diff options
Diffstat (limited to 'src/static/js')
| -rw-r--r-- | src/static/js/client.js | 3483 | ||||
| -rw-r--r-- | src/static/js/lazy-loading.js | 54 | ||||
| -rw-r--r-- | src/static/js/xhr-util.js | 64 |
3 files changed, 3601 insertions, 0 deletions
diff --git a/src/static/js/client.js b/src/static/js/client.js new file mode 100644 index 00000000..4fadffc4 --- /dev/null +++ b/src/static/js/client.js @@ -0,0 +1,3483 @@ +/* eslint-env browser */ + +// This is the JS file that gets loaded on the client! It's only really used for +// the random track feature right now - the idea is we only use it for stuff +// that cannot 8e done at static-site compile time, 8y its fundamentally +// ephemeral nature. + +import {accumulateSum, empty, filterMultipleArrays, stitchArrays} + from '../shared-util/sugar.js'; +import {fetchWithProgress} from './xhr-util.js'; + +const clientInfo = window.hsmusicClientInfo = Object.create(null); + +const clientSteps = { + getPageReferences: [], + addInternalListeners: [], + mutatePageContent: [], + initializeState: [], + addPageListeners: [], +}; + +function initInfo(infoKey, description) { + const object = {...description}; + + for (const obj of [ + object, + object.state, + object.setting, + object.event, + ]) { + if (!obj) continue; + Object.preventExtensions(obj); + } + + if (object.session) { + const sessionDefaults = object.session; + + object.session = {}; + + for (const [key, defaultValue] of Object.entries(sessionDefaults)) { + const storageKey = `hsmusic.${infoKey}.${key}`; + + let fallbackValue = defaultValue; + + Object.defineProperty(object.session, key, { + get: () => { + try { + return sessionStorage.getItem(storageKey) ?? defaultValue; + } catch (error) { + if (error instanceof DOMException) { + return fallbackValue; + } else { + throw error; + } + } + }, + + set: (value) => { + try { + sessionStorage.setItem(storageKey, value); + } catch (error) { + if (error instanceof DOMException) { + fallbackValue = value; + } else { + throw error; + } + } + }, + }); + } + + Object.preventExtensions(object.session); + } + + clientInfo[infoKey] = object; + + return object; +} + +// Localiz8tion nonsense ---------------------------------- + +/* +const language = document.documentElement.getAttribute('lang'); + +let list; +if (typeof Intl === 'object' && typeof Intl.ListFormat === 'function') { + const getFormat = (type) => { + const formatter = new Intl.ListFormat(language, {type}); + return formatter.format.bind(formatter); + }; + + list = { + conjunction: getFormat('conjunction'), + disjunction: getFormat('disjunction'), + unit: getFormat('unit'), + }; +} else { + // Not a gr8 mock we've got going here, 8ut it's *mostly* language-free. + // We use the same mock for every list 'cuz we don't have any of the + // necessary CLDR info to appropri8tely distinguish 8etween them. + const arbitraryMock = (array) => array.join(', '); + + list = { + conjunction: arbitraryMock, + disjunction: arbitraryMock, + unit: arbitraryMock, + }; +} +*/ + +// Miscellaneous helpers ---------------------------------- + +function rebase(href, rebaseKey = 'rebaseLocalized') { + const relative = (document.documentElement.dataset[rebaseKey] || '.') + '/'; + if (relative) { + return relative + href; + } else { + return href; + } +} + +function pick(array) { + return array[Math.floor(Math.random() * array.length)]; +} + +function cssProp(el, ...args) { + if (typeof args[0] === 'string' && args.length === 1) { + return getComputedStyle(el).getPropertyValue(args[0]).trim(); + } + + if (typeof args[0] === 'string' && args.length === 2) { + if (args[1] === null) { + el.style.removeProperty(args[0]); + } else { + el.style.setProperty(args[0], args[1]); + } + return; + } + + if (typeof args[0] === 'object') { + for (const [property, value] of Object.entries(args[0])) { + cssProp(el, property, value); + } + } +} + +// Curry-style, so multiple points can more conveniently be tested at once. +function pointIsOverAnyOf(elements) { + return (clientX, clientY) => { + const element = document.elementFromPoint(clientX, clientY); + return elements.some(el => el.contains(element)); + }; +} + +function getVisuallyContainingElement(child) { + let parent = child.parentElement; + + while (parent) { + if ( + cssProp(parent, 'overflow') === 'hidden' || + cssProp(parent, 'contain') === 'paint' + ) { + return parent; + } + + parent = parent.parentElement; + } + + return null; +} + +// TODO: These should pro8a8ly access some shared urlSpec path. We'd need to +// separ8te the tooling around that into common-shared code too. + +/* +const getLinkHref = (type, directory) => rebase(`${type}/${directory}`); +*/ + +const openAlbum = (d) => rebase(`album/${d}`); +const openTrack = (d) => rebase(`track/${d}`); +const openArtist = (d) => rebase(`artist/${d}`); + +// TODO: This should also use urlSpec. + +/* +function fetchData(type, directory) { + return fetch(rebase(`${type}/${directory}/data.json`, 'rebaseData')).then( + (res) => res.json() + ); +} +*/ + +function dispatchInternalEvent(event, eventName, ...args) { + const [infoName] = + Object.entries(clientInfo) + .find(pair => pair[1].event === event); + + if (!infoName) { + throw new Error(`Expected event to be stored on clientInfo`); + } + + const {[eventName]: listeners} = event; + + if (!listeners) { + throw new Error(`Event name "${eventName}" isn't stored on ${infoName}.event`); + } + + let results = []; + for (const listener of listeners) { + try { + results.push(listener(...args)); + } catch (error) { + console.warn(`Uncaught error in listener for ${infoName}.${eventName}`); + console.debug(error); + results.push(undefined); + } + } + + return results; +} + +// Rectangle math ----------------------------------------- + +class WikiRect extends DOMRect { + // Useful constructors + + static fromWindow() { + const {clientWidth: width, clientHeight: height} = + document.documentElement; + + return Reflect.construct(this, [0, 0, width, height]); + } + + static fromElement(element) { + return this.fromRect(element.getBoundingClientRect()); + } + + static fromMouse() { + const {clientX, clientY} = liveMousePositionInfo.state; + + return WikiRect.fromRect({ + x: clientX, + y: clientY, + width: 0, + height: 0, + }); + } + + static fromElementUnderMouse(element) { + const mouseRect = WikiRect.fromMouse(); + + const rects = + Array.from(element.getClientRects()) + .map(rect => WikiRect.fromRect(rect)); + + const rectUnderMouse = + rects.find(rect => rect.contains(mouseRect)); + + if (rectUnderMouse) { + return rectUnderMouse; + } else { + return rects[0]; + } + } + + static leftOf(origin, offset = 0) { + // Returns a rectangle representing everywhere to the left of the provided + // point or rectangle (with no top or bottom bounds), towards negative x. + // If an offset is provided, this is added onto the origin. + + return this.#past(origin, offset, { + origin: 'x', + extent: 'width', + edge: 'left', + direction: -Infinity, + construct: from => + [from, -Infinity, -Infinity, Infinity], + }); + } + + static rightOf(origin, offset = 0) { + // Returns a rectangle representing everywhere to the right of the + // provided point or rectangle (with no top or bottom bounds), towards + // positive x. If an offset is provided, this is added onto the origin. + + return this.#past(origin, offset, { + origin: 'x', + extent: 'width', + edge: 'right', + direction: Infinity, + construct: from => + [from, -Infinity, Infinity, Infinity], + }); + } + + static above(origin, offset = 0) { + // Returns a rectangle representing everywhere above the provided point + // or rectangle (with no left or right bounds), towards negative y. + // If an offset is provided, this is added onto the origin. + + return this.#past(origin, offset, { + origin: 'y', + extent: 'height', + edge: 'top', + direction: -Infinity, + construct: from => + [-Infinity, from, Infinity, -Infinity], + }); + } + + static beneath(origin, offset = 0) { + // Returns a rectangle representing everywhere beneath the provided point + // or rectangle (with no left or right bounds), towards positive y. + // If an offset is provided, this is added onto the origin. + + return this.#past(origin, offset, { + origin: 'y', + extent: 'height', + edge: 'bottom', + direction: Infinity, + construct: from => + [-Infinity, from, Infinity, Infinity], + }); + } + + // Constructor helpers + + static #past(origin, offset, opts) { + if (!isFinite(offset)) { + throw new TypeError(`Didn't expect infinite offset`); + } + + const {direction, edge} = opts; + + if (typeof origin === 'object') { + const {origin: originProperty, extent: extentProperty} = opts; + + const normalized = + WikiRect.fromRect(origin).toNormalized(); + + if (normalized[extentProperty] === direction) { + throw new TypeError(`Provided rectangle already extends to ${edge} edge`); + } + + if (normalized[extentProperty] === -direction) { + return this.#past(normalized[originProperty], offset, opts); + } + + if (normalized.y === direction) { + throw new TypeError(`Provided rectangle already starts at ${edge} edge`); + } + + return this.#past(normalized[edge], offset, opts); + } + + const {construct} = opts; + + if (origin === direction) { + throw new TypeError(`Provided point is already at ${edge} edge`); + } + + return Reflect.construct(this, construct(origin + offset)).toNormalized(); + } + + // Predicates + + static rejectInfiniteOriginNonZeroFiniteExtent({origin, extent}) { + // Indicate that, in this context, it's meaningless to provide + // a finite extent starting at an infinite origin and going towards + // or away from zero (i.e. a rectangle along a cardinal edge). + + if (!isFinite(origin) && isFinite(extent) && extent !== 0) { + throw new TypeError(`Didn't expect infinite origin paired with finite extent`); + } + } + + static rejectInfiniteOriginZeroExtent({origin, extent}) { + // Indicate that, in this context, it's meaningless to provide + // a zero extent at an infinite origin (i.e. a cardinal edge). + + if (!isFinite(origin) && extent === 0) { + throw new TypeError(`Didn't expect infinite origin paired with zero extent`); + } + } + + static rejectNonOpposingInfiniteOriginInfiniteExtent({origin, extent}) { + // Indicate that, in this context, it's meaningless to provide + // an infinite extent going in the same direction as its infinite + // origin (an area "infinitely past" a cardinal edge). + + if (!isFinite(origin) && origin === extent) { + throw new TypeError(`Didn't expect non-opposing infinite origin and extent`); + } + } + + // Transformations + + static normalizeOriginExtent({origin, extent}) { + // Varying behavior based on inputs: + // + // - For finite origin and finite extent, flip the orientation + // (if necessary) so that extent is positive. + // - For finite origin and infinite extent (i.e. an origin up to + // a cardinal edge), leave as-is. + // - For infinite origin and infinite extent, flip the orientation + // (if necessary) so origin is negative and extent is positive. + // - For infinite origin and zero extent (i.e. a cardinal edge), + // leave as-is. + // - For all other cases, error. + // + + this.rejectInfiniteOriginNonZeroFiniteExtent({origin, extent}); + this.rejectNonOpposingInfiniteOriginInfiniteExtent({origin, extent}); + + if (isFinite(origin) && isFinite(extent) && extent < 0) { + return {origin: origin + extent, extent: -extent}; + } + + if (!isFinite(origin) && !isFinite(extent)) { + return {origin: -Infinity, extent: Infinity}; + } + + return {origin, extent}; + } + + toNormalized() { + const {origin: newX, extent: newWidth} = + WikiRect.normalizeOriginExtent({ + origin: this.x, + extent: this.width, + }); + + const {origin: newY, extent: newHeight} = + WikiRect.normalizeOriginExtent({ + origin: this.y, + extent: this.height, + }); + + return Reflect.construct(this.constructor, [newX, newY, newWidth, newHeight]); + } + + static intersectionFromOriginsExtents(...entries) { + // An intersection is the common subsection across two or more regions. + + const [first, second, ...rest] = entries; + + if (entries.length >= 3) { + return this.intersection(first, this.intersection(second, ...rest)); + } + + if (entries.length === 2) { + if (first === null || second === null) { + return null; + } + + this.rejectInfiniteOriginZeroExtent(first); + this.rejectInfiniteOriginZeroExtent(second); + + const {origin: origin1, extent: extent1} = this.normalizeOriginExtent(first); + const {origin: origin2, extent: extent2} = this.normalizeOriginExtent(second); + + // After normalizing, *each* region will be one of these: + // + // - Finite origin, finite extent + // (a standard region, bounded on both sides) + // - Finite origin, infinite extent + // (everything to one direction of a given origin) + // - Infinite origin, infinite extent + // (everything everywhere) + // + // So we need to handle any *combination* of these kinds of regions. + + // If either origin is infinite, that region represents everywhere, + // so it'll never limit the region of the other. + + if (!isFinite(origin1)) { + return {origin: origin2, extent: extent2}; + } + + if (!isFinite(origin2)) { + return {origin: origin1, extent: extent1}; + } + + // If neither origin is infinite, both regions are bounded on at least + // one side, and may limit the other accordingly. Find the minimum and + // maximum points in each region, letting Infinity propagate through, + // which represents no boundary in that direction. + + const minimum1 = Math.min(origin1, origin1 + extent1); + const minimum2 = Math.min(origin2, origin2 + extent2); + const maximum1 = Math.max(origin1, origin1 + extent1); + const maximum2 = Math.max(origin2, origin2 + extent2); + + // Now get the maximum of the regions' minimums, and the minimum of the + // regions' maximums. These are the limits of the new region; computing + // with minimums and maximums in this way "polarizes" the limits, so we + // can perform specific polarized math in the following steps. + // + // Infinity will also propagate here, but with some important + // restricitons: only maxOfMinimums can be positive Infinity, and only + // minOfMaximums can be negative Infinity; and if either is Infinity, + // the other is not, since otherwise we'd be working with two everywhere + // regions, and would've just returned an everywhere region above. + + const maxOfMinimums = Math.max(minimum1, minimum2); + const minOfMaximums = Math.min(maximum1, maximum2); + + // Now check if the maximum of minimums is greater than the minimum of + // maximums. If so, the regions don't have any overlap - one region + // limits the overlap to end before the other region starts. This works + // because we've polarized the limits above! + + if (maxOfMinimums > minOfMaximums) { + return null; + } + + // Otherwise there's at least some overlap, even if it's just one point + // (i.e. one ends exactly where the other begins). We have to take care + // of infinities in particular, now. As mentioned above, only one of the + // points will be infinity (at most). So the origin is the non-infinite + // point, and the extent is in the direction of the infinite point. + + if (minOfMaximums === -Infinity) { + return {origin: maxOfMinimums, extent: -Infinity}; + } + + if (maxOfMinimums === Infinity) { + return {origin: minOfMaximums, extent: Infinity}; + } + + // If neither point is infinity, we're working with two regions that are + // both bounded on both sides, so the overlapping region is just the + // region constrained by the limits above. Since these are polarized, + // start from maxOfMinimums and extend to minOfMaximums, resulting in + // a standard, already-normalized region. + + return { + origin: maxOfMinimums, + extent: minOfMaximums - maxOfMinimums, + }; + } + + if (entries.length === 1) { + return first; + } + + throw new TypeError(`Expected at least one {origin, extent} entry`); + } + + intersectionWith(rect) { + const horizontalIntersection = + WikiRect.intersectionFromOriginsExtents( + {origin: this.x, extent: this.width}, + {origin: rect.x, extent: rect.width}); + + const verticalIntersection = + WikiRect.intersectionFromOriginsExtents( + {origin: this.y, extent: this.height}, + {origin: rect.y, extent: rect.height}); + + if (!horizontalIntersection) return null; + if (!verticalIntersection) return null; + + const {origin: x, extent: width} = horizontalIntersection; + const {origin: y, extent: height} = verticalIntersection; + + return Reflect.construct(this.constructor, [x, y, width, height]); + } + + chopExtendingOutside(rect) { + this.intersectionWith(rect).writeOnto(this); + } + + static insetOriginExtent({origin, extent, start = 0, end = 0}) { + const normalized = + this.normalizeOriginExtent({origin, extent}); + + // If this would crush the bounds past each other, just return + // the halfway point. + if (extent < start + end) { + return {origin: origin + (start + end) / 2, extent: 0}; + } + + return { + origin: normalized.origin + start, + extent: normalized.extent - start - end, + }; + } + + toInset(arg1, arg2) { + if (typeof arg1 === 'number' && typeof arg2 === 'number') { + return this.toInset({ + left: arg2, + right: arg2, + top: arg1, + bottom: arg1, + }); + } else if (typeof arg1 === 'number') { + return this.toInset({ + left: arg1, + right: arg1, + top: arg1, + bottom: arg1, + }); + } + + const {top, left, bottom, right} = arg1; + + const {origin: x, extent: width} = + WikiRect.insetOriginExtent({ + origin: this.x, + extent: this.width, + start: left, + end: right, + }); + + const {origin: y, extent: height} = + WikiRect.insetOriginExtent({ + origin: this.y, + extent: this.height, + start: top, + end: bottom, + }); + + return Reflect.construct(this.constructor, [x, y, width, height]); + } + + static extendOriginExtent({origin, extent, start = 0, end = 0}) { + const normalized = + this.normalizeOriginExtent({origin, extent}); + + return { + origin: normalized.origin - start, + extent: normalized.extent + start + end, + }; + } + + toExtended(arg1, arg2) { + if (typeof arg1 === 'number' && typeof arg2 === 'number') { + return this.toExtended({ + left: arg2, + right: arg2, + top: arg1, + bottom: arg1, + }); + } else if (typeof arg1 === 'number') { + return this.toExtended({ + left: arg1, + right: arg1, + top: arg1, + bottom: arg1, + }); + } + + const {top, left, bottom, right} = arg1; + + const {origin: x, extent: width} = + WikiRect.extendOriginExtent({ + origin: this.x, + extent: this.width, + start: left, + end: right, + }); + + const {origin: y, extent: height} = + WikiRect.extendOriginExtent({ + origin: this.y, + extent: this.height, + start: top, + end: bottom, + }); + + return Reflect.construct(this.constructor, [x, y, width, height]); + } + + // Comparisons + + equals(rect) { + const rectNormalized = WikiRect.fromRect(rect).toNormalized(); + const thisNormalized = this.toNormalized(); + + return ( + rectNormalized.x === thisNormalized.x && + rectNormalized.y === thisNormalized.y && + rectNormalized.width === thisNormalized.width && + rectNormalized.height === thisNormalized.height + ); + } + + contains(rect) { + return !!this.intersectionWith(rect)?.equals(rect); + } + + containedWithin(rect) { + return !!this.intersectionWith(rect)?.equals(this); + } + + fits(rect) { + const rectNormalized = WikiRect.fromRect(rect).toNormalized(); + const thisNormalized = this.toNormalized(); + + return ( + (!isFinite(this.width) || rectNormalized.width <= thisNormalized.width) && + (!isFinite(this.height) || rectNormalized.height <= thisNormalized.height) + ); + } + + fitsWithin(rect) { + const rectNormalized = WikiRect.fromRect(rect).toNormalized(); + const thisNormalized = this.toNormalized(); + + return ( + (!isFinite(rect.width) || thisNormalized.width <= rectNormalized.width) && + (!isFinite(rect.height) || thisNormalized.height <= rectNormalized.height) + ); + } + + // Interfacing utilities + + static fromRect(rect) { + return Reflect.construct(this, [rect.x, rect.y, rect.width, rect.height]); + } + + writeOnto(destination) { + Object.assign(destination, { + x: this.x, + y: this.y, + width: this.width, + height: this.height, + }); + } +} + +// CSS compatibility-assistant ---------------------------- + +const cssCompatibilityAssistantInfo = clientInfo.cssCompatibilityAssistantInfo = { + coverArtContainer: null, + coverArtImageDetails: null, +}; + +function getCSSCompatibilityAssistantInfoReferences() { + const info = cssCompatibilityAssistantInfo; + + info.coverArtContainer = + document.getElementById('cover-art-container'); + + info.coverArtImageDetails = + info.coverArtContainer?.querySelector('.image-details'); +} + +function mutateCSSCompatibilityContent() { + const info = cssCompatibilityAssistantInfo; + + if (info.coverArtImageDetails) { + info.coverArtContainer.classList.add('has-image-details'); + } +} + +clientSteps.getPageReferences.push(getCSSCompatibilityAssistantInfoReferences); +clientSteps.mutatePageContent.push(mutateCSSCompatibilityContent); + +// Ever-updating mouse position helper -------------------- + +const liveMousePositionInfo = initInfo('liveMousePositionInfo', { + state: { + clientX: null, + clientY: null, + }, +}); + +function addLiveMousePositionPageListeners() { + const info = liveMousePositionInfo; + const {state} = info; + + document.body.addEventListener('mousemove', domEvent => { + Object.assign(state, { + clientX: domEvent.clientX, + clientY: domEvent.clientY, + }); + }); +} + +clientSteps.addPageListeners.push(addLiveMousePositionPageListeners); + +// JS-based links ----------------------------------------- + +const scriptedLinkInfo = initInfo('scriptedLinkInfo', { + randomLinks: null, + revealLinks: null, + revealContainers: null, + + nextNavLink: null, + previousNavLink: null, + randomNavLink: null, + + state: { + albumDirectories: null, + albumTrackDirectories: null, + artistDirectories: null, + artistNumContributions: null, + }, +}); + +function getScriptedLinkReferences() { + scriptedLinkInfo.randomLinks = + document.querySelectorAll('[data-random]'); + + scriptedLinkInfo.revealLinks = + document.querySelectorAll('.reveal .image-outer-area > *'); + + scriptedLinkInfo.revealContainers = + Array.from(scriptedLinkInfo.revealLinks) + .map(link => link.closest('.reveal')); + + scriptedLinkInfo.nextNavLink = + document.getElementById('next-button'); + + scriptedLinkInfo.previousNavLink = + document.getElementById('previous-button'); + + scriptedLinkInfo.randomNavLink = + document.getElementById('random-button'); +} + +function addRandomLinkListeners() { + for (const a of scriptedLinkInfo.randomLinks ?? []) { + a.addEventListener('click', domEvent => { + handleRandomLinkClicked(a, domEvent); + }); + } +} + +function handleRandomLinkClicked(a, domEvent) { + const href = determineRandomLinkHref(a); + + if (!href) { + domEvent.preventDefault(); + return; + } + + setTimeout(() => { + a.href = '#' + }); + + a.href = href; +} + +function determineRandomLinkHref(a) { + const {state} = scriptedLinkInfo; + + const trackDirectoriesFromAlbumDirectories = albumDirectories => + albumDirectories + .map(directory => state.albumDirectories.indexOf(directory)) + .map(index => state.albumTrackDirectories[index]) + .reduce((acc, trackDirectories) => acc.concat(trackDirectories, [])); + + switch (a.dataset.random) { + case 'album': { + const {albumDirectories} = state; + if (!albumDirectories) return null; + + return openAlbum(pick(albumDirectories)); + } + + case 'track': { + const {albumDirectories} = state; + if (!albumDirectories) return null; + + const trackDirectories = + trackDirectoriesFromAlbumDirectories( + albumDirectories); + + return openTrack(pick(trackDirectories)); + } + + case 'album-in-group-dl': { + const albumLinks = + Array.from(a + .closest('dt') + .nextElementSibling + .querySelectorAll('li a')) + + const listAlbumDirectories = + albumLinks + .map(a => cssProp(a, '--album-directory')); + + return openAlbum(pick(listAlbumDirectories)); + } + + case 'track-in-group-dl': { + const {albumDirectories} = state; + if (!albumDirectories) return null; + + const albumLinks = + Array.from(a + .closest('dt') + .nextElementSibling + .querySelectorAll('li a')) + + const listAlbumDirectories = + albumLinks + .map(a => cssProp(a, '--album-directory')); + + const trackDirectories = + trackDirectoriesFromAlbumDirectories( + listAlbumDirectories); + + return openTrack(pick(trackDirectories)); + } + + case 'track-in-sidebar': { + // Note that the container for track links may be <ol> or <ul>, and + // they can't be identified by href, since links from one track to + // another don't include "track" in the href. + const trackLinks = + Array.from(document + .querySelector('.track-list-sidebar-box') + .querySelectorAll('li a')); + + return pick(trackLinks).href; + } + + case 'track-in-album': { + const {albumDirectories, albumTrackDirectories} = state; + if (!albumDirectories || !albumTrackDirectories) return null; + + const albumDirectory = cssProp(a, '--album-directory'); + const albumIndex = albumDirectories.indexOf(albumDirectory); + const trackDirectories = albumTrackDirectories[albumIndex]; + + return openTrack(pick(trackDirectories)); + } + + case 'artist': { + const {artistDirectories} = state; + if (!artistDirectories) return null; + + return openArtist(pick(artistDirectories)); + } + + case 'artist-more-than-one-contrib': { + const {artistDirectories, artistNumContributions} = state; + if (!artistDirectories || !artistNumContributions) return null; + + const filteredArtistDirectories = + artistDirectories + .filter((_artist, index) => artistNumContributions[index] > 1); + + return openArtist(pick(filteredArtistDirectories)); + } + } +} + +function mutateNavigationLinkContent() { + const prependTitle = (el, prepend) => + el?.setAttribute('title', + (el.hasAttribute('title') + ? prepend + ' ' + el.getAttribute('title') + : prepend)); + + prependTitle(scriptedLinkInfo.nextNavLink, '(Shift+N)'); + prependTitle(scriptedLinkInfo.previousNavLink, '(Shift+P)'); + prependTitle(scriptedLinkInfo.randomNavLink, '(Shift+R)'); +} + +function addNavigationKeyPressListeners() { + document.addEventListener('keypress', (event) => { + if (event.shiftKey) { + if (event.charCode === 'N'.charCodeAt(0)) { + scriptedLinkInfo.nextNavLink?.click(); + } else if (event.charCode === 'P'.charCodeAt(0)) { + scriptedLinkInfo.previousNavLink?.click(); + } else if (event.charCode === 'R'.charCodeAt(0)) { + scriptedLinkInfo.randomNavLink?.click(); + } + } + }); +} + +function addRevealLinkClickListeners() { + const info = scriptedLinkInfo; + + for (const {revealLink, revealContainer} of stitchArrays({ + revealLink: Array.from(info.revealLinks ?? []), + revealContainer: Array.from(info.revealContainers ?? []), + })) { + revealLink.addEventListener('click', (event) => { + handleRevealLinkClicked(event, revealLink, revealContainer); + }); + } +} + +function handleRevealLinkClicked(domEvent, _revealLink, revealContainer) { + if (revealContainer.classList.contains('revealed')) { + return; + } + + domEvent.preventDefault(); + revealContainer.classList.add('revealed'); + revealContainer.dispatchEvent(new CustomEvent('hsmusic-reveal')); +} + +clientSteps.getPageReferences.push(getScriptedLinkReferences); +clientSteps.addPageListeners.push(addRandomLinkListeners); +clientSteps.addPageListeners.push(addNavigationKeyPressListeners); +clientSteps.addPageListeners.push(addRevealLinkClickListeners); +clientSteps.mutatePageContent.push(mutateNavigationLinkContent); + +if ( + document.documentElement.dataset.urlKey === 'localized.listing' && + document.documentElement.dataset.urlValue0 === 'random' +) { + const dataLoadingLine = document.getElementById('data-loading-line'); + const dataLoadedLine = document.getElementById('data-loaded-line'); + const dataErrorLine = document.getElementById('data-error-line'); + + dataLoadingLine.style.display = 'block'; + + fetch(rebase('random-link-data.json', 'rebaseShared')) + .then(data => data.json()) + .then(data => { + const {state} = scriptedLinkInfo; + + Object.assign(state, { + albumDirectories: data.albumDirectories, + albumTrackDirectories: data.albumTrackDirectories, + artistDirectories: data.artistDirectories, + artistNumContributions: data.artistNumContributions, + }); + + dataLoadingLine.style.display = 'none'; + dataLoadedLine.style.display = 'block'; + }, () => { + dataLoadingLine.style.display = 'none'; + dataErrorLine.style.display = 'block'; + }) + .then(() => { + const {randomLinks} = scriptedLinkInfo; + for (const a of randomLinks) { + const href = determineRandomLinkHref(a); + if (!href) { + a.removeAttribute('href'); + } + } + }); +} + +// Tooltip-style hover (infrastructure) ------------------- + +const hoverableTooltipInfo = initInfo('hoverableTooltipInfo', { + settings: { + // Hovering has two speed settings. The normal setting is used by default, + // and once a tooltip is displayed as a result of hover, the entire tooltip + // system will enter a "fast hover mode" - hovering will activate tooltips + // sooner. "Fast hover mode" is disabled after a sustained duration of not + // hovering over any hoverables; it's meant only to accelerate switching + // tooltips while still deciding, or getting a quick overview across more + // than one tooltip. + normalHoverInfoDelay: 400, + fastHoveringInfoDelay: 150, + endFastHoveringDelay: 500, + + // Focusing has a single speed setting, which is how long it will take to + // enter a functional "focus mode" (though it's not actually implemented + // in terms of this state). As soon as "focus mode" is entered, the tooltip + // for the current hoverable is displayed, and focusing another hoverable + // will cause the current tooltip to be swapped for that one immediately. + // "Focus mode" ends as soon as anything apart from a tooltip or hoverable + // is focused, and it will be necessary to wait on this delay again. + focusInfoDelay: 750, + + hideTooltipDelay: 500, + + // If a tooltip that's transitioning to hidden is hovered during the grace + // period (or the corresponding hoverable is hovered at any point in the + // transition), it'll cancel out of this animation immediately. + transitionHiddenDuration: 300, + inertGracePeriod: 100, + }, + + state: { + // These maps store a record for each registered element and related state + // and registration info, if applicable. + registeredTooltips: new Map(), + registeredHoverables: new Map(), + + // These are common across all tooltips, rather than stored individually, + // based on the principles that 1) only a single tooltip can be displayed + // at once, and 2) likewise, only a single hoverable can be hovered, + // focused, or otherwise active at once. + hoverTimeout: null, + focusTimeout: null, + touchTimeout: null, + hideTimeout: null, + transitionHiddenTimeout: null, + inertGracePeriodTimeout: null, + currentlyShownTooltip: null, + currentlyActiveHoverable: null, + currentlyTransitioningHiddenTooltip: null, + previouslyActiveHoverable: null, + tooltipWasJustHidden: false, + hoverableWasRecentlyTouched: false, + + // Fast hovering is a global mode which is activated as soon as any tooltip + // is displayed and turns off after a delay of no hoverables being hovered. + // Note that fast hovering may be turned off while hovering a tooltip, but + // it will never be turned off while idling over a hoverable. + fastHovering: false, + endFastHoveringTimeout: false, + + // These track the identifiers of current touches and a record of current + // identifiers that are "banished" by scrolling - that is, touches which + // existed while the page scrolled and were probably responsible for that + // scrolling. This is a bit loose (we can't actually tell which touches + // caused the page to scroll) but it's intended to keep scrolling the page + // from causing the current tooltip to be hidden. + currentTouchIdentifiers: new Set(), + touchIdentifiersBanishedByScrolling: new Set(), + }, + + event: { + whenTooltipShows: [], + whenTooltipHides: [], + }, +}); + +// Adds DOM event listeners, so must be called during addPageListeners step. +function registerTooltipElement(tooltip) { + const {state} = hoverableTooltipInfo; + + if (!tooltip) + throw new Error(`Expected tooltip`); + + if (state.registeredTooltips.has(tooltip)) + throw new Error(`This tooltip is already registered`); + + // No state or registration info here. + state.registeredTooltips.set(tooltip, {}); + + tooltip.addEventListener('mouseenter', () => { + handleTooltipMouseEntered(tooltip); + }); + + tooltip.addEventListener('mouseleave', () => { + handleTooltipMouseLeft(tooltip); + }); + + tooltip.addEventListener('focusin', event => { + handleTooltipReceivedFocus(tooltip, event.relatedTarget); + }); + + tooltip.addEventListener('focusout', event => { + // This event gets activated for tabbing *between* links inside the + // tooltip, which is no good and certainly doesn't represent the focus + // leaving the tooltip. + if (currentlyShownTooltipHasFocus(event.relatedTarget)) return; + + handleTooltipLostFocus(tooltip, event.relatedTarget); + }); +} + +// Adds DOM event listeners, so must be called during addPageListeners step. +function registerTooltipHoverableElement(hoverable, tooltip) { + const {state} = hoverableTooltipInfo; + + if (!hoverable || !tooltip) + if (hoverable) + throw new Error(`Expected hoverable and tooltip, got only hoverable`); + else + throw new Error(`Expected hoverable and tooltip, got neither`); + + if (!state.registeredTooltips.has(tooltip)) + throw new Error(`Register tooltip before registering hoverable`); + + if (state.registeredHoverables.has(hoverable)) + throw new Error(`This hoverable is already registered`); + + state.registeredHoverables.set(hoverable, {tooltip}); + + hoverable.addEventListener('mouseenter', () => { + handleTooltipHoverableMouseEntered(hoverable); + }); + + hoverable.addEventListener('mouseleave', () => { + handleTooltipHoverableMouseLeft(hoverable); + }); + + hoverable.addEventListener('focusin', event => { + handleTooltipHoverableReceivedFocus(hoverable, event); + }); + + hoverable.addEventListener('focusout', event => { + handleTooltipHoverableLostFocus(hoverable, event); + }); + + hoverable.addEventListener('touchend', event => { + handleTooltipHoverableTouchEnded(hoverable, event); + }); + + hoverable.addEventListener('click', event => { + handleTooltipHoverableClicked(hoverable, event); + }); +} + +function handleTooltipMouseEntered(tooltip) { + const {state} = hoverableTooltipInfo; + + if (state.currentlyTransitioningHiddenTooltip) { + cancelTransitioningTooltipHidden(true); + return; + } + + if (state.currentlyShownTooltip !== tooltip) return; + + // Don't time out the current tooltip while hovering it. + + if (state.hideTimeout) { + clearTimeout(state.hideTimeout); + state.hideTimeout = null; + } +} + +function handleTooltipMouseLeft(tooltip) { + const {settings, state} = hoverableTooltipInfo; + + if (state.currentlyShownTooltip !== tooltip) return; + + // Start timing out the current tooltip when it's left. This could be + // canceled by mousing over a hoverable, or back over the tooltip again. + if (!state.hideTimeout) { + state.hideTimeout = + setTimeout(() => { + state.hideTimeout = null; + hideCurrentlyShownTooltip(); + }, settings.hideTooltipDelay); + } +} + +function handleTooltipReceivedFocus(_tooltip) { + const {state} = hoverableTooltipInfo; + + // Cancel the tooltip-hiding timeout if it exists. The tooltip will never + // be hidden while it contains the focus anyway, but this ensures the timeout + // will be suitably reset when the tooltip loses focus. + if (state.hideTimeout) { + clearTimeout(state.hideTimeout); + state.hideTimeout = null; + } +} + +function handleTooltipLostFocus(_tooltip) { + // Hide the current tooltip right away when it loses focus. Specify intent + // to replace - while we don't strictly know if another tooltip is going to + // immediately replace it, the mode of navigating with tab focus (once one + // tooltip has been activated) is a "switch focus immediately" kind of + // interaction in its nature. + hideCurrentlyShownTooltip(true); +} + +function handleTooltipHoverableMouseEntered(hoverable) { + const {settings, state} = hoverableTooltipInfo; + const {tooltip} = state.registeredHoverables.get(hoverable); + + // If this tooltip was transitioning to hidden, hovering should cancel that + // animation and show it immediately. + + if (tooltip === state.currentlyTransitioningHiddenTooltip) { + cancelTransitioningTooltipHidden(true); + return; + } + + // Start a timer to show the corresponding tooltip, with the delay depending + // on whether fast hovering or not. This could be canceled by mousing out of + // the hoverable. + + const hoverTimeoutDelay = + (state.fastHovering + ? settings.fastHoveringInfoDelay + : settings.normalHoverInfoDelay); + + state.hoverTimeout = + setTimeout(() => { + state.hoverTimeout = null; + state.fastHovering = true; + showTooltipFromHoverable(hoverable); + }, hoverTimeoutDelay); + + // Don't stop fast hovering while over any hoverable. + if (state.endFastHoveringTimeout) { + clearTimeout(state.endFastHoveringTimeout); + state.endFastHoveringTimeout = null; + } + + // Don't time out the current tooltip while over any hoverable. + if (state.hideTimeout) { + clearTimeout(state.hideTimeout); + state.hideTimeout = null; + } +} + +function handleTooltipHoverableMouseLeft(_hoverable) { + const {settings, state} = hoverableTooltipInfo; + + // Don't show a tooltip when not over a hoverable! + if (state.hoverTimeout) { + clearTimeout(state.hoverTimeout); + state.hoverTimeout = null; + } + + // Start timing out fast hovering (if active) when not over a hoverable. + // This will only be canceled by mousing over another hoverable. + if (state.fastHovering && !state.endFastHoveringTimeout) { + state.endFastHoveringTimeout = + setTimeout(() => { + state.endFastHoveringTimeout = null; + state.fastHovering = false; + }, settings.endFastHoveringDelay); + } + + // Start timing out the current tooltip when mousing not over a hoverable. + // This could be canceled by mousing over another hoverable, or over the + // currently shown tooltip. + if (state.currentlyShownTooltip && !state.hideTimeout) { + state.hideTimeout = + setTimeout(() => { + state.hideTimeout = null; + hideCurrentlyShownTooltip(); + }, settings.hideTooltipDelay); + } +} + +function handleTooltipHoverableReceivedFocus(hoverable) { + const {settings, state} = hoverableTooltipInfo; + + // By default, display the corresponding tooltip after a delay. + + state.focusTimeout = + setTimeout(() => { + state.focusTimeout = null; + showTooltipFromHoverable(hoverable); + }, settings.focusInfoDelay); + + // If a tooltip was just hidden - which is almost certainly a result of the + // focus changing - then display this tooltip immediately, canceling the + // above timeout. + + if (state.tooltipWasJustHidden) { + clearTimeout(state.focusTimeout); + state.focusTimeout = null; + + showTooltipFromHoverable(hoverable); + } +} + +function handleTooltipHoverableLostFocus(hoverable, domEvent) { + const {state} = hoverableTooltipInfo; + + // Don't show a tooltip from focusing a hoverable if it isn't focused + // anymore! If another hoverable is receiving focus, that will be evaluated + // and set its own focus timeout after we clear the previous one here. + if (state.focusTimeout) { + clearTimeout(state.focusTimeout); + state.focusTimeout = null; + } + + // Unless focus is entering the tooltip itself, hide the tooltip immediately. + // This will set the tooltipWasJustHidden flag, which is detected by a newly + // focused hoverable, if applicable. Always specify intent to replace when + // navigating via tab focus. (Check `handleTooltipLostFocus` for details.) + if (!currentlyShownTooltipHasFocus(domEvent.relatedTarget)) { + hideCurrentlyShownTooltip(true); + } +} + +function handleTooltipHoverableTouchEnded(hoverable, domEvent) { + const {state} = hoverableTooltipInfo; + const {tooltip} = state.registeredHoverables.get(hoverable); + + // Don't proceed if this hoverable's tooltip is already visible - in that + // case touching the hoverable again should behave just like a normal click. + if (state.currentlyShownTooltip === tooltip) { + // If the hoverable was *recently* touched - meaning that this is a second + // touchend in short succession - then just letting the click come through + // naturally would (depending on timing) not actually navigate anywhere, + // because we've deliberately banished the *first* touch from navigation. + // We do want the second touch to navigate, so clear that recently-touched + // state, allowing this touch's click to behave as normal. + if (state.hoverableWasRecentlyTouched) { + clearTimeout(state.touchTimeout); + state.touchTimeout = null; + state.hoverableWasRecentlyTouched = false; + } + + // Otherwise, this is just a second touch after enough time has passed + // that the one which showed the tooltip is no longer "recent", and we're + // not in any special state. The link will navigate to its page just like + // normal. + return; + } + + const touches = Array.from(domEvent.changedTouches); + const identifiers = touches.map(touch => touch.identifier); + + // Don't process touch events that were "banished" because the page was + // scrolled while those touches were active, and most likely as a result of + // them. + filterMultipleArrays(touches, identifiers, + (_touch, identifier) => + !state.touchIdentifiersBanishedByScrolling.has(identifier)); + + if (empty(touches)) return; + + // Don't proceed if none of the (just-ended) touches ended over the + // hoverable. + + const pointIsOverThisHoverable = pointIsOverAnyOf([hoverable]); + + const anyTouchEndedOverHoverable = + touches.some(({clientX, clientY}) => + pointIsOverThisHoverable(clientX, clientY)); + + if (!anyTouchEndedOverHoverable) { + return; + } + + if (state.touchTimeout) { + clearTimeout(state.touchTimeout); + state.touchTimeout = null; + } + + // Show the tooltip right away. + showTooltipFromHoverable(hoverable); + + // Set a state, for a brief but not instantaneous period, indicating that a + // hoverable was recently touched. The touchend event may precede the click + // event by some time, and we don't want to navigate away from the page as + // a result of the click event which this touch precipitated. + state.hoverableWasRecentlyTouched = true; + state.touchTimeout = + setTimeout(() => { + state.touchTimeout = null; + state.hoverableWasRecentlyTouched = false; + }, 1200); +} + +function handleTooltipHoverableClicked(hoverable) { + const {state} = hoverableTooltipInfo; + + // Don't navigate away from the page if the this hoverable was recently + // touched (and had its tooltip activated). That flag won't be set if its + // tooltip was already open before the touch. + if ( + state.currentlyActiveHoverable === hoverable && + state.hoverableWasRecentlyTouched + ) { + event.preventDefault(); + } +} + +function currentlyShownTooltipHasFocus(focusElement = document.activeElement) { + const {state} = hoverableTooltipInfo; + + const { + currentlyShownTooltip: tooltip, + currentlyActiveHoverable: hoverable, + } = state; + + // If there's no tooltip, it can't possibly have focus. + if (!tooltip) return false; + + // If the tooltip literally contains (or is) the focused element, then that's + // the principle condition we're looking for. + if (tooltip.contains(focusElement)) return true; + + // If the hoverable *which opened the tooltip* is focused, then that also + // represents the tooltip being focused (in its currently shown state). + if (hoverable.contains(focusElement)) return true; + + return false; +} + +function beginTransitioningTooltipHidden(tooltip) { + const {settings, state} = hoverableTooltipInfo; + + if (state.currentlyTransitioningHiddenTooltip) { + cancelTransitioningTooltipHidden(); + } + + cssProp(tooltip, { + 'display': 'block', + 'opacity': '0', + + 'transition-property': 'opacity', + 'transition-timing-function': + `steps(${Math.ceil(settings.transitionHiddenDuration / 60)}, end)`, + 'transition-duration': + `${settings.transitionHiddenDuration / 1000}s`, + }); + + state.currentlyTransitioningHiddenTooltip = tooltip; + state.transitionHiddenTimeout = + setTimeout(() => { + endTransitioningTooltipHidden(); + }, settings.transitionHiddenDuration); +} + +function cancelTransitioningTooltipHidden(andShow = false) { + const {state} = hoverableTooltipInfo; + + endTransitioningTooltipHidden(); + + if (andShow) { + showTooltipFromHoverable(state.previouslyActiveHoverable); + } +} + +function endTransitioningTooltipHidden() { + const {state} = hoverableTooltipInfo; + const {currentlyTransitioningHiddenTooltip: tooltip} = state; + + if (!tooltip) return; + + cssProp(tooltip, { + 'display': null, + 'opacity': null, + 'transition-property': null, + 'transition-timing-function': null, + 'transition-duration': null, + }); + + state.currentlyTransitioningHiddenTooltip = null; + + if (state.inertGracePeriodTimeout) { + clearTimeout(state.inertGracePeriodTimeout); + state.inertGracePeriodTimeout = null; + } + + if (state.transitionHiddenTimeout) { + clearTimeout(state.transitionHiddenTimeout); + state.transitionHiddenTimeout = null; + } +} + +function hideCurrentlyShownTooltip(intendingToReplace = false) { + const {settings, state, event} = hoverableTooltipInfo; + const {currentlyShownTooltip: tooltip} = state; + + // If there was no tooltip to begin with, we're functionally in the desired + // state already, so return true. + if (!tooltip) return true; + + // Never hide the tooltip if it's focused. + if (currentlyShownTooltipHasFocus()) return false; + + state.currentlyActiveHoverable.classList.remove('has-visible-tooltip'); + + // If there's no intent to replace this tooltip, it's the last one currently + // apparent in the interaction, and should be hidden with a transition. + if (intendingToReplace) { + cssProp(tooltip, 'display', 'none'); + } else { + beginTransitioningTooltipHidden(state.currentlyShownTooltip); + } + + // Wait just a moment before making the tooltip inert. You might react + // (to the ghosting, or just to time passing) and realize you wanted + // to look at the tooltip after all - this delay gives a little buffer + // to second guess letting it disappear. + state.inertGracePeriodTimeout = + setTimeout(() => { + tooltip.inert = true; + }, settings.inertGracePeriod); + + state.previouslyActiveHoverable = state.currentlyActiveHoverable; + + state.currentlyShownTooltip = null; + state.currentlyActiveHoverable = null; + + // Set this for one tick of the event cycle. + state.tooltipWasJustHidden = true; + setTimeout(() => { + state.tooltipWasJustHidden = false; + }); + + dispatchInternalEvent(event, 'whenTooltipHides', { + tooltip, + }); + + return true; +} + +function showTooltipFromHoverable(hoverable) { + const {state, event} = hoverableTooltipInfo; + const {tooltip} = state.registeredHoverables.get(hoverable); + + if (!hideCurrentlyShownTooltip(true)) return false; + + // Cancel out another tooltip that's transitioning hidden, if that's going + // on - it's a distraction that this tooltip is now replacing. + cancelTransitioningTooltipHidden(); + + hoverable.classList.add('has-visible-tooltip'); + + positionTooltipFromHoverableWithBrains(hoverable); + + cssProp(tooltip, 'display', 'block'); + tooltip.inert = false; + + state.currentlyShownTooltip = tooltip; + state.currentlyActiveHoverable = hoverable; + + state.tooltipWasJustHidden = false; + + dispatchInternalEvent(event, 'whenTooltipShows', { + tooltip, + }); + + return true; +} + +function peekTooltipClientRect(tooltip) { + const oldDisplayStyle = cssProp(tooltip, 'display'); + cssProp(tooltip, 'display', 'block'); + + // Tooltips have a bit of padding that makes the interactive + // area wider, so that you're less likely to accidentally let + // the tooltip disappear (by hovering outside it). But this + // isn't visual at all, so for placement we only care about + // the content element. + const content = + tooltip.querySelector('.tooltip-content'); + + try { + return WikiRect.fromElement(content); + } finally { + cssProp(tooltip, 'display', oldDisplayStyle); + } +} + +function positionTooltipFromHoverableWithBrains(hoverable) { + const {state} = hoverableTooltipInfo; + const {tooltip} = state.registeredHoverables.get(hoverable); + + // Reset before doing anything else. We're going to adapt to + // its natural placement, adjusted by CSS, which otherwise + // could be obscured by a placement we've previously provided. + resetDynamicTooltipPositioning(tooltip); + + const opportunities = + getTooltipFromHoverablePlacementOpportunityAreas(hoverable); + + const tooltipRect = + peekTooltipClientRect(tooltip); + + // If the tooltip is already in the baseline containing area, + // prefer to keep it positioned naturally, adjusted by CSS + // instead of JavaScript. + + const {numBaselineRects, idealBaseline: baselineRect} = opportunities; + + if (baselineRect.contains(tooltipRect)) { + return; + } + + let selectedRect = null; + for (let i = 0; i < numBaselineRects; i++) { + selectedRect = opportunities.right.down[i]; + if (selectedRect) break; + + selectedRect = opportunities.left.down[i]; + if (selectedRect) break; + + selectedRect = opportunities.right.up[i]; + if (selectedRect) break; + + selectedRect = opportunities.left.up[i]; + if (selectedRect) break; + } + + selectedRect ??= baselineRect; + + positionTooltip(tooltip, selectedRect.x, selectedRect.y); +} + +function positionTooltip(tooltip, x, y) { + // Imagine what it'd be like if the tooltip were positioned + // with zero left/top offset, and calculate its actual offsets + // based on that. + + cssProp(tooltip, { + left: `0`, + top: `0`, + }); + + const tooltipRect = + peekTooltipClientRect(tooltip); + + cssProp(tooltip, { + left: `${x - tooltipRect.x}px`, + top: `${y - tooltipRect.y}px`, + }); +} + +function resetDynamicTooltipPositioning(tooltip) { + cssProp(tooltip, { + left: null, + top: null, + }); +} + +function getTooltipFromHoverablePlacementOpportunityAreas(hoverable) { + const {state} = hoverableTooltipInfo; + const {tooltip} = state.registeredHoverables.get(hoverable); + + const baselineRects = + getTooltipBaselineOpportunityAreas(tooltip); + + const hoverableRect = + WikiRect.fromElementUnderMouse(hoverable).toExtended(5, 10); + + const tooltipRect = + peekTooltipClientRect(tooltip); + + // Get placements relative to the hoverable. Make these available by key, + // allowing the caller to choose by preferred orientation. Each value is + // an array which corresponds to the baseline areas - placement closer to + // front of the array indicates stronger preference. Since not all relative + // placements cooperate with all baseline areas, any of these arrays may + // include (or be entirely made of) null. + + const keepIfFits = (rect) => + (rect?.fits(tooltipRect) + ? rect + : null); + + const prepareRegionRects = (relationalRect, direct) => + baselineRects + .map(rect => rect.intersectionWith(relationalRect)) + .map(direct) + .map(keepIfFits); + + const regionRects = { + left: + prepareRegionRects( + WikiRect.leftOf(hoverableRect), + rect => WikiRect.fromRect({ + x: rect.right, + y: rect.y, + width: -rect.width, + height: rect.height, + })), + + right: + prepareRegionRects( + WikiRect.rightOf(hoverableRect), + rect => rect), + + top: + prepareRegionRects( + WikiRect.above(hoverableRect), + rect => WikiRect.fromRect({ + x: rect.x, + y: rect.bottom, + width: rect.width, + height: -rect.height, + })), + + bottom: + prepareRegionRects( + WikiRect.beneath(hoverableRect), + rect => rect), + }; + + const neededVerticalOverlap = 30; + const neededHorizontalOverlap = 30; + + // Please don't ask us to make this but horizontal? + const prepareVerticalOrientationRects = (regionRects) => { + const orientations = {}; + + const upTopDown = + WikiRect.beneath( + hoverableRect.top + neededVerticalOverlap - tooltipRect.height); + + const downBottomUp = + WikiRect.above( + hoverableRect.bottom - neededVerticalOverlap + tooltipRect.height); + + const orientHorizontally = (rect, i) => { + if (!rect) return null; + + const regionRect = regionRects[i]; + if (regionRect.width > 0) { + return rect; + } else { + return WikiRect.fromRect({ + x: regionRect.right - tooltipRect.width, + y: rect.y, + width: rect.width, + height: rect.height, + }); + } + }; + + orientations.up = + regionRects + .map(rect => rect?.intersectionWith(upTopDown)) + .map(orientHorizontally) + .map(keepIfFits); + + orientations.down = + regionRects + .map(rect => rect?.intersectionWith(downBottomUp)) + .map(rect => + (rect + ? rect.intersectionWith(WikiRect.fromRect({ + x: rect.x, + y: rect.bottom - tooltipRect.height, + width: rect.width, + height: tooltipRect.height, + })) + : null)) + .map(orientHorizontally) + .map(keepIfFits); + + const centerRect = + WikiRect.fromRect({ + x: -Infinity, width: Infinity, + y: hoverableRect.top + + hoverableRect.height / 2 + - tooltipRect.height / 2, + height: tooltipRect.height, + }); + + orientations.center = + regionRects + .map(rect => rect?.intersectionWith(centerRect)) + .map(orientHorizontally) + .map(keepIfFits); + + return orientations; + }; + + const orientationRects = { + left: prepareVerticalOrientationRects(regionRects.left), + right: prepareVerticalOrientationRects(regionRects.right), + }; + + return { + numBaselineRects: baselineRects.length, + idealBaseline: baselineRects[0], + ...orientationRects, + }; +} + +function getTooltipBaselineOpportunityAreas(tooltip) { + // Returns multiple basic areas in order of preference, with front of the + // array representing greater preference. + + const {stickyContainers} = stickyHeadingInfo; + const results = []; + + const windowRect = + WikiRect.fromWindow().toInset(10); + + const workingRect = + WikiRect.fromRect(windowRect); + + const tooltipRect = + peekTooltipClientRect(tooltip); + + // As a baseline, always treat the window rect as fitting the tooltip. + results.unshift(WikiRect.fromRect(workingRect)); + + const containingParent = + getVisuallyContainingElement(tooltip); + + if (containingParent) { + const containingRect = + WikiRect.fromElement(containingParent); + + // Only respect a portion of the container's padding, giving + // the tooltip the impression of a "raised" element. + const padding = side => + 0.5 * + parseFloat(cssProp(containingParent, 'padding-' + side)); + + const insetContainingRect = + containingRect.toInset({ + left: padding('left'), + right: padding('right'), + top: padding('top'), + bottom: padding('bottom'), + }); + + workingRect.chopExtendingOutside(insetContainingRect); + + if (!workingRect.fits(tooltipRect)) { + return results; + } + + results.unshift(WikiRect.fromRect(workingRect)); + } + + // This currently assumes a maximum of one sticky container + // per visually containing element. + + const stickyContainer = + stickyContainers + .find(el => el.parentElement === containingParent); + + if (stickyContainer) { + const stickyRect = + stickyContainer.getBoundingClientRect() + + // Add some padding so the tooltip doesn't line up exactly + // with the edge of the sticky container. + const beneathStickyContainer = + WikiRect.beneath(stickyRect, 10); + + workingRect.chopExtendingOutside(beneathStickyContainer); + + if (!workingRect.fits(tooltipRect)) { + return results; + } + + results.unshift(WikiRect.fromRect(workingRect)); + } + + return results; +} + +function addHoverableTooltipPageListeners() { + const {state} = hoverableTooltipInfo; + + const getTouchIdentifiers = domEvent => + Array.from(domEvent.changedTouches) + .map(touch => touch.identifier) + .filter(identifier => typeof identifier !== 'undefined'); + + document.body.addEventListener('touchstart', domEvent => { + for (const identifier of getTouchIdentifiers(domEvent)) { + state.currentTouchIdentifiers.add(identifier); + } + }); + + window.addEventListener('scroll', () => { + for (const identifier of state.currentTouchIdentifiers) { + state.touchIdentifiersBanishedByScrolling.add(identifier); + } + }); + + document.body.addEventListener('touchend', domEvent => { + setTimeout(() => { + for (const identifier of getTouchIdentifiers(domEvent)) { + state.currentTouchIdentifiers.delete(identifier); + state.touchIdentifiersBanishedByScrolling.delete(identifier); + } + }); + }); + + const getHoverablesAndTooltips = () => [ + ...Array.from(state.registeredHoverables.keys()), + ...Array.from(state.registeredTooltips.keys()), + ]; + + document.body.addEventListener('touchend', domEvent => { + const touches = Array.from(domEvent.changedTouches); + const identifiers = touches.map(touch => touch.identifier); + + // Don't process touch events that were "banished" because the page was + // scrolled while those touches were active, and most likely as a result of + // them. + filterMultipleArrays(touches, identifiers, + (_touch, identifier) => + !state.touchIdentifiersBanishedByScrolling.has(identifier)); + + if (empty(touches)) return; + + const pointIsOverHoverableOrTooltip = + pointIsOverAnyOf(getHoverablesAndTooltips()); + + const anyTouchOverAnyHoverableOrTooltip = + touches.some(({clientX, clientY}) => + pointIsOverHoverableOrTooltip(clientX, clientY)); + + if (!anyTouchOverAnyHoverableOrTooltip) { + hideCurrentlyShownTooltip(); + } + }); + + document.body.addEventListener('click', domEvent => { + const {clientX, clientY} = domEvent; + + const pointIsOverHoverableOrTooltip = + pointIsOverAnyOf(getHoverablesAndTooltips()); + + if (!pointIsOverHoverableOrTooltip(clientX, clientY)) { + // Hide with "intent to replace" - we aren't actually going to replace + // the tooltip with a new one, but this intent indicates that it should + // be hidden right away, instead of showing. What we're really replacing, + // or rather removing, is the state of interacting with tooltips at all. + hideCurrentlyShownTooltip(true); + + // Part of that state is fast hovering, which should be canceled out. + state.fastHovering = false; + if (state.endFastHoveringTimeout) { + clearTimeout(state.endFastHoveringTimeout); + state.endFastHoveringTimeout = null; + } + + // Also cancel out of transitioning a tooltip hidden - this isn't caught + // by `hideCurrentlyShownTooltip` because a transitioning-hidden tooltip + // doesn't count as "shown" anymore. + cancelTransitioningTooltipHidden(); + } + }); +} + +clientSteps.addPageListeners.push(addHoverableTooltipPageListeners); + +// Data & info card --------------------------------------- + +/* +function colorLink(a, color) { + console.warn('Info card link colors temporarily disabled: chroma.js required, no dependency linking for client.js yet'); + return; + + // eslint-disable-next-line no-unreachable + const chroma = {}; + + if (color) { + const {primary, dim} = getColors(color, {chroma}); + a.style.setProperty('--primary-color', primary); + a.style.setProperty('--dim-color', dim); + } +} + +function link(a, type, {name, directory, color}) { + colorLink(a, color); + a.innerText = name; + a.href = getLinkHref(type, directory); +} + +function joinElements(type, elements) { + // We can't use the Intl APIs with elements, 8ecuase it only oper8tes on + // strings. So instead, we'll pass the element's outer HTML's (which means + // the entire HTML of that element). + // + // That does mean this function returns a string, so always 8e sure to + // set innerHTML when using it (not appendChild). + + return list[type](elements.map((el) => el.outerHTML)); +} + +const infoCard = (() => { + const container = document.getElementById('info-card-container'); + + let cancelShow = false; + let hideTimeout = null; + let showing = false; + + container.addEventListener('mouseenter', cancelHide); + container.addEventListener('mouseleave', readyHide); + + function show(type, target) { + cancelShow = false; + + fetchData(type, target.dataset[type]).then((data) => { + // Manual DOM 'cuz we're laaaazy. + + if (cancelShow) { + return; + } + + showing = true; + + const rect = target.getBoundingClientRect(); + + container.style.setProperty('--primary-color', data.color); + + container.style.top = window.scrollY + rect.bottom + 'px'; + container.style.left = window.scrollX + rect.left + 'px'; + + // Use a short timeout to let a currently hidden (or not yet shown) + // info card teleport to the position set a8ove. (If it's currently + // shown, it'll transition to that position.) + setTimeout(() => { + container.classList.remove('hide'); + container.classList.add('show'); + }, 50); + + // 8asic details. + + const nameLink = container.querySelector('.info-card-name a'); + link(nameLink, 'track', data); + + const albumLink = container.querySelector('.info-card-album a'); + link(albumLink, 'album', data.album); + + const artistSpan = container.querySelector('.info-card-artists span'); + artistSpan.innerHTML = joinElements( + 'conjunction', + data.artists.map(({artist}) => { + const a = document.createElement('a'); + a.href = getLinkHref('artist', artist.directory); + a.innerText = artist.name; + return a; + }) + ); + + const coverArtistParagraph = container.querySelector( + '.info-card-cover-artists' + ); + const coverArtistSpan = coverArtistParagraph.querySelector('span'); + if (data.coverArtists.length) { + coverArtistParagraph.style.display = 'block'; + coverArtistSpan.innerHTML = joinElements( + 'conjunction', + data.coverArtists.map(({artist}) => { + const a = document.createElement('a'); + a.href = getLinkHref('artist', artist.directory); + a.innerText = artist.name; + return a; + }) + ); + } else { + coverArtistParagraph.style.display = 'none'; + } + + // Cover art. + + const [containerNoReveal, containerReveal] = [ + container.querySelector('.info-card-art-container.no-reveal'), + container.querySelector('.info-card-art-container.reveal'), + ]; + + const [containerShow, containerHide] = data.cover.warnings.length + ? [containerReveal, containerNoReveal] + : [containerNoReveal, containerReveal]; + + containerHide.style.display = 'none'; + containerShow.style.display = 'block'; + + const img = containerShow.querySelector('.info-card-art'); + img.src = rebase(data.cover.paths.small, 'rebaseMedia'); + + const imgLink = containerShow.querySelector('a'); + colorLink(imgLink, data.color); + imgLink.href = rebase(data.cover.paths.original, 'rebaseMedia'); + + if (containerShow === containerReveal) { + const cw = containerShow.querySelector('.info-card-art-warnings'); + cw.innerText = list.unit(data.cover.warnings); + + const reveal = containerShow.querySelector('.reveal'); + reveal.classList.remove('revealed'); + } + }); + } + + function hide() { + container.classList.remove('show'); + container.classList.add('hide'); + cancelShow = true; + showing = false; + } + + function readyHide() { + if (!hideTimeout && showing) { + hideTimeout = setTimeout(hide, HIDE_HOVER_DELAY); + } + } + + function cancelHide() { + if (hideTimeout) { + clearTimeout(hideTimeout); + hideTimeout = null; + } + } + + return { + show, + hide, + readyHide, + cancelHide, + }; +})(); + +// Info cards are disa8led for now since they aren't quite ready for release, +// 8ut you can try 'em out 8y setting this localStorage flag! +// +// localStorage.tryInfoCards = true; +// +if (localStorage.tryInfoCards) { + addInfoCardLinkHandlers('track'); +} +*/ + +// Custom hash links -------------------------------------- + +const hashLinkInfo = initInfo('hashLinkInfo', { + links: null, + hrefs: null, + targets: null, + + state: { + highlightedTarget: null, + scrollingAfterClick: false, + concludeScrollingStateInterval: null, + }, + + event: { + beforeHashLinkScrolls: [], + whenHashLinkClicked: [], + }, +}); + +function getHashLinkReferences() { + const info = hashLinkInfo; + + info.links = + Array.from(document.querySelectorAll('a[href^="#"]:not([href="#"])')); + + info.hrefs = + info.links + .map(link => link.getAttribute('href')); + + info.targets = + info.hrefs + .map(href => document.getElementById(href.slice(1))); + + filterMultipleArrays( + info.links, + info.hrefs, + info.targets, + (_link, _href, target) => target); +} + +function processScrollingAfterHashLinkClicked() { + const {state} = hashLinkInfo; + + if (state.concludeScrollingStateInterval) return; + + let lastScroll = window.scrollY; + state.scrollingAfterClick = true; + state.concludeScrollingStateInterval = setInterval(() => { + if (Math.abs(window.scrollY - lastScroll) < 10) { + clearInterval(state.concludeScrollingStateInterval); + state.scrollingAfterClick = false; + state.concludeScrollingStateInterval = null; + } else { + lastScroll = window.scrollY; + } + }, 200); +} + +function addHashLinkListeners() { + // Instead of defining a scroll offset (to account for the sticky heading) + // in JavaScript, we interface with the CSS property 'scroll-margin-top'. + // This lets the scroll offset be consolidated where it makes sense, and + // sets an appropriate offset when (re)loading a page with hash for free! + + const info = hashLinkInfo; + const {state, event} = info; + + for (const {hashLink, href, target} of stitchArrays({ + hashLink: info.links, + href: info.hrefs, + target: info.targets, + })) { + hashLink.addEventListener('click', evt => { + if (evt.metaKey || evt.shiftKey || evt.ctrlKey || evt.altKey) { + return; + } + + // Don't do anything if the target element isn't actually visible! + if (target.offsetParent === null) { + return; + } + + // Allow event handlers to prevent scrolling. + const listenerResults = + dispatchInternalEvent(event, 'beforeHashLinkScrolls', { + link: hashLink, + target, + }); + + if (listenerResults.includes(false)) { + return; + } + + // Hide skipper box right away, so the layout is updated on time for the + // math operations coming up next. + const skipper = document.getElementById('skippers'); + skipper.style.display = 'none'; + setTimeout(() => skipper.style.display = ''); + + const box = target.getBoundingClientRect(); + const style = window.getComputedStyle(target); + + const scrollY = + window.scrollY + + box.top + - style['scroll-margin-top'].replace('px', ''); + + evt.preventDefault(); + history.pushState({}, '', href); + window.scrollTo({top: scrollY, behavior: 'smooth'}); + target.focus({preventScroll: true}); + + const maxScroll = + document.body.scrollHeight + - window.innerHeight; + + if (scrollY > maxScroll && target.classList.contains('content-heading')) { + if (state.highlightedTarget) { + state.highlightedTarget.classList.remove('highlight-hash-link'); + } + + target.classList.add('highlight-hash-link'); + state.highlightedTarget = target; + } + + processScrollingAfterHashLinkClicked(); + + dispatchInternalEvent(event, 'whenHashLinkClicked', { + link: hashLink, + target, + }); + }); + } + + for (const target of info.targets) { + target.addEventListener('animationend', evt => { + if (evt.animationName !== 'highlight-hash-link') return; + target.classList.remove('highlight-hash-link'); + if (target !== state.highlightedTarget) return; + state.highlightedTarget = null; + }); + } +} + +clientSteps.getPageReferences.push(getHashLinkReferences); +clientSteps.addPageListeners.push(addHashLinkListeners); + +// Sticky content heading --------------------------------- + +const stickyHeadingInfo = initInfo('stickyHeadingInfo', { + stickyContainers: null, + + stickySubheadingRows: null, + stickySubheadings: null, + + stickyCoverContainers: null, + stickyCoverTextAreas: null, + stickyCovers: null, + + contentContainers: null, + contentHeadings: null, + contentCovers: null, + contentCoversReveal: null, + + state: { + displayedHeading: null, + }, + + event: { + whenDisplayedHeadingChanges: [], + }, +}); + +function getStickyHeadingReferences() { + const info = stickyHeadingInfo; + + info.stickyContainers = + Array.from(document.getElementsByClassName('content-sticky-heading-container')); + + info.stickyCoverContainers = + info.stickyContainers + .map(el => el.querySelector('.content-sticky-heading-cover-container')); + + info.stickyCovers = + info.stickyCoverContainers + .map(el => el?.querySelector('.content-sticky-heading-cover')); + + info.stickyCoverTextAreas = + info.stickyCovers + .map(el => el?.querySelector('.image-text-area')); + + info.stickySubheadingRows = + info.stickyContainers + .map(el => el.querySelector('.content-sticky-subheading-row')); + + info.stickySubheadings = + info.stickySubheadingRows + .map(el => el.querySelector('h2')); + + info.contentContainers = + info.stickyContainers + .map(el => el.parentElement); + + info.contentCovers = + info.contentContainers + .map(el => el.querySelector('#cover-art-container')); + + info.contentCoversReveal = + info.contentCovers + .map(el => el ? !!el.querySelector('.reveal') : null); + + info.contentHeadings = + info.contentContainers + .map(el => Array.from(el.querySelectorAll('.content-heading'))); +} + +function removeTextPlaceholderStickyHeadingCovers() { + const info = stickyHeadingInfo; + + const hasTextArea = + info.stickyCoverTextAreas.map(el => !!el); + + const coverContainersWithTextArea = + info.stickyCoverContainers + .filter((_el, index) => hasTextArea[index]); + + for (const el of coverContainersWithTextArea) { + el.remove(); + } + + info.stickyCoverContainers = + info.stickyCoverContainers + .map((el, index) => hasTextArea[index] ? null : el); + + info.stickyCovers = + info.stickyCovers + .map((el, index) => hasTextArea[index] ? null : el); + + info.stickyCoverTextAreas = + info.stickyCoverTextAreas + .slice() + .fill(null); +} + +function addRevealClassToStickyHeadingCovers() { + const info = stickyHeadingInfo; + + const stickyCoversWhichReveal = + info.stickyCovers + .filter((_el, index) => info.contentCoversReveal[index]); + + for (const el of stickyCoversWhichReveal) { + el.classList.add('content-sticky-heading-cover-needs-reveal'); + } +} + +function addRevealListenersForStickyHeadingCovers() { + const info = stickyHeadingInfo; + + const stickyCovers = info.stickyCovers.slice(); + const contentCovers = info.contentCovers.slice(); + + filterMultipleArrays( + stickyCovers, + contentCovers, + (_stickyCover, _contentCover, index) => info.contentCoversReveal[index]); + + for (const {stickyCover, contentCover} of stitchArrays({ + stickyCover: stickyCovers, + contentCover: contentCovers, + })) { + // TODO: Janky - should use internal event instead of DOM event + contentCover.querySelector('.reveal').addEventListener('hsmusic-reveal', () => { + stickyCover.classList.remove('content-sticky-heading-cover-needs-reveal'); + }); + } +} + +function topOfViewInside(el, scroll = window.scrollY) { + return ( + scroll > el.offsetTop && + scroll < el.offsetTop + el.offsetHeight); +} + +function updateStickyCoverVisibility(index) { + const info = stickyHeadingInfo; + + const stickyCoverContainer = info.stickyCoverContainers[index]; + const contentCover = info.contentCovers[index]; + + if (contentCover && stickyCoverContainer) { + if (contentCover.getBoundingClientRect().bottom < 4) { + stickyCoverContainer.classList.add('visible'); + } else { + stickyCoverContainer.classList.remove('visible'); + } + } +} + +function getContentHeadingClosestToStickySubheading(index) { + const info = stickyHeadingInfo; + + const contentContainer = info.contentContainers[index]; + + if (!topOfViewInside(contentContainer)) { + return null; + } + + const stickySubheading = info.stickySubheadings[index]; + + if (stickySubheading.childNodes.length === 0) { + // Supply a non-breaking space to ensure correct basic line height. + stickySubheading.appendChild(document.createTextNode('\xA0')); + } + + const stickyContainer = info.stickyContainers[index]; + const stickyRect = stickyContainer.getBoundingClientRect(); + + // TODO: Should this compute with the subheading row instead of h2? + const subheadingRect = stickySubheading.getBoundingClientRect(); + + const stickyBottom = stickyRect.bottom + subheadingRect.height; + + // Iterate from bottom to top of the content area. + const contentHeadings = info.contentHeadings[index]; + for (const heading of contentHeadings.slice().reverse()) { + const headingRect = heading.getBoundingClientRect(); + if (headingRect.y + headingRect.height / 1.5 < stickyBottom + 20) { + return heading; + } + } + + return null; +} + +function updateStickySubheadingContent(index) { + const info = stickyHeadingInfo; + const {event, state} = info; + + const closestHeading = getContentHeadingClosestToStickySubheading(index); + + if (state.displayedHeading === closestHeading) return; + + const stickySubheadingRow = info.stickySubheadingRows[index]; + + if (closestHeading) { + const stickySubheading = info.stickySubheadings[index]; + + // Array.from needed to iterate over a live array with for..of + for (const child of Array.from(stickySubheading.childNodes)) { + child.remove(); + } + + const textContainer = + closestHeading.querySelector('.content-heading-main-title') + // Just for compatibility with older builds of the site. + ?? closestHeading; + + for (const child of textContainer.childNodes) { + if (child.tagName === 'A') { + for (const grandchild of child.childNodes) { + stickySubheading.appendChild(grandchild.cloneNode(true)); + } + } else { + stickySubheading.appendChild(child.cloneNode(true)); + } + } + + stickySubheadingRow.classList.add('visible'); + } else { + stickySubheadingRow.classList.remove('visible'); + } + + const oldDisplayedHeading = state.displayedHeading; + + state.displayedHeading = closestHeading; + + dispatchInternalEvent(event, 'whenDisplayedHeadingChanges', index, { + oldHeading: oldDisplayedHeading, + newHeading: closestHeading, + }); +} + +function updateStickyHeadings(index) { + updateStickyCoverVisibility(index); + updateStickySubheadingContent(index); +} + +function initializeStateForStickyHeadings() { + for (let i = 0; i < stickyHeadingInfo.stickyContainers.length; i++) { + updateStickyHeadings(i); + } +} + +function addScrollListenerForStickyHeadings() { + document.addEventListener('scroll', () => { + for (let i = 0; i < stickyHeadingInfo.stickyContainers.length; i++) { + updateStickyHeadings(i); + } + }); +} + +clientSteps.getPageReferences.push(getStickyHeadingReferences); +clientSteps.mutatePageContent.push(removeTextPlaceholderStickyHeadingCovers); +clientSteps.mutatePageContent.push(addRevealClassToStickyHeadingCovers); +clientSteps.initializeState.push(initializeStateForStickyHeadings); +clientSteps.addPageListeners.push(addRevealListenersForStickyHeadingCovers); +clientSteps.addPageListeners.push(addScrollListenerForStickyHeadings); + +// Image overlay ------------------------------------------ + +// TODO: Update to clientSteps style. + +function addImageOverlayClickHandlers() { + const container = document.getElementById('image-overlay-container'); + + if (!container) { + console.warn(`#image-overlay-container missing, image overlay module disabled.`); + return; + } + + for (const link of document.querySelectorAll('.image-link')) { + if (link.closest('.no-image-preview')) { + continue; + } + + link.addEventListener('click', handleImageLinkClicked); + } + + const actionContainer = document.getElementById('image-overlay-action-container'); + + container.addEventListener('click', handleContainerClicked); + document.body.addEventListener('keydown', handleKeyDown); + + function handleContainerClicked(evt) { + // Only hide the image overlay if actually clicking the background. + if (evt.target !== container) { + return; + } + + // If you clicked anything close to or beneath the action bar, don't hide + // the image overlay. + const rect = actionContainer.getBoundingClientRect(); + if (evt.clientY >= rect.top - 40) { + return; + } + + container.classList.remove('visible'); + } + + function handleKeyDown(evt) { + if (evt.key === 'Escape' || evt.key === 'Esc' || evt.keyCode === 27) { + container.classList.remove('visible'); + } + } +} + +async function handleImageLinkClicked(evt) { + if (evt.metaKey || evt.shiftKey || evt.altKey) { + return; + } + + evt.preventDefault(); + + // Don't show the overlay if the image still needs to be revealed. + if (evt.target.closest('.reveal:not(.revealed)')) { + return; + } + + const container = document.getElementById('image-overlay-container'); + container.classList.add('visible'); + container.classList.remove('loaded'); + container.classList.remove('errored'); + + const allViewOriginal = document.getElementsByClassName('image-overlay-view-original'); + const mainImage = document.getElementById('image-overlay-image'); + const thumbImage = document.getElementById('image-overlay-image-thumb'); + + const {href: originalSrc} = evt.target.closest('a'); + + const { + src: embeddedSrc, + dataset: { + originalSize: originalFileSize, + thumbs: availableThumbList, + }, + } = evt.target.closest('a').querySelector('img'); + + updateFileSizeInformation(originalFileSize); + + let mainSrc = null; + let thumbSrc = null; + + if (availableThumbList) { + const {thumb: mainThumb, length: mainLength} = getPreferredThumbSize(availableThumbList); + const {thumb: smallThumb, length: smallLength} = getSmallestThumbSize(availableThumbList); + mainSrc = embeddedSrc.replace(/\.[a-z]+\.(jpg|png)$/, `.${mainThumb}.jpg`); + thumbSrc = embeddedSrc.replace(/\.[a-z]+\.(jpg|png)$/, `.${smallThumb}.jpg`); + // Show the thumbnail size on each <img> element's data attributes. + // Y'know, just for debugging convenience. + mainImage.dataset.displayingThumb = `${mainThumb}:${mainLength}`; + thumbImage.dataset.displayingThumb = `${smallThumb}:${smallLength}`; + } else { + mainSrc = originalSrc; + thumbSrc = null; + mainImage.dataset.displayingThumb = ''; + thumbImage.dataset.displayingThumb = ''; + } + + if (thumbSrc) { + thumbImage.src = thumbSrc; + thumbImage.style.display = null; + } else { + thumbImage.src = ''; + thumbImage.style.display = 'none'; + } + + for (const viewOriginal of allViewOriginal) { + viewOriginal.href = originalSrc; + } + + mainImage.addEventListener('load', handleMainImageLoaded); + mainImage.addEventListener('error', handleMainImageErrored); + + const showProgress = amount => { + cssProp(container, '--download-progress', `${amount * 100}%`); + }; + + showProgress(0.00); + + const response = + await fetchWithProgress(mainSrc, progress => { + if (progress === -1) { + // TODO: Indeterminate response progress cue + showProgress(0.00); + } else { + showProgress(0.20 + 0.80 * progress); + } + }); + + if (!response.status.toString().startsWith('2')) { + handleMainImageErrored(); + return; + } + + const blob = await response.blob(); + const blobSrc = URL.createObjectURL(blob); + + mainImage.src = blobSrc; + showProgress(1.00); + + function handleMainImageLoaded() { + container.classList.add('loaded'); + removeEventListeners(); + } + + function handleMainImageErrored() { + container.classList.add('errored'); + removeEventListeners(); + } + + function removeEventListeners() { + mainImage.removeEventListener('load', handleMainImageLoaded); + mainImage.removeEventListener('error', handleMainImageErrored); + } +} + +function parseThumbList(availableThumbList) { + // Parse all the available thumbnail sizes! These are provided by the actual + // content generation on each image. + const defaultThumbList = 'huge:1400 semihuge:1200 large:800 medium:400 small:250' + const availableSizes = + (availableThumbList || defaultThumbList) + .split(' ') + .map(part => part.split(':')) + .map(([thumb, length]) => ({thumb, length: parseInt(length)})) + .sort((a, b) => a.length - b.length); + + return availableSizes; +} + +function getPreferredThumbSize(availableThumbList) { + // Assuming a square, the image will be constrained to the lesser window + // dimension. Coefficient here matches CSS dimensions for image overlay. + const constrainedLength = Math.floor(Math.min( + 0.80 * window.innerWidth, + 0.80 * window.innerHeight)); + + // Match device pixel ratio, which is 2x for "retina" displays and certain + // device configurations. + const visualLength = window.devicePixelRatio * constrainedLength; + + const availableSizes = parseThumbList(availableThumbList); + + // Starting from the smallest dimensions, find (and return) the first + // available length which hits a "good enough" threshold - it's got to be + // at least that percent of the way to the actual displayed dimensions. + const goodEnoughThreshold = 0.90; + + // (The last item is skipped since we'd be falling back to it anyway.) + for (const {thumb, length} of availableSizes.slice(0, -1)) { + if (Math.floor(visualLength * goodEnoughThreshold) <= length) { + return {thumb, length}; + } + } + + // If none of the items in the list were big enough to hit the "good enough" + // threshold, just use the largest size available. + return availableSizes[availableSizes.length - 1]; +} + +function getSmallestThumbSize(availableThumbList) { + // Just snag the smallest size. This'll be used for displaying the "preview" + // as the bigger one is loading. + const availableSizes = parseThumbList(availableThumbList); + return availableSizes[0]; +} + +function updateFileSizeInformation(fileSize) { + const fileSizeWarningThreshold = 8 * 10 ** 6; + + const actionContentWithoutSize = document.getElementById('image-overlay-action-content-without-size'); + const actionContentWithSize = document.getElementById('image-overlay-action-content-with-size'); + + if (!fileSize) { + actionContentWithSize.classList.remove('visible'); + actionContentWithoutSize.classList.add('visible'); + return; + } + + actionContentWithoutSize.classList.remove('visible'); + actionContentWithSize.classList.add('visible'); + + const megabytesContainer = document.getElementById('image-overlay-file-size-megabytes'); + const kilobytesContainer = document.getElementById('image-overlay-file-size-kilobytes'); + const megabytesContent = megabytesContainer.querySelector('.image-overlay-file-size-count'); + const kilobytesContent = kilobytesContainer.querySelector('.image-overlay-file-size-count'); + const fileSizeWarning = document.getElementById('image-overlay-file-size-warning'); + + fileSize = parseInt(fileSize); + const round = (exp) => Math.round(fileSize / 10 ** (exp - 1)) / 10; + + if (fileSize > fileSizeWarningThreshold) { + fileSizeWarning.classList.add('visible'); + } else { + fileSizeWarning.classList.remove('visible'); + } + + if (fileSize > 10 ** 6) { + megabytesContainer.classList.add('visible'); + kilobytesContainer.classList.remove('visible'); + megabytesContent.innerText = round(6); + } else { + megabytesContainer.classList.remove('visible'); + kilobytesContainer.classList.add('visible'); + kilobytesContent.innerText = round(3); + } + + void fileSizeWarning; +} + +addImageOverlayClickHandlers(); + +// "Additional names" box --------------------------------- + +const additionalNamesBoxInfo = initInfo('additionalNamesBox', { + box: null, + links: null, + mainContentContainer: null, + + state: { + visible: false, + }, +}); + +function getAdditionalNamesBoxReferences() { + const info = additionalNamesBoxInfo; + + info.box = + document.getElementById('additional-names-box'); + + info.links = + document.querySelectorAll('a[href="#additional-names-box"]'); + + info.mainContentContainer = + document.querySelector('#content .main-content-container'); +} + +function addAdditionalNamesBoxInternalListeners() { + const info = additionalNamesBoxInfo; + + hashLinkInfo.event.beforeHashLinkScrolls.push(({target}) => { + if (target === info.box) { + return false; + } + }); +} + +function addAdditionalNamesBoxListeners() { + const info = additionalNamesBoxInfo; + + for (const link of info.links) { + link.addEventListener('click', domEvent => { + handleAdditionalNamesBoxLinkClicked(domEvent); + }); + } +} + +function handleAdditionalNamesBoxLinkClicked(domEvent) { + const info = additionalNamesBoxInfo; + const {state} = info; + + domEvent.preventDefault(); + + if (!info.box || !info.mainContentContainer) return; + + const margin = + +(cssProp(info.box, 'scroll-margin-top').replace('px', '')); + + const {top} = + (state.visible + ? info.box.getBoundingClientRect() + : info.mainContentContainer.getBoundingClientRect()); + + if (top + 20 < margin || top > 0.4 * window.innerHeight) { + if (!state.visible) { + toggleAdditionalNamesBox(); + } + + window.scrollTo({ + top: window.scrollY + top - margin, + behavior: 'smooth', + }); + } else { + toggleAdditionalNamesBox(); + } +} + +function toggleAdditionalNamesBox() { + const info = additionalNamesBoxInfo; + const {state} = info; + + state.visible = !state.visible; + info.box.style.display = + (state.visible + ? 'block' + : 'none'); +} + +clientSteps.getPageReferences.push(getAdditionalNamesBoxReferences); +clientSteps.addInternalListeners.push(addAdditionalNamesBoxInternalListeners); +clientSteps.addPageListeners.push(addAdditionalNamesBoxListeners); + +// Group contributions table ------------------------------ + +// TODO: Update to clientSteps style. + +const groupContributionsTableInfo = + Array.from(document.querySelectorAll('#content dl')) + .filter(dl => dl.querySelector('a.group-contributions-sort-button')) + .map(dl => ({ + sortingByCountLink: dl.querySelector('dt.group-contributions-sorted-by-count a.group-contributions-sort-button'), + sortingByDurationLink: dl.querySelector('dt.group-contributions-sorted-by-duration a.group-contributions-sort-button'), + sortingByCountElements: dl.querySelectorAll('.group-contributions-sorted-by-count'), + sortingByDurationElements: dl.querySelectorAll('.group-contributions-sorted-by-duration'), + })); + +function sortGroupContributionsTableBy(info, sort) { + const [showThese, hideThese] = + (sort === 'count' + ? [info.sortingByCountElements, info.sortingByDurationElements] + : [info.sortingByDurationElements, info.sortingByCountElements]); + + for (const element of showThese) element.classList.add('visible'); + for (const element of hideThese) element.classList.remove('visible'); +} + +for (const info of groupContributionsTableInfo) { + info.sortingByCountLink.addEventListener('click', evt => { + evt.preventDefault(); + sortGroupContributionsTableBy(info, 'duration'); + }); + + info.sortingByDurationLink.addEventListener('click', evt => { + evt.preventDefault(); + sortGroupContributionsTableBy(info, 'count'); + }); +} + +// Generic links with tooltips ---------------------------- + +const textWithTooltipInfo = initInfo('textWithTooltipInfo', { + hoverables: null, + tooltips: null, +}); + +function getTextWithTooltipReferences() { + const info = textWithTooltipInfo; + + const spans = + Array.from(document.querySelectorAll('.text-with-tooltip')); + + info.hoverables = + spans.map(span => span.children[0]); + + info.tooltips = + spans.map(span => span.children[1]); +} + +function addTextWithTooltipPageListeners() { + const info = textWithTooltipInfo; + + for (const {hoverable, tooltip} of stitchArrays({ + hoverable: info.hoverables, + tooltip: info.tooltips, + })) { + registerTooltipElement(tooltip); + registerTooltipHoverableElement(hoverable, tooltip); + } +} + +clientSteps.getPageReferences.push(getTextWithTooltipReferences); +clientSteps.addPageListeners.push(addTextWithTooltipPageListeners); + +// Datetimestamp tooltips --------------------------------- + +const datetimestampTooltipInfo = initInfo('datetimestampTooltipInfo', { + hoverables: null, + tooltips: null, +}); + +function getDatestampTooltipReferences() { + const info = datetimestampTooltipInfo; + + const spans = + Array.from(document.querySelectorAll('span.datetimestamp.has-tooltip')); + + info.hoverables = + spans.map(span => span.querySelector('time')); + + info.tooltips = + spans.map(span => span.querySelector('span.datetimestamp-tooltip')); +} + +function addDatestampTooltipPageListeners() { + const info = datetimestampTooltipInfo; + + for (const {hoverable, tooltip} of stitchArrays({ + hoverable: info.hoverables, + tooltip: info.tooltips, + })) { + registerTooltipElement(tooltip); + registerTooltipHoverableElement(hoverable, tooltip); + } +} + +clientSteps.getPageReferences.push(getDatestampTooltipReferences); +clientSteps.addPageListeners.push(addDatestampTooltipPageListeners); + +// Artist external link tooltips -------------------------- + +// These don't need to have tooltip events specially added as +// they're implemented with "text with tooltip" components. + +const artistExternalLinkTooltipInfo = initInfo('artistExternalLinkTooltipInfo', { + tooltips: null, + tooltipRows: null, + + settings: { + // This is the maximum distance, in CSS pixels, that the mouse + // can appear to be moving per second while still considered + // "idle". A greater value means higher tolerance for small + // movements. + maximumIdleSpeed: 40, + + // Leaving the mouse idle for this amount of time, over a single + // row of the tooltip, will cause a column of supplemental info + // to display. + mouseIdleShowInfoDelay: 1000, + + // If none of these tooltips are visible for this amount of time, + // the supplemental info column is hidden. It'll never disappear + // while a tooltip is actually visible. + hideInfoAfterTooltipHiddenDelay: 2250, + }, + + state: { + // This is shared by all tooltips. + showingTooltipInfo: false, + + mouseIdleTimeout: null, + hideInfoTimeout: null, + + mouseMovementPositions: [], + mouseMovementTimestamps: [], + }, +}); + +function getArtistExternalLinkTooltipPageReferences() { + const info = artistExternalLinkTooltipInfo; + + info.tooltips = + Array.from(document.getElementsByClassName('icons-tooltip')); + + info.tooltipRows = + info.tooltips.map(tooltip => + Array.from(tooltip.getElementsByClassName('icon'))); +} + +function addArtistExternalLinkTooltipInternalListeners() { + const info = artistExternalLinkTooltipInfo; + + hoverableTooltipInfo.event.whenTooltipShows.push(({tooltip}) => { + const {state} = info; + + if (info.tooltips.includes(tooltip)) { + clearTimeout(state.hideInfoTimeout); + state.hideInfoTimeout = null; + } + }); + + hoverableTooltipInfo.event.whenTooltipHides.push(() => { + const {settings, state} = info; + + if (state.showingTooltipInfo) { + state.hideInfoTimeout = + setTimeout(() => { + state.hideInfoTimeout = null; + hideArtistExternalLinkTooltipInfo(); + }, settings.hideInfoAfterTooltipHiddenDelay); + } else { + clearTimeout(state.mouseIdleTimeout); + state.mouseIdleTimeout = null; + } + }); +} + +function addArtistExternalLinkTooltipPageListeners() { + const info = artistExternalLinkTooltipInfo; + + for (const tooltip of info.tooltips) { + tooltip.addEventListener('mousemove', domEvent => { + handleArtistExternalLinkTooltipMouseMoved(domEvent); + }); + + tooltip.addEventListener('mouseout', () => { + const {state} = info; + + clearTimeout(state.mouseIdleTimeout); + state.mouseIdleTimeout = null; + }); + } + + for (const tooltipRow of info.tooltipRows.flat()) { + tooltipRow.addEventListener('mouseover', () => { + const {state} = info; + + clearTimeout(state.mouseIdleTimeout); + state.mouseIdleTimeout = null; + }); + } +} + +function handleArtistExternalLinkTooltipMouseMoved(domEvent) { + const info = artistExternalLinkTooltipInfo; + const {settings, state} = info; + + if (state.showingTooltipInfo) { + return; + } + + // Clean out expired mouse movements + + const expiryTime = 1000; + + if (!empty(state.mouseMovementTimestamps)) { + const firstRecentMovementIndex = + state.mouseMovementTimestamps + .findIndex(value => Date.now() - value <= expiryTime); + + if (firstRecentMovementIndex === -1) { + state.mouseMovementTimestamps.splice(0); + state.mouseMovementPositions.splice(0); + } else if (firstRecentMovementIndex > 0) { + state.mouseMovementTimestamps.splice(0, firstRecentMovementIndex - 1); + state.mouseMovementPositions.splice(0, firstRecentMovementIndex - 1); + } + } + + const currentMovementDistance = + Math.sqrt(domEvent.movementX ** 2 + domEvent.movementY ** 2); + + state.mouseMovementTimestamps.push(Date.now()); + state.mouseMovementPositions.push([domEvent.screenX, domEvent.screenY]); + + // We can't really compute speed without having + // at least two data points! + if (state.mouseMovementPositions.length < 2) { + return; + } + + const movementTravelDistances = + state.mouseMovementPositions.map((current, index, array) => { + if (index === 0) return 0; + + const previous = array[index - 1]; + const deltaX = current[0] - previous[0]; + const deltaY = current[1] - previous[1]; + return Math.sqrt(deltaX ** 2 + deltaY ** 2); + }); + + const totalTravelDistance = + accumulateSum(movementTravelDistances); + + // In seconds rather than milliseconds. + const timeSinceFirstMovement = + (Date.now() - state.mouseMovementTimestamps[0]) / 1000; + + const averageSpeed = + Math.floor(totalTravelDistance / timeSinceFirstMovement); + + if (averageSpeed > settings.maximumIdleSpeed) { + clearTimeout(state.mouseIdleTimeout); + state.mouseIdleTimeout = null; + } + + if (state.mouseIdleTimeout) { + return; + } + + state.mouseIdleTimeout = + setTimeout(() => { + state.mouseIdleTimeout = null; + showArtistExternalLinkTooltipInfo(); + }, settings.mouseIdleShowInfoDelay); +} + +function showArtistExternalLinkTooltipInfo() { + const info = artistExternalLinkTooltipInfo; + const {state} = info; + + state.showingTooltipInfo = true; + + for (const tooltip of info.tooltips) { + tooltip.classList.add('show-info'); + } +} + +function hideArtistExternalLinkTooltipInfo() { + const info = artistExternalLinkTooltipInfo; + const {state} = info; + + state.showingTooltipInfo = false; + + for (const tooltip of info.tooltips) { + tooltip.classList.remove('show-info'); + } +} + +clientSteps.getPageReferences.push(getArtistExternalLinkTooltipPageReferences); +clientSteps.addInternalListeners.push(addArtistExternalLinkTooltipInternalListeners); +clientSteps.addPageListeners.push(addArtistExternalLinkTooltipPageListeners); + +// Sticky commentary sidebar ------------------------------ + +const albumCommentarySidebarInfo = initInfo('albumCommentarySidebarInfo', { + sidebar: null, + sidebarHeading: null, + + sidebarTrackLinks: null, + sidebarTrackDirectories: null, + + sidebarTrackSections: null, + sidebarTrackSectionStartIndices: null, + + state: { + currentTrackSection: null, + currentTrackLink: null, + justChangedTrackSection: false, + }, +}); + +function getAlbumCommentarySidebarReferences() { + const info = albumCommentarySidebarInfo; + + info.sidebar = + document.getElementById('sidebar-left'); + + info.sidebarHeading = + info.sidebar.querySelector('h1'); + + info.sidebarTrackLinks = + Array.from(info.sidebar.querySelectorAll('li a')); + + info.sidebarTrackDirectories = + info.sidebarTrackLinks + .map(el => el.getAttribute('href')?.slice(1) ?? null); + + info.sidebarTrackSections = + Array.from(info.sidebar.getElementsByTagName('details')); + + info.sidebarTrackSectionStartIndices = + info.sidebarTrackSections + .map(details => details.querySelector('ol, ul')) + .reduce( + (accumulator, _list, index, array) => + (empty(accumulator) + ? [0] + : [ + ...accumulator, + (accumulator[accumulator.length - 1] + + array[index - 1].querySelectorAll('li a').length), + ]), + []); +} + +function scrollAlbumCommentarySidebar() { + const info = albumCommentarySidebarInfo; + const {state} = info; + const {currentTrackLink, currentTrackSection} = state; + + if (!currentTrackLink) { + return; + } + + const {sidebar, sidebarHeading} = info; + + const scrollTop = sidebar.scrollTop; + + const headingRect = sidebarHeading.getBoundingClientRect(); + const sidebarRect = sidebar.getBoundingClientRect(); + + const stickyPadding = headingRect.height; + const sidebarViewportHeight = sidebarRect.height - stickyPadding; + + const linkRect = currentTrackLink.getBoundingClientRect(); + const sectionRect = currentTrackSection.getBoundingClientRect(); + + const sectionTopEdge = + sectionRect.top - (sidebarRect.top - scrollTop); + + const sectionHeight = + sectionRect.height; + + const sectionScrollTop = + sectionTopEdge - stickyPadding - 10; + + const linkTopEdge = + linkRect.top - (sidebarRect.top - scrollTop); + + const linkBottomEdge = + linkRect.bottom - (sidebarRect.top - scrollTop); + + const linkScrollTop = + linkTopEdge - stickyPadding - 5; + + const linkVisibleFromTopOfSection = + linkBottomEdge - sectionTopEdge > sidebarViewportHeight; + + const linkScrollBottom = + linkScrollTop - sidebarViewportHeight + linkRect.height + 20; + + const maxScrollInViewport = + scrollTop + stickyPadding + sidebarViewportHeight; + + const minScrollInViewport = + scrollTop + stickyPadding; + + if (linkBottomEdge > maxScrollInViewport) { + if (linkVisibleFromTopOfSection) { + sidebar.scrollTo({top: linkScrollBottom, behavior: 'smooth'}); + } else { + sidebar.scrollTo({top: sectionScrollTop, behavior: 'smooth'}); + } + } else if (linkTopEdge < minScrollInViewport) { + if (linkVisibleFromTopOfSection) { + sidebar.scrollTo({top: linkScrollTop, behavior: 'smooth'}); + } else { + sidebar.scrollTo({top: sectionScrollTop, behavior: 'smooth'}); + } + } else if (state.justChangedTrackSection) { + if (sectionHeight < sidebarViewportHeight) { + sidebar.scrollTo({top: sectionScrollTop, behavior: 'smooth'}); + } + } +} + +function markDirectoryAsCurrentForAlbumCommentary(trackDirectory) { + const info = albumCommentarySidebarInfo; + const {state} = info; + + const trackIndex = + (trackDirectory + ? info.sidebarTrackDirectories + .indexOf(trackDirectory) + : -1); + + const sectionIndex = + (trackIndex >= 0 + ? info.sidebarTrackSectionStartIndices + .findIndex((start, index, array) => + (index === array.length - 1 + ? true + : trackIndex < array[index + 1])) + : -1); + + const sidebarTrackLink = + (trackIndex >= 0 + ? info.sidebarTrackLinks[trackIndex] + : null); + + const sidebarTrackSection = + (sectionIndex >= 0 + ? info.sidebarTrackSections[sectionIndex] + : null); + + state.currentTrackLink?.classList?.remove('current'); + state.currentTrackLink = sidebarTrackLink; + state.currentTrackLink?.classList?.add('current'); + + if (sidebarTrackSection !== state.currentTrackSection) { + if (sidebarTrackSection && !sidebarTrackSection.open) { + if (state.currentTrackSection) { + state.currentTrackSection.open = false; + } + + sidebarTrackSection.open = true; + } + + state.currentTrackSection?.classList?.remove('current'); + state.currentTrackSection = sidebarTrackSection; + state.currentTrackSection?.classList?.add('current'); + state.justChangedTrackSection = true; + } else { + state.justChangedTrackSection = false; + } +} + +function addAlbumCommentaryInternalListeners() { + const info = albumCommentarySidebarInfo; + + const mainContentIndex = + (stickyHeadingInfo.contentContainers ?? []) + .findIndex(({id}) => id === 'content'); + + if (mainContentIndex === -1) return; + + stickyHeadingInfo.event.whenDisplayedHeadingChanges.push((index, {newHeading}) => { + if (index !== mainContentIndex) return; + if (hashLinkInfo.state.scrollingAfterClick) return; + + const trackDirectory = + (newHeading + ? newHeading.id + : null); + + markDirectoryAsCurrentForAlbumCommentary(trackDirectory); + scrollAlbumCommentarySidebar(); + }); + + hashLinkInfo.event.whenHashLinkClicked.push(({link}) => { + const hash = link.getAttribute('href').slice(1); + if (!info.sidebarTrackDirectories.includes(hash)) return; + markDirectoryAsCurrentForAlbumCommentary(hash); + }); +} + +if (document.documentElement.dataset.urlKey === 'localized.albumCommentary') { + clientSteps.getPageReferences.push(getAlbumCommentarySidebarReferences); + clientSteps.addInternalListeners.push(addAlbumCommentaryInternalListeners); +} + +// Run setup steps ---------------------------------------- + +for (const [key, steps] of Object.entries(clientSteps)) { + for (const step of steps) { + try { + step(); + } catch (error) { + console.warn(`During ${key}, failed to run ${step.name}`); + console.debug(error); + } + } +} diff --git a/src/static/js/lazy-loading.js b/src/static/js/lazy-loading.js new file mode 100644 index 00000000..1df56f08 --- /dev/null +++ b/src/static/js/lazy-loading.js @@ -0,0 +1,54 @@ +/* eslint-env browser */ + +// Lazy loading! Roll your own. Woot. +// This file includes a 8unch of fall8acks and stuff like that, and is written +// with fairly Olden JavaScript(TM), so as to work on pretty much any 8rowser +// with JS ena8led. (If it's disa8led, there are gener8ted <noscript> tags to +// work there.) + +var observer; + +function loadImage(image) { + image.src = image.dataset.original; +} + +function lazyLoad(elements) { + for (var i = 0; i < elements.length; i++) { + var item = elements[i]; + if (item.intersectionRatio > 0) { + observer.unobserve(item.target); + loadImage(item.target); + } + } +} + +function lazyLoadMain() { + // This is a live HTMLCollection! We can't iter8te over it normally 'cuz + // we'd 8e mutating its value just 8y interacting with the DOM elements it + // contains. A while loop works just fine, even though you'd think reading + // over this code that this would 8e an infinitely hanging loop. It isn't! + var elements = document.getElementsByClassName('js-hide'); + while (elements.length) { + elements[0].classList.remove('js-hide'); + } + + var lazyElements = document.getElementsByClassName('lazy'); + var i; + if (window.IntersectionObserver) { + observer = new IntersectionObserver(lazyLoad, { + rootMargin: '200px', + threshold: 0, + }); + for (i = 0; i < lazyElements.length; i++) { + observer.observe(lazyElements[i]); + } + } else { + for (i = 0; i < lazyElements.length; i++) { + var element = lazyElements[i]; + var original = element.getAttribute('data-original'); + element.setAttribute('src', original); + } + } +} + +document.addEventListener('DOMContentLoaded', lazyLoadMain); diff --git a/src/static/js/xhr-util.js b/src/static/js/xhr-util.js new file mode 100644 index 00000000..8a43072c --- /dev/null +++ b/src/static/js/xhr-util.js @@ -0,0 +1,64 @@ +/* eslint-env browser */ + +/** + * This fetch function is adapted from a `loadImage` function + * credited to Parziphal, Feb 13, 2017. + * https://stackoverflow.com/a/42196770 + * + * The callback is generally run with the loading progress as a decimal 0-1. + * However, if it's not possible to compute the progress ration (which might + * only become apparent after a progress amount *has* been sent!), + * the callback will be run with the value -1. + * + * The return promise resolves to a manually instantiated Response object + * which generally behaves the same as a normal fetch response; access headers, + * text, blob, arrayBuffer as usual. Accordingly, non-200 responses do *not* + * reject the prmoise, so be sure to check the response status yourself. + */ +export function fetchWithProgress(url, progressCallback) { + return new Promise(resolve => { + const xhr = new XMLHttpRequest(); + let notifiedNotComputable = false; + + xhr.open('GET', url, true); + xhr.responseType = 'arraybuffer'; + + xhr.onprogress = event => { + if (notifiedNotComputable) { + return; + } + + if (!event.lengthComputable) { + notifiedNotComputable = true; + progressCallback(-1); + return; + } + + progressCallback(event.loaded / event.total); + }; + + xhr.onloadend = () => { + const body = xhr.response; + + const options = { + status: xhr.status, + headers: + parseResponseHeaders(xhr.getAllResponseHeaders()), + }; + + resolve(new Response(body, options)); + }; + + xhr.send(); + }); + + function parseResponseHeaders(headers) { + return ( + Object.fromEntries( + headers + .trim() + .split(/[\r\n]+/) + .map(line => line.match(/(.+?):\s*(.+)/)) + .map(match => [match[1], match[2]]))); + } +} |