@shopify/polaris/dist/esm/components/Tabs/utilities.js

Shopify’s product component library

function getVisibleAndHiddenTabIndices(tabs, selected, disclosureWidth, tabWidths, containerWidth) {
  var sumTabWidths = tabWidths.reduce((sum, width) => sum + width, 0);
  var arrayOfTabIndices = tabs.map((_, index) => {
    return index;
  });
  var visibleTabs = [];
  var hiddenTabs = [];

  if (containerWidth > sumTabWidths) {
    visibleTabs.push(...arrayOfTabIndices);
  } else {
    visibleTabs.push(selected);
    var tabListWidth = tabWidths[selected];
    arrayOfTabIndices.forEach(currentTabIndex => {
      if (currentTabIndex !== selected) {
        var currentTabWidth = tabWidths[currentTabIndex];

        if (tabListWidth + currentTabWidth > containerWidth - disclosureWidth) {
          hiddenTabs.push(currentTabIndex);
          return;
        }

        visibleTabs.push(currentTabIndex);
        tabListWidth += currentTabWidth;
      }
    });
  }

  return {
    visibleTabs,
    hiddenTabs
  };
}

export { getVisibleAndHiddenTabIndices };