chrome-devtools-frontend
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Chrome DevTools UI
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text/typescript
// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/* eslint-disable rulesdir/no-imperative-dom-api */
import type * as Common from '../../core/common/common.js';
import * as Platform from '../../core/platform/platform.js';
import * as VisualLogging from '../visual_logging/visual_logging.js';
import * as ARIAUtils from './ARIAUtils.js';
import {Events as ListModelEvents, type ItemsReplacedEvent, type ListModel} from './ListModel.js';
import {measurePreferredSize} from './UIUtils.js';
export interface ListDelegate<T> {
createElementForItem(item: T): Element;
/**
* This method is not called in NonViewport mode.
* Return zero to make list measure the item (only works in SameHeight mode).
*/
heightForItem(item: T): number;
isItemSelectable(item: T): boolean;
selectedItemChanged(from: T|null, to: T|null, fromElement: HTMLElement|null, toElement: HTMLElement|null): void;
updateSelectedItemARIA(fromElement: Element|null, toElement: Element|null): boolean;
}
export enum ListMode {
/* eslint-disable @typescript-eslint/naming-convention -- Used by web_tests. */
NonViewport = 'UI.ListMode.NonViewport',
EqualHeightItems = 'UI.ListMode.EqualHeightItems',
VariousHeightItems = 'UI.ListMode.VariousHeightItems',
/* eslint-enable @typescript-eslint/naming-convention */
}
export class ListControl<T> {
element: HTMLDivElement;
private topElement: HTMLElement;
private bottomElement: HTMLElement;
private firstIndex: number;
private lastIndex: number;
private renderedHeight: number;
private topHeight: number;
private bottomHeight: number;
private model: ListModel<T>;
private itemToElement: Map<T, Element>;
private selectedIndexInternal: number;
private selectedItemInternal: T|null;
private delegate: ListDelegate<T>;
private readonly mode: ListMode;
private fixedHeight: number;
private variableOffsets: Int32Array;
constructor(model: ListModel<T>, delegate: ListDelegate<T>, mode?: ListMode) {
this.element = document.createElement('div');
this.element.style.overflowY = 'auto';
this.topElement = this.element.createChild('div');
this.bottomElement = this.element.createChild('div');
this.firstIndex = 0;
this.lastIndex = 0;
this.renderedHeight = 0;
this.topHeight = 0;
this.bottomHeight = 0;
this.model = model;
this.model.addEventListener(ListModelEvents.ITEMS_REPLACED, this.replacedItemsInRange, this);
this.itemToElement = new Map();
this.selectedIndexInternal = -1;
this.selectedItemInternal = null;
this.element.tabIndex = -1;
this.element.addEventListener('click', this.onClick.bind(this), false);
this.element.addEventListener('keydown', this.onKeyDown.bind(this), false);
ARIAUtils.markAsListBox(this.element);
this.delegate = delegate;
this.mode = mode || ListMode.EqualHeightItems;
this.fixedHeight = 0;
this.variableOffsets = new Int32Array(0);
this.clearContents();
if (this.mode !== ListMode.NonViewport) {
this.element.addEventListener('scroll', () => {
this.updateViewport(this.element.scrollTop, this.element.offsetHeight);
}, false);
}
}
setModel(model: ListModel<T>): void {
this.itemToElement.clear();
const length = this.model.length;
this.model.removeEventListener(ListModelEvents.ITEMS_REPLACED, this.replacedItemsInRange, this);
this.model = model;
this.model.addEventListener(ListModelEvents.ITEMS_REPLACED, this.replacedItemsInRange, this);
this.invalidateRange(0, length);
}
private replacedItemsInRange(event: Common.EventTarget.EventTargetEvent<ItemsReplacedEvent<T>>): void {
const data = event.data;
const from = data.index;
const to = from + data.removed.length;
const keepSelectedIndex = data.keepSelectedIndex;
const oldSelectedItem = this.selectedItemInternal;
const oldSelectedElement = oldSelectedItem !== null ? (this.itemToElement.get(oldSelectedItem) || null) : null;
for (let i = 0; i < data.removed.length; i++) {
this.itemToElement.delete(data.removed[i]);
}
this.invalidate(from, to, data.inserted);
if (this.selectedIndexInternal >= to) {
this.selectedIndexInternal += data.inserted - (to - from);
this.selectedItemInternal = this.model.at(this.selectedIndexInternal);
} else if (this.selectedIndexInternal >= from) {
const selectableIndex = keepSelectedIndex ? from : from + data.inserted;
let index = this.findFirstSelectable(selectableIndex, +1, false);
if (index === -1) {
const alternativeSelectableIndex = keepSelectedIndex ? from : from - 1;
index = this.findFirstSelectable(alternativeSelectableIndex, -1, false);
}
this.select(index, oldSelectedItem, oldSelectedElement);
}
}
refreshItem(item: T): void {
const index = this.model.indexOf(item);
if (index === -1) {
console.error('Item to refresh is not present');
return;
}
this.refreshItemByIndex(index);
}
refreshItemByIndex(index: number): void {
const item = this.model.at(index);
this.itemToElement.delete(item);
this.invalidateRange(index, index + 1);
if (this.selectedIndexInternal !== -1) {
this.select(this.selectedIndexInternal, null, null);
}
}
refreshAllItems(): void {
this.itemToElement.clear();
this.invalidateRange(0, this.model.length);
if (this.selectedIndexInternal !== -1) {
this.select(this.selectedIndexInternal, null, null);
}
}
invalidateRange(from: number, to: number): void {
this.invalidate(from, to, to - from);
}
viewportResized(): void {
if (this.mode === ListMode.NonViewport) {
return;
}
// TODO(dgozman): try to keep visible scrollTop the same.
const scrollTop = this.element.scrollTop;
const viewportHeight = this.element.offsetHeight;
this.clearViewport();
this.updateViewport(
Platform.NumberUtilities.clamp(scrollTop, 0, this.totalHeight() - viewportHeight), viewportHeight);
}
invalidateItemHeight(): void {
if (this.mode !== ListMode.EqualHeightItems) {
console.error('Only supported in equal height items mode');
return;
}
this.fixedHeight = 0;
if (this.model.length) {
this.itemToElement.clear();
this.invalidate(0, this.model.length, this.model.length);
}
}
itemForNode(node: Node|null): T|null {
while (node && node.parentNodeOrShadowHost() !== this.element) {
node = node.parentNodeOrShadowHost();
}
if (!node) {
return null;
}
const element = (node as Element);
const index = this.model.findIndex(item => this.itemToElement.get(item) === element);
return index !== -1 ? this.model.at(index) : null;
}
scrollItemIntoView(item: T, center?: boolean): void {
const index = this.model.indexOf(item);
if (index === -1) {
console.error('Attempt to scroll onto missing item');
return;
}
this.scrollIntoView(index, center);
}
selectedItem(): T|null {
return this.selectedItemInternal;
}
selectedIndex(): number {
return this.selectedIndexInternal;
}
selectItem(item: T|null, center?: boolean, dontScroll?: boolean): void {
let index = -1;
if (item !== null) {
index = this.model.indexOf(item);
if (index === -1) {
console.error('Attempt to select missing item');
return;
}
if (!this.delegate.isItemSelectable(item)) {
console.error('Attempt to select non-selectable item');
return;
}
}
// Scrolling the item before selection ensures it is in the DOM.
if (index !== -1 && !dontScroll) {
this.scrollIntoView(index, center);
}
if (this.selectedIndexInternal !== index) {
this.select(index);
}
}
selectPreviousItem(canWrap?: boolean, center?: boolean): boolean {
if (this.selectedIndexInternal === -1 && !canWrap) {
return false;
}
let index: number = this.selectedIndexInternal === -1 ? this.model.length - 1 : this.selectedIndexInternal - 1;
index = this.findFirstSelectable(index, -1, Boolean(canWrap));
if (index !== -1) {
this.scrollIntoView(index, center);
this.select(index);
return true;
}
return false;
}
selectNextItem(canWrap?: boolean, center?: boolean): boolean {
if (this.selectedIndexInternal === -1 && !canWrap) {
return false;
}
let index: number = this.selectedIndexInternal === -1 ? 0 : this.selectedIndexInternal + 1;
index = this.findFirstSelectable(index, +1, Boolean(canWrap));
if (index !== -1) {
this.scrollIntoView(index, center);
this.select(index);
return true;
}
return false;
}
selectItemPreviousPage(center?: boolean): boolean {
if (this.mode === ListMode.NonViewport) {
return false;
}
let index: number = this.selectedIndexInternal === -1 ? this.model.length - 1 : this.selectedIndexInternal;
index = this.findPageSelectable(index, -1);
if (index !== -1) {
this.scrollIntoView(index, center);
this.select(index);
return true;
}
return false;
}
selectItemNextPage(center?: boolean): boolean {
if (this.mode === ListMode.NonViewport) {
return false;
}
let index: number = this.selectedIndexInternal === -1 ? 0 : this.selectedIndexInternal;
index = this.findPageSelectable(index, +1);
if (index !== -1) {
this.scrollIntoView(index, center);
this.select(index);
return true;
}
return false;
}
private scrollIntoView(index: number, center?: boolean): void {
if (this.mode === ListMode.NonViewport) {
this.elementAtIndex(index).scrollIntoViewIfNeeded(Boolean(center));
return;
}
const top = this.offsetAtIndex(index);
const bottom = this.offsetAtIndex(index + 1);
const viewportHeight = this.element.offsetHeight;
if (center) {
const scrollTo = (top + bottom) / 2 - viewportHeight / 2;
this.updateViewport(
Platform.NumberUtilities.clamp(scrollTo, 0, this.totalHeight() - viewportHeight), viewportHeight);
return;
}
const scrollTop = this.element.scrollTop;
if (top < scrollTop) {
this.updateViewport(top, viewportHeight);
} else if (bottom > scrollTop + viewportHeight) {
this.updateViewport(bottom - viewportHeight, viewportHeight);
}
}
private onClick(event: Event): void {
const item = this.itemForNode((event.target as Node | null));
if (item !== null && this.delegate.isItemSelectable(item)) {
this.selectItem(item);
}
}
private onKeyDown(event: KeyboardEvent): void {
let selected = false;
switch (event.key) {
case 'ArrowUp':
selected = this.selectPreviousItem(true, false);
break;
case 'ArrowDown':
selected = this.selectNextItem(true, false);
break;
case 'PageUp':
selected = this.selectItemPreviousPage(false);
break;
case 'PageDown':
selected = this.selectItemNextPage(false);
break;
}
if (selected) {
event.consume(true);
}
}
private totalHeight(): number {
return this.offsetAtIndex(this.model.length);
}
private indexAtOffset(offset: number): number {
if (this.mode === ListMode.NonViewport) {
throw new Error('There should be no offset conversions in non-viewport mode');
}
if (!this.model.length || offset < 0) {
return 0;
}
if (this.mode === ListMode.VariousHeightItems) {
return Math.min(
this.model.length - 1,
Platform.ArrayUtilities.lowerBound(
this.variableOffsets, offset, Platform.ArrayUtilities.DEFAULT_COMPARATOR, 0, this.model.length));
}
if (!this.fixedHeight) {
this.measureHeight();
}
return Math.min(this.model.length - 1, Math.floor(offset / this.fixedHeight));
}
elementAtIndex(index: number): Element {
const item = this.model.at(index);
let element = this.itemToElement.get(item);
if (!element) {
element = this.delegate.createElementForItem(item);
if (!element.hasAttribute('jslog')) {
element.setAttribute(
'jslog', `${VisualLogging.item().track({click: true, keydown: 'ArrowUp|ArrowDown|PageUp|PageDown'})}`);
}
this.itemToElement.set(item, element);
this.updateElementARIA(element, index);
}
return element;
}
private refreshARIA(): void {
for (let index = this.firstIndex; index <= this.lastIndex; index++) {
const item = this.model.at(index);
const element = this.itemToElement.get(item);
if (element) {
this.updateElementARIA(element, index);
}
}
}
private updateElementARIA(element: Element, index: number): void {
if (!ARIAUtils.hasRole(element)) {
ARIAUtils.markAsOption(element);
}
ARIAUtils.setSetSize(element, this.model.length);
ARIAUtils.setPositionInSet(element, index + 1);
}
private offsetAtIndex(index: number): number {
if (this.mode === ListMode.NonViewport) {
throw new Error('There should be no offset conversions in non-viewport mode');
}
if (!this.model.length) {
return 0;
}
if (this.mode === ListMode.VariousHeightItems) {
return this.variableOffsets[index];
}
if (!this.fixedHeight) {
this.measureHeight();
}
return index * this.fixedHeight;
}
private measureHeight(): void {
this.fixedHeight = this.delegate.heightForItem(this.model.at(0));
if (!this.fixedHeight) {
this.fixedHeight = measurePreferredSize(this.elementAtIndex(0), this.element).height;
}
}
private select(index: number, oldItem?: T|null, oldElement?: Element|null): void {
if (oldItem === undefined) {
oldItem = this.selectedItemInternal;
}
if (oldElement === undefined) {
oldElement = this.itemToElement.get((oldItem as T)) || null;
}
this.selectedIndexInternal = index;
this.selectedItemInternal = index === -1 ? null : this.model.at(index);
const newItem = this.selectedItemInternal;
const newElement = this.selectedIndexInternal !== -1 ? this.elementAtIndex(index) : null;
this.delegate.selectedItemChanged(
oldItem, newItem, (oldElement as HTMLElement | null), (newElement as HTMLElement | null));
if (!this.delegate.updateSelectedItemARIA((oldElement), newElement)) {
if (oldElement) {
ARIAUtils.setSelected(oldElement, false);
}
if (newElement) {
ARIAUtils.setSelected(newElement, true);
}
ARIAUtils.setActiveDescendant(this.element, newElement);
}
}
private findFirstSelectable(index: number, direction: number, canWrap: boolean): number {
const length = this.model.length;
if (!length) {
return -1;
}
for (let step = 0; step <= length; step++) {
if (index < 0 || index >= length) {
if (!canWrap) {
return -1;
}
index = (index + length) % length;
}
if (this.delegate.isItemSelectable(this.model.at(index))) {
return index;
}
index += direction;
}
return -1;
}
private findPageSelectable(index: number, direction: number): number {
let lastSelectable = -1;
const startOffset = this.offsetAtIndex(index);
// Compensate for zoom rounding errors with -1.
const viewportHeight = this.element.offsetHeight - 1;
while (index >= 0 && index < this.model.length) {
if (this.delegate.isItemSelectable(this.model.at(index))) {
if (Math.abs(this.offsetAtIndex(index) - startOffset) >= viewportHeight) {
return index;
}
lastSelectable = index;
}
index += direction;
}
return lastSelectable;
}
private reallocateVariableOffsets(length: number, copyTo: number): void {
if (this.variableOffsets.length < length) {
const variableOffsets = new Int32Array(Math.max(length, this.variableOffsets.length * 2));
variableOffsets.set(this.variableOffsets.slice(0, copyTo), 0);
this.variableOffsets = variableOffsets;
} else if (this.variableOffsets.length >= 2 * length) {
const variableOffsets = new Int32Array(length);
variableOffsets.set(this.variableOffsets.slice(0, copyTo), 0);
this.variableOffsets = variableOffsets;
}
}
private invalidate(from: number, to: number, inserted: number): void {
if (this.mode === ListMode.NonViewport) {
this.invalidateNonViewportMode(from, to - from, inserted);
return;
}
if (this.mode === ListMode.VariousHeightItems) {
this.reallocateVariableOffsets(this.model.length + 1, from + 1);
for (let i = from + 1; i <= this.model.length; i++) {
this.variableOffsets[i] = this.variableOffsets[i - 1] + this.delegate.heightForItem(this.model.at(i - 1));
}
}
const viewportHeight = this.element.offsetHeight;
const totalHeight = this.totalHeight();
const scrollTop = this.element.scrollTop;
if (this.renderedHeight < viewportHeight || totalHeight < viewportHeight) {
this.clearViewport();
this.updateViewport(Platform.NumberUtilities.clamp(scrollTop, 0, totalHeight - viewportHeight), viewportHeight);
return;
}
const heightDelta = totalHeight - this.renderedHeight;
if (to <= this.firstIndex) {
const topHeight = this.topHeight + heightDelta;
this.topElement.style.height = topHeight + 'px';
this.element.scrollTop = scrollTop + heightDelta;
this.topHeight = topHeight;
this.renderedHeight = totalHeight;
const indexDelta = inserted - (to - from);
this.firstIndex += indexDelta;
this.lastIndex += indexDelta;
return;
}
if (from >= this.lastIndex) {
const bottomHeight = this.bottomHeight + heightDelta;
this.bottomElement.style.height = bottomHeight + 'px';
this.bottomHeight = bottomHeight;
this.renderedHeight = totalHeight;
return;
}
// TODO(dgozman): try to keep visible scrollTop the same
// when invalidating after firstIndex but before first visible element.
this.clearViewport();
this.updateViewport(Platform.NumberUtilities.clamp(scrollTop, 0, totalHeight - viewportHeight), viewportHeight);
this.refreshARIA();
}
private invalidateNonViewportMode(start: number, remove: number, add: number): void {
let startElement: HTMLElement = this.topElement;
for (let index = 0; index < start; index++) {
startElement = (startElement.nextElementSibling as HTMLElement);
}
while (remove--) {
(startElement.nextElementSibling as HTMLElement).remove();
}
while (add--) {
this.element.insertBefore(this.elementAtIndex(start + add), startElement.nextElementSibling);
}
}
private clearViewport(): void {
if (this.mode === ListMode.NonViewport) {
console.error('There should be no viewport updates in non-viewport mode');
return;
}
this.firstIndex = 0;
this.lastIndex = 0;
this.renderedHeight = 0;
this.topHeight = 0;
this.bottomHeight = 0;
this.clearContents();
}
private clearContents(): void {
// Note: this method should not force layout. Be careful.
this.topElement.style.height = '0';
this.bottomElement.style.height = '0';
this.element.removeChildren();
this.element.appendChild(this.topElement);
this.element.appendChild(this.bottomElement);
}
private updateViewport(scrollTop: number, viewportHeight: number): void {
// Note: this method should not force layout. Be careful.
if (this.mode === ListMode.NonViewport) {
console.error('There should be no viewport updates in non-viewport mode');
return;
}
const totalHeight = this.totalHeight();
if (!totalHeight) {
this.firstIndex = 0;
this.lastIndex = 0;
this.topHeight = 0;
this.bottomHeight = 0;
this.renderedHeight = 0;
this.topElement.style.height = '0';
this.bottomElement.style.height = '0';
return;
}
const firstIndex = this.indexAtOffset(scrollTop - viewportHeight);
const lastIndex = this.indexAtOffset(scrollTop + 2 * viewportHeight) + 1;
while (this.firstIndex < Math.min(firstIndex, this.lastIndex)) {
this.elementAtIndex(this.firstIndex).remove();
this.firstIndex++;
}
while (this.lastIndex > Math.max(lastIndex, this.firstIndex)) {
this.elementAtIndex(this.lastIndex - 1).remove();
this.lastIndex--;
}
this.firstIndex = Math.min(this.firstIndex, lastIndex);
this.lastIndex = Math.max(this.lastIndex, firstIndex);
for (let index = this.firstIndex - 1; index >= firstIndex; index--) {
const element = this.elementAtIndex(index);
this.element.insertBefore(element, this.topElement.nextSibling);
}
for (let index = this.lastIndex; index < lastIndex; index++) {
const element = this.elementAtIndex(index);
this.element.insertBefore(element, this.bottomElement);
}
this.firstIndex = firstIndex;
this.lastIndex = lastIndex;
this.topHeight = this.offsetAtIndex(firstIndex);
this.topElement.style.height = this.topHeight + 'px';
this.bottomHeight = totalHeight - this.offsetAtIndex(lastIndex);
this.bottomElement.style.height = this.bottomHeight + 'px';
this.renderedHeight = totalHeight;
this.element.scrollTop = scrollTop;
}
}