Method _findFirstVisibleItem

packages/main/src/TabContainer.ts:1244–1263

(itemsDomRefs: Array<TabInStrip | TabSeparatorInStrip>, containerWidth: number, selectedItemWidth: number, startIndex?: number)

	}

	_findFirstVisibleItem(itemsDomRefs: Array<TabInStrip | TabSeparatorInStrip>, containerWidth: number, selectedItemWidth: number, startIndex?: number) {
		if (startIndex === undefined) {
			startIndex = itemsDomRefs.length - 1;
		}

		let lastVisible = startIndex + 1;

		for (let index = startIndex; index >= 0; index--) {
			const itemWidth = this._getItemWidth(itemsDomRefs[index]);

			if (containerWidth < selectedItemWidth + itemWidth) {
				break;
			}

			selectedItemWidth += itemWidth;
			lastVisible = index;
		}

		return lastVisible;
	}

	_findLastVisibleItem(itemsDomRefs: Array<TabInStrip | TabSeparatorInStrip>, containerWidth: number, selectedItemWidth: number, startIndex = 0) {
		let lastVisibleIndex = startIndex - 1;