NavigationEventCallback

Artifact: androidx.navigationevent:navigationevent

Kotlin |Java

public abstract class NavigationEventCallback

Known direct subclasses

TestNavigationEventCallback

TestNavigationEventCallback

A test implementation of NavigationEventCallback that records received events and invocation counts.

Callback for handling NavigationEvents.

This class maintains its own isEnabled state and will only receive callbacks when enabled.

See also
`NavigationEventDispatcher`

Summary

Public constructors
`NavigationEventCallback(boolean isEnabled, boolean isPassThrough)`

Public methods
`final boolean`	`isEnabled()` Controls whether this callback is active and should be considered for event dispatching.
`final boolean`	`isPassThrough()` Whether this callback should consume the events from `NavigationEventDispatcher` or allow it to continue.
`void`	`onEventCancelled()` Callback for handling `NavigationEventDispatcher.dispatchOnCancelled`.
`void`	`onEventCompleted()` Callback for handling `NavigationEventDispatcher.dispatchOnCompleted`.
`void`	`onEventProgressed(@NonNull NavigationEvent event)` Callback for handling `NavigationEventDispatcher.dispatchOnProgressed`.
`void`	`onEventStarted(@NonNull NavigationEvent event)` Callback for handling `NavigationEventDispatcher.dispatchOnStarted`.
`final void`	`remove()`
`final void`	`setEnabled(boolean isEnabled)` Controls whether this callback is active and should be considered for event dispatching.

Public constructors

NavigationEventCallback

Added in 1.0.0-alpha05

public NavigationEventCallback(boolean isEnabled, boolean isPassThrough)

Parameters
`boolean isEnabled`	The enabled state for this callback.
`boolean isPassThrough`	Whether this callback should consume the events from `NavigationEventDispatcher` or allow it to continue.

Public methods

isEnabled

Added in 1.0.0-alpha05

public final boolean isEnabled()

Controls whether this callback is active and should be considered for event dispatching.

A callback's effective enabled state is hierarchical; it is directly influenced by the NavigationEventDispatcher it is registered with.

Getting the value:

This will return false if the associated dispatcher exists and its isEnabled state is false, regardless of the callback's own local setting. This provides a powerful mechanism to disable a whole group of callbacks at once by simply disabling their dispatcher.
Otherwise, it returns the callback's own locally stored state.

Setting the value:

This updates the local enabled state of the callback itself.
More importantly, it immediately notifies the dispatcher (if one is attached) that its list of enabled callbacks might have changed, prompting a re-evaluation. This ensures the system's state remains consistent and responsive to changes.

For a callback to be truly active, both its local isEnabled property and its dispatcher's isEnabled property must evaluate to true.

isPassThrough

Added in 1.0.0-alpha05

public final boolean isPassThrough()

Whether this callback should consume the events from NavigationEventDispatcher or allow it to continue.

onEventCancelled

Added in 1.0.0-alpha05

public void onEventCancelled()

Callback for handling NavigationEventDispatcher.dispatchOnCancelled.

onEventCompleted

Added in 1.0.0-alpha05

public void onEventCompleted()

Callback for handling NavigationEventDispatcher.dispatchOnCompleted.

onEventProgressed

Added in 1.0.0-alpha05

public void onEventProgressed(@NonNull NavigationEvent event)

Callback for handling NavigationEventDispatcher.dispatchOnProgressed.

onEventStarted

Added in 1.0.0-alpha05

public void onEventStarted(@NonNull NavigationEvent event)

Callback for handling NavigationEventDispatcher.dispatchOnStarted.

remove

Added in 1.0.0-alpha05

public final void remove()

setEnabled

Added in 1.0.0-alpha05

public final void setEnabled(boolean isEnabled)

Controls whether this callback is active and should be considered for event dispatching.

A callback's effective enabled state is hierarchical; it is directly influenced by the NavigationEventDispatcher it is registered with.

Getting the value:

This will return false if the associated dispatcher exists and its isEnabled state is false, regardless of the callback's own local setting. This provides a powerful mechanism to disable a whole group of callbacks at once by simply disabling their dispatcher.
Otherwise, it returns the callback's own locally stored state.

Setting the value:

This updates the local enabled state of the callback itself.
More importantly, it immediately notifies the dispatcher (if one is attached) that its list of enabled callbacks might have changed, prompting a re-evaluation. This ensures the system's state remains consistent and responsive to changes.

For a callback to be truly active, both its local isEnabled property and its dispatcher's isEnabled property must evaluate to true.