Support an entry ID in CircularList

This is needed to keep track of which row is which outside of the class

src/utils/CircularList.ts

@@ -6,14 +6,21 @@
  */
 import { EventEmitter } from '../EventEmitter';
 
+interface ListEntry<T> {
+ id: number;
+ value: T;
+}
+
 export class CircularList<T> extends EventEmitter {
- private _array: T[];
+ private _array: ListEntry<T>[];
  private _startIndex: number;
  private _length: number;
 
+ private _nextId = 0;
+
  constructor(maxLength: number) {
  super();
- this._array = new Array<T>(maxLength);
+ this._array = new Array<ListEntry<T>>(maxLength);
  this._startIndex = 0;
  this._length = 0;
  }
@@ -25,9 +32,14 @@ export class CircularList<T> extends EventEmitter {
  public set maxLength(newMaxLength: number) {
  // Reconstruct array, starting at index 0. Only transfer values from the
  // indexes 0 to length.
- let newArray = new Array<T>(newMaxLength);
+ let newArray = new Array<ListEntry<T>>(newMaxLength);
+ // Reset ids when maxLength is changed
+ this._nextId = 0;
  for (let i = 0; i < Math.min(newMaxLength, this.length); i++) {
- newArray[i] = this._array[this._getCyclicIndex(i)];
+ newArray[i] = {
+ id: this._nextId++,
+ value: this._array[this._getCyclicIndex(i)].value
+ };
  }
  this._array = newArray;
  this._startIndex = 0;
@@ -46,8 +58,14 @@ export class CircularList<T> extends EventEmitter {
  this._length = newLength;
  }
 
- public get forEach(): (callbackfn: (value: T, index: number, array: T[]) => void) => void {
- return this._array.forEach;
+ public get forEach(): (callbackfn: (value: T, index: number) => void) => void {
+ return (callbackfn: (value: T, index: number) => void) => {
+ let i = 0;
+ let length = this.length;
+ for (let i = 0; i < length; i++) {
+ callbackfn(this.get(i), i);
+ }
+ };
  }
 
  /**
@@ -59,6 +77,10 @@ export class CircularList<T> extends EventEmitter {
  * @return The value corresponding to the index.
  */
  public get(index: number): T {
+ return this.getEntry(index).value;
+ }
+
+ public getEntry(index: number): ListEntry<T> {
  return this._array[this._getCyclicIndex(index)];
  }
 
@@ -71,7 +93,11 @@ export class CircularList<T> extends EventEmitter {
  * @param value The value to set.
  */
  public set(index: number, value: T): void {
- this._array[this._getCyclicIndex(index)] = value;
+ this._array[this._getCyclicIndex(index)].value = value;
+ }
+
+ private _setEntry(index: number, entry: ListEntry<T>): void {
+ this._array[this._getCyclicIndex(index)] = entry;
  }
 
  /**
@@ -80,7 +106,10 @@ export class CircularList<T> extends EventEmitter {
  * @param value The value to push onto the list.
  */
  public push(value: T): void {
- this._array[this._getCyclicIndex(this._length)] = value;
+ this._array[this._getCyclicIndex(this._length)] = {
+ id: this._nextId,
+ value
+ };
  if (this._length === this.maxLength) {
  this._startIndex++;
  if (this._startIndex === this.maxLength) {
@@ -97,7 +126,7 @@ export class CircularList<T> extends EventEmitter {
  * @return The popped value.
  */
  public pop(): T {
- return this._array[this._getCyclicIndex(this._length-- - 1)];
+ return this._array[this._getCyclicIndex(this._length-- - 1)].value;
  }
 
  /**
@@ -110,20 +139,27 @@ export class CircularList<T> extends EventEmitter {
  * @param items The items to insert.
  */
  public splice(start: number, deleteCount: number, ...items: T[]): void {
+ // Delete items
  if (deleteCount) {
  for (let i = start; i < this._length - deleteCount; i++) {
  this._array[this._getCyclicIndex(i)] = this._array[this._getCyclicIndex(i + deleteCount)];
  }
  this._length -= deleteCount;
  }
+
  if (items && items.length) {
+ // Add items
  for (let i = this._length - 1; i >= start; i--) {
  this._array[this._getCyclicIndex(i + items.length)] = this._array[this._getCyclicIndex(i)];
  }
  for (let i = 0; i < items.length; i++) {
- this._array[this._getCyclicIndex(start + i)] = items[i];
+ this._array[this._getCyclicIndex(start + i)] = {
+ id: this._nextId,
+ value: items[i]
+ };
  }
 
+ // Adjust length as needed
  if (this._length + items.length > this.maxLength) {
  const countToTrim = (this._length + items.length) - this.maxLength;
  this._startIndex += countToTrim;
@@ -161,7 +197,7 @@ export class CircularList<T> extends EventEmitter {
 
  if (offset > 0) {
  for (let i = count - 1; i >= 0; i--) {
- this.set(start + i + offset, this.get(start + i));
+ this._setEntry(start + i + offset, this.getEntry(start + i));
  }
  const expandListBy = (start + count + offset) - this._length;
  if (expandListBy > 0) {