# Progress Indicators
[Progress indicators](https://material.io/components/progress-indicators)
express an unspecified wait time or display the length of a process.
**Contents**
* [Design and API Documentation](#design-and-api-documentation)
* [Using progress indicators](#using-progress-indicators)
* [Linear progress indicators](#linear-progress-indicators)
* [Circular progress indicators](#circular-progress-indicators)
* [Anatomy and key properties](#anatomy-and-key-properties)
* [Theming progress indicators](#theming-progress-indicators)
## Design and API Documentation
* [Google Material3 Spec](https://material.io/components/progress-indicators/overview)
* [API Reference](https://developer.android.com/reference/com/google/android/material/progressindicator/package-summary)
## Using progress indicators
Before you can use Material sliders, you need to add a dependency to the
Material Components for Android library. For more information, go to the
[Getting started](https://github.com/material-components/material-components-android/tree/master/docs/getting-started.md)
page.
Progress indicators inform users about the status of ongoing processes, such as
loading an app, submitting a form, or saving updates. They communicate an app’s
state and indicate available actions, such as whether users can navigate away
from the current screen.
**Note:** When displaying progress for a sequence of processes, indicate overall
progress rather than the progress of each activity.
### Usage
A determinate progress indicator can be added to a layout:
```xml
```
An indeterminate progress indicator can be added:
```xml
```
1. Determinate
2. Indeterminate
### Switching from indeterminate to determinate
Indeterminate progress indicators can smoothly transit to determinate progress
indicators by setting the `progress` programmatically:
```kt
int progress = getLoadingProgress()
indicator.setProgressCompat(progress, true)
```
**Note:** Once indeterminate progress indicators are switched to the
determinate mode (or initialized as determinate), they can be set back to
indeterminate mode via calling the `setIndeterminate(true)` method.
### Making progress indicators accessible
Progress indicators inherit accessibility support from the `ProgressBar` class
in the framework. Please consider setting the content descriptor for use with
screen readers.
That can be done in XML via the `android:contentDescription` attribute or
programmatically like so:
```kt
progressIndicator.contentDescription = contentDescription
```
**Note:** Depending on the track thickness of the linear progress indicator, the
component could be less than or equal to 4dp tall. There's a known limitation in
the focus indicator (green box) while using the talkback. It will fail to draw
the focus indicator, if the component bounds is less than or equal to 4dp in
either dimension. Consider to use `android:paddingTop` and
`android:paddingBottom` to increase the bounds height when available.
### Showing/hiding the progress indicator
By default, the progress indicator will be shown or hidden without animations.
You can change the animation behaviors via `app:showAnimationBehavior` (or
`setShowAnimationBehavior` method) and `app:hideAnimationBehavior` (or
`setHideAnimationBehavior` method).
The modes of behaviors are:
* `none` (default) - shows/hides the view immediately when the visibility is
being changed via `show`, `hide` or `setVisibility` method.
* `outward` - for the linear type, shows the view by expanding from the
baseline (or bottom edge) and hides the view by collapsing to the top edge;
for the circular type, shows the view by expanding from the inner edge and
hides the view by collapsing to the outer edge.
* `inward` - for the linear type, shows the view by expanding from the top
edge and hides the view by collapsing to the baseline (bottom edge); for the
circular type, shows the view by expanding from the outer edge and hides the
view by collapsing to the inner edge.
* `escape` - for the linear type, escapes in the progression direction; for the
circular type, no effect.
When the hide animation behavior is not none, the visibility of the view will be
changed after the animation finishes. Please use `setVisibilityAfterHide` method
to set the target visibility as `Visibility.INVISIBLE` (default) or
`Visibility.GONE`.
### Rounded corners
Progress indicators can have rounded corners via `app:trackCornerRadius` or the
`setTrackCornerRadius` method.
### Types
Material Design offers two visually distinct types of progress indicators: 1\.
[linear](#linear-progress-indicators) 2\.
[circular](#circular-progress-indicators)
Only one type should represent each kind of activity in an app. For example, if
a refresh action displays a circular indicator on one screen, that same action
shouldn’t use a linear indicator elsewhere in the app.
## Linear progress indicators
Linear progress indicators display progress by animating an indicator along the
length of a fixed, visible track. The behavior of the indicator is dependent on
whether the progress of a process is known.
Linear progress indicators support both determinate and indeterminate
operations.
* Determinate operations display the indicator increasing in width from 0 to
100% of the track, in sync with the process’s progress.
* Indeterminate operations display the indicator continually growing and
shrinking along the track until the process is complete.
API and source code:
* `LinearProgressIndicator`
* [Class description](https://developer.android.com/reference/com/google/android/material/progressindicator/LinearProgressIndicator)
* [Class source](https://github.com/material-components/material-components-android/tree/master/lib/java/com/google/android/material/progressindicator/LinearProgressIndicator.java)
The following example shows a determinate linear progress indicator.
In the layout:
```xml
```
The following example shows an indeterminate linear progress indicator.
In the layout:
```xml
```
#### Multi-color indeterminate animation type
For linear progress indicator, there are two indeterminate animation types:
* `disjoint` - animates as repeated cycles with two disjoint segments in the
same color at a time. 
* `contiguous` - animates as repeated cycles with three adjacent segments in
different colors. 
**Note:** There is a minimum requirement of 3 indicator colors to use the
**contiguous** animation. Otherwise, an IllegalArgumentException will be thrown.
## Circular progress indicators
Circular progress indicators display progress by animating an indicator along an
invisible circular track in a clockwise direction. They can be applied directly
to a surface, such as a button or card.
Circular progress indicators support both determinate and indeterminate
processes.
* Determinate circular indicators fill the invisible, circular track with
color, as the indicator moves from 0 to 360 degrees.
* Indeterminate circular indicators grow and shrink in size while moving along
the invisible track.
API and source code:
* `CircularProgressIndicator`
* [Class description](https://developer.android.com/reference/com/google/android/material/progressindicator/CircularProgressIndicator)
* [Class source](https://github.com/material-components/material-components-android/tree/master/lib/java/com/google/android/material/progressindicator/CircularProgressIndicator.java)
The following example shows a determinate circular progress indicator.
In the layout:
```xml
```
The following example shows an indeterminate circular progress indicator.
In the layout:
```xml
```
### Anatomy and key properties
A progress indicator consists of a track and an indicator.
1. Active indicator
2. Track
3. Stop indicator
#### Common attributes
The following attributes are shared between linear and circular progress
indicators:
Element | Attribute | Related method(s) | Default value
----------------------------------------- | ---------------------------------------- | ------------------------------------------------------------- | -------------
**Track thickness** | `app:trackThickness` | `setTrackThickness``getTrackThickness` | `4dp`
**Indicator color** | `app:indicatorColor` | `setIndicatorColor``getIndicatorColor` | `colorPrimary`
**Track color** | `app:trackColor` | `setTrackColor``getTrackColor` | `colorPrimaryContainer` (linear)`@android:color/transparent` (circular)
**Track corner radius** | `app:trackCornerRadius` | `setTrackCornerRadius``getTrackCornerRadius` | `2dp`
**Indicator track gap size** | `app:indicatorTrackGapSize` | `setIndicatorTrackGapSize``getIndicatorTrackGapSize` | `4dp`
**Show animation behavior** | `app:showAnimationBehavior` | `setShowAnimationBehavior``getShowAnimationBehavior` | `none`
**Hide animation behavior** | `app:hideAnimationBehavior` | `setHideAnimationBehavior``getHideAnimationBehavior` | `none`
**Delay (in ms) to show** | `app:showDelay` | N/A | 0
**Min delay (in ms) to hide** | `app:minHideDelay` | N/A | 0
**Wavelength** | `app:wavelength` | `setWavelength` | 0
**Wavelength in determinate mode** | `app:wavelengthDeterminate` | `setWavelengthDeterminate``getWavelenthDeterminate` | `wavelength`
**Wavelength in indeterminate mode** | `app:wavelengthIndeterminate` | `setWavelengthIndeterminate``getWavelengthIndeterminate` | `wavelength`
**Wave amplitude** | `app:waveAmplitude` | `setWaveAmplitude``getWaveAmplitude` | 0
**Wave speed** | `app:waveSpeed` | `setWaveSpeed``getWaveSpeed` | 0
**Indeterminate animator duration scale** | `app:indeterminateAnimatorDurationScale` | `setIndeterminateAnimatorDurationScale` | 1
#### Linear type specific attributes
Linear type progress indicators also have the following attributes:
Element | Attribute | Related method(s) | Default value
-------------------------------- | -------------------------------- | ------------------------------------------------------------------- | -------------
**Indeterminate animation type** | `app:indeterminateAnimationType` | `setIndeterminateAnimationType``getIndeterminateAnimationType` | `disjoint`
**Indicator direction** | `app:indicatorDirectionLinear` | `setIndicatorDirection``getIndicatorDirection` | `leftToRight`
**Track stop indicator size** | `app:trackStopIndicatorSize` | `setTrackStopIndicatorSize``getTrackStopIndicatorSize` | `4dp`
#### Circular type specific attributes
Circular type progress indicators also have the following attributes:
Element | Attribute | Related method(s) | Default value
--------------------------------- | ---------------------------------------- | ------------------------------------------------------------------- | -------------
**Spinner size (outer diameter)** | `app:indicatorSize` | `setIndicatorSize``getIndicatorSize` | `40dp`
**Inset** | `app:indicatorInset` | `setIndicatorInset``getIndicatorInset` | `4dp`
**Indicator direction** | `app:indicatorDirectionCircular` | `setIndicatorDirection``getIndicatorDirection` | `clockwise`
**Indeterminate animation type** | `app:indeterminateAnimationTypeCircular` | `setIndeterminateAnimationType``getIndeterminateAnimationType` | `advance`
#### Styles
Element | Style
-------------------------------------- | -----
**Default linear**
**style** | `Widget.Material3.LinearProgressIndicator`
**Default circular**
**style** | `Widget.Material3.CircularProgressIndicator`
**Medium circular**
**style** | `Widget.Material3.CircularProgressIndicator.Medium`
**Small circular**
**style** | `Widget.Material3.CircularProgressIndicator.Small`
**Extra small circular**
**style** | `Widget.Material3.CircularProgressIndicator.ExtraSmall`
Default linear style theme attribute: `?attr/linearProgressIndicatorStyle`
Default circular style theme attribute: `?attr/circularProgressIndicatorStyle`
See the full list of
[styles](https://github.com/material-components/material-components-android/tree/master/lib/java/com/google/android/material/progressindicator/res/values/styles.xml)
and
[attributes](https://github.com/material-components/material-components-android/tree/master/lib/java/com/google/android/material/progressindicator/res/values/attrs.xml).
#### Non-Text Contrast update
In order to comply with the latest accessibility requirements, the
`LinearProgressIndicator` and `CircularProgressIndicator` have been updated with
additional attributes:
- `app:indicatorTrackGapSize`: size of the gap between the indicator and the
track, 4dp by default.
- `app:trackStopIndicatorSize`: size of the stop at the end of the track, 4dp by
default. Only applies to the linear determinate configuration.
`*.Legacy` styles have been added to revert to the previous behavior (**not
recommended**):
- `Widget.Material3.LinearProgressIndicator.Legacy`
- `Widget.Material3.CircularProgressIndicator.Legacy`
## Theming
Progress indicators support Material theming which can customize color and size.
### Theming progress indicators
API and source code:
* `LinearProgressIndicator`
* [Class description](https://developer.android.com/reference/com/google/android/material/progressindicator/LinearProgressIndicator)
* [Class source](https://github.com/material-components/material-components-android/tree/master/lib/java/com/google/android/material/progressindicator/LinearProgressIndicator.java)
* `CircularProgressIndicator`
* [Class description](https://developer.android.com/reference/com/google/android/material/progressindicator/CircularProgressIndicator)
* [Class source](https://github.com/material-components/material-components-android/tree/master/lib/java/com/google/android/material/progressindicator/CircularProgressIndicator.java)
The following example shows a circular progress indicator with Material Theming.
#### Implementing progress indicator theming
Use theme attributes and styles in `res/values/styles.xml`, which applies to all
circular progress indicators and affects other components:
```xml
```
Use a default type theme attribute, styles and a theme overlay, which applies to
all circular progress indicators but does not affect other components:
```xml
```
Use the style in the layout, which affects only this specific circular progress
indicator:
```xml
```