Modernizing the Fitbit Developer Experience.
The Fitbit Web APIs are moving to a new, scalable infrastructure. We will be deprecating the legacy Fitbit Web API in September 2026. To ensure uninterrupted data continuity for your users, you will need to migrate your applications. Detailed migration guides are live on the Google Health API developer site.
Button Components Guide
chevron down
back search icon cancel search
 
 

Button Components Guide

Overview

Buttons represent the most common user interaction method within applications in Fitbit OS.

Common Options

There are a large amount of options for using buttons within an application. This guide provides practical examples of each style. There are some aspects that are common to all buttons:

Styling

The Text Button styling is inherited from the system text-button styling, and developers can define the following classes to control the colors of their button throughout the application.

.application-fill           { fill: fb-yellow; }
.foreground-fill            { fill: fb-white; }
.background-fill            { fill: fb-black; }

Developers should import the system definitions in their widget.defs file in order to use the associated helper CSS classes.

<link rel="import" href="/mnt/sysassets/system_widget.defs" />

Button Text

Developers can set the button's text in 3 different ways:

  1. To set the text of a button via SVG, use the <set> tag to update the <text> element with an ID of #text:
<use href="#text-button">
  <set href="#text" attributeName="text-buffer" to="BUTTON" />
</use>
  1. To set the button text via CSS, use the text-buffer attribute on the element with an ID of #text:
#myButton #text {
  text-buffer: "BUTTON";
}
  1. To set the text of a button via JavaScript, get a handle on the element, then set the .text property:
import * as document from "document";
const myButton = document.getElementById("myButton");
myButton.text = "BUTTON";

Click Events

The button click event occurs when a user presses a button with their finger:

import * as document from "document";
const myButton = document.getElementById("myButton");

myButton.addEventListener("click", (evt) => {
  console.log("CLICKED");
})

Text Button

The text-button component will render a single button which can trigger the click event.

Imports

In addition to any existing imports, developers must include the following import within the widget.defs file:

<link rel="import" href="/mnt/sysassets/widgets/text_button.defs" />

Usage

Include the following SVG in the index.view file:

<use id="button-1" href="#text-button" class="text-button bottom application-fill" />

Include the following CSS in the styles.css file:

.application-fill           { fill: fb-yellow; }
.foreground-fill            { fill: fb-white; }
.background-fill            { fill: fb-black; }

#myButton #text {
  text-buffer: "BUTTON";
}

Developers can control the button's physical location using the helper class top or bottom.

Primary and Secondary Buttons

The text-button component can be used to render a primary and secondary button.

Imports

In addition to any existing imports, developers must include the following import within the widget.defs file:

<link rel="import" href="/mnt/sysassets/widgets/text_button.defs" />

Usage

Include the following SVG in the index.view file:

<use id="button-1" href="#text-button" class="text-button primary application-fill" />
<use id="button-2" href="#text-button" class="text-button secondary application-fill" />

Include the following CSS in the styles.css file:

.application-fill           { fill: fb-mint; }
.foreground-fill            { fill: fb-white; }
.background-fill            { fill: fb-black; }

#button-1 #text {
  text-buffer: "PRIMARY";
}
#button-2 #text {
  text-buffer: "SECONDARY";
}

Left and Right Buttons

The text-button component can render buttons side by side.

Imports

In addition to any existing imports, developers must include the following import within the widget.defs file:

<link rel="import" href="/mnt/sysassets/widgets/text_button.defs" />

Usage

Include the following SVG in the index.view file:

<use id="button-1" href="#text-button" class="text-button bottom left secondary application-fill" />
<use id="button-2" href="#text-button" class="text-button bottom right application-fill" />

The button's physical location is controlled using the helper class left or right, and the class bottom.

Include the following CSS in the styles.css file:

.application-fill           { fill: fb-pink; }
.foreground-fill            { fill: fb-white; }
.background-fill            { fill: fb-black; }

#button-1 #text {
  text-buffer: "LEFT";
}

#button-2 #text {
  text-buffer: "RIGHT";
}

Developers can control the button's physical location using the helper class top or bottom.

Textarea Button

The text-button component can be used to render a button that contains text which spans multiple lines.

Imports

In addition to any existing imports, developers must include the following import within the widget.defs file:

<link rel="import" href="/mnt/sysassets/widgets/text_button.defs" />

Usage

Include the following SVG in the index.view file:

<use id="button-1" href="#textarea-button" class="text-button bottom application-fill" />

Include the following CSS in the styles.css file:

.application-fill           { fill: fb-green; }
.foreground-fill            { fill: fb-white; }
.background-fill            { fill: fb-black; }

#button-1 #text {
  text-buffer: "MULTILINE TEXTAREA BUTTON";
}

Icon Text Button

The icon-text-button component can be used to render a button that has an icon with text.

Note: The icon image should be 48x48px grayscale 8-bit PNG to support the fill color. See Grayscale Magic

Imports

In addition to any existing imports, developers must include the following import within the widget.defs file:

<link rel="import" href="/mnt/sysassets/widgets/text_button.defs" />

Usage

Include the following SVG in the index.view file:

<use id="button-1" href="#icon-text-button" class="icon-text-button bottom application-fill" />

Include the following CSS in the styles.css file:

.application-fill           { fill: fb-blue; }
.foreground-fill            { fill: fb-white; }
.background-fill            { fill: fb-black; }

#button-1 #text {
  text-buffer: "ICON BUTTON";
}

#button-1 #image {
  href: "filename.png";
}

Icon Button

The icon-button component can be used to render a icon button.

Icon buttons have 4 sizes:

  • Extra Large: 132x132
  • Large: 96x96
  • Medium: 72x72
  • Small: 32x32

The icon button images need to be the following sizes to avoid scaling:

  • Extra Large image: 66x66
  • Large button image: 48x48
  • Medium button image: 48x48
  • Small button image: 18x18

Note: The icon image should be grayscale 8-bit PNG to support the fill color. See Grayscale Magic

Imports

In addition to any existing imports, developers must include the following import within the widget.defs file:

<link rel="import" href="/mnt/sysassets/widgets/icon_button.defs" />

Usage

Include the following SVG in the index.view file:

<use id="button-1" href="#icon-button" class="extra-large-button application-fill plus-button" />
<use id="button-2" href="#icon-button" class="large-button application-fill plus-button" />
<use id="button-3" href="#icon-button" class="medium-button application-fill plus-button" />
<use id="button-4" href="#icon-button" class="small-button application-fill plus-button" />

Include the following CSS in the styles.css file:

.application-fill           { fill: fb-orange; }
.foreground-fill            { fill: fb-white; }
.background-fill            { fill: fb-black; }

.plus-button #image {
  href: “filename.png”;
}

// Positioning for demo:
#button-1 {
  x: 30;
  y: 30;
}

#button-2 {
  x: 180;
  y: 45;
}

#button-3 {
  x: 60;
  y: 200;
}

#button-4 {
  x: 200;
  y: 225;
}
Text Components Guide
next