@m3e/fab

@m3e/fab

The m3e-fab component is a prominent, expressive UI component that represents the primary action on a screen. Designed according to Material Design 3 guidelines, it supports seven visual variants, specified using the variant attribute—primary, primary-container, secondary, secondary-container, tertiary, tertiary-container and surface—each with dynamic elevation and adaptive color theming.

The component is accessible by default, with ARIA roles, contrast-safe color tokens, and strong focus indicators. It can be extended to display a label alongside its icon, and responds to interaction states (hover, focus, press, disabled) with smooth motion transitions, elevation changes, and adaptive color theming. It can also function as a link or be used to submit form data.

Native disabled <button> elements cannot receive focus. This can be problematic in some cases because it can prevent you from telling the user why the button is disabled. You can use the disabled-interactive attribute to style a m3e-fab as disabled but allow for it to receive focus. The button will have aria-disabled="true" for assistive technology.

This package is part of M3E monorepo, a unified suite of Material 3 web components. Explore the docs to see them in action.

📦 Installation

npm install @m3e/fab

💻 Editor Integration

This package includes a Custom Elements Manifest to support enhanced editor tooling and developer experience.

Visual Studio Code

To enable autocomplete and hover documentation for @m3e/fab, install the Custom Elements Manifest Language Server extension. It will automatically detect the manifest bundled with this package and surface tag names, attributes, slots, and events in supported files.

Alternately, you can explicitly reference the html-custom-data.json and css-custom-data.json in your workspace settings:

{
  "html.customData": ["./node_modules/@m3e/fab/dist/html-custom-data.json"],
  "css.customData": ["./node_modules/@m3e/fab/dist/css-custom-data.json"]
}

🚀 Native Module Support

This package uses JavaScript Modules. To use it directly in a browser without a bundler, use a module script similar to the following.

<script type="module" src="/node_modules/@m3e/fab/dist/index.js"></script>

In addition, you must use an import map to include dependencies.

<script type="importmap">
  {
    "imports": {
      "lit": "https://cdn.jsdelivr.net/npm/lit@3.3.0/+esm",
      "@m3e/core": "/node_modules/@m3e/core/dist/index.js"
    }
  }
</script>

For production, use index.min.js for faster load times.

🗂️ Elements

• m3e-fab — A floating action button (FAB) used to present important actions.

🧪 Examples

The following example illustrates a basic floating action button.

<m3e-fab>
  <m3e-icon>add</m3e-icon>
</m3e-fab>

The next example illustrates an extended floating action button.

<m3e-fab extended>
  <m3e-icon>add</m3e-icon>
  <span slot="label">Add</span>
</m3e-fab>

📖 API Reference

This section details the attributes, slots and CSS custom properties available for the m3e-fab component.

⚙️ Attributes

Attribute	Type	Default	Description
variant	"primary" | "primary-container" | "secondary" | "secondary-container" | "tertiary" | "tertiary-container" | "surface"	"primary-container"	The appearance variant of the FAB.
size	"small" | "medium" | "large"	"medium"	The size of the FAB.
extended	boolean	false	Whether the FAB is extended to show the label.
lowered	boolean	false	Whether to present a lowered elevation.
disabled	boolean	false	Whether the element is disabled.
disabled-interactive	boolean	false	Whether the element is disabled and interactive.
type	"button" | "submit" | "reset"	"button"	The type of the element.
name	string		The name of the element, submitted as a pair with the element's value as part of form data, when the element is used to submit a form.
value	string		The value associated with the element's name when it's submitted with form data.
href	string		The URL to which the link FAB points.
target	string		The target of the link FAB.
rel	string		The relationship between the target of the link FAB and the document.
download	string		A value indicating whether the target of the link FAB will be downloaded, optionally specifying the new name of the file.

🧩 Slots

Slot	Description
(default)	Renders the icon of the button.
label	Renders the label of an extended FAB.
close-icon	Renders the close icon when used to open a FAB menu.

🎛️ CSS Custom Properties

🧱 Size Properties

All size variants (small, medium, large) support:

Property	Description
--m3e-fab-[size]-container-height	Height of the FAB container
--m3e-fab-[size]-label-text-font-size	Font size for label
--m3e-fab-[size]-label-text-font-weight	Font weight for label
--m3e-fab-[size]-label-text-line-height	Line height for label
--m3e-fab-[size]-label-text-tracking	Letter tracking for label
--m3e-fab-[size]-icon-size	Icon size
--m3e-fab-[size]-shape	Corner radius
--m3e-fab-[size]-leading-space	Space before icon/label
--m3e-fab-[size]-trailing-space	Space after icon/label
--m3e-fab-[size]-icon-label-space	Space between icon and label

🎨 Appearance Variant Properties

All appearance variants (primary, primary-container, secondary, secondary-container, tertiary, tertiary-container, surface) support:

Property	Description
--m3e-[variant]-fab-label-text-color	Label color
--m3e-[variant]-fab-icon-color	Icon color
--m3e-[variant]-fab-container-color	Container background color
--m3e-[variant]-fab-container-elevation	Elevation
--m3e-[variant]-fab-lowered-container-elevation	Lowered elevation

🟫 State Properties

Each variant supports state properties for disabled, hover, focus, and pressed. For each variant, the following properties are available (replace [variant] with the variant name):

Property	Description
--m3e-[variant]-fab-disabled-label-text-color	Label color when disabled
--m3e-[variant]-fab-disabled-label-text-opacity	Label opacity when disabled
--m3e-[variant]-fab-disabled-icon-color	Icon color when disabled
--m3e-[variant]-fab-disabled-icon-opacity	Icon opacity when disabled
--m3e-[variant]-fab-disabled-container-color	Container color when disabled
--m3e-[variant]-fab-disabled-container-opacity	Container opacity when disabled
--m3e-[variant]-fab-disabled-container-elevation	Elevation when disabled
--m3e-[variant]-fab-lowered-disabled-container-elevation	Lowered elevation when disabled
--m3e-[variant]-fab-hover-label-text-color	Label color on hover
--m3e-[variant]-fab-hover-icon-color	Icon color on hover
--m3e-[variant]-fab-hover-state-layer-color	State layer color on hover
--m3e-[variant]-fab-hover-state-layer-opacity	State layer opacity on hover
--m3e-[variant]-fab-hover-container-elevation	Elevation on hover
--m3e-[variant]-fab-lowered-hover-container-elevation	Lowered elevation on hover
--m3e-[variant]-fab-focus-label-text-color	Label color on focus
--m3e-[variant]-fab-focus-icon-color	Icon color on focus
--m3e-[variant]-fab-focus-state-layer-color	State layer color on focus
--m3e-[variant]-fab-focus-state-layer-opacity	State layer opacity on focus
--m3e-[variant]-fab-focus-container-elevation	Elevation on focus
--m3e-[variant]-fab-lowered-focus-container-elevation	Lowered elevation on focus
--m3e-[variant]-fab-pressed-label-text-color	Label color on press
--m3e-[variant]-fab-pressed-icon-color	Icon color on press
--m3e-[variant]-fab-pressed-state-layer-color	State layer color on press
--m3e-[variant]-fab-pressed-state-layer-opacity	State layer opacity on press
--m3e-[variant]-fab-pressed-container-elevation	Elevation on press
--m3e-[variant]-fab-lowered-pressed-container-elevation	Lowered elevation on press

🤝 Contributing

See the root monorepo CONTRIBUTING.md for guidelines on contributing to this package.

📄 License

This package is licensed under the MIT License.