@m3e/button

@m3e/button

The m3e-button component is a semantic, expressive UI primitive users interact with to perform an action. Designed according to Material Design 3 guidelines, it supports five visual variants, specified using the variant attribute—filled, tonal, elevated, outlined, and text—each with dynamic elevation, shape morphing, and adaptive color theming. The component responds to interaction states (hover, focus, press, disabled) with smooth motion transitions, ensuring emotional clarity and visual hierarchy.

The component is accessible by default, with ARIA roles, contrast-safe color tokens, and strong focus indicators. It supports optional icons and states for binary actions. When using m3e-icon for icons, filled is automatically set based on the selected state of a toggle button. 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-button 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/button

💻 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/button, 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/button/dist/html-custom-data.json"],
  "css.customData": ["./node_modules/@m3e/button/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/button/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-button — A button users interact with to perform an action.

🧪 Examples

The following example illustrates changing the appearance from text (default) to tonal using the variant attribute.

<m3e-button variant="tonal">Tonal Button</m3e-button>

📖 API Reference

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

⚙️ Attributes

Attribute	Type	Default	Description
variant	"elevated" | "filled" | "tonal" | "outlined" | "text"	"text"	The appearance variant of the button.
shape	"rounded" | "square"	"rounded"	The shape of the button.
size	"extra-small" | "small" | "medium" | "large" | "extra-large"	"small"	The size of the button.
toggle	boolean	false	Whether the button will toggle between selected and unselected states.
selected	boolean	false	Whether the toggle button is selected.
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 button points.
target	string		The target of the link button.
rel	string		The relationship between the target of the link button and the document.
download	string		A value indicating whether the target of the link button will be downloaded, optionally specifying the new name of the file.

🧩 Slots

Slot	Description
(default)	Renders button label/content.
icon	Renders leading icon before label.
trailing-icon	Renders trailing icon after label.
selected	Renders label when toggle button is selected.
selected-icon	Renders icon before label when selected.

🎛️ CSS Custom Properties

🧱 Size Properties

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

Property	Description
--m3e-button-[size]-container-height	Height of the button container
--m3e-button-[size]-outline-thickness	Outline thickness
--m3e-button-[size]-label-text-font-size	Font size for label
--m3e-button-[size]-label-text-font-weight	Font weight for label
--m3e-button-[size]-label-text-line-height	Line height for label
--m3e-button-[size]-label-text-tracking	Letter tracking for label
--m3e-button-[size]-icon-size	Icon size
--m3e-button-[size]-shape-round	Corner radius for round shape
--m3e-button-[size]-shape-square	Corner radius for square shape
--m3e-button-[size]-selected-shape-round	Corner radius when selected (round)
--m3e-button-[size]-selected-shape-square	Corner radius when selected (square)
--m3e-button-[size]-shape-pressed-morph	Corner radius when pressed
--m3e-button-[size]-leading-space	Space before icon/label
--m3e-button-[size]-trailing-space	Space after icon/label
--m3e-button-[size]-icon-label-space	Space between icon and label

🎨 Appearance Variant Properties

All appearance variants (filled, tonal, elevated, outlined, text) support the following properties (replace [variant] with the variant name):

Property	Description
--m3e-[variant]-button-label-text-color	Label color
--m3e-[variant]-button-icon-color	Icon color
--m3e-[variant]-button-container-color	Container background color
--m3e-[variant]-button-container-elevation	Elevation
--m3e-[variant]-button-outline-color	Outline color (outlined only)
--m3e-[variant]-button-outline-thickness	Outline thickness (outlined only)

🟫 State Properties

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

Property	Description
--m3e-[variant]-button-disabled-label-text-color	Label color when disabled
--m3e-[variant]-button-disabled-label-text-opacity	Label opacity when disabled
--m3e-[variant]-button-disabled-icon-color	Icon color when disabled
--m3e-[variant]-button-disabled-icon-opacity	Icon opacity when disabled
--m3e-[variant]-button-disabled-container-color	Container color when disabled
--m3e-[variant]-button-disabled-container-opacity	Container opacity when disabled
--m3e-[variant]-button-disabled-container-elevation	Elevation when disabled
--m3e-[variant]-button-hover-label-text-color	Label color on hover
--m3e-[variant]-button-hover-icon-color	Icon color on hover
--m3e-[variant]-button-hover-state-layer-color	State layer color on hover
--m3e-[variant]-button-hover-state-layer-opacity	State layer opacity on hover
--m3e-[variant]-button-hover-container-elevation	Elevation on hover
--m3e-[variant]-button-hover-outline-color	Outline color on hover (outlined only)
--m3e-[variant]-button-focus-label-text-color	Label color on focus
--m3e-[variant]-button-focus-icon-color	Icon color on focus
--m3e-[variant]-button-focus-state-layer-color	State layer color on focus
--m3e-[variant]-button-focus-state-layer-opacity	State layer opacity on focus
--m3e-[variant]-button-focus-container-elevation	Elevation on focus
--m3e-[variant]-button-focus-outline-color	Outline color on focus (outlined only)
--m3e-[variant]-button-pressed-label-text-color	Label color on press
--m3e-[variant]-button-pressed-icon-color	Icon color on press
--m3e-[variant]-button-pressed-state-layer-color	State layer color on press
--m3e-[variant]-button-pressed-state-layer-opacity	State layer opacity on press
--m3e-[variant]-button-pressed-container-elevation	Elevation on press
--m3e-[variant]-button-pressed-outline-color	Outline color on press (outlined only)

🟦 Selected/Unselected State Properties

For toggle buttons, each variant supports selected/unselected state properties:

Property	Description
--m3e-[variant]-button-selected-label-text-color	Label color when selected
--m3e-[variant]-button-selected-icon-color	Icon color when selected
--m3e-[variant]-button-selected-container-color	Container color when selected
--m3e-[variant]-button-selected-state-layer-color	State layer color when selected
--m3e-[variant]-button-unselected-label-text-color	Label color when unselected
--m3e-[variant]-button-unselected-icon-color	Icon color when unselected
--m3e-[variant]-button-unselected-container-color	Container color when unselected
--m3e-[variant]-button-unselected-state-layer-color	State layer color when unselected

🤝 Contributing

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

📄 License

This package is licensed under the MIT License.