height - 1);
position(visual, x, y, false);
});
};
const returnHome = () => {
cancelAnimationFrame(frame);
frame = 0;
position(visual, 0, 0, !reduced.matches);
};
button.addEventListener('pointerenter', follow);
button.addEventListener('pointermove', follow);
button.addEventListener('pointerleave', returnHome);
button.addEventListener('pointercancel', returnHome);
button.addEventListener('blur', returnHome);
window.addEventListener('blur', returnHome);
reduced.addEventListener('change', returnHome);
button.addEventListener('click', () => {
confirmations += 1;
status.textContent = `已确认 · 第 ${confirmations} 次`;
});
button.hidden = false;
}
function positionWithGsap(visual, x, y, returning) {
gsap.killTweensOf(visual);
if (returning) gsap.to(visual, { x, y, duration: returnDuration / 1000, ease: 'expo.out' });
else gsap.set(visual, { x, y });
}
const demo = document.querySelector('[data-pointer-comparison]');
bindMagneticButton(demo, window.gsap ? positionWithGsap : undefined);
</script>
<script>
(() => {
/** @param {number} duration @param {AbortSignal} signal @param {(progress: number) => void} [render] */
function guideBeat(duration, signal, render) {
if (signal.aborted) return Promise.resolve();
if (duration === 0) {
render?.(1);
return Promise.resolve();
}
return new Promise((resolve) => {
let timer = 0;
let frame = 0;
const done = () => {
clearTimeout(timer);
cancelAnimationFrame(frame);
signal.removeEventListener('abort', done);
resolve(undefined);
};
signal.addEventListener('abort', done, { once: true });
if (!render) {
timer = window.setTimeout(done, duration);
return;
}
const start = performance.now();
const tick = (now) => {
const progress = Math.min(1, (now - start) / duration);
render(progress);
if (progress === 1) done();
else if (!signal.aborted) frame = requestAnimationFrame(tick);
};
frame = requestAnimationFrame(tick);
});
}
/** @param {HTMLElement} root @param {import('./demo-guide-cases').DemoGuide} guide */
function bindDemoGuide(root, guide) {
const view = root.querySelector(guide.view);
if (!view || root.dataset.guideState || guide.steps.some(({ target }) => !root.querySelector(target))) return;
const dock = guide.dock ? root.querySelector(guide.dock) : null;
const bar = document.createElement('div');
bar.className = 'demo-guide';
bar.innerHTML = '<p data-guide-caption></p><button type="button" data-guide-replay>重播导览</button>';
const caption = bar.querySelector('[data-guide-caption]');
const replay = bar.querySelector('button');
const heading = root === document.body ? root.querySelector('h1') : null;
if (dock) dock.prepend(bar);
else if (heading) heading.after(bar);
else root.prepend(bar);
const cursor = document.createElement('div');
cursor.className = 'demo-guide-cursor';
cursor.setAttribute('aria-hidden', 'true');
cursor.hidden = true;
cursor.innerHTML = '<svg viewBox="0 0 20 24" focusable="false"><path d="M2 2v17l4.8-4.5L10 21l3.2-1.6-3.2-6.2 6.6-.7L2 2Z" fill="#222c36" stroke="#fff" stroke-width="1.5" stroke-linejoin="round"/></svg>';
document.body.append(cursor);
const reduced = matchMedia('(prefers-reduced-motion: reduce)');
const threshold = .5;
const idleCaption = '导览在画面进入视口后播放一次。';
const reducedCaption = '可重播关键状态,或直接操作。';
const reset = guide.reset ? (root.matches(guide.reset) ? root : root.querySelector(guide.reset)) : null;
const releaseTarget = guide.release ? root.querySelector(guide.release) : null;
let autoPending = !reduced.matches;
let inView = false;
let playbackScroll = window.scrollY;
/** @type {AbortController | undefined} */
let run;
/** @type {[number, number] | undefined} */
let cursorPosition;
root.dataset.guideState = 'idle';
caption.textContent = reduced.matches ? reducedCaption : idleCaption;
function hideCursor() {
cursor.hidden = true;
delete cursor.dataset.press;
cursorPosition = undefined;
}
/** @param {PointerEvent} [pointer] */
function stop(pointer) {
autoPending = false;
if (!run) return;
run.abort();
run = undefined;
hideCursor();
if (releaseTarget) {
// A real pointer inside the target keeps its hover when the guide yields.
if (pointer) sendPointer(releaseTarget, 'pointerenter', [pointer.clientX, pointer.clientY]);
else sendPointer(releaseTarget, 'pointerleave', [0, 0]);
}
reset?.dispatchEvent(new Event('formtempo:guide-cancel'));
root.dataset.guideState = 'interrupted';
caption.textContent = '导览已停止,可以继续手动操作。';
}
/** @param {[number, number]} position */
function moveCursor(position) {
cursor.hidden = false;
cursor.style.transform = `translate3d(${position[0]}px, ${position[1]}px, 0)`;
cursorPosition = position;
}
/** @param {Element} target @param {readonly [number, number]} point */
function location(target, [x, y]) {
const rect = target.getBoundingClientRect();
return /** @type {[number, number]} */ ([rect.left + rect.width * x, rect.top + rect.height * y]);
}
/** @param {Element} target @param {string} type @param {readonly [number, number]} position */
function sendPointer(target, type, [clientX, clientY]) {
target.dispatchEvent(new PointerEvent(type, { pointerType: 'mouse', clientX, clientY }));
}
/** @param {HTMLInputElement} slider @param {number} value */
function setProgress(slider, value) {
const next = Math.round(value);
if (slider.valueAsNumber === next) return;
slider.value = String(next);
slider.dispatchEvent(new Event('input', { bubbles: true }));
}
/** @param {number} value */
function showReducedProgress(value) {
const options = Array.from(root.querySelectorAll('button[data-driven-step], button[data-scale-step], button[data-progress-step], button[data-progress]'));
const percent = (button) => button.hasAttribute('data-progress')
? Number(button.getAttribute('data-progress')) * 100
: Number(button.getAttribute('data-driven-step') ?? button.getAttribute('data-scale-step') ?? button.getAttribute('data-progress-step'));
options.sort((a, b) => Math.abs(percent(a) - value) - Math.abs(percent(b) - value));
if (options[0] instanceof HTMLButtonElement) options[0].click();
}
/** @param {import('./demo-guide-cases').DemoGuide['steps'][number]} step @param {AbortSignal} signal */
async function playStep(step, signal) {
const target = root.querySelector(step.target);
if (!target) return;
caption.textContent = step.text;
const { action, value = 0, point = [.5, .5] } = step;
if (action === 'progress' && target instanceof HTMLInputElement) {
if (reduced.matches) {
showReducedProgress(value);
} else {
const from = target.valueAsNumber;
await guideBeat(step.duration ?? 0, signal, (progress) => {
const current = from + (value - from) * progress;
setProgress(target, current);
moveCursor(location(target, [.04 + .92 * current / 100, .65]));
});
}
} else {
if (!reduced.matches) {
const to = location(target, point);
const [x, y] = point;
const entry = x < .25 ? [-.08, y] : x > .75 ? [1.08, y] : [x, y < .5 ? -.08 : 1.08];
const from = action === 'enter' ? location(target, /** @type {[number, number]} */ (entry))
: cursorPosition ?? [to[0] + 26, to[1] + 19];
const duration = action === 'leave' ? 200 : 340;
await guideBeat(duration, signal, (progress) => {
const t = 1 - (1 - progress) ** 3;
const end = location(target, point);
const position = /** @type {[number, number]} */ ([
from[0] + (end[0] - from[0]) * t,
from[1] + (end[1] - from[1]) * t,
]);
moveCursor(position);
if (action === 'move') sendPointer(target, 'pointermove', position);
});
}
if (signal.aborted) return;
if (action === 'click' && target instanceof HTMLElement) {
if (!reduced.matches) {
cursor.dataset.press = '';
await guideBeat(125, signal);
if (signal.aborted) return;
}
target.click();
delete cursor.dataset.press;
} else if (action === 'enter' || action === 'leave') {
sendPointer(target, `pointer${action}`, location(target, point));
}
}
await guideBeat(reduced.matches ? 600 : step.hold ?? 500, signal);
}
function bringViewIntoFrame() {
const rect = view.getBoundingClientRect();
const visibleHeight = Math.min(rect.bottom, window.innerHeight) - Math.max(rect.top, 0);
if (visibleHeight < rect.height * threshold) view.scrollIntoView({ block: 'center', behavior: 'instant' });
}
async function start(replaying = false) {
stop();
const controller = new AbortController();
const { signal } = controller;
run = controller;
root.dataset.guideState = 'playing';
if (guide.ready) {
caption.textContent = '正在等待视频就绪…';
const deadline = performance.now() + 4000;
while (!signal.aborted && !root.querySelector(guide.ready) && performance.now() < deadline &&
!root.querySelector('[data-video-state="error"]')) {
await guideBeat(90, signal);
}
if (signal.aborted) return;
if (!root.querySelector(guide.ready)) {
run = undefined;
root.dataset.guideState = 'unavailable';
caption.textContent = '视频暂未就绪,可以查看关键帧或重播。';
return;
}
}
reset?.dispatchEvent(new Event('formtempo:guide-reset'));
if (replaying) bringViewIntoFrame();
playbackScroll = window.scrollY;
const steps = (reduced.matches && guide.reducedSteps) || guide.steps;
for (const step of steps) {
if (signal.aborted) return;
await playStep(step, signal);
}
if (signal.aborted) return;
run = undefined;
hideCursor();
root.dataset.guideState = 'complete';
caption.textContent = '导览结束,可以继续手动操作。';
}
function tryAutoplay() {
if (autoPending && inView && !document.hidden) void start();
}
if (typeof IntersectionObserver === 'function') {
const observer = new IntersectionObserver(([entry]) => {
inView = entry.intersectionRatio >= threshold;
if (!entry.isIntersecting && run) stop();
tryAutoplay();
}, { threshold: [0, threshold] });
observer.observe(view);
}
replay.addEventListener('click', () => {
bringViewIntoFrame();
void start(true);
});
const takeOver = (event) => {
if (!event.isTrusted || replay.contains(event.target)) return;
if (!run) {
if (event.type === 'wheel' || !(event.target instanceof Element)) return;
if (!event.target.closest('button, input') && !view.contains(event.target)) return;
}
const pointer = event instanceof PointerEvent && event.pointerType === 'mouse' && releaseTarget?.contains(event.target)
? event : undefined;
stop(pointer);
};
for (const event of ['pointerdown', 'keydown', 'focusin', 'input', 'click', 'wheel']) {
root.addEventListener(event, takeOver, { capture: true, passive: true });
}
if (guide.steps.some(({ action }) => action === 'enter' || action === 'move')) {
view.addEventListener('pointermove', takeOver, { capture: true, passive: true });
}
if (guide.pageScrollInput) {
window.addEventListener('scroll', () => {
if (run && window.scrollY !== playbackScroll) stop();
}, { passive: true });
}
document.addEventListener('visibilitychange', () => {
if (document.hidden && run) stop();
else tryAutoplay();
});
reduced.addEventListener('change', () => {
if (!reduced.matches) return;
const wasIdle = root.dataset.guideState === 'idle';
stop();
if (wasIdle) caption.textContent = reducedCaption;
});
}
bindDemoGuide(document.body, {"view":"[data-magnetic-hit]","release":"[data-magnetic-hit]","reducedSteps":[{"target":"[data-magnetic-hit]","action":"click","text":"减少动态效果时,按钮保持原位,仍可点按确认。"}],"steps":[{"target":"[data-magnetic-hit]","action":"move","text":"指针靠左时,按钮视觉层向左偏移。","point":[0.12,0.45],"hold":360},{"target":"[data-magnetic-hit]","action":"move","text":"移向右下角,按钮跟着偏移。","point":[0.88,0.8],"hold":360},{"target":"[data-magnetic-hit]","action":"leave","text":"离开热区,按钮回到虚线标出的原位。","point":[1.15,0.85]}]});
})();
</script>
</body>
</html>