Method _handleItemNavigation

packages/main/src/ComboBox.ts:915–952

(e: KeyboardEvent, indexOfItem: number, isForward: boolean)

	}

	_handleItemNavigation(e: KeyboardEvent, indexOfItem: number, isForward: boolean) {
		const allItems = this._getItems();

		const currentItem: IComboBoxItem = allItems[indexOfItem];
		const isGroupItem = currentItem && currentItem.isGroupItem;
		const nextItem = isForward ? allItems[indexOfItem + 1] : allItems[indexOfItem - 1];

		if ((!this.open) && ((isGroupItem && !nextItem) || (!isGroupItem && !currentItem))) {
			return;
		}

		this._clearFocus();

		if (this.open) {
			this._itemFocused = true;
			this.value = isGroupItem ? "" : currentItem.text!;
			this.selectedValue = isGroupItem ? undefined : currentItem.value;
			this.focused = false;

			currentItem.focused = true;
		} else {
			this.focused = true;
			this.value = isGroupItem ? nextItem.text! : currentItem.text!;
			this.selectedValue = currentItem.value;
			currentItem.focused = false;
		}

		this._announceSelectedItem(indexOfItem);
		this._scrollToItem(indexOfItem);

		if (isGroupItem && this.open) {
			return;
		}
		// autocomplete
		this._handleTypeAhead(this.value, this.open ? this._userTypedValue : "");

		this.fireDecoratorEvent("input");
	}

	_handleTypeAhead(value: string, filterValue: string) {
		const item = this._getFirstMatchingItem(value);