61 lines
1.3 KiB
HTML
61 lines
1.3 KiB
HTML
<!DOCTYPE html>
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<html>
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<head>
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<meta charset="utf-8">
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<style>
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.message-ball {
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font-size: 20px;
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line-height: 200px;
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text-align: center;
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}
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.circle {
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transition-property: width, height, margin-left, margin-top;
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transition-duration: 2s;
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position: fixed;
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transform: translateX(-50%) translateY(-50%);
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background-color: red;
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border-radius: 50%;
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}
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</style>
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</head>
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<body>
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<button onclick="go()">Click me</button>
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<script>
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function go() {
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showCircle(150, 150, 100).then(div => {
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div.classList.add('message-ball');
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div.append("Hello, world!");
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});
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}
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function showCircle(cx, cy, radius) {
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let div = document.createElement('div');
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div.style.width = 0;
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div.style.height = 0;
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div.style.left = cx + 'px';
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div.style.top = cy + 'px';
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div.className = 'circle';
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document.body.append(div);
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return new Promise(resolve => {
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setTimeout(() => {
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div.style.width = radius * 2 + 'px';
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div.style.height = radius * 2 + 'px';
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div.addEventListener('transitionend', function handler() {
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div.removeEventListener('transitionend', handler);
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resolve(div);
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});
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}, 0);
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})
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}
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</script>
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</body>
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</html>
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