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- import defineConfigurable from './defineConfigurable.js';
- import getWindowOf from './getWindowOf.js';
- import isBrowser from './isBrowser.js';
- // Placeholder of an empty content rectangle.
- const emptyRect = createRectInit(0, 0, 0, 0);
- /**
- * Converts provided string to a number.
- *
- * @param {number|string} value
- * @returns {number}
- */
- function toFloat(value) {
- return parseFloat(value) || 0;
- }
- /**
- * Extracts borders size from provided styles.
- *
- * @param {CSSStyleDeclaration} styles
- * @param {...string} positions - Borders positions (top, right, ...)
- * @returns {number}
- */
- function getBordersSize(styles, ...positions) {
- return positions.reduce((size, position) => {
- const value = styles['border-' + position + '-width'];
- return size + toFloat(value);
- }, 0);
- }
- /**
- * Extracts paddings sizes from provided styles.
- *
- * @param {CSSStyleDeclaration} styles
- * @returns {Object} Paddings box.
- */
- function getPaddings(styles) {
- const positions = ['top', 'right', 'bottom', 'left'];
- const paddings = {};
- for (const position of positions) {
- const value = styles['padding-' + position];
- paddings[position] = toFloat(value);
- }
- return paddings;
- }
- /**
- * Calculates content rectangle of provided SVG element.
- *
- * @param {SVGGraphicsElement} target - Element content rectangle of which needs
- * to be calculated.
- * @returns {DOMRectInit}
- */
- function getSVGContentRect(target) {
- const bbox = target.getBBox();
- return createRectInit(0, 0, bbox.width, bbox.height);
- }
- /**
- * Calculates content rectangle of provided HTMLElement.
- *
- * @param {HTMLElement} target - Element for which to calculate the content rectangle.
- * @returns {DOMRectInit}
- */
- function getHTMLElementContentRect(target) {
- // Client width & height properties can't be
- // used exclusively as they provide rounded values.
- const {clientWidth, clientHeight} = target;
- // By this condition we can catch all non-replaced inline, hidden and
- // detached elements. Though elements with width & height properties less
- // than 0.5 will be discarded as well.
- //
- // Without it we would need to implement separate methods for each of
- // those cases and it's not possible to perform a precise and performance
- // effective test for hidden elements. E.g. even jQuery's ':visible' filter
- // gives wrong results for elements with width & height less than 0.5.
- if (!clientWidth && !clientHeight) {
- return emptyRect;
- }
- const styles = getWindowOf(target).getComputedStyle(target);
- const paddings = getPaddings(styles);
- const horizPad = paddings.left + paddings.right;
- const vertPad = paddings.top + paddings.bottom;
- // Computed styles of width & height are being used because they are the
- // only dimensions available to JS that contain non-rounded values. It could
- // be possible to utilize the getBoundingClientRect if only it's data wasn't
- // affected by CSS transformations let alone paddings, borders and scroll bars.
- let width = toFloat(styles.width),
- height = toFloat(styles.height);
- // Width & height include paddings and borders when the 'border-box' box
- // model is applied (except for IE).
- if (styles.boxSizing === 'border-box') {
- // Following conditions are required to handle Internet Explorer which
- // doesn't include paddings and borders to computed CSS dimensions.
- //
- // We can say that if CSS dimensions + paddings are equal to the "client"
- // properties then it's either IE, and thus we don't need to subtract
- // anything, or an element merely doesn't have paddings/borders styles.
- if (Math.round(width + horizPad) !== clientWidth) {
- width -= getBordersSize(styles, 'left', 'right') + horizPad;
- }
- if (Math.round(height + vertPad) !== clientHeight) {
- height -= getBordersSize(styles, 'top', 'bottom') + vertPad;
- }
- }
- // Following steps can't be applied to the document's root element as its
- // client[Width/Height] properties represent viewport area of the window.
- // Besides, it's as well not necessary as the <html> itself neither has
- // rendered scroll bars nor it can be clipped.
- if (!isDocumentElement(target)) {
- // In some browsers (only in Firefox, actually) CSS width & height
- // include scroll bars size which can be removed at this step as scroll
- // bars are the only difference between rounded dimensions + paddings
- // and "client" properties, though that is not always true in Chrome.
- const vertScrollbar = Math.round(width + horizPad) - clientWidth;
- const horizScrollbar = Math.round(height + vertPad) - clientHeight;
- // Chrome has a rather weird rounding of "client" properties.
- // E.g. for an element with content width of 314.2px it sometimes gives
- // the client width of 315px and for the width of 314.7px it may give
- // 314px. And it doesn't happen all the time. So just ignore this delta
- // as a non-relevant.
- if (Math.abs(vertScrollbar) !== 1) {
- width -= vertScrollbar;
- }
- if (Math.abs(horizScrollbar) !== 1) {
- height -= horizScrollbar;
- }
- }
- return createRectInit(paddings.left, paddings.top, width, height);
- }
- /**
- * Checks whether provided element is an instance of the SVGGraphicsElement.
- *
- * @param {Element} target - Element to be checked.
- * @returns {boolean}
- */
- const isSVGGraphicsElement = (() => {
- // Some browsers, namely IE and Edge, don't have the SVGGraphicsElement
- // interface.
- if (typeof SVGGraphicsElement !== 'undefined') {
- return target => target instanceof getWindowOf(target).SVGGraphicsElement;
- }
- // If it's so, then check that element is at least an instance of the
- // SVGElement and that it has the "getBBox" method.
- // eslint-disable-next-line no-extra-parens
- return target => (
- target instanceof getWindowOf(target).SVGElement &&
- typeof target.getBBox === 'function'
- );
- })();
- /**
- * Checks whether provided element is a document element (<html>).
- *
- * @param {Element} target - Element to be checked.
- * @returns {boolean}
- */
- function isDocumentElement(target) {
- return target === getWindowOf(target).document.documentElement;
- }
- /**
- * Calculates an appropriate content rectangle for provided html or svg element.
- *
- * @param {Element} target - Element content rectangle of which needs to be calculated.
- * @returns {DOMRectInit}
- */
- export function getContentRect(target) {
- if (!isBrowser) {
- return emptyRect;
- }
- if (isSVGGraphicsElement(target)) {
- return getSVGContentRect(target);
- }
- return getHTMLElementContentRect(target);
- }
- /**
- * Creates rectangle with an interface of the DOMRectReadOnly.
- * Spec: https://drafts.fxtf.org/geometry/#domrectreadonly
- *
- * @param {DOMRectInit} rectInit - Object with rectangle's x/y coordinates and dimensions.
- * @returns {DOMRectReadOnly}
- */
- export function createReadOnlyRect({x, y, width, height}) {
- // If DOMRectReadOnly is available use it as a prototype for the rectangle.
- const Constr = typeof DOMRectReadOnly !== 'undefined' ? DOMRectReadOnly : Object;
- const rect = Object.create(Constr.prototype);
- // Rectangle's properties are not writable and non-enumerable.
- defineConfigurable(rect, {
- x, y, width, height,
- top: y,
- right: x + width,
- bottom: height + y,
- left: x
- });
- return rect;
- }
- /**
- * Creates DOMRectInit object based on the provided dimensions and the x/y coordinates.
- * Spec: https://drafts.fxtf.org/geometry/#dictdef-domrectinit
- *
- * @param {number} x - X coordinate.
- * @param {number} y - Y coordinate.
- * @param {number} width - Rectangle's width.
- * @param {number} height - Rectangle's height.
- * @returns {DOMRectInit}
- */
- export function createRectInit(x, y, width, height) {
- return {x, y, width, height};
- }
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