73 lines
1.7 KiB
JavaScript
73 lines
1.7 KiB
JavaScript
var props = ["bottom", "height", "left", "right", "top", "width"];
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var rectChanged = function rectChanged(a, b) {
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if (a === void 0) {
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a = {};
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}
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if (b === void 0) {
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b = {};
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}
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return props.some(function (prop) {
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return a[prop] !== b[prop];
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});
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};
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var observedNodes = /*#__PURE__*/new Map();
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var rafId;
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var run = function run() {
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var changedStates = [];
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observedNodes.forEach(function (state, node) {
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var newRect = node.getBoundingClientRect();
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if (rectChanged(newRect, state.rect)) {
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state.rect = newRect;
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changedStates.push(state);
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}
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});
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changedStates.forEach(function (state) {
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state.callbacks.forEach(function (cb) {
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return cb(state.rect);
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});
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});
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rafId = window.requestAnimationFrame(run);
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};
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function observeRect(node, cb) {
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return {
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observe: function observe() {
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var wasEmpty = observedNodes.size === 0;
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if (observedNodes.has(node)) {
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observedNodes.get(node).callbacks.push(cb);
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} else {
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observedNodes.set(node, {
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rect: undefined,
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hasRectChanged: false,
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callbacks: [cb]
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});
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}
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if (wasEmpty) run();
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},
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unobserve: function unobserve() {
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var state = observedNodes.get(node);
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if (state) {
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// Remove the callback
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var index = state.callbacks.indexOf(cb);
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if (index >= 0) state.callbacks.splice(index, 1); // Remove the node reference
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if (!state.callbacks.length) observedNodes["delete"](node); // Stop the loop
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if (!observedNodes.size) cancelAnimationFrame(rafId);
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}
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}
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};
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}
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export default observeRect;
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//# sourceMappingURL=observe-rect.esm.js.map
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