shoelace/docs/components/split-panel.md

Split Panel

[component-header:sl-split-panel]

Split panels display two adjacent panels, allowing the user to reposition them.

<sl-split-panel>
  <div slot="start" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    Start
  </div>
  <div slot="end" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    End
  </div>
</sl-split-panel>

import { SlSplitPanel } from '@shoelace-style/shoelace/dist/react';

const App = () => (
  <SlSplitPanel>
    <div slot="start" style={{
      height: '200px',
      background: 'var(--sl-color-neutral-50)',
      display: 'flex',
      alignItems: 'center',
      justifyContent: 'center'
    }}>
      Start
    </div>
    <div slot="end" style={{
      height: '200px',
      background: 'var(--sl-color-neutral-50)',
      display: 'flex',
      alignItems: 'center',
      justifyContent: 'center'
    }}>
      End
    </div>
  </SlSplitPanel>
);

Examples

Initial Position

To set the initial position, use the position attribute. If no position is provided, it will default to 50% of the available space.

<sl-split-panel position="75">
  <div slot="start" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    Start
  </div>
  <div slot="end" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    End
  </div>
</sl-split-panel>

Initial Position in Pixels

To set the initial position in pixels instead of a percentage, use the position-in-pixels attribute.

<sl-split-panel position-in-pixels="150">
  <div slot="start" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    Start
  </div>
  <div slot="end" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    End
  </div>
</sl-split-panel>

import { SlSplitPanel } from '@shoelace-style/shoelace/dist/react';

const App = () => (
  <SlSplitPanel position="200">
    <div 
      slot="start" 
      style={{
        height: '200px',
        background: 'var(--sl-color-neutral-50)',
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center'
      }}
    >
      Start
    </div>
    <div 
      slot="end" 
      style={{
        height: '200px',
        background: 'var(--sl-color-neutral-50)',
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center'
      }}
    >
      End
    </div>
  </SlSplitPanel>
);

Vertical

Add the vertical attribute to render the split panel in a vertical orientation where the start and end panels are stacked. You also need to set a height when using the vertical orientation.

<sl-split-panel vertical style="height: 400px;">
  <div slot="start" style="height: 100%; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    Start
  </div>
  <div slot="end" style="height: 100%; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    End
  </div>
</sl-split-panel>

import { SlSplitPanel } from '@shoelace-style/shoelace/dist/react';

const App = () => (
  <SlSplitPanel vertical style={{ height: '400px' }}>
    <div 
      slot="start" 
      style={{ 
        height: '100%', 
        background: 'var(--sl-color-neutral-50)', 
        display: 'flex', 
        alignItems: 'center',
        justifyContent: 'center' 
      }}
    >
      Start
    </div>
    <div 
      slot="end"
      style={{ 
        height: '100%', 
        background: 'var(--sl-color-neutral-50)', 
        display: 'flex', 
        alignItems: 'center',
        justifyContent: 'center' 
      }}
    >
      End
    </div>
  </SlSplitPanel>
);

Snapping

To snap panels at specific positions while dragging, add the snap attribute with one or more space-separated values. Values must be in pixels or percentages. For example, to snap the panel at 100px and 50%, use snap="100px 50%". You can also customize how close the divider must be before snapping with the snap-threshold attribute.

<div class="split-panel-snapping">
  <sl-split-panel snap="100px 50%">
    <div slot="start" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
      Start
    </div>
    <div slot="end" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
      End
    </div>
  </sl-split-panel>

  <div class="split-panel-snapping-dots"></div>
</div>

<style>
  .split-panel-snapping {
    position: relative;
  }

  .split-panel-snapping-dots::before,
  .split-panel-snapping-dots::after {
    content: '';
    position: absolute;
    bottom: -12px;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--sl-color-neutral-400);
    transform: translateX(-3px);
  }

  .split-panel-snapping-dots::before {
    left: 100px;
  }

  .split-panel-snapping-dots::after {
    left: 50%;
  }
</style>

import { SlSplitPanel } from '@shoelace-style/shoelace/dist/react';

const css = `
  .split-panel-snapping {
    position: relative;
  }

  .split-panel-snapping-dots::before,
  .split-panel-snapping-dots::after {
    content: '';
    position: absolute;
    bottom: -12px;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--sl-color-neutral-400);
    transform: translateX(-3px);
  }

  .split-panel-snapping-dots::before {
    left: 100px;
  }

  .split-panel-snapping-dots::after {
    left: 50%;
  }
`;

const App = () => (
  <>
    <div className="split-panel-snapping">
      <SlSplitPanel snap="100px 50%">
        <div 
          slot="start" 
          style={{
            height: '200px',
            background: 'var(--sl-color-neutral-50)',
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center'
          }}
        >
          Start
        </div>
        <div 
          slot="end" 
          style={{
            height: '200px',
            background: 'var(--sl-color-neutral-50)',
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center'
          }}
        >
          End
        </div>
      </SlSplitPanel>

      <div className="split-panel-snapping-dots" />
    </div>

    <style>{css}</style>
  </>
);

Disabled

Add the disabled attribute to prevent the divider from being repositioned.

<sl-split-panel disabled>
  <div slot="start" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    Start
  </div>
  <div slot="end" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    End
  </div>
</sl-split-panel>

import { SlSplitPanel } from '@shoelace-style/shoelace/dist/react';

const App = () => (
  <SlSplitPanel disabled>
    <div 
      slot="start" 
      style={{
        height: '200px',
        background: 'var(--sl-color-neutral-50)',
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center'
      }}
    >
      Start
    </div>
    <div 
      slot="end" 
      style={{
        height: '200px',
        background: 'var(--sl-color-neutral-50)',
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center'
      }}
    >
      End
    </div>
  </SlSplitPanel>
);

Setting the Primary Panel

By default, both panels will grow or shrink proportionally when the host element is resized. If a primary panel is designated, it will maintain its size and the secondary panel will grow or shrink to fit the remaining space. You can set the primary panel to start or end using the primary attribute.

Try resizing the example below with each option and notice how the panels respond.

<div class="split-panel-primary">
  <sl-split-panel>
    <div slot="start" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
      Start
    </div>
    <div slot="end" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
      End
    </div>
  </sl-split-panel>

  <sl-select label="Primary Panel" value="" style="max-width: 200px; margin-top: 1rem;">
    <sl-menu-item value="">None</sl-menu-item>
    <sl-menu-item value="start">Start</sl-menu-item>
    <sl-menu-item value="end">End</sl-menu-item>
  </sl-select>
</div>

<script>
  const container = document.querySelector('.split-panel-primary');
  const splitPanel = container.querySelector('sl-split-panel');
  const select = container.querySelector('sl-select');

  select.addEventListener('sl-change', () => splitPanel.primary = select.value);
</script>

import { useState } from 'react';
import { SlSplitPanel, SlSelect, SlMenuItem } from '@shoelace-style/shoelace/dist/react';

const App = () => {
  const [primary, setPrimary] = useState('');

  return (
    <>
      <SlSplitPanel primary={primary}>
        <div 
          slot="start" 
          style={{
            height: '200px',
            background: 'var(--sl-color-neutral-50)',
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center'
          }}
        >
          Start
        </div>
        <div 
          slot="end" 
          style={{
            height: '200px',
            background: 'var(--sl-color-neutral-50)',
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center'
          }}
        >
          End
        </div>
      </SlSplitPanel>

      <SlSelect 
        label="Primary Panel" 
        value={primary} 
        style={{ maxWidth: '200px', marginTop: '1rem' }} 
        onSlChange={event => setPrimary(event.target.value)}
      >
        <SlMenuItem value="">None</SlMenuItem>
        <SlMenuItem value="start">Start</SlMenuItem>
        <SlMenuItem value="end">End</SlMenuItem>
      </SlSelect>      
    </>
  );
};

Min & Max

To set a minimum or maximum size of the primary panel, use the --min and --max custom properties. Since the secondary panel is flexible, size constraints can only be applied to the primary panel. If no primary panel is designated, these constraints will be applied to the start panel.

This examples demonstrates how you can ensure both panels are at least 150px using --min, --max, and the calc() function.

<sl-split-panel style="--min: 150px; --max: calc(100% - 150px);">
  <div slot="start" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    Start
  </div>
  <div slot="end" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    End
  </div>
</sl-split-panel>

import { SlSplitPanel } from '@shoelace-style/shoelace/dist/react';

const App = () => (
  <SlSplitPanel style={{ '--min': '150px', '--max': 'calc(100% - 150px)' }}>
    <div 
      slot="start" 
      style={{
        height: '200px',
        background: 'var(--sl-color-neutral-50)',
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center'
      }}
    >
      Start
    </div>
    <div 
      slot="end" 
      style={{
        height: '200px',
        background: 'var(--sl-color-neutral-50)',
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center'
      }}
    >
      End
    </div>
  </SlSplitPanel>
);

Nested Split Panels

Create complex layouts that can be repositioned independently by nesting split panels.

<sl-split-panel>
  <div slot="start" style="height: 400px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    Start
  </div>
  <div slot="end">
    <sl-split-panel vertical style="height: 400px;">
      <div slot="start" style="height: 100%; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
        Top
      </div>
      <div slot="end" style="height: 100%; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
        Bottom
      </div>
    </sl-split-panel>    
  </div>
</sl-split-panel>

import { SlSplitPanel } from '@shoelace-style/shoelace/dist/react';

const App = () => (
  <SlSplitPanel>
    <div 
      slot="start" 
      style={{
        height: '400px',
        background: 'var(--sl-color-neutral-50)',
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center'
      }}
    >
      Start
    </div>
    <div slot="end">
      <SlSplitPanel vertical style={{ height: '400px' }}>
        <div 
          slot="start" 
          style={{ 
            height: '100%',
            background: 'var(--sl-color-neutral-50)',
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center'
          }}
        >
          Start
        </div>
        <div 
          slot="end" 
          style={{ 
            height: '100%',
            background: 'var(--sl-color-neutral-50)',
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center'
          }}      
        >
          End
        </div>
      </SlSplitPanel>
    </div>
  </SlSplitPanel>
);

Customizing the Divider

You can target the divider part to apply CSS properties to the divider. To add a handle, slot an icon or another element into the handle slot. When customizing the divider, make sure to think about focus styles for keyboard users.

<sl-split-panel style="--divider-width: 20px;">
  <sl-icon slot="handle" name="grip-vertical"></sl-icon>
  <div slot="start" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    Start
  </div>
  <div slot="end" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
    End
  </div>
</sl-split-panel>

import { SlSplitPanel, SlIcon } from '@shoelace-style/shoelace/dist/react';

const App = () => (
  <SlSplitPanel style={{ '--divider-width': '20px' }}>
    <SlIcon slot="handle" name="grip-vertical" />
    <div slot="start" style={{
      height: '200px',
      background: 'var(--sl-color-neutral-50)',
      display: 'flex',
      alignItems: 'center',
      justifyContent: 'center'
    }}>
      Start
    </div>
    <div slot="end" style={{
      height: '200px',
      background: 'var(--sl-color-neutral-50)',
      display: 'flex',
      alignItems: 'center',
      justifyContent: 'center'
    }}>
      End
    </div>
  </SlSplitPanel>
);

Here's a more elaborate example that changes the divider's color and width and adds a styled handle.

<div class="split-panel-handle">
  <sl-split-panel>
    <sl-icon slot="handle" name="grip-vertical"></sl-icon>
    <div slot="start" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
      Start
    </div>
    <div slot="end" style="height: 200px; background: var(--sl-color-neutral-50); display: flex; align-items: center; justify-content: center;">
      End
    </div>
  </sl-split-panel>
</div>

<style>
  .split-panel-handle sl-split-panel {
    --divider-width: 2px;
  }

  .split-panel-handle sl-split-panel::part(divider) {
    background-color: var(--sl-color-pink-600);
  }

  .split-panel-handle sl-icon {
    position: absolute;
    border-radius: var(--sl-border-radius-small);
    background: var(--sl-color-pink-600);
    color: var(--sl-color-neutral-0);
    padding: .5rem .125rem;
  }

  .split-panel-handle sl-split-panel::part(divider):focus-visible {
    background-color: var(--sl-color-primary-600);
  }

  .split-panel-handle sl-split-panel:focus-within sl-icon {
    background-color: var(--sl-color-primary-600);
    color: var(--sl-color-neutral-0);
  }
</style>

import { SlSplitPanel, SlIcon } from '@shoelace-style/shoelace/dist/react';

const css = `
  .split-panel-handle sl-split-panel {
    --divider-width: 2px;
  }

  .split-panel-handle sl-split-panel::part(divider) {
    background-color: var(--sl-color-pink-600);
  }

  .split-panel-handle sl-icon {
    position: absolute;
    border-radius: var(--sl-border-radius-small);
    background: var(--sl-color-pink-600);
    color: var(--sl-color-neutral-0);
    padding: .5rem .125rem;
  }

  .split-panel-handle sl-split-panel::part(divider):focus-visible {
    background-color: var(--sl-color-primary-600);
  }

  .split-panel-handle sl-split-panel:focus-within sl-icon {
    background-color: var(--sl-color-primary-600);
    color: var(--sl-color-neutral-0);
  }
`;

const App = () => (
  <>
  <div className="split-panel-handle">
    <SlSplitPanel>
      <SlIcon slot="handle" name="grip-vertical" />
      <div slot="start" style={{
        height: '200px',
        background: 'var(--sl-color-neutral-50)',
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center'
      }}>
        Start
      </div>
      <div slot="end" style={{
        height: '200px',
        background: 'var(--sl-color-neutral-50)',
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center'
      }}>
        End
      </div>
    </SlSplitPanel>
  </div>

    <style>{css}</style>
  </>
);

[component-metadata:sl-split-panel]