src/vs/workbench/contrib/preferences/browser/settingsWidgets.ts/AbstractListSettingWidget/getClickedItemIndex
class AbstractListSettingWidget:	private getClickedItemIndex(e: MouseEvent): number {
		if (!e.target) {
			return -1;
		}

		const actionbar = DOM.findParentWithClass(e.target as HTMLElement, 'monaco-action-bar');
		if (actionbar) {
			// Don't handle doubleclicks inside the action bar
			return -1;
		}

		const element = DOM.findParentWithClass(e.target as HTMLElement, 'setting-list-row');
		if (!element) {
			return -1;
		}

		const targetIdxStr = element.getAttribute('data-index');
		if (!targetIdxStr) {
			return -1;
		}

		const targetIdx = parseInt(targetIdxStr);
		return targetIdx;
	}