Main action button
Performs the single most important action of a screen on a raised container that floats above the content, with its name written out, or collapsed to its icon alone.
- Category
- Actions
- Tokens
comp.main-action-button- Level
- Base
- Web
tanrei-main-action-buttonschedule - SwiftUI
TanreiMainActionButtonradio_button_unchecked - Jetpack Compose
TanreiMainActionButtonradio_button_unchecked - Flutter
TanreiMainActionButtonradio_button_unchecked - React Native
MainActionButtonradio_button_unchecked
Generated from docs/status/status.json, specs/main-action-button.spec.json
Extended and collapsed
The main action button is the one action a screen exists for: Compose in a mailbox, New event in a calendar, Add in a list. It sits on a raised container that floats above the content, so it stays in reach while the content scrolls beneath it.
It is one button with two forms. Extended (the default) shows its icon and its label. Collapsed shows the icon alone, in a square as high as the extended form, a circle in the default system. The product moves it between the two, for example collapsing it while the content scrolls and extending it again at the top. It is an action, never a toggle: collapsing changes its shape, not its meaning, and the label stays its accessible name in both forms.
On the web it is <tanrei-main-action-button>, and MainActionButton in React. SwiftUI, Compose, Flutter and React Native have not implemented it yet.
The label is a prop, not content, because it is needed in both forms: drawn while extended, and the accessible name always. The icon is a glyph of the icon set. The button does not place itself: your layout puts it, normally in the inline-end bottom corner of the screen, clear of a navigation bar.
<tanrei-main-action-button class="primary-action" label="Compose">
<span slot="icon">edit</span>
</tanrei-main-action-button>
<!-- Collapsed: the attribute is the inverse of the extended property. -->
<tanrei-main-action-button label="Compose" collapsed><span slot="icon">edit</span></tanrei-main-action-button>
<!-- A glyph that points where the action goes sits after the label. -->
<tanrei-main-action-button label="Next" icon-position="trailing"><span slot="icon">arrow_forward</span></tanrei-main-action-button>
<style>
/* The element places nothing: the page puts it in the inline-end bottom corner. */
tanrei-main-action-button.primary-action {
position: fixed;
inset-inline-end: var(--tanrei-sys-space-space400);
inset-block-end: var(--tanrei-sys-space-space400);
}
</style>
<script type="module">
import '@tanrei/web/components/main-action-button';
const compose = document.querySelector('tanrei-main-action-button.primary-action');
compose.addEventListener('click', newMessage);
// extended is a property that defaults to true; collapse it from outside, for example while the page is scrolled.
addEventListener('scroll', () => (compose.extended = scrollY === 0), { passive: true });
</script>import { MainActionButton } from '@tanrei/react';
<MainActionButton className="primary-action" label="Compose" extended={atTop} onClick={newMessage}>
<span slot="icon">edit</span>
</MainActionButton>
<MainActionButton variant="tonal" label="Next" iconPosition="trailing" onClick={next}>
<span slot="icon">arrow_forward</span>
</MainActionButton>The main action button replaces the floating action button and the extended FAB. What were two components that a product swapped between are now two forms of one.
| Before | Now |
|---|---|
Floating action button (fab) |
A collapsed main action button: extended set to false |
Extended FAB (extended-fab) |
An extended main action button (the default) |
The extended FAB’s expanded |
extended |
comp.fab.*, comp.extended-fab.* |
comp.main-action-button.* |
- Material 3’s FAB, small FAB and large FAB are a collapsed main action button at the medium, small and large sizes. Its extended FAB is the extended form.
- Compose’s
expanded(onExtendedFloatingActionButton) and Flutter’sisExtended(onFloatingActionButton.extended) areextended. - Material 3’s primary, secondary, tertiary and surface FAB colors map onto the
filled,tonalandsurfacevariants and the values a preset adds. The m3-like preset draws Material’s rounded-square corners and 56 / 96 heights through this component’s tokens. - In Material’s terms the main action button is the FAB. Material’s FAB menu is the FAB menu, a component of the m3-like layer: the systems that descend from it have it.
Variants
Sizes, extended and collapsed
A trailing icon, no icon, and disabled
Anatomy
Anatomy
filled-extended, as the web package draws it.Measurements
Measurements
| Length | Token | Value (px) |
|---|---|---|
container padding-inline-start-with-icon | tanrei.comp.main-action-button.container.padding-inline-start-with-icon.medium | 16 |
container gap | tanrei.comp.main-action-button.container.gap.medium | 12 |
container padding-inline-end | tanrei.comp.main-action-button.container.padding-inline-end.medium | 20 |
container height | tanrei.comp.main-action-button.container.height.medium | 56 |
icon size | tanrei.comp.main-action-button.icon.size.medium | 24 |
filled-extended, as the web package draws it.Properties
| Property | Type | Default | Description |
|---|---|---|---|
variant | filled | tonal | surface | "filled" | Emphasis. Filled is the screen's main action at full strength; tonal is quieter; surface keeps the container neutral where a colored one would compete with the content beneath (a map, a photo). A design system may add values. |
size | small | medium | large | "medium" | Visual height (40 / 56 / 96), which is also the side of the collapsed form, so one button keeps its height while it collapses and extends. Small sits beside a medium one for a related action; large marks the action on a wide or empty screen. The hit area always meets the minimum target. A design system may add values. |
extended | boolean | true | Shows the label beside the icon. False collapses the button to its icon (for example while the content scrolls); the label stays the accessible name. It changes the button's form, never its meaning: this is not a toggle. A button without an icon stays extended, and one without a label never extends (MAB-15, MAB-16). |
fullWidth | boolean | false | Makes the button take the whole width its container gives it, its icon and label centred: the one action of a screen held across its foot on a narrow screen (MAB-24). A full-width button is always drawn extended, so extended is ignored while it is true. |
iconPosition | leading | trailing | "leading" | The side of the label the icon is on, in the reading direction. Trailing is for a glyph that points where the action goes, such as the arrow of Next. Collapsed, the icon is centered whichever side it is on. |
disabled | boolean | false | Prevents interaction and removes the button from the focus order. Hiding it when its action is unavailable is usually better than disabling it. |
label | string | "" | The visible text while extended, and the accessible name in either form. Required: an icon alone is not a name. |
Slots
| Slot | Description |
|---|---|
icon | The icon (a glyph of the system's icon set). |
Events
| Event | Description |
|---|---|
click | The button was activated by pointer, touch, keyboard or assistive technology. |
States
Behavior
Requirements in EARS form. Every platform implementation is tested against these ids.
| ID | Requirement |
|---|---|
MAB-1 | WHEN the user activates the main action button by pointer, touch, Enter or Space THE main action button SHALL emit click exactly once. |
MAB-2 | WHILE disabled is true THE main action button SHALL NOT emit click, SHALL NOT be focusable and SHALL expose the disabled state to assistive technology. |
MAB-3 | WHILE hovered, keyboard-focused or pressed THE main action button SHALL render its container, label, icon, elevation and opacity from the component tokens of the highest-precedence active state, with precedence pressed over focused over hovered; focus gained by pointer or touch SHALL NOT select the focused state. |
MAB-4 | WHEN the main action button receives keyboard focus THE main action button SHALL show the focus ring without animation; focus gained by pointer or touch SHALL NOT show it. |
MAB-5 | WHERE the visual size is below the minimum target THE main action button SHALL extend its hit area on both axes to sys.target.touch for touch input and sys.target.pointer for fine pointers, without changing its visual size; a platform that cannot tell the input type SHALL use sys.target.touch. |
MAB-6 | WHILE disabled is true THE main action button SHALL render its container, label, icon, elevation and opacity from the disabled component tokens of its variant. |
MAB-7 | WHEN variant or size names a value that the active design system does not have THE main action button SHALL render with the default value's tokens, and in debug builds report the unknown value. |
MAB-8 | WHEN the main action button is pressed by pointer, touch, Enter or Space THE main action button SHALL show the pressed state without delay and SHALL keep it visible for at least sys.motion.duration.press-hold, even when the press ends sooner. |
MAB-9 | WHILE pressed THE main action button SHALL answer as sys.behavior.pressed-feedback names: overlay applies the pressed tokens to the whole container at once; ripple grows the pressed state layer from the point of contact (from the center for keyboard activation); dim applies the pressed opacity to the whole control and draws no state layer; none draws no answer to the press. Under ripple and dim only the container color stays with the state under the press; label, icon, elevation, opacity and shape still come from the pressed tokens. Under none every part stays with the state under the press. The ripple grows over comp.main-action-button.motion.feedback-duration with comp.main-action-button.motion.state-easing, fades over the state duration of its size (comp.main-action-button.motion.state-duration.small, .medium or .large) with comp.main-action-button.motion.state-easing once the press has ended and press-hold has passed, and appears whole where motion is reduced. |
MAB-10 | THE main action button SHALL ease its container corners by sys.shape.corner-smoothing (0 is a quarter circle, 0.6 the iOS continuous corner; a platform with only the OS curve draws it for any amount above 0) and show its keyboard focus as sys.behavior.focus-style names (ring or glow); a platform that cannot draw a choice SHALL fall back to the first value and state that in its README. |
MAB-11 | WHILE it is extended THE main action button SHALL draw a container at least the height of its size (comp.main-action-button.container.height.medium for medium, and so on) with the corners of its size (comp.main-action-button.container.shape.medium, and so on), holding its label and, when it has one, its icon on the side iconPosition names (leading: before the label in the reading direction; trailing: after it), the two separated by comp.main-action-button.container.gap.medium (and so on); it SHALL pad the icon's side by comp.main-action-button.container.padding-inline-start-with-icon.medium for a leading icon or comp.main-action-button.container.padding-inline-end-with-icon.medium for a trailing one, a start without an icon by comp.main-action-button.container.padding-inline-start.medium and an end without an icon by comp.main-action-button.container.padding-inline-end.medium, and the top and bottom by at least comp.main-action-button.container.padding-block.medium (and so on for each size), and SHALL be as wide as that content. |
MAB-12 | THE main action button SHALL set its label in the text style of its size (comp.main-action-button.label.typescale.medium, and so on) and the label color of its variant and state (comp.main-action-button.filled.label.color for filled at rest, and so on), SHALL NOT truncate it (it stays on one line while it fits, wraps when the layout gives it less width, and the container grows in both axes with it), and SHALL draw the icon, in either form, in the same color at the icon size of its size (comp.main-action-button.icon.size.medium, and so on) with the family and fill of an unselected icon, sys.icon.weight, and an optical size clamped between sys.icon.optical-size.min and sys.icon.optical-size.max. |
MAB-13 | WHILE it is collapsed THE main action button SHALL hide its label and draw a square container whose side is the height of its size (comp.main-action-button.container.height.medium, and so on) with the corners of its size (comp.main-action-button.container.shape.medium, and so on; a circle where they are full, as in the default system) and its icon centered in it whichever side iconPosition names, and SHALL keep label as its accessible name. |
MAB-14 | WHEN extended changes THE main action button SHALL change its width between the two forms over comp.main-action-button.motion.resize-duration with comp.main-action-button.motion.resize-easing, keeping its height and corners, fading the label out as it narrows and in as it widens, and moving the icon between its side of the label and the center, and SHALL change at once where motion is reduced; which edge stays in place is decided by the layout that holds it, as for any change of its width. |
MAB-15 | IF the main action button has no icon THEN THE main action button SHALL draw its extended form whatever extended says (there is no empty collapsed form), and in debug builds report it while extended is false. |
MAB-16 | WHILE label is not empty THE main action button SHALL expose it as its accessible name, in either form, over a name the product gives it on the element (aria-label or aria-labelledby). IF label is empty THEN THE main action button SHALL draw its collapsed form whatever extended says, SHALL expose the name the product gives it on the element — aria-label, or aria-labelledby naming an element — as its accessible name, and WHILE the product gives it none SHALL in debug builds report that it has no accessible name; this holds over MAB-15 when it has no icon either. |
MAB-17 | THE main action button SHALL cast the elevation of its variant and state (comp.main-action-button.filled.container.elevation for filled at rest, and so on) outside its container without clipping it, in either form and while it changes between them, and WHEN the elevation or the colors change between states SHALL animate the change over the state duration of its size (comp.main-action-button.motion.state-duration.small, .medium or .large) with comp.main-action-button.motion.state-easing, changing them at once where motion is reduced. |
MAB-18 | THE main action button SHALL NOT position itself: it SHALL lay out at its own size, or across the width of its container while fullWidth is true (MAB-24), where the layout that holds it places it (normally the inline-end bottom corner of the screen, clear of any navigation bar), and SHALL NOT draw a scrim or move content. |
MAB-19 | WHEN the layout direction is right-to-left THE main action button SHALL mirror the order of its icon and label (a leading icon on the right, a trailing one on the left) and apply its paddings by logical start and end, SHALL NOT mirror the glyph itself (the icon helper mirrors a glyph the icon set marks, MAB-22), and SHALL grow a ripple from the point of contact as in left-to-right. |
MAB-20 | THE main action button SHALL expose itself to assistive technology as a button named by label with no pressed, selected, checked or expanded state, and WHEN extended changes SHALL NOT change its role, its name or its focus, and SHALL NOT announce the change. |
MAB-21 | THE main action button SHALL take its layout direction from where it is used — the direction of the nearest ancestor that sets one, and the platform's own where none does — and SHALL have no direction setting of its own; WHEN that direction changes while the main action button is shown THE main action button SHALL draw itself for the new direction at once, without a motion of its own, keeping what it shows and its state. |
MAB-22 | WHERE the layout direction is right-to-left THE main action button SHALL draw the glyph of its icon slot mirrored left to right exactly when the system's icon set marks that glyph's name as mirrored or the product forces mirroring for that use, and unmirrored when the product forbids it: the icon helper mirrors the glyph inside its own box, about the box's vertical centre line, changing neither its place, size, color and fill nor the order MAB-19 gives. THE main action button SHALL NOT mirror a glyph itself, and SHALL NOT mirror content the product gives as an image or a view of its own rather than by a glyph's name. |
MAB-23 | THE main action button SHALL lay out its label as text of its own direction, isolated from the text around it: each takes the base direction of its first strong character, or the layout direction where it has none, so that a left-to-right word, a number with its sign or unit, a telephone number and an address keep their own order in a right-to-left layout and reorder nothing beside them; THE main action button SHALL still place the label and align its lines by the layout direction, not by the text's own. |
MAB-24 | WHILE fullWidth is true THE main action button SHALL take the whole inline size its container gives it and SHALL draw its extended form whatever extended says — the height, corners, paddings, elevation and states of MAB-11 and MAB-17 — with its icon and label centred in that width as one row, in the order MAB-19 gives them; WHERE that width is narrower than the label THE main action button SHALL wrap the label, its lines centred (MAB-12). WHEN extended changes while fullWidth is true THE main action button SHALL NOT change its form, and in debug builds SHALL report that a full-width button does not collapse. MAB-16 holds over this rule: a button with no label draws its collapsed form, at its own size, and is reported. |
MAB-25 | WHERE the platform has ARIA attributes (the web), WHEN the product sets an aria- attribute on the host, by the attribute or by the ARIA property that reflects it, THE main action button SHALL move it to the data-aria- attribute of the same name, so that the host is no second node with its name, description or state, and SHALL expose it on the element that carries its role — an id reference by the elements it names in the host's tree or a tree around it, an error message as part of the description while the main action button is invalid — except those the main action button owns (aria-disabled), which it SHALL move and not expose. WHEN the product removes the aria- attribute or its data-aria- twin, or sets the ARIA property that reflects it (ariaLabel, ariaDescribedByElements…) to null, THE main action button SHALL take it off that element. WHEN the product sets an aria- attribute the main action button owns THE main action button SHALL report it in debug builds. |
Platform name mapping
Parity does not mean identical APIs. Each platform uses its own idiom for the same contract.
| Spec | Web | SwiftUI | Jetpack Compose | Flutter | React Native |
|---|---|---|---|---|---|
| Component | tanrei-main-action-button | TanreiMainActionButton | TanreiMainActionButton | TanreiMainActionButton | MainActionButton |
variant · Property | variant | variant | variant | variant | variant |
size · Property | size | size | size | size | size |
extended · Property | extended | isExtended | expanded | isExtended | extended |
fullWidth · Property | fullWidth | fullWidth | fullWidth | fullWidth | fullWidth |
iconPosition · Property | iconPosition | iconPosition | iconPosition | iconPosition | iconPosition |
disabled · Property | disabled | disabled | enabled | onPressed | disabled |
label · Property | label | title | text | label | label |
click · Event | click | action | onClick | onPressed | onPress |
| Notes | The icon is the icon slot (a glyph of the icon font). extended is a boolean property that defaults to true; its attribute is the inverse collapsed, because an HTML boolean attribute cannot default to true. iconPosition is the icon-position attribute. The host has no aria-expanded or aria-pressed (MAB-20). The element is inline; the page positions it (for example with position: fixed or a sticky container). fullWidth is the full-width attribute: the host is then a block-level flex box as wide as its container, and the native <button> fills it (MAB-24). | The initializer takes the title first, as Button(_:action:) does, and an optional icon name. disabled follows .disabled(_:). The view is placed by the caller, typically in an .overlay(alignment: .bottomTrailing). | Compose idiom (as Material 3's extended FAB composable): expanded collapses it; enabled is the inverse flag; text is a String so it is also the content description. Placed through Scaffold's floatingActionButton slot or by the caller. | Flutter idiom (as Material 3's extended FAB): isExtended collapses it and a null onPressed disables it. Placed through Scaffold.floatingActionButton or by the caller; it adds no Hero. | The icon is the icon prop (a glyph name). The caller positions it (for example absolutely inside the screen's root view). |
Tokens
| Token | Aliases | Resolved (light) |
|---|---|---|
--tanrei-comp-main-action-button-container-gap-large | sys.space.space200 | 16px |
--tanrei-comp-main-action-button-container-gap-medium | sys.space.space150 | 12px |
--tanrei-comp-main-action-button-container-gap-small | sys.space.space100 | 8px |
--tanrei-comp-main-action-button-container-height-large | — | 96px |
--tanrei-comp-main-action-button-container-height-medium | — | 56px |
--tanrei-comp-main-action-button-container-height-small | — | 40px |
--tanrei-comp-main-action-button-container-padding-block-large | — | 6px |
--tanrei-comp-main-action-button-container-padding-block-medium | — | 6px |
--tanrei-comp-main-action-button-container-padding-block-small | — | 6px |
--tanrei-comp-main-action-button-container-padding-inline-end-with-icon-large | sys.space.space400 | 32px |
--tanrei-comp-main-action-button-container-padding-inline-end-with-icon-medium | sys.space.space250 | 20px |
--tanrei-comp-main-action-button-container-padding-inline-end-with-icon-small | sys.space.space150 | 12px |
--tanrei-comp-main-action-button-container-padding-inline-end-large | sys.space.space400 | 32px |
--tanrei-comp-main-action-button-container-padding-inline-end-medium | sys.space.space250 | 20px |
--tanrei-comp-main-action-button-container-padding-inline-end-small | sys.space.space200 | 16px |
--tanrei-comp-main-action-button-container-padding-inline-start-with-icon-large | sys.space.space300 | 24px |
--tanrei-comp-main-action-button-container-padding-inline-start-with-icon-medium | sys.space.space200 | 16px |
--tanrei-comp-main-action-button-container-padding-inline-start-with-icon-small | sys.space.space150 | 12px |
--tanrei-comp-main-action-button-container-padding-inline-start-large | sys.space.space400 | 32px |
--tanrei-comp-main-action-button-container-padding-inline-start-medium | sys.space.space250 | 20px |
--tanrei-comp-main-action-button-container-padding-inline-start-small | sys.space.space200 | 16px |
--tanrei-comp-main-action-button-container-shape-large | sys.shape.corner.full | 9999px |
--tanrei-comp-main-action-button-container-shape-medium | sys.shape.corner.full | 9999px |
--tanrei-comp-main-action-button-container-shape-small | sys.shape.corner.full | 9999px |
--tanrei-comp-main-action-button-disabled-opacity | — | 1 |
--tanrei-comp-main-action-button-filled-container-color | sys.color.primary | |
--tanrei-comp-main-action-button-filled-container-elevation | sys.elevation.level3 | 0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 1px 0px rgb(0 0 0 / 0.04), 0px 4px 8px -4px rgb(0 0 0 / 0.04), 0px 16px 24px -8px rgb(0 0 0 / 0.06) |
--tanrei-comp-main-action-button-filled-disabled-container-color | — | |
--tanrei-comp-main-action-button-filled-disabled-container-elevation | — | |
--tanrei-comp-main-action-button-filled-disabled-label-color | — | |
--tanrei-comp-main-action-button-filled-disabled-state-layer-color | — | |
--tanrei-comp-main-action-button-filled-focused-container-color | — | |
--tanrei-comp-main-action-button-filled-focused-container-elevation | — | 0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 1px 0px rgb(0 0 0 / 0.04), 0px 4px 8px -4px rgb(0 0 0 / 0.04), 0px 16px 24px -8px rgb(0 0 0 / 0.06) |
--tanrei-comp-main-action-button-filled-focused-label-color | — | |
--tanrei-comp-main-action-button-filled-focused-state-layer-color | — | |
--tanrei-comp-main-action-button-filled-hovered-container-color | — | |
--tanrei-comp-main-action-button-filled-hovered-container-elevation | — | 0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 1px 0px rgb(0 0 0 / 0.04), 0px 8px 16px -4px rgb(0 0 0 / 0.04), 0px 24px 32px -8px rgb(0 0 0 / 0.06) |
--tanrei-comp-main-action-button-filled-hovered-label-color | — | |
--tanrei-comp-main-action-button-filled-hovered-state-layer-color | — | |
--tanrei-comp-main-action-button-filled-label-color | sys.color.on-primary | |
--tanrei-comp-main-action-button-filled-pressed-container-color | — | |
--tanrei-comp-main-action-button-filled-pressed-container-elevation | — | 0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 1px 0px rgb(0 0 0 / 0.04), 0px 4px 8px -4px rgb(0 0 0 / 0.04), 0px 16px 24px -8px rgb(0 0 0 / 0.06) |
--tanrei-comp-main-action-button-filled-pressed-label-color | — | |
--tanrei-comp-main-action-button-filled-pressed-state-layer-color | — | |
--tanrei-comp-main-action-button-filled-state-layer-color | comp.main-action-button.filled.label.color | |
--tanrei-comp-main-action-button-focused-opacity | — | 1 |
--tanrei-comp-main-action-button-hovered-opacity | — | 1 |
--tanrei-comp-main-action-button-icon-size-large | sys.icon.large | 32px |
--tanrei-comp-main-action-button-icon-size-medium | sys.icon.medium | 24px |
--tanrei-comp-main-action-button-icon-size-small | sys.icon.medium | 24px |
--tanrei-comp-main-action-button-motion-feedback-duration | sys.motion.role.feedback | 450ms |
--tanrei-comp-main-action-button-motion-resize-duration | sys.motion.role.resize.large | 400ms |
--tanrei-comp-main-action-button-motion-resize-easing | sys.motion.easing.spatial | cubic-bezier(0.2, 0, 0, 1) |
--tanrei-comp-main-action-button-motion-state-duration-large | sys.motion.role.state.large | 250ms |
--tanrei-comp-main-action-button-motion-state-duration-medium | sys.motion.role.state.default | 250ms |
--tanrei-comp-main-action-button-motion-state-duration-small | sys.motion.role.state.compact | 200ms |
--tanrei-comp-main-action-button-motion-state-easing | sys.motion.easing.state | cubic-bezier(0.2, 0, 0, 1) |
--tanrei-comp-main-action-button-pressed-opacity | — | 1 |
--tanrei-comp-main-action-button-surface-container-color | sys.color.surface-container-lowest | |
--tanrei-comp-main-action-button-surface-container-elevation | sys.elevation.level3 | 0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 1px 0px rgb(0 0 0 / 0.04), 0px 4px 8px -4px rgb(0 0 0 / 0.04), 0px 16px 24px -8px rgb(0 0 0 / 0.06) |
--tanrei-comp-main-action-button-surface-disabled-container-color | — | |
--tanrei-comp-main-action-button-surface-disabled-container-elevation | — | |
--tanrei-comp-main-action-button-surface-disabled-label-color | — | |
--tanrei-comp-main-action-button-surface-disabled-state-layer-color | — | |
--tanrei-comp-main-action-button-surface-focused-container-color | — | |
--tanrei-comp-main-action-button-surface-focused-container-elevation | — | 0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 1px 0px rgb(0 0 0 / 0.04), 0px 4px 8px -4px rgb(0 0 0 / 0.04), 0px 16px 24px -8px rgb(0 0 0 / 0.06) |
--tanrei-comp-main-action-button-surface-focused-label-color | — | |
--tanrei-comp-main-action-button-surface-focused-state-layer-color | — | |
--tanrei-comp-main-action-button-surface-hovered-container-color | — | |
--tanrei-comp-main-action-button-surface-hovered-container-elevation | — | 0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 1px 0px rgb(0 0 0 / 0.04), 0px 8px 16px -4px rgb(0 0 0 / 0.04), 0px 24px 32px -8px rgb(0 0 0 / 0.06) |
--tanrei-comp-main-action-button-surface-hovered-label-color | — | |
--tanrei-comp-main-action-button-surface-hovered-state-layer-color | — | |
--tanrei-comp-main-action-button-surface-label-color | sys.color.primary | |
--tanrei-comp-main-action-button-surface-pressed-container-color | — | |
--tanrei-comp-main-action-button-surface-pressed-container-elevation | — | 0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 1px 0px rgb(0 0 0 / 0.04), 0px 4px 8px -4px rgb(0 0 0 / 0.04), 0px 16px 24px -8px rgb(0 0 0 / 0.06) |
--tanrei-comp-main-action-button-surface-pressed-label-color | — | |
--tanrei-comp-main-action-button-surface-pressed-state-layer-color | — | |
--tanrei-comp-main-action-button-surface-state-layer-color | comp.main-action-button.surface.label.color | |
--tanrei-comp-main-action-button-tonal-container-color | sys.color.secondary-container | |
--tanrei-comp-main-action-button-tonal-container-elevation | sys.elevation.level3 | 0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 1px 0px rgb(0 0 0 / 0.04), 0px 4px 8px -4px rgb(0 0 0 / 0.04), 0px 16px 24px -8px rgb(0 0 0 / 0.06) |
--tanrei-comp-main-action-button-tonal-disabled-container-color | — | |
--tanrei-comp-main-action-button-tonal-disabled-container-elevation | — | |
--tanrei-comp-main-action-button-tonal-disabled-label-color | — | |
--tanrei-comp-main-action-button-tonal-disabled-state-layer-color | — | |
--tanrei-comp-main-action-button-tonal-focused-container-color | — | |
--tanrei-comp-main-action-button-tonal-focused-container-elevation | — | 0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 1px 0px rgb(0 0 0 / 0.04), 0px 4px 8px -4px rgb(0 0 0 / 0.04), 0px 16px 24px -8px rgb(0 0 0 / 0.06) |
--tanrei-comp-main-action-button-tonal-focused-label-color | — | |
--tanrei-comp-main-action-button-tonal-focused-state-layer-color | — | |
--tanrei-comp-main-action-button-tonal-hovered-container-color | — | |
--tanrei-comp-main-action-button-tonal-hovered-container-elevation | — | 0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 1px 0px rgb(0 0 0 / 0.04), 0px 8px 16px -4px rgb(0 0 0 / 0.04), 0px 24px 32px -8px rgb(0 0 0 / 0.06) |
--tanrei-comp-main-action-button-tonal-hovered-label-color | — | |
--tanrei-comp-main-action-button-tonal-hovered-state-layer-color | — | |
--tanrei-comp-main-action-button-tonal-label-color | sys.color.on-secondary-container | |
--tanrei-comp-main-action-button-tonal-pressed-container-color | — | |
--tanrei-comp-main-action-button-tonal-pressed-container-elevation | — | 0px 0px 0px 1px rgb(0 0 0 / 0.08), 0px 1px 1px 0px rgb(0 0 0 / 0.04), 0px 4px 8px -4px rgb(0 0 0 / 0.04), 0px 16px 24px -8px rgb(0 0 0 / 0.06) |
--tanrei-comp-main-action-button-tonal-pressed-label-color | — | |
--tanrei-comp-main-action-button-tonal-pressed-state-layer-color | — | |
--tanrei-comp-main-action-button-tonal-state-layer-color | comp.main-action-button.tonal.label.color | |
--tanrei-comp-main-action-button-label-typescale-large | sys.typescale.heading-5 | 500 16px/1.5 |
--tanrei-comp-main-action-button-label-typescale-medium | sys.typescale.label | 500 14px/1.4286 |
--tanrei-comp-main-action-button-label-typescale-small | sys.typescale.label | 500 14px/1.4286 |
Fixtures
Canonical renderings. Every platform snapshots each fixture under the same id so the results can be compared.
variant: filled (11)
filled-extended
variant: filled label: Compose slots: icon filled-collapsed
variant: filled extended: false label: Compose slots: icon filled-icon-trailing
variant: filled iconPosition: trailing label: Next slots: icon filled-label-only
variant: filled label: Compose filled-small-extended
variant: filled size: small label: Compose slots: icon filled-small-collapsed
variant: filled size: small extended: false label: Compose slots: icon filled-large-extended
variant: filled size: large label: Compose slots: icon filled-large-collapsed
variant: filled size: large extended: false label: Compose slots: icon filled-disabled
variant: filled disabled: true label: Compose slots: icon filled-full-width
variant: filled fullWidth: true label: Compose slots: icon filled-full-width-collapsed
variant: filled extended: false fullWidth: true label: Compose slots: icon variant: tonal (2)
tonal-extended
variant: tonal label: Compose slots: icon tonal-collapsed
variant: tonal extended: false label: Compose slots: icon variant: surface (2)
surface-extended
variant: surface label: Compose slots: icon surface-collapsed
variant: surface extended: false label: Compose slots: icon Generated from specs/main-action-button.spec.json, tokens/comp/main-action-button.tokens.json, design/tokens/
Use a main action button for the action that most people come to the screen to take, when it should stay in reach wherever they have scrolled: writing a message, adding an item, starting a recording. A screen has one, or none. Many screens need none: a settings page or a reading view has no single action that deserves to float over it.
- For an action that belongs to a form, a dialog or one item in the content, use a button where that content is.
- For several actions on the current screen or selection, use a toolbar.
- When the main action comes in a few related forms (a new document, a folder or an upload), let the main action button open a bottom sheet that lists them. The FAB menu does that job in the systems of the m3-like layer, where it lives; the default system does not have it.
- It performs an action and takes no destination. A control that only takes people somewhere else is a link: a button with
href.
Start extended. The written name is what tells people what the button does, and an icon alone is only safe once they have learned it.
Collapse it when the label costs more than it gives: while the content scrolls and the button would cover it, or in a narrow window. Extend it again when there is room, such as back at the top of the list. The change is yours to make, by setting extended; pressing the button never changes its form.
- The button keeps its height and its corners while it changes, and which edge stays in place is your layout’s decision. Anchored at the inline end, it collapses toward that edge.
- A button without an icon stays extended, because there would be nothing to collapse to. A button without a label draws the collapsed form and is reported in debug builds: it has no name.
- Where motion is reduced, the form changes at once.
| Variant | Emphasis | Use for |
|---|---|---|
| Filled (default) | Highest | The screen’s main action at full strength. |
| Tonal | High | A main action on a screen whose content should lead. |
| Surface | Neutral | A main action over content that already has color, such as a map or a photo, where a colored container would compete with it. |
A design system may add variants of its own.
| Size | Height in the default system | Use for |
|---|---|---|
| Small | 40 | A second, related action beside a medium one, or a dense layout. |
| Medium (default) | 56 | The main action of most screens. |
| Large | 96 | The action of a wide or nearly empty screen, where a medium button would be lost. |
The height is also the side of the collapsed form, so one button keeps its height while it collapses and extends.
The button draws no scrim and moves no content. Place it over the content, normally in the inline-end bottom corner, and keep it clear of a navigation bar, a docked toolbar and the system’s insets. Leave room at the end of scrolling content, so that the button never permanently covers the last item. Its shadow is cast outside its container: give it room if the container that holds it clips.
Set full-width to make the button as wide as its container, its icon and label centred: the one action of a screen held across its foot on a narrow screen, such as Check out or Send. A full-width button is always extended: it does not collapse while the content scrolls, and setting extended to false is reported in debug builds. It keeps the height, the corners and the elevation of its size, and a label that does not fit wraps. It still does not place itself: put it in the container that holds it at the foot of the screen.
A full-width main action button
- Label it with the action as a verb, or a verb and a noun: Compose, New event, Add photo.
- Choose a glyph that people already connect with the action, such as
editfor writing oraddfor creating. - Use
iconPositionset totrailingfor a glyph that points where the action goes, such as the arrow of Next. - Keep it in the same place on every screen that has one.
- Hide it when its action is unavailable on a screen. That usually serves people better than a disabled button floating over the content.
- Don’t put two main action buttons of the same size on one screen. If two actions feel equally important, neither is the main one: use buttons in the content.
- Don’t use it for minor, destructive or navigation-only actions, such as Delete, Settings or Back.
- Don’t use it as a toggle, and don’t change its label or icon to show a state.
- Don’t collapse it on a screen people are seeing for the first time, when nothing else says what the icon means.
- Don’t let it cover content that people need in order to decide whether to press it.
Labels use sentence case and have no trailing punctuation. Aim for one or two words. The label does not truncate: it stays on one line while it fits, and wraps when the layout gives it less width.
- Role
button- Labeling
- label is the accessible name, whether it is shown or collapsed away. The icon is decorative to assistive technology. A tooltip may show the same text to sighted pointer users while it is collapsed, but it never replaces label.
- Minimum target
- The hit area meets the minimum target size even when the visual size is smaller. minimum 32px · pointer 44px · spacing 8px · touch 48px
Keyboard
| Keys | Action |
|---|---|
| Tab | Moves focus to the main action button. |
| Enter / Space | Activates it. |
Notes
- It is an action, never a toggle. Collapsing and extending change what is drawn, not what is announced: the role stays button, the name stays label, and there is no expanded state to report (MAB-20).
- Its place in the focus and reading order is where the layout puts it in the element tree, not where it is drawn. Put it where its action belongs: after the content it acts on, or first when it is the screen's reason to exist.
- Extended, text must remain readable at 200% text size: the container grows, the label never truncates. Collapsed, the icon is not text: where sizes are points or dp (SwiftUI, Compose, Flutter, React Native), text size leaves the square and the icon as they are; on the web every Tanrei size follows the root font size (rem), so the square and its icon grow together and stay square and whole. Either way the label is still announced.
- A trailing icon that points (an arrow) keeps its glyph in right-to-left layouts; the product chooses the glyph that points the right way for the direction.
- How a state looks is a value decision of the active design system; components read the state's tokens and never compute the effect themselves.
Generated from specs/main-action-button.spec.json, tokens/sys/measure.tokens.json
- It is a button named by
labelin both forms. The icon is hidden from assistive technology. - Collapsing and extending change what is drawn, not what is announced: the role, the name and the focus stay as they are, nothing is announced, and there is no pressed or expanded state.
- Enter and Space activate it. Disabled, it emits nothing, leaves the focus order and is exposed as disabled.
- Its hit area meets the minimum target at every size, the small one included.
- It shows the focus indicator for keyboard focus only, without animation.
- Extended, the container grows with the text size and the label never truncates. Collapsed, the icon is not text. On the web every Tanrei size follows the root font size, so the square and its icon grow together and stay square.
- In a right-to-left layout the icon and the label change sides, and the paddings follow. The glyph itself is mirrored only when the icon set marks it as showing a direction.
- Debug builds report a button without a label, and a collapsed button without an icon.
- Always give it a
label, in your product’s language, even when it will only ever be collapsed. - Put it in the element tree where its action belongs: after the content it acts on, or first when it is the screen’s reason to exist. Assistive technology and the Tab key reach it in tree order, not where it is drawn.
- When it is collapsed, consider a tooltip with the same text for people who use a pointer. The tooltip never replaces
label. - Make sure it does not hide the content or the control that has keyboard focus. Leave space at the end of the content, or move the button out of the way.
- Do not rely on the variant’s color to carry meaning. Say it in the label.