react-split-viewer

react-split-viewer

Resizable split pane layouts for React applications 🖖

• Compound component API that works with any styling method
• Built with modern CSS, a grid-based layout and custom properties
• Works with any amount of panes in a vertical or horizontal layout
• Built following the Window Splitter pattern for accessibility and keyboard controls

Example of a code editor built with react-split-viewer

Development

Run the development server:

yarn dev

The files for the development app can be found in src, and the library files in lib.

Usage

Install the package using your package manager of choice.

npm install react-split-viewer

Import Resplit from react-split-viewer and render the Root, Pane(s) and Splitter(s).

import { Resplit } from 'react-split-viewer';

function App() {
  return (
    <Resplit.Root direction="horizontal">
      <Resplit.Pane order={0} initialSize="0.5fr">
        Pane 1
      </Resplit.Pane>
      <Resplit.Splitter order={1} size="10px" />
      <Resplit.Pane order={2} initialSize="0.5fr">
        Pane 2
      </Resplit.Pane>
    </Resplit.Root>
  );
}

Styling

The Root, Splitter and Pane elements are all unstyled by default apart from a few styles that are necessary for the layout - this is intentional so that the library remains flexible.

Resplit will apply the correct cursor based on the direction provided to the hook.

As a basic example, you could provide a className prop to the Splitter elements and style them as a solid 10px divider.

<Resplit.Splitter className="splitter" order={0} size="10px" />

.splitter {
  width: 100%;
  height: 100%;
  background: #ccc;
}

Accessibility

Resplit has been implemented using guidence from the Window Splitter pattern.

In addition to built-in accessibility considerations, you should also ensure that splitters are correctly labelled.

If the primary pane has a visible label, the aria-labelledby attribute can be used.

<Resplit.Pane order={0}>
  <h2 id="pane-1-label">Pane 1</h2>
</Resplit.Pane>
<Resplit.Splitter order={1} aria-labelledby="pane-1-label" />

Alternatively, if the pane does not have a visible label, the aria-label attribute can be used on the Splitter instead.

<Resplit.Splitter order={1} aria-label="Pane 1" />

API

All of the resplit components extend the React.HTMLAttributes<HTMLDivElement> interface, so you can pass any valid HTML attribute to them.

Root (ResplitRootProps)

The root component of a resplit layout. Provides context to all child components.

Prop	Type	Default	Description
direction	"horizontal" | "vertical"	"horizontal"	Direction of the panes
asChild	boolean	false	Merges props onto the immediate child
children	ReactNode		Child elements
className	string		Class name
style	CSSProperties		Style object

Pane (ResplitPaneProps)

A pane is a container that can be resized.

Prop	Type	Default	Description
order	number		Specifies the order of the resplit child (pane or splitter) in the DOM
initialSize	${number}fr	[available space]/[number of panes]	Set the initial size of the pane as a fractional unit (fr)
minSize	${number}fr | ${number}px	"0fr"	Set the minimum size of the pane as a fractional (fr) or pixel (px) unit
collapsible	boolean	false	Whether the pane can be collapsed below its minimum size
defaultCollapse	boolean	false	Whether the pane collapsed by default to it's collapsible size.
collapsedSize	${number}fr | ${number}px	"0fr"	Set the collapsed size of the pane as a fractional (fr) or pixel (px) unit
onResizeStart	() => void		Callback function that is called when the pane starts being resized.
onResize	(size: FrValue) => void		Callback function that is called when the pane is actively being resized.
onResizeEnd	(size: FrValue) => void		Callback function that is called when the pane is actively being resized.
onCollapse	(size: FrValue) => void		Callback function that is called when the collapsible pane is collapsed.
onExpand	(size: FrValue) => void		Callback function that is called when the collapsible pane is expanded.
asChild	boolean	false	Merges props onto the immediate child
children	ReactNode		Child elements
className	string		Class name
style	CSSProperties		Style object

Splitter (ResplitSplitterProps)

A splitter is a draggable element that can be used to resize panes.

Name	Type	Default	Description
order	number		Specifies the order of the resplit child (pane or splitter) in the DOM
size	${number}px	"10px"	Set the size of the splitter as a pixel unit
asChild	boolean	false	Merges props onto the immediate child
children	ReactNode		Child elements
className	string		Class name
style	CSSProperties		Style object

useResplitContext () => ResplitContextValue

The useResplitContext hook provides access to the context of the nearest Resplit.Root component.

See the methods below for more information on what is available.

setPaneSizes (paneSizes: FrValue[]) => void

Get the collapsed state of a pane.

Specify the size of each pane as a fractional unit (fr). The number of values should match the number of panes.

setPaneSizes(['0.6fr', '0.4fr']);

If your pane has an onResize callback, it will be called with the new size.

isPaneCollapsed (order: number) => boolean

Get the collapsed state of a pane.

Note: The returned value will not update on every render and should be used in a callback e.g. used in combination with a pane's onResize callback.

import { Resplit, useResplitContext, ResplitPaneProps, FrValue } from 'react-split-viewer';

function CustomPane(props: ResplitPaneProps) {
  const { isPaneCollapsed } = useResplitContext();

  const handleResize = (size: FrValue) => {
    if (isPaneCollapsed(props.order)) {
      // Do something
    }
  };

  return (
    <Resplit.Pane
      {...props}
      initialSize="0.5fr"
      collapsedSize="0.2fr"
      collapsible
      onResize={handleResize}
    />
  );
}

function App() {
  return (
    <Resplit.Root>
      <CustomPane order={0} />
      <Resplit.Splitter order={1} />
      <CustomPane order={2} />
    </Resplit.Root>
  );
}

isPaneMinSize (order: number) => boolean

Get the min size state of a pane.

Note: The returned value will not update on every render and should be used in a callback e.g. used in combination with a pane's onResize callback.

import { Resplit, useResplitContext, ResplitPaneProps, FrValue } from 'react-split-viewer';

function CustomPane(props: ResplitPaneProps) {
  const { isPaneMinSize } = useResplitContext();

  const handleResize = (size: FrValue) => {
    if (isPaneMinSize(props.order)) {
      // Do something
    }
  };

  return <Resplit.Pane {...props} initialSize="0.5fr" minSize="0.2fr" onResize={handleResize} />;
}

function App() {
  return (
    <Resplit.Root>
      <CustomPane order={0} />
      <Resplit.Splitter order={1} />
      <CustomPane order={2} />
    </Resplit.Root>
  );
}