69 lines
1.8 KiB
JavaScript
69 lines
1.8 KiB
JavaScript
/* @flow */
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'use strict';
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import type NodeContainer from './NodeContainer';
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const LENGTH_WITH_UNIT = /([\d.]+)(px|r?em|%)/i;
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export const LENGTH_TYPE = {
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PX: 0,
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PERCENTAGE: 1
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};
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export type LengthType = $Values<typeof LENGTH_TYPE>;
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export default class Length {
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type: LengthType;
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value: number;
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constructor(value: string) {
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this.type =
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value.substr(value.length - 1) === '%' ? LENGTH_TYPE.PERCENTAGE : LENGTH_TYPE.PX;
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const parsedValue = parseFloat(value);
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if (__DEV__ && isNaN(parsedValue)) {
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console.error(`Invalid value given for Length: "${value}"`);
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}
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this.value = isNaN(parsedValue) ? 0 : parsedValue;
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}
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isPercentage(): boolean {
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return this.type === LENGTH_TYPE.PERCENTAGE;
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}
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getAbsoluteValue(parentLength: number): number {
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return this.isPercentage() ? parentLength * (this.value / 100) : this.value;
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}
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static create(v): Length {
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return new Length(v);
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}
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}
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const getRootFontSize = (container: NodeContainer): number => {
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const parent = container.parent;
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return parent ? getRootFontSize(parent) : parseFloat(container.style.font.fontSize);
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};
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export const calculateLengthFromValueWithUnit = (
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container: NodeContainer,
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value: string,
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unit: string
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): Length => {
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switch (unit) {
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case 'px':
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case '%':
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return new Length(value + unit);
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case 'em':
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case 'rem':
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const length = new Length(value);
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length.value *=
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unit === 'em'
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? parseFloat(container.style.font.fontSize)
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: getRootFontSize(container);
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return length;
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default:
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// TODO: handle correctly if unknown unit is used
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return new Length('0');
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}
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};
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