36 lines
1.3 KiB
Plaintext
36 lines
1.3 KiB
Plaintext
import { resolveEdge, namedEdges } from './edge.mjs';
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const defaultOffset = [0, 0];
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function resolveOffset(offset, containerLength, targetLength, targetInset) {
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let offsetDefinition = Array.isArray(offset) ? offset : defaultOffset;
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let targetPoint = 0;
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let containerPoint = 0;
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if (typeof offset === "number") {
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/**
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* If we're provided offset: [0, 0.5, 1] then each number x should become
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* [x, x], so we default to the behaviour of mapping 0 => 0 of both target
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* and container etc.
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*/
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offsetDefinition = [offset, offset];
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}
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else if (typeof offset === "string") {
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offset = offset.trim();
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if (offset.includes(" ")) {
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offsetDefinition = offset.split(" ");
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}
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else {
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/**
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* If we're provided a definition like "100px" then we want to apply
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* that only to the top of the target point, leaving the container at 0.
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* Whereas a named offset like "end" should be applied to both.
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*/
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offsetDefinition = [offset, namedEdges[offset] ? offset : `0`];
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}
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}
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targetPoint = resolveEdge(offsetDefinition[0], targetLength, targetInset);
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containerPoint = resolveEdge(offsetDefinition[1], containerLength);
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return targetPoint - containerPoint;
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}
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export { resolveOffset };
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