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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
import {
classMap,
html,
ifDefined,
repeat,
styleMap,
when,
} from "chrome://global/content/vendor/lit.all.mjs";
import { MozLitElement } from "chrome://global/content/lit-utils.mjs";
import { escapeRegExp } from "./search-helpers.mjs";
// eslint-disable-next-line import/no-unassigned-import
import "chrome://global/content/elements/moz-button.mjs";
const NOW_THRESHOLD_MS = 91000;
const FXVIEW_ROW_HEIGHT_PX = 32;
const lazy = {};
let XPCOMUtils;
if (!window.IS_STORYBOOK) {
XPCOMUtils = ChromeUtils.importESModule(
"resource://gre/modules/XPCOMUtils.sys.mjs"
).XPCOMUtils;
XPCOMUtils.defineLazyPreferenceGetter(
lazy,
"virtualListEnabledPref",
"browser.firefox-view.virtual-list.enabled"
);
ChromeUtils.defineLazyGetter(lazy, "relativeTimeFormat", () => {
return new Services.intl.RelativeTimeFormat(undefined, {
style: "narrow",
});
});
ChromeUtils.defineESModuleGetters(lazy, {
BrowserUtils: "resource://gre/modules/BrowserUtils.sys.mjs",
});
}
/**
* A list of clickable tab items
*
* @property {boolean} compactRows - Whether to hide the URL and date/time for each tab.
* @property {string} dateTimeFormat - Expected format for date and/or time
* @property {string} hasPopup - The aria-haspopup attribute for the secondary action, if required
* @property {number} maxTabsLength - The max number of tabs for the list
* @property {Array} tabItems - Items to show in the tab list
* @property {string} searchQuery - The query string to highlight, if provided.
* @property {string} secondaryActionClass - The class used to style the secondary action element
* @property {string} tertiaryActionClass - The class used to style the tertiary action element
*/
export class FxviewTabListBase extends MozLitElement {
constructor() {
super();
window.MozXULElement.insertFTLIfNeeded("toolkit/branding/brandings.ftl");
window.MozXULElement.insertFTLIfNeeded("browser/fxviewTabList.ftl");
this.activeIndex = 0;
this.currentActiveElementId = "fxview-tab-row-main";
this.hasPopup = null;
this.dateTimeFormat = "relative";
this.maxTabsLength = 25;
this.tabItems = [];
this.compactRows = false;
this.updatesPaused = true;
this.#register();
}
static properties = {
activeIndex: { type: Number },
compactRows: { type: Boolean },
currentActiveElementId: { type: String },
dateTimeFormat: { type: String },
hasPopup: { type: String },
maxTabsLength: { type: Number },
tabItems: { type: Array },
updatesPaused: { type: Boolean },
searchQuery: { type: String },
secondaryActionClass: { type: String },
tertiaryActionClass: { type: String },
};
static queries = {
emptyState: "fxview-empty-state",
rowEls: {
all: "fxview-tab-row",
},
rootVirtualListEl: "virtual-list",
};
willUpdate(changes) {
this.activeIndex = Math.min(
Math.max(this.activeIndex, 0),
this.tabItems.length - 1
);
if (changes.has("dateTimeFormat") || changes.has("updatesPaused")) {
this.clearIntervalTimer();
if (
!this.updatesPaused &&
this.dateTimeFormat == "relative" &&
!window.IS_STORYBOOK
) {
this.startIntervalTimer();
this.onIntervalUpdate();
}
}
if (this.maxTabsLength > 0) {
this.tabItems = this.tabItems.slice(0, this.maxTabsLength);
}
}
startIntervalTimer() {
this.clearIntervalTimer();
this.intervalID = setInterval(
() => this.onIntervalUpdate(),
this.timeMsPref
);
}
clearIntervalTimer() {
if (this.intervalID) {
clearInterval(this.intervalID);
delete this.intervalID;
}
}
#register() {
if (!window.IS_STORYBOOK) {
XPCOMUtils.defineLazyPreferenceGetter(
this,
"timeMsPref",
"browser.tabs.firefox-view.updateTimeMs",
NOW_THRESHOLD_MS,
() => {
this.clearIntervalTimer();
if (!this.isConnected) {
return;
}
this.startIntervalTimer();
this.requestUpdate();
}
);
}
}
connectedCallback() {
super.connectedCallback();
if (
!this.updatesPaused &&
this.dateTimeFormat === "relative" &&
!window.IS_STORYBOOK
) {
this.startIntervalTimer();
}
}
disconnectedCallback() {
super.disconnectedCallback();
this.clearIntervalTimer();
}
async getUpdateComplete() {
await super.getUpdateComplete();
await Promise.all(Array.from(this.rowEls).map(item => item.updateComplete));
}
onIntervalUpdate() {
this.requestUpdate();
Array.from(this.rowEls).forEach(fxviewTabRow =>
fxviewTabRow.requestUpdate()
);
}
/**
* Focuses the expected element (either the link or button) within fxview-tab-row
* The currently focused/active element ID within a row is stored in this.currentActiveElementId
*/
handleFocusElementInRow(e) {
let fxviewTabRow = e.target;
if (e.code == "ArrowUp") {
// Focus either the link or button of the previous row based on this.currentActiveElementId
e.preventDefault();
this.focusPrevRow();
} else if (e.code == "ArrowDown") {
// Focus either the link or button of the next row based on this.currentActiveElementId
e.preventDefault();
this.focusNextRow();
} else if (e.code == "ArrowRight") {
// Focus either the link or the button in the current row and
// set this.currentActiveElementId to that element's ID
e.preventDefault();
if (document.dir == "rtl") {
fxviewTabRow.moveFocusLeft();
} else {
fxviewTabRow.moveFocusRight();
}
} else if (e.code == "ArrowLeft") {
// Focus either the link or the button in the current row and
// set this.currentActiveElementId to that element's ID
e.preventDefault();
if (document.dir == "rtl") {
fxviewTabRow.moveFocusRight();
} else {
fxviewTabRow.moveFocusLeft();
}
}
}
focusPrevRow() {
this.focusIndex(this.activeIndex - 1);
}
focusNextRow() {
this.focusIndex(this.activeIndex + 1);
}
async focusIndex(index) {
// Focus link or button of item
if (lazy.virtualListEnabledPref) {
let row = this.rootVirtualListEl.getItem(index);
if (!row) {
return;
}
let subList = this.rootVirtualListEl.getSubListForItem(index);
if (!subList) {
return;
}
this.activeIndex = index;
// and scrollIntoView() should also be iterated on so that we aren't constantly
// moving the focused item to the center of the viewport
for (const sublist of Array.from(this.rootVirtualListEl.children)) {
await sublist.requestUpdate();
await sublist.updateComplete;
}
row.scrollIntoView({ block: "center" });
row.focus();
} else if (index >= 0 && index < this.rowEls?.length) {
this.rowEls[index].focus();
this.activeIndex = index;
}
}
shouldUpdate(changes) {
if (changes.has("updatesPaused")) {
if (this.updatesPaused) {
this.clearIntervalTimer();
}
}
return !this.updatesPaused;
}
itemTemplate = (tabItem, i) => {
let time;
if (tabItem.time || tabItem.closedAt) {
let stringTime = (tabItem.time || tabItem.closedAt).toString();
// Different APIs return time in different units, so we use
// the length to decide if it's milliseconds or nanoseconds.
if (stringTime.length === 16) {
time = (tabItem.time || tabItem.closedAt) / 1000;
} else {
time = tabItem.time || tabItem.closedAt;
}
}
return html`
<fxview-tab-row
?active=${i == this.activeIndex}
?compact=${this.compactRows}
.currentActiveElementId=${this.currentActiveElementId}
.favicon=${tabItem.icon}
.primaryL10nId=${tabItem.primaryL10nId}
.primaryL10nArgs=${ifDefined(tabItem.primaryL10nArgs)}
.secondaryL10nId=${tabItem.secondaryL10nId}
.secondaryL10nArgs=${ifDefined(tabItem.secondaryL10nArgs)}
.tertiaryL10nId=${ifDefined(tabItem.tertiaryL10nId)}
.tertiaryL10nArgs=${ifDefined(tabItem.tertiaryL10nArgs)}
.secondaryActionClass=${this.secondaryActionClass}
.tertiaryActionClass=${ifDefined(this.tertiaryActionClass)}
.sourceClosedId=${ifDefined(tabItem.sourceClosedId)}
.sourceWindowId=${ifDefined(tabItem.sourceWindowId)}
.closedId=${ifDefined(tabItem.closedId || tabItem.closedId)}
role="listitem"
.tabElement=${ifDefined(tabItem.tabElement)}
.time=${ifDefined(time)}
.title=${tabItem.title}
.url=${tabItem.url}
.searchQuery=${ifDefined(this.searchQuery)}
.timeMsPref=${ifDefined(this.timeMsPref)}
.hasPopup=${this.hasPopup}
.dateTimeFormat=${this.dateTimeFormat}
></fxview-tab-row>
`;
};
stylesheets() {
return html`<link
rel="stylesheet"
href="chrome://browser/content/firefoxview/fxview-tab-list.css"
/>`;
}
render() {
if (this.searchQuery && !this.tabItems.length) {
return this.emptySearchResultsTemplate();
}
return html`
${this.stylesheets()}
<div
id="fxview-tab-list"
class="fxview-tab-list"
data-l10n-id="firefoxview-tabs"
role="list"
@keydown=${this.handleFocusElementInRow}
>
${when(
lazy.virtualListEnabledPref,
() => html`
<virtual-list
.activeIndex=${this.activeIndex}
.items=${this.tabItems}
.template=${this.itemTemplate}
></virtual-list>
`,
() =>
html`${this.tabItems.map((tabItem, i) =>
this.itemTemplate(tabItem, i)
)}`
)}
</div>
<slot name="menu"></slot>
`;
}
emptySearchResultsTemplate() {
return html` <fxview-empty-state
class="search-results"
headerLabel="firefoxview-search-results-empty"
.headerArgs=${{ query: this.searchQuery }}
isInnerCard
>
</fxview-empty-state>`;
}
}
customElements.define("fxview-tab-list", FxviewTabListBase);
/**
* A tab item that displays favicon, title, url, and time of last access
*
* @property {boolean} active - Should current item have focus on keydown
* @property {boolean} compact - Whether to hide the URL and date/time for this tab.
* @property {string} currentActiveElementId - ID of currently focused element within each tab item
* @property {string} dateTimeFormat - Expected format for date and/or time
* @property {string} hasPopup - The aria-haspopup attribute for the secondary action, if required
* @property {number} closedId - The tab ID for when the tab item was closed.
* @property {number} sourceClosedId - The closedId of the closed window its from if applicable
* @property {number} sourceWindowId - The sessionstore id of the window its from if applicable
* @property {string} favicon - The favicon for the tab item.
* @property {string} primaryL10nId - The l10n id used for the primary action element
* @property {string} primaryL10nArgs - The l10n args used for the primary action element
* @property {string} secondaryL10nId - The l10n id used for the secondary action button
* @property {string} secondaryL10nArgs - The l10n args used for the secondary action element
* @property {string} secondaryActionClass - The class used to style the secondary action element
* @property {string} tertiaryL10nId - The l10n id used for the tertiary action button
* @property {string} tertiaryL10nArgs - The l10n args used for the tertiary action element
* @property {string} tertiaryActionClass - The class used to style the tertiary action element
* @property {object} tabElement - The MozTabbrowserTab element for the tab item.
* @property {number} time - The timestamp for when the tab was last accessed.
* @property {string} title - The title for the tab item.
* @property {string} url - The url for the tab item.
* @property {number} timeMsPref - The frequency in milliseconds of updates to relative time
* @property {string} searchQuery - The query string to highlight, if provided.
*/
export class FxviewTabRowBase extends MozLitElement {
static properties = {
active: { type: Boolean },
compact: { type: Boolean },
currentActiveElementId: { type: String },
dateTimeFormat: { type: String },
favicon: { type: String },
hasPopup: { type: String },
primaryL10nId: { type: String },
primaryL10nArgs: { type: String },
secondaryL10nId: { type: String },
secondaryL10nArgs: { type: String },
secondaryActionClass: { type: String },
tertiaryL10nId: { type: String },
tertiaryL10nArgs: { type: String },
tertiaryActionClass: { type: String },
closedId: { type: Number },
sourceClosedId: { type: Number },
sourceWindowId: { type: String },
tabElement: { type: Object },
time: { type: Number },
title: { type: String },
timeMsPref: { type: Number },
url: { type: String },
searchQuery: { type: String },
};
constructor() {
super();
this.active = false;
this.currentActiveElementId = "fxview-tab-row-main";
}
static queries = {
mainEl: "#fxview-tab-row-main",
secondaryButtonEl: "#fxview-tab-row-secondary-button:not([hidden])",
tertiaryButtonEl: "#fxview-tab-row-tertiary-button",
};
get currentFocusable() {
let focusItem = this.renderRoot.getElementById(this.currentActiveElementId);
if (!focusItem) {
focusItem = this.renderRoot.getElementById("fxview-tab-row-main");
}
return focusItem;
}
focus() {
this.currentFocusable.focus();
}
focusSecondaryButton() {
let tabList = this.getRootNode().host;
this.secondaryButtonEl.focus();
tabList.currentActiveElementId = this.secondaryButtonEl.id;
}
focusTertiaryButton() {
let tabList = this.getRootNode().host;
this.tertiaryButtonEl.focus();
tabList.currentActiveElementId = this.tertiaryButtonEl.id;
}
focusLink() {
let tabList = this.getRootNode().host;
this.mainEl.focus();
tabList.currentActiveElementId = this.mainEl.id;
}
moveFocusRight() {
if (this.currentActiveElementId === "fxview-tab-row-main") {
this.focusSecondaryButton();
} else if (
this.tertiaryButtonEl &&
this.currentActiveElementId === "fxview-tab-row-secondary-button"
) {
this.focusTertiaryButton();
}
}
moveFocusLeft() {
if (this.currentActiveElementId === "fxview-tab-row-tertiary-button") {
this.focusSecondaryButton();
} else {
this.focusLink();
}
}
dateFluentArgs(timestamp, dateTimeFormat) {
if (dateTimeFormat === "date" || dateTimeFormat === "dateTime") {
return JSON.stringify({ date: timestamp });
}
return null;
}
dateFluentId(timestamp, dateTimeFormat, _nowThresholdMs = NOW_THRESHOLD_MS) {
if (!timestamp) {
return null;
}
if (dateTimeFormat === "relative") {
const elapsed = Date.now() - timestamp;
if (elapsed <= _nowThresholdMs || !lazy.relativeTimeFormat) {
// Use a different string for very recent timestamps
return "fxviewtabrow-just-now-timestamp";
}
return null;
} else if (dateTimeFormat === "date" || dateTimeFormat === "dateTime") {
return "fxviewtabrow-date";
}
return null;
}
relativeTime(timestamp, dateTimeFormat, _nowThresholdMs = NOW_THRESHOLD_MS) {
if (dateTimeFormat === "relative") {
const elapsed = Date.now() - timestamp;
if (elapsed > _nowThresholdMs && lazy.relativeTimeFormat) {
return lazy.relativeTimeFormat.formatBestUnit(new Date(timestamp));
}
}
return null;
}
timeFluentId(dateTimeFormat) {
if (dateTimeFormat === "time" || dateTimeFormat === "dateTime") {
return "fxviewtabrow-time";
}
return null;
}
formatURIForDisplay(uriString) {
return !window.IS_STORYBOOK
? lazy.BrowserUtils.formatURIStringForDisplay(uriString)
: uriString;
}
getImageUrl(icon, targetURI) {
if (window.IS_STORYBOOK) {
}
if (!icon) {
if (targetURI?.startsWith("moz-extension")) {
return "chrome://mozapps/skin/extensions/extension.svg";
}
}
// If the icon is not for website (doesn't begin with http), we
// display it directly. Otherwise we go through the page-icon
// protocol to try to get a cached version. We don't load
// favicons directly.
if (icon.startsWith("http")) {
return `page-icon:${targetURI}`;
}
return icon;
}
primaryActionHandler(event) {
if (
(event.type == "click" && !event.altKey) ||
(event.type == "keydown" && event.code == "Enter") ||
(event.type == "keydown" && event.code == "Space")
) {
event.preventDefault();
if (!window.IS_STORYBOOK) {
this.dispatchEvent(
new CustomEvent("fxview-tab-list-primary-action", {
bubbles: true,
composed: true,
detail: { originalEvent: event, item: this },
})
);
}
}
}
secondaryActionHandler(event) {
if (
(event.type == "click" && event.detail && !event.altKey) ||
// detail=0 is from keyboard
(event.type == "click" && !event.detail)
) {
event.preventDefault();
this.dispatchEvent(
new CustomEvent("fxview-tab-list-secondary-action", {
bubbles: true,
composed: true,
detail: { originalEvent: event, item: this },
})
);
}
}
tertiaryActionHandler(event) {
if (
(event.type == "click" && event.detail && !event.altKey) ||
// detail=0 is from keyboard
(event.type == "click" && !event.detail)
) {
event.preventDefault();
this.dispatchEvent(
new CustomEvent("fxview-tab-list-tertiary-action", {
bubbles: true,
composed: true,
detail: { originalEvent: event, item: this },
})
);
}
}
/**
* Find all matches of query within the given string, and compute the result
* to be rendered.
*
* @param {string} query
* @param {string} string
*/
highlightSearchMatches(query, string) {
const fragments = [];
const regex = RegExp(escapeRegExp(query), "dgi");
let prevIndexEnd = 0;
let result;
while ((result = regex.exec(string)) !== null) {
const [indexStart, indexEnd] = result.indices[0];
fragments.push(string.substring(prevIndexEnd, indexStart));
fragments.push(
html`<strong>${string.substring(indexStart, indexEnd)}</strong>`
);
prevIndexEnd = regex.lastIndex;
}
fragments.push(string.substring(prevIndexEnd));
return fragments;
}
stylesheets() {
return html`<link
rel="stylesheet"
href="chrome://browser/content/firefoxview/fxview-tab-row.css"
/>`;
}
faviconTemplate() {
return html`<span
class="fxview-tab-row-favicon icon"
id="fxview-tab-row-favicon"
style=${styleMap({
backgroundImage: `url(${this.getImageUrl(this.favicon, this.url)})`,
})}
></span>`;
}
titleTemplate() {
const title = this.title;
return html`<span
class="fxview-tab-row-title text-truncated-ellipsis"
id="fxview-tab-row-title"
dir="auto"
>
${when(
this.searchQuery,
() => this.highlightSearchMatches(this.searchQuery, title),
() => title
)}
</span>`;
}
urlTemplate() {
return html`<span
class="fxview-tab-row-url text-truncated-ellipsis"
id="fxview-tab-row-url"
>
${when(
this.searchQuery,
() =>
this.highlightSearchMatches(
this.searchQuery,
this.formatURIForDisplay(this.url)
),
() => this.formatURIForDisplay(this.url)
)}
</span>`;
}
dateTemplate() {
const relativeString = this.relativeTime(
this.time,
this.dateTimeFormat,
!window.IS_STORYBOOK ? this.timeMsPref : NOW_THRESHOLD_MS
);
const dateString = this.dateFluentId(
this.time,
this.dateTimeFormat,
!window.IS_STORYBOOK ? this.timeMsPref : NOW_THRESHOLD_MS
);
const dateArgs = this.dateFluentArgs(this.time, this.dateTimeFormat);
return html`<span class="fxview-tab-row-date" id="fxview-tab-row-date">
<span
?hidden=${relativeString || !dateString}
data-l10n-id=${ifDefined(dateString)}
data-l10n-args=${ifDefined(dateArgs)}
></span>
<span ?hidden=${!relativeString}>${relativeString}</span>
</span>`;
}
timeTemplate() {
const timeString = this.timeFluentId(this.dateTimeFormat);
const time = this.time;
const timeArgs = JSON.stringify({ time });
return html`<span
class="fxview-tab-row-time"
id="fxview-tab-row-time"
?hidden=${!timeString}
data-timestamp=${ifDefined(this.time)}
data-l10n-id=${ifDefined(timeString)}
data-l10n-args=${ifDefined(timeArgs)}
>
</span>`;
}
secondaryButtonTemplate() {
return html`${when(
this.secondaryL10nId && this.secondaryActionHandler,
() =>
html`<moz-button
type="icon ghost"
class=${classMap({
"fxview-tab-row-button": true,
[this.secondaryActionClass]: this.secondaryActionClass,
})}
id="fxview-tab-row-secondary-button"
data-l10n-id=${this.secondaryL10nId}
data-l10n-args=${ifDefined(this.secondaryL10nArgs)}
aria-haspopup=${ifDefined(this.hasPopup)}
@click=${this.secondaryActionHandler}
tabindex="${this.active &&
this.currentActiveElementId === "fxview-tab-row-secondary-button"
? "0"
: "-1"}"
></moz-button>`
)}`;
}
tertiaryButtonTemplate() {
return html`${when(
this.tertiaryL10nId && this.tertiaryActionHandler,
() =>
html`<moz-button
type="icon ghost"
class=${classMap({
"fxview-tab-row-button": true,
[this.tertiaryActionClass]: this.tertiaryActionClass,
})}
id="fxview-tab-row-tertiary-button"
data-l10n-id=${this.tertiaryL10nId}
data-l10n-args=${ifDefined(this.tertiaryL10nArgs)}
aria-haspopup=${ifDefined(this.hasPopup)}
@click=${this.tertiaryActionHandler}
tabindex="${this.active &&
this.currentActiveElementId === "fxview-tab-row-tertiary-button"
? "0"
: "-1"}"
></moz-button>`
)}`;
}
}
export class FxviewTabRow extends FxviewTabRowBase {
render() {
return html`
${this.stylesheets()}
<a
href=${ifDefined(this.url)}
class="fxview-tab-row-main"
id="fxview-tab-row-main"
tabindex=${this.active &&
this.currentActiveElementId === "fxview-tab-row-main"
? "0"
: "-1"}
data-l10n-id=${ifDefined(this.primaryL10nId)}
data-l10n-args=${ifDefined(this.primaryL10nArgs)}
@click=${this.primaryActionHandler}
@keydown=${this.primaryActionHandler}
title=${!this.primaryL10nId ? this.url : null}
>
${this.faviconTemplate()} ${this.titleTemplate()}
${when(
!this.compact,
() =>
html`${this.urlTemplate()} ${this.dateTemplate()}
${this.timeTemplate()}`
)}
</a>
${this.secondaryButtonTemplate()} ${this.tertiaryButtonTemplate()}
`;
}
}
customElements.define("fxview-tab-row", FxviewTabRow);
export class VirtualList extends MozLitElement {
static properties = {
items: { type: Array },
template: { type: Function },
activeIndex: { type: Number },
itemOffset: { type: Number },
maxRenderCountEstimate: { type: Number, state: true },
itemHeightEstimate: { type: Number, state: true },
isAlwaysVisible: { type: Boolean },
isVisible: { type: Boolean, state: true },
isSubList: { type: Boolean },
pinnedTabsIndexOffset: { type: Number },
};
createRenderRoot() {
return this;
}
constructor() {
super();
this.activeIndex = 0;
this.itemOffset = 0;
this.pinnedTabsIndexOffset = 0;
this.items = [];
this.subListItems = [];
this.itemHeightEstimate = FXVIEW_ROW_HEIGHT_PX;
this.maxRenderCountEstimate = Math.max(
40,
2 * Math.ceil(window.innerHeight / this.itemHeightEstimate)
);
this.isSubList = false;
this.isVisible = false;
this.intersectionObserver = new IntersectionObserver(
([entry]) => {
this.isVisible = entry.isIntersecting;
},
{ root: this.ownerDocument }
);
this.selfResizeObserver = new ResizeObserver(() => {
// Trigger the intersection observer once the tab rows have rendered
this.triggerIntersectionObserver();
});
this.childResizeObserver = new ResizeObserver(([entry]) => {
if (entry.contentRect?.height > 0) {
// Update properties on top-level virtual-list
this.parentElement.itemHeightEstimate = entry.contentRect.height;
this.parentElement.maxRenderCountEstimate = Math.max(
40,
2 * Math.ceil(window.innerHeight / this.itemHeightEstimate)
);
}
});
}
disconnectedCallback() {
super.disconnectedCallback();
this.intersectionObserver.disconnect();
this.childResizeObserver.disconnect();
this.selfResizeObserver.disconnect();
}
triggerIntersectionObserver() {
this.intersectionObserver.unobserve(this);
this.intersectionObserver.observe(this);
}
getSubListForItem(index) {
if (this.isSubList) {
throw new Error("Cannot get sublist for item");
}
return this.children[parseInt(index / this.maxRenderCountEstimate, 10)];
}
getItem(index) {
if (!this.isSubList) {
return this.getSubListForItem(index)?.getItem(
index % this.maxRenderCountEstimate
);
}
return this.children[index];
}
willUpdate(changedProperties) {
if (changedProperties.has("items") && !this.isSubList) {
this.subListItems = [];
for (let i = 0; i < this.items.length; i += this.maxRenderCountEstimate) {
this.subListItems.push(
this.items.slice(i, i + this.maxRenderCountEstimate)
);
}
}
}
recalculateAfterWindowResize() {
this.maxRenderCountEstimate = Math.max(
40,
2 * Math.ceil(window.innerHeight / this.itemHeightEstimate)
);
}
firstUpdated() {
this.intersectionObserver.observe(this);
this.selfResizeObserver.observe(this);
if (this.isSubList && this.children[0]) {
this.childResizeObserver.observe(this.children[0]);
}
}
updated(changedProperties) {
this.updateListHeight(changedProperties);
if (changedProperties.has("items") && !this.isSubList) {
this.triggerIntersectionObserver();
}
}
updateListHeight(changedProperties) {
if (
changedProperties.has("isAlwaysVisible") ||
changedProperties.has("isVisible")
) {
this.style.height =
this.isAlwaysVisible || this.isVisible
? "auto"
: `${this.items.length * this.itemHeightEstimate}px`;
}
}
get renderItems() {
return this.isSubList ? this.items : this.subListItems;
}
subListTemplate = (data, i) => {
return html`<virtual-list
.template=${this.template}
.items=${data}
.itemHeightEstimate=${this.itemHeightEstimate}
.itemOffset=${i * this.maxRenderCountEstimate +
this.pinnedTabsIndexOffset}
.isAlwaysVisible=${i ==
parseInt(this.activeIndex / this.maxRenderCountEstimate, 10)}
isSubList
></virtual-list>`;
};
itemTemplate = (data, i) =>
this.template(data, this.itemOffset + i + this.pinnedTabsIndexOffset);
render() {
if (this.isAlwaysVisible || this.isVisible) {
return html`
${repeat(
this.renderItems,
(data, i) => i,
this.isSubList ? this.itemTemplate : this.subListTemplate
)}
`;
}
return "";
}
}
customElements.define("virtual-list", VirtualList);