Method _updateInternalValue

src/cdk/listbox/listbox.ts:924–935

Update the internal value of the listbox based on the selection model.

()

  /** Update the internal value of the listbox based on the selection model. */
  private _updateInternalValue() {
    const indexCache = new Map<T, number>();
    this.selectionModel.sort((a: T, b: T) => {
      const aIndex = this._getIndexForValue(indexCache, a);
      const bIndex = this._getIndexForValue(indexCache, b);
      return aIndex - bIndex;
    });
    const selected = this.selectionModel.selected;
    this._invalid =
      (!this.multiple && selected.length > 1) || !!this._getInvalidOptionValues(selected).length;
    this.changeDetectorRef.markForCheck();
  }

  /**
   * Gets the index of the given value in the given list of options.