54 lines
2.4 KiB
JavaScript
54 lines
2.4 KiB
JavaScript
import { __assign } from "tslib";
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import { useMemo, useRef } from 'react';
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import useMountedState from './useMountedState';
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import useUpdate from './useUpdate';
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import useUpdateEffect from './useUpdateEffect';
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export default function useStateList(stateSet) {
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if (stateSet === void 0) { stateSet = []; }
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var isMounted = useMountedState();
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var update = useUpdate();
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var index = useRef(0);
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// If new state list is shorter that before - switch to the last element
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useUpdateEffect(function () {
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if (stateSet.length <= index.current) {
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index.current = stateSet.length - 1;
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update();
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}
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}, [stateSet.length]);
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var actions = useMemo(function () { return ({
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next: function () { return actions.setStateAt(index.current + 1); },
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prev: function () { return actions.setStateAt(index.current - 1); },
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setStateAt: function (newIndex) {
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// do nothing on unmounted component
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if (!isMounted())
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return;
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// do nothing on empty states list
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if (!stateSet.length)
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return;
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// in case new index is equal current - do nothing
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if (newIndex === index.current)
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return;
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// it gives the ability to travel through the left and right borders.
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// 4ex: if list contains 5 elements, attempt to set index 9 will bring use to 5th element
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// in case of negative index it will start counting from the right, so -17 will bring us to 4th element
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index.current =
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newIndex >= 0
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? newIndex % stateSet.length
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: stateSet.length + (newIndex % stateSet.length);
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update();
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},
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setState: function (state) {
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// do nothing on unmounted component
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if (!isMounted())
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return;
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var newIndex = stateSet.length ? stateSet.indexOf(state) : -1;
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if (newIndex === -1) {
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throw new Error("State '" + state + "' is not a valid state (does not exist in state list)");
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}
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index.current = newIndex;
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update();
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},
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}); }, [stateSet]);
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return __assign({ state: stateSet[index.current], currentIndex: index.current, isFirst: index.current === 0, isLast: index.current === stateSet.length - 1 }, actions);
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}
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