# CustomTabsCallback

Artifact: [androidx.browser:browser](https://developer.android.com/jetpack/androidx/releases/browser) [View Source](https://cs.android.com/search?q=file:androidx/browser/customtabs/CustomTabsCallback.java+class:androidx.browser.customtabs.CustomTabsCallback) Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

*** ** * ** ***


```
public class CustomTabsCallback
```

<br />

*** ** * ** ***

A callback class for custom tabs client to get messages regarding events in their custom tabs. In the implementation, all callbacks are sent to the UI thread for the client.

## Summary

| ### Constants |
|---|---|
| `static final int` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#ACTIVITY_LAYOUT_STATE_BOTTOM_SHEET() = 1` The activity is being displayed as a bottom-sheet at its initial height. |
| `static final int` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#ACTIVITY_LAYOUT_STATE_BOTTOM_SHEET_MAXIMIZED() = 2` The activity is being displayed as a bottom-sheet at its maximized height. |
| `static final int` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#ACTIVITY_LAYOUT_STATE_FULL_SCREEN() = 5` The activity is being displayed over the whole window. |
| `static final int` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#ACTIVITY_LAYOUT_STATE_SIDE_SHEET() = 3` The activity is being displayed as a side-sheet at its initial width. |
| `static final int` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#ACTIVITY_LAYOUT_STATE_SIDE_SHEET_MAXIMIZED() = 4` The activity is being displayed as a side-sheet at its maximized width. |
| `static final int` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#ACTIVITY_LAYOUT_STATE_UNKNOWN() = 0` The activity's layout state is unknown. |
| `static final int` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#NAVIGATION_ABORTED() = 4` Sent when loading was aborted by a user action before it finishes like clicking on a link or refreshing the page. |
| `static final int` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#NAVIGATION_FAILED() = 3` Sent when the tab couldn't finish loading due to a failure. |
| `static final int` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#NAVIGATION_FINISHED() = 2` Sent when the tab has finished loading a page. |
| `static final int` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#NAVIGATION_STARTED() = 1` Sent when the tab has started loading a page. |
| `static final int` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#TAB_HIDDEN() = 6` Sent when the tab becomes hidden. |
| `static final int` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#TAB_SHOWN() = 5` Sent when the tab becomes visible. |

| ### Public constructors |
|---|
| `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#CustomTabsCallback()()` |

| ### Public methods |
|---|---|
| `void` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#extraCallback(java.lang.String,android.os.Bundle)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/java/lang/String.html callbackName, @https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html args)` Unsupported callbacks that may be provided by the implementation. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#extraCallbackWithResult(java.lang.String,android.os.Bundle)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/java/lang/String.html callbackName, @https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html args )` The same as `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#extraCallback(java.lang.String,android.os.Bundle)`, except that this method allows the custom tabs provider to return a result. |
| `void` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#onActivityLayout(int,int,int,int,int,android.os.Bundle)( @https://developer.android.com/reference/androidx/annotation/Dimension(unit = 1) int left, @https://developer.android.com/reference/androidx/annotation/Dimension(unit = 1) int top, @https://developer.android.com/reference/androidx/annotation/Dimension(unit = 1) int right, @https://developer.android.com/reference/androidx/annotation/Dimension(unit = 1) int bottom, int state, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/os/Bundle.html extras )` Called when the Partial Custom Tab's layout has changed. |
| `void` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#onActivityResized(int,int,android.os.Bundle)( @https://developer.android.com/reference/androidx/annotation/Dimension(unit = 1) int height, @https://developer.android.com/reference/androidx/annotation/Dimension(unit = 1) int width, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/os/Bundle.html extras )` Called when the tab is resized. |
| `void` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#onMessageChannelReady(android.os.Bundle)(@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html extras)` Called when `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsSession` has requested a postMessage channel through `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsService#requestPostMessageChannel(androidx.browser.customtabs.CustomTabsSessionToken,android.net.Uri)` and the channel is ready for sending and receiving messages on both ends. |
| `void` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#onMinimized(android.os.Bundle)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/os/Bundle.html extras)` Called when the Custom Tab is minimized by the user such that it covers a small part of the screen. |
| `void` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#onNavigationEvent(int,android.os.Bundle)(int navigationEvent, @https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html extras)` To be called when a navigation event happens. |
| `void` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#onPostMessage(java.lang.String,android.os.Bundle)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/java/lang/String.html message, @https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html extras)` Called when a tab controlled by this `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsSession` has sent a postMessage. |
| `void` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#onRelationshipValidationResult(int,android.net.Uri,boolean,android.os.Bundle)( @https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsService.Relation int relation, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/net/Uri.html requestedOrigin, boolean result, @https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html extras )` Called when a relationship validation result is available. |
| `void` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#onUnminimized(android.os.Bundle)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/os/Bundle.html extras)` Called when the Custom Tab is unminimized by the user such that it returns back to its original state. |
| `void` | `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#onWarmupCompleted(android.os.Bundle)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/os/Bundle.html extras)` Called when the browser process finished warming up initiated by warmup. |

## Constants

### ACTIVITY_LAYOUT_STATE_BOTTOM_SHEET

Added in [1.8.0](https://developer.android.com/jetpack/androidx/releases/browser#1.8.0)

```
public static final int ACTIVITY_LAYOUT_STATE_BOTTOM_SHEET = 1
```

The activity is being displayed as a bottom-sheet at its initial height.

### ACTIVITY_LAYOUT_STATE_BOTTOM_SHEET_MAXIMIZED

Added in [1.8.0](https://developer.android.com/jetpack/androidx/releases/browser#1.8.0)

```
public static final int ACTIVITY_LAYOUT_STATE_BOTTOM_SHEET_MAXIMIZED = 2
```

The activity is being displayed as a bottom-sheet at its maximized height.

### ACTIVITY_LAYOUT_STATE_FULL_SCREEN

Added in [1.8.0](https://developer.android.com/jetpack/androidx/releases/browser#1.8.0)

```
public static final int ACTIVITY_LAYOUT_STATE_FULL_SCREEN = 5
```

The activity is being displayed over the whole window. This will be the case when a Partial Custom Tab bottom sheet or side sheet cannot be displayed due to minimum width restrictions (see `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsIntent#EXTRA_INITIAL_ACTIVITY_WIDTH_PX()`) or browser limitations.

### ACTIVITY_LAYOUT_STATE_SIDE_SHEET

Added in [1.8.0](https://developer.android.com/jetpack/androidx/releases/browser#1.8.0)

```
public static final int ACTIVITY_LAYOUT_STATE_SIDE_SHEET = 3
```

The activity is being displayed as a side-sheet at its initial width.

### ACTIVITY_LAYOUT_STATE_SIDE_SHEET_MAXIMIZED

Added in [1.8.0](https://developer.android.com/jetpack/androidx/releases/browser#1.8.0)

```
public static final int ACTIVITY_LAYOUT_STATE_SIDE_SHEET_MAXIMIZED = 4
```

The activity is being displayed as a side-sheet at its maximized width.

### ACTIVITY_LAYOUT_STATE_UNKNOWN

Added in [1.8.0](https://developer.android.com/jetpack/androidx/releases/browser#1.8.0)

```
public static final int ACTIVITY_LAYOUT_STATE_UNKNOWN = 0
```

The activity's layout state is unknown. This value communicates an error state, the fact that the state cannot be determined, or that the browser implementation does not provide support for this feature.

### NAVIGATION_ABORTED

Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

```
public static final int NAVIGATION_ABORTED = 4
```

Sent when loading was aborted by a user action before it finishes like clicking on a link or refreshing the page.

### NAVIGATION_FAILED

Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

```
public static final int NAVIGATION_FAILED = 3
```

Sent when the tab couldn't finish loading due to a failure.

### NAVIGATION_FINISHED

Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

```
public static final int NAVIGATION_FINISHED = 2
```

Sent when the tab has finished loading a page.

### NAVIGATION_STARTED

Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

```
public static final int NAVIGATION_STARTED = 1
```

Sent when the tab has started loading a page.

### TAB_HIDDEN

Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

```
public static final int TAB_HIDDEN = 6
```

Sent when the tab becomes hidden.

### TAB_SHOWN

Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

```
public static final int TAB_SHOWN = 5
```

Sent when the tab becomes visible.

## Public constructors

### CustomTabsCallback

Added in 1.2.0

```
public CustomTabsCallback()
```

## Public methods

### extraCallback

Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

```
public void extraCallback(@NonNull String callbackName, @Nullable Bundle args)
```

Unsupported callbacks that may be provided by the implementation.

**Note:** Clients should **never** rely on this callback to be called and/or to have a defined behavior, as it is entirely implementation-defined and not supported.

This can be used by implementations to add extra callbacks, for testing or experimental purposes.

| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/java/lang/String.html callbackName` | Name of the extra callback. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html args` | Arguments for the callback |

### extraCallbackWithResult

Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

```
public @Nullable Bundle extraCallbackWithResult(
    @NonNull String callbackName,
    @Nullable Bundle args
)
```

The same as `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsCallback#extraCallback(java.lang.String,android.os.Bundle)`, except that this method allows the custom tabs provider to return a result. A return value of `null` will be used to signify that the client does not know how to handle the callback. As optional best practices, `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsService#KEY_SUCCESS()` could be use to identify that callback was \*successfully\* handled. For example, when returning a message with result:

```
    Bundle result = new Bundle();
    result.putString("message", message);
    if (success)
        result.putBoolean(CustomTabsService#KEY_SUCCESS, true);
    return result;
```
The caller side:

```
    Bundle result = extraCallbackWithResult(callbackName, args);
    if (result.getBoolean(CustomTabsService#KEY_SUCCESS)) {
        // callback was successfully handled
    }
```

### onActivityLayout

Added in [1.8.0](https://developer.android.com/jetpack/androidx/releases/browser#1.8.0)

```
public void onActivityLayout(
    @Dimension(unit = 1) int left,
    @Dimension(unit = 1) int top,
    @Dimension(unit = 1) int right,
    @Dimension(unit = 1) int bottom,
    int state,
    @NonNull Bundle extras
)
```

Called when the Partial Custom Tab's layout has changed. This callback is not applicable to Custom Tabs that are not launched with `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsIntent#EXTRA_INITIAL_ACTIVITY_WIDTH_PX()` or `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsIntent#EXTRA_INITIAL_ACTIVITY_HEIGHT_PX()` set to their intent.

| Parameters |
|---|---|
| `@https://developer.android.com/reference/androidx/annotation/Dimension(unit = 1) int left` | The new left coordinate of the Partial Custom Tab's window in pixels. |
| `@https://developer.android.com/reference/androidx/annotation/Dimension(unit = 1) int top` | The new top coordinate of the Partial Custom Tab's window in pixels. |
| `@https://developer.android.com/reference/androidx/annotation/Dimension(unit = 1) int right` | The new right coordinate of the Partial Custom Tab's window in pixels. |
| `@https://developer.android.com/reference/androidx/annotation/Dimension(unit = 1) int bottom` | The new bottom coordinate of the Partial Custom Tab's window in pixels. |
| `int state` | The type of Partial Custom Tab that is currently displayed on the screen. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/os/Bundle.html extras` | Reserved for future use. |

### onActivityResized

Added in [1.5.0](https://developer.android.com/jetpack/androidx/releases/browser#1.5.0)

```
public void onActivityResized(
    @Dimension(unit = 1) int height,
    @Dimension(unit = 1) int width,
    @NonNull Bundle extras
)
```

Called when the tab is resized.

| Parameters |
|---|---|
| `@https://developer.android.com/reference/androidx/annotation/Dimension(unit = 1) int height` | The updated height in px. |
| `@https://developer.android.com/reference/androidx/annotation/Dimension(unit = 1) int width` | The updated width in px. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/os/Bundle.html extras` | Reserved for future use. |

### onMessageChannelReady

Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

```
public void onMessageChannelReady(@Nullable Bundle extras)
```

Called when `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsSession` has requested a postMessage channel through `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsService#requestPostMessageChannel(androidx.browser.customtabs.CustomTabsSessionToken,android.net.Uri)` and the channel is ready for sending and receiving messages on both ends.

| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html extras` | Reserved for future use. |

### onMinimized

Added in [1.8.0](https://developer.android.com/jetpack/androidx/releases/browser#1.8.0)

```
public void onMinimized(@NonNull Bundle extras)
```

Called when the Custom Tab is minimized by the user such that it covers a small part of the screen.

| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/os/Bundle.html extras` | Reserved for future use. |

### onNavigationEvent

Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

```
public void onNavigationEvent(int navigationEvent, @Nullable Bundle extras)
```

To be called when a navigation event happens.

| Parameters |
|---|---|
| `int navigationEvent` | The code corresponding to the navigation event. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html extras` | Reserved for future use. |

### onPostMessage

Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

```
public void onPostMessage(@NonNull String message, @Nullable Bundle extras)
```

Called when a tab controlled by this `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsSession` has sent a postMessage. If postMessage() is called from a single thread, then the messages will be posted in the same order. When received on the client side, it is the client's responsibility to preserve the ordering further.

| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/java/lang/String.html message` | The message sent. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html extras` | Reserved for future use. |

### onRelationshipValidationResult

Added in [1.2.0](https://developer.android.com/jetpack/androidx/releases/browser#1.2.0)

```
public void onRelationshipValidationResult(
    @CustomTabsService.Relation int relation,
    @NonNull Uri requestedOrigin,
    boolean result,
    @Nullable Bundle extras
)
```

Called when a relationship validation result is available.

| Parameters |
|---|---|
| `@https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsService.Relation int relation` | Relation for which the result is available. Value previously passed to `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsSession#validateRelationship(int,android.net.Uri,android.os.Bundle)`. Must be one of the `CustomTabsService#RELATION_* ` constants. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/net/Uri.html requestedOrigin` | Origin requested. Value previously passed to `https://developer.android.com/reference/androidx/browser/customtabs/CustomTabsSession#validateRelationship(int,android.net.Uri,android.os.Bundle)`. |
| `boolean result` | Whether the relation was validated. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html extras` | Reserved for future use. |

### onUnminimized

Added in [1.8.0](https://developer.android.com/jetpack/androidx/releases/browser#1.8.0)

```
public void onUnminimized(@NonNull Bundle extras)
```

Called when the Custom Tab is unminimized by the user such that it returns back to its original state.

| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/os/Bundle.html extras` | Reserved for future use. |

### onWarmupCompleted

Added in [1.8.0](https://developer.android.com/jetpack/androidx/releases/browser#1.8.0)

```
public void onWarmupCompleted(@NonNull Bundle extras)
```

Called when the browser process finished warming up initiated by warmup.

| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/os/Bundle.html extras` | Reserved for future use. |