lbry-desktop/ui/component/common/tabs.jsx
2020-01-13 13:32:03 -05:00

130 lines
3.6 KiB
JavaScript

// @flow
import React, { Fragment, useState, useRef, useContext, useLayoutEffect, createContext } from 'react';
import {
Tabs as ReachTabs,
Tab as ReachTab,
TabList as ReachTabList,
TabPanels as ReachTabPanels,
TabPanel as ReachTabPanel,
} from '@reach/tabs';
import classnames from 'classnames';
import { useRect } from '@reach/rect';
// Tabs are a compound component
// The components are used individually, but they will still interact and share state
// When using, at a minimum you must arrange the components in this pattern
// When the <Tab> at index 0 is active, the TabPanel at index 0 will be displayed
//
// <Tabs onChange={...} index={...}>
// <TabList>
// <Tab>Tab label 1</Tab>
// <Tab>Tab label 2</Tab>
// ...
// </TabList>
// <TabPanels>
// <TabPanel>Content for Tab 1</TabPanel>
// <TabPanel>Content for Tab 2</TabPanel>
// ...
// </TabPanels>
// </Tabs>
//
// the base @reach/tabs components handle all the focus/accessibilty labels
// We're just adding some styling
type TabsProps = {
index?: number,
onChange?: number => void,
children: Array<React$Node>,
};
// Use context so child TabPanels can set the active tab, which is kept in Tabs' state
const AnimatedContext = createContext<any>();
function Tabs(props: TabsProps) {
// Store the position of the selected Tab so we can animate the "active" bar to its position
const [selectedRect, setSelectedRect] = useState(null);
// Create a ref of the parent element so we can measure the relative "left" for the bar for the child Tab's
const tabsRef = useRef();
const tabsRect = useRect(tabsRef);
const tabLabels = props.children[0];
const tabContent = props.children[1];
return (
<AnimatedContext.Provider value={setSelectedRect}>
<ReachTabs className="tabs" {...props} ref={tabsRef}>
{tabLabels}
<div
className="tab__divider"
style={{
left: selectedRect && tabsRect && selectedRect.left - tabsRect.left,
width: selectedRect && selectedRect.width,
}}
/>
{tabContent}
</ReachTabs>
</AnimatedContext.Provider>
);
}
//
// The wrapper for the list of tab labels that users can click
type TabListProps = {
className?: string,
};
function TabList(props: TabListProps) {
const { className, ...rest } = props;
return <ReachTabList className={classnames('tabs__list', className)} {...rest} />;
}
//
// The links that users click
// Accesses `setSelectedRect` from context to set itself as active if needed
// Flow doesn't understand we don't have to pass it in ourselves
type TabProps = {
isSelected?: Boolean,
};
function Tab(props: TabProps) {
// @reach/tabs provides an `isSelected` prop
// We could also useContext to read it manually
const { isSelected } = props;
// Each tab measures itself
const ref = useRef();
const rect = useRect(ref, isSelected);
// and calls up to the parent when it becomes selected
// we useLayoutEffect to avoid flicker
const setSelectedRect = useContext(AnimatedContext);
useLayoutEffect(() => {
if (isSelected) setSelectedRect(rect);
}, [isSelected, rect, setSelectedRect]);
return <ReachTab ref={ref} {...props} className="tab" />;
}
//
// The wrapper for TabPanel
type TabPanelsProps = {
header?: React$Node,
};
function TabPanels(props: TabPanelsProps) {
const { header, ...rest } = props;
return (
<Fragment>
{header}
<ReachTabPanels {...rest} />
</Fragment>
);
}
//
// The wrapper for content when it's associated Tab is selected
function TabPanel(props: any) {
return <ReachTabPanel className="tab__panel" {...props} />;
}
export { Tabs, TabList, Tab, TabPanels, TabPanel };