@lion/tooltip

Tooltip

lion-tooltip is a component used for basic popups on hover. Its purpose is to show content appearing when the user hovers over an invoker element with the cursor or with the keyboard, or if the invoker element is focused.

import { css, html } from '@lion/core';
import { LionTooltip } from './src/LionTooltip.js';
import './lion-tooltip.js';

export default {
  title: 'Overlays/Tooltip',
  // parameters: {
  //   component: 'lion-tooltip',
  //   options: {
  //     selectedPanel: 'storybookjs/knobs/panel'
  //   }
  // }
  // decorators: [withKnobs]
};

const tooltipDemoStyles = css`
  .demo-tooltip-invoker {
    margin: 50px;
  }

  .demo-tooltip-content {
    display: block;
    font-size: 16px;
    color: white;
    background-color: black;
    border-radius: 4px;
    padding: 8px;
  }

  .demo-box-placements {
    display: flex;
    flex-direction: column;
    margin: 40px 0 0 200px;
  }

  .demo-box-placements lion-tooltip {
    margin: 20px;
  }
`;

export const main = () => html`
  <style>
    ${tooltipDemoStyles}
  </style>
  <lion-tooltip has-arrow .config=${{ popperConfig: { placement: 'right' } }}>
    <button slot="invoker" class="demo-tooltip-invoker">Hover me</button>
    <div slot="content" class="demo-tooltip-content">This is a tooltip</div>
  </lion-tooltip>
`;

Features

• Show content when hovering the invoker
• Show content when the invoker is focused
• Does not show content when invoker is disabled
• Uses Popper.js under the hood, to have the content pop up relative to the invoker
• Use .config to override the overlay configuration
• Config has popperConfig property that has a one to one relation with Popper.js configuration API.

How to use

Installation

npm i --save @lion/tooltip

import { LionTooltip } from '@lion/tooltip';
// or
import '@lion/tooltip/lion-tooltip.js';

Examples

invokerRelation

There is a difference between tooltips used as a primary label or as a description. In most cases a button will already have its own label, so the tooltip will be used as a description with extra information, which is already set as default. Only in case of icon buttons you want to use the tooltip as the primary label. To do so you need to set the invokerRelation to label.

For detailed information please read: inclusive tooltips.

export const invokerRelation = () => html`
  <style>
    ${tooltipDemoStyles}
  </style>
  <lion-tooltip .config=${{ invokerRelation: 'label' }}>
    <button slot="invoker" class="demo-tooltip-invoker">📅</button>
    <div slot="content" class="demo-tooltip-content">Agenda<div>
  </lion-tooltip>
`;

Placements

You can easily change the placement of the content node relative to the invoker.

export const placements = () => html`
  <style>
    ${tooltipDemoStyles}
  </style>
  <div class="demo-box-placements">
    <lion-tooltip has-arrow .config=${{ popperConfig: { placement: 'top' } }}>
      <button slot="invoker">Top</button>
      <div slot="content" class="demo-tooltip-content">Its top placement</div>
    </lion-tooltip>
    <lion-tooltip has-arrow .config=${{ popperConfig: { placement: 'right' } }}>
      <button slot="invoker">Right</button>
      <div slot="content" class="demo-tooltip-content">Its right placement</div>
    </lion-tooltip>
    <lion-tooltip has-arrow .config=${{ popperConfig: { placement: 'bottom' } }}>
      <button slot="invoker">Bottom</button>
      <div slot="content" class="demo-tooltip-content">Its bottom placement</div>
    </lion-tooltip>
    <lion-tooltip has-arrow .config=${{ popperConfig: { placement: 'left' } }}>
      <button slot="invoker">Left</button>
      <div slot="content" class="demo-tooltip-content">Its left placement</div>
    </lion-tooltip>
  </div>
`;

Override Popper configuration

You can override the Popper configuration, the API is one to one with Popper's API, and includes modifiers.

export const overridePopperConfig = () => html`
    <style>${tooltipDemoStyles}</style>
    <lion-tooltip .config=${{
      popperConfig: {
        placement: 'bottom-start',
        strategy: 'fixed',
        modifiers: [
          {
            name: 'keepTogether',
            options: {},
            enabled: true,
          },
          {
            name: 'preventOverflow',
            options: {
              boundariesElement: 'viewport',
              padding: 16,
            },
            enabled: false,
          },
          {
            name: 'flip',
            options: {
              boundariesElement: 'viewport',
              padding: 4,
            },
            enabled: true,
          },
          {
            name: 'offset',
            options: {
              // Note the different offset notation
              offset: [0, 4],
            },
            enabled: true,
          },
        ],
      },
    }}>
      <button slot="invoker" class="demo-tooltip-invoker">Hover me</button>
      <div slot="content" class="demo-tooltip-content">This is a tooltip<div>
    </lion-tooltip>
  `;

Modifier explanations:

• keepTogether: prevents detachment of content element from reference element, which could happen if the invoker is not in the viewport anymore. If this is disabled, the content will always be in view.
• preventOverflow: enables shifting and sliding behavior on the secondary axis (e.g. if top placement, this is horizontal shifting and sliding). The padding property defines the margin with the boundariesElement, which is usually the viewport.
• flip: enables flipping behavior on the primary axis (e.g. if top placement, flipping to bottom if there is not enough space on the top). The padding property defines the margin with the boundariesElement, which is usually the viewport.
• offset: enables an offset between the content node and the invoker node. First argument is horizontal marign, second argument is vertical margin.

Arrow

By default, the arrow is disabled for our tooltip. Via the has-arrow property it can be enabled.

As a Subclasser, you can decide to turn the arrow on by default if this fits your Design System, by setting this.hasArrow = true; in the constructor.

export const arrow = () => html`
  <style>
    ${tooltipDemoStyles}
  </style>
  <lion-tooltip has-arrow>
    <button slot="invoker">Hover me</button>
    <div slot="content">This is a tooltip</div>
  </lion-tooltip>
`;

Use a custom arrow

If you plan on providing a custom arrow, you can extend the lion-tooltip.

All you need to do is override the _arrowTemplate method to pass your own SVG, and extend the styles to pass the proper dimensions of your arrow. The rest of the work is done by Popper.js (for positioning) and the lion-tooltip-arrow (arrow dimensions, rotation, etc.).

export const customArrow = () => {
  if (!customElements.get('custom-tooltip')) {
    customElements.define(
      'custom-tooltip',
      class extends LionTooltip {
        static get styles() {
          return [
            super.styles,
            css`
              :host {
                --tooltip-arrow-width: 20px;
                --tooltip-arrow-height: 8px;
              }
            `,
          ];
        }
        constructor() {
          super();
          this.hasArrow = true;
        }
        _arrowTemplate() {
          return html`
            <svg viewBox="0 0 20 8">
              <path d="M 0,0 h 20 L 10,8 z"></path>
            </svg>
          `;
        }
      },
    );
  }
  return html`
    <style>
      ${tooltipDemoStyles}
    </style>
    <custom-tooltip>
      <button slot="invoker" class="demo-tooltip-invoker">Hover me</button>
      <div slot="content" class="demo-tooltip-content">This is a tooltip</div>
    </custom-tooltip>
  `;
};