Project import generated by Copybara.
GitOrigin-RevId: 63746295f1a5ab5a619056791995793d65529e62
diff --git a/node_modules/mdl-ext/src/utils/dom-utils.js b/node_modules/mdl-ext/src/utils/dom-utils.js
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+/**
+ * Remove child element(s)
+ * element.innerHTNL = '' has a performance penality!
+ * @see http://jsperf.com/empty-an-element/16
+ * @see http://jsperf.com/force-reflow
+ * @param element
+ * @param forceReflow
+ */
+const removeChildElements = (element, forceReflow = true) => {
+
+ // See: http://jsperf.com/empty-an-element/16
+ while (element.lastChild) {
+ element.removeChild(element.lastChild);
+ }
+ if(forceReflow) {
+ // See: http://jsperf.com/force-reflow
+ const d = element.style.display;
+
+ element.style.display = 'none';
+ element.style.display = d;
+ }
+};
+
+/**
+ * Moves child elements from a DOM node to another dom node.
+ * @param source {HTMLElement}
+ * @param target {HTMLElement} If the target parameter is ommited, a document fragment is created
+ * @return {HTMLElement} The target node
+ *
+ * @example
+ * // Moves child elements from a DOM node to another dom node.
+ * moveElements(source, destination);
+ *
+ * @example
+ * // If the second parameter is ommited, a document fragment is created:
+ * let fragment = moveElements(source);
+ *
+ * @See: https://github.com/webmodules/dom-move
+ */
+const moveElements = (source, target) => {
+ if (!target) {
+ target = source.ownerDocument.createDocumentFragment();
+ }
+ while (source.firstChild) {
+ target.appendChild(source.firstChild);
+ }
+ return target;
+};
+
+
+/**
+ * Get the browser viewport dimensions
+ * @see http://stackoverflow.com/questions/1248081/get-the-browser-viewport-dimensions-with-javascript
+ * @return {{windowWidth: number, windowHeight: number}}
+ */
+const getWindowViewport = () => {
+ return {
+ viewportWidth: Math.max(document.documentElement.clientWidth || 0, window.innerWidth || 0),
+ viewportHeight: Math.max(document.documentElement.clientHeight || 0, window.innerHeight || 0)
+ };
+};
+
+
+/**
+ * Check whether an element is in the window viewport
+ * @see http://stackoverflow.com/questions/123999/how-to-tell-if-a-dom-element-is-visible-in-the-current-viewport/
+ * @param top
+ * @param left
+ * @param bottom
+ * @param right
+ * @return {boolean} true if rectangle is inside window viewport, otherwise false
+ */
+const isRectInsideWindowViewport = ({ top, left, bottom, right }) => {
+ const { viewportWidth, viewportHeight } = getWindowViewport();
+ return top >= 0 &&
+ left >= 0 &&
+ bottom <= viewportHeight &&
+ right <= viewportWidth;
+};
+
+
+/**
+ * Get a list of parent elements that can possibly scroll
+ * @param el the element to get parents for
+ * @returns {Array}
+ */
+const getScrollParents = el => {
+ const elements = [];
+
+ /*
+ for (el = el.parentNode; el; el = el.parentNode) {
+ const cs = window.getComputedStyle(el);
+ if(!(cs.overflowY === 'hidden' && cs.overflowX === 'hidden')) {
+ elements.unshift(el);
+ }
+ if(el === document.body) {
+ break;
+ }
+ }
+ */
+
+ let element = el.parentNode;
+ while (element) {
+ const cs = window.getComputedStyle(element);
+ if(!(cs.overflowY === 'hidden' && cs.overflowX === 'hidden')) {
+ elements.unshift(element);
+ }
+ if(element === document.body) {
+ break;
+ }
+ element = element.parentNode;
+ }
+
+ return elements;
+};
+
+/**
+ * Get a list of parent elements, from a given element to a given element
+ * @param {HTMLElement} from
+ * @param {HTMLElement} to
+ * @return {Array<HTMLElement>} the parent elements, not including from and to
+ */
+const getParentElements = (from, to) => {
+ const result = [];
+ let element = from.parentNode;
+ while (element) {
+ if(element === to) {
+ break;
+ }
+ result.unshift(element);
+ element = element.parentNode;
+ }
+ return result;
+};
+
+/**
+ * Position element next to button
+ *
+ * Positioning strategy
+ * 1. element.height > viewport.height
+ * let element.height = viewport.heigt
+ * let element.overflow-y = auto
+ * 2. element.width > viewport.width
+ * let element.width = viewport.width
+ * 3. position element below button, align left edge of element with button left
+ * done if element inside viewport
+ * 4. position element below button, align right edge of element with button right
+ * done if element inside viewport
+ * 5. positions element above button, aligns left edge of element with button left
+ * done if element inside viewport
+ * 6. position element above the control element, aligned to its right.
+ * done if element inside viewport
+ * 7. position element at button right hand side, aligns element top with button top
+ * done if element inside viewport
+ * 8. position element at button left hand side, aligns element top with button top
+ * done if element inside viewport
+ * 9. position element inside viewport
+ * 1. position element at viewport bottom
+ * 2. position element at button right hand side
+ * done if element inside viewport
+ * 3. position element at button left hand side
+ * done if element inside viewport
+ * 4. position element at viewport right
+ * 10. done
+ *
+ */
+const tether = (controlledBy, element) => {
+ const controlRect = controlledBy.getBoundingClientRect();
+
+ // 1. will element height fit inside window viewport?
+ const { viewportWidth, viewportHeight } = getWindowViewport();
+
+ element.style.height = 'auto';
+ //element.style.overflowY = 'hidden';
+ if(element.offsetHeight > viewportHeight) {
+ element.style.height = `${viewportHeight}px`;
+ element.style.overflowY = 'auto';
+ }
+
+ // 2. will element width fit inside window viewport?
+ element.style.width = 'auto';
+ if(element.offsetWidth > viewportWidth) {
+ element.style.width = `${viewportWidth}px`;
+ }
+
+ const elementRect = element.getBoundingClientRect();
+
+ // element to control distance
+ const dy = controlRect.top - elementRect.top;
+ const dx = controlRect.left - elementRect.left;
+
+ // element rect, window coordinates relative to top,left of control
+ const top = elementRect.top + dy;
+ const left = elementRect.left + dx;
+ const bottom = top + elementRect.height;
+ const right = left + elementRect.width;
+
+ // Position relative to control
+ let ddy = dy;
+ let ddx = dx;
+
+ if(isRectInsideWindowViewport({
+ top: top + controlRect.height,
+ left: left,
+ bottom: bottom + controlRect.height,
+ right: right
+ })) {
+ // 3 position element below the control element, aligned to its left
+ ddy = controlRect.height + dy;
+ //console.log('***** 3');
+ }
+ else if(isRectInsideWindowViewport({
+ top: top + controlRect.height,
+ left: left + controlRect.width - elementRect.width,
+ bottom: bottom + controlRect.height,
+ right: left + controlRect.width
+ })) {
+ // 4 position element below the control element, aligned to its right
+ ddy = controlRect.height + dy;
+ ddx = dx + controlRect.width - elementRect.width;
+ //console.log('***** 4');
+ }
+ else if(isRectInsideWindowViewport({
+ top: top - elementRect.height,
+ left: left,
+ bottom: bottom - elementRect.height,
+ right: right
+ })) {
+ // 5. position element above the control element, aligned to its left.
+ ddy = dy - elementRect.height;
+ //console.log('***** 5');
+ }
+ else if(isRectInsideWindowViewport({
+ top: top - elementRect.height,
+ left: left + controlRect.width - elementRect.width,
+ bottom: bottom - elementRect.height,
+ right: left + controlRect.width
+ })) {
+ // 6. position element above the control element, aligned to its right.
+ ddy = dy - elementRect.height;
+ ddx = dx + controlRect.width - elementRect.width;
+ //console.log('***** 6');
+ }
+ else if(isRectInsideWindowViewport({
+ top: top,
+ left: left + controlRect.width,
+ bottom: bottom,
+ right: right + controlRect.width
+ })) {
+ // 7. position element at button right hand side
+ ddx = controlRect.width + dx;
+ //console.log('***** 7');
+ }
+ else if(isRectInsideWindowViewport({
+ top: top,
+ left: left - controlRect.width,
+ bottom: bottom,
+ right: right - controlRect.width
+ })) {
+ // 8. position element at button left hand side
+ ddx = dx - elementRect.width;
+ //console.log('***** 8');
+ }
+ else {
+ // 9. position element inside viewport, near controlrect if possible
+ //console.log('***** 9');
+
+ // 9.1 position element near controlrect bottom
+ ddy = dy - bottom + viewportHeight;
+ if(top + controlRect.height >= 0 && bottom + controlRect.height <= viewportHeight) {
+ ddy = controlRect.height + dy;
+ }
+ else if(top - elementRect.height >= 0 && bottom - elementRect.height <= viewportHeight) {
+ ddy = dy - elementRect.height;
+ }
+
+ if(left + elementRect.width + controlRect.width <= viewportWidth) {
+ // 9.2 Position element at button right hand side
+ ddx = controlRect.width + dx;
+ //console.log('***** 9.2');
+ }
+ else if(left - elementRect.width >= 0) {
+ // 9.3 Position element at button left hand side
+ ddx = dx - elementRect.width;
+ //console.log('***** 9.3');
+ }
+ else {
+ // 9.4 position element at (near) viewport right
+ const r = left + elementRect.width - viewportWidth;
+ ddx = dx - r;
+ //console.log('***** 9.4');
+ }
+ }
+
+ // 10. done
+ element.style.top = `${element.offsetTop + ddy}px`;
+ element.style.left = `${element.offsetLeft + ddx}px`;
+ //console.log('***** 10. done');
+};
+
+/**
+ * Check if the given element can receive focus
+ * @param {HTMLElement} element the element to check
+ * @return {boolean} true if the element is focusable, otherwise false
+ */
+const isFocusable = (element) => {
+ // https://github.com/stephenmathieson/is-focusable/blob/master/index.js
+ // http://stackoverflow.com/questions/1599660/which-html-elements-can-receive-focus
+
+ if (element.hasAttribute('tabindex')) {
+ const tabindex = element.getAttribute('tabindex');
+ if (!Number.isNaN(tabindex)) {
+ return parseInt(tabindex) > -1;
+ }
+ }
+
+ if (element.hasAttribute('contenteditable') &&
+ element.getAttribute('contenteditable') !== 'false') {
+ // https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes#attr-contenteditable
+ return true;
+ }
+
+ // natively focusable, but only when enabled
+ const selector = /input|select|textarea|button|details/i;
+ const name = element.nodeName;
+ if (selector.test(name)) {
+ return element.type.toLowerCase() !== 'hidden' && !element.disabled;
+ }
+
+ // anchors and area must have an href
+ if (name === 'A' || name === 'AREA') {
+ return !!element.href;
+ }
+
+ if (name === 'IFRAME') {
+ // Check visible iframe
+ const cs = window.getComputedStyle(element);
+ return cs.getPropertyValue('display').toLowerCase() !== 'none';
+ }
+
+ return false;
+};
+
+
+/**
+ * Get a list of offset parents for given element
+ * @see https://www.benpickles.com/articles/51-finding-a-dom-nodes-common-ancestor-using-javascript
+ * @param el the element
+ * @return {Array} a list of offset parents
+ */
+/*
+const offsetParents = (el) => {
+ const elements = [];
+ for (; el; el = el.offsetParent) {
+ elements.unshift(el);
+ }
+ if(!elements.find(e => e === document.body)) {
+ elements.unshift(document.body);
+ }
+ return elements;
+};
+*/
+
+/**
+ * Finds the common offset ancestor of two DOM nodes
+ * @see https://www.benpickles.com/articles/51-finding-a-dom-nodes-common-ancestor-using-javascript
+ * @see https://gist.github.com/benpickles/4059636
+ * @param a
+ * @param b
+ * @return {Element} The common offset ancestor of a and b
+ */
+/*
+const commonOffsetAncestor = (a, b) => {
+ const parentsA = offsetParents(a);
+ const parentsB = offsetParents(b);
+
+ for (let i = 0; i < parentsA.length; i++) {
+ if (parentsA[i] !== parentsB[i]) return parentsA[i-1];
+ }
+};
+*/
+
+/**
+ * Calculate position relative to a target element
+ * @see http://stackoverflow.com/questions/21064101/understanding-offsetwidth-clientwidth-scrollwidth-and-height-respectively
+ * @param target
+ * @param el
+ * @return {{top: number, left: number}}
+ */
+/*
+const calcPositionRelativeToTarget = (target, el) => {
+ let top = 0;
+ let left = 0;
+
+ while(el) {
+ top += (el.offsetTop - el.scrollTop + el.clientTop) || 0;
+ left += (el.offsetLeft - el.scrollLeft + el.clientLeft) || 0;
+ el = el.offsetParent;
+
+ if(el === target) {
+ break;
+ }
+ }
+ return { top: top, left: left };
+};
+*/
+
+export {
+ getWindowViewport,
+ getParentElements,
+ getScrollParents,
+ isFocusable,
+ isRectInsideWindowViewport,
+ moveElements,
+ removeChildElements,
+ tether,
+};
+