SceneStrategy

public fun interface SceneStrategy<T extends Object>

Known direct subclasses
DialogSceneStrategy

A SceneStrategy that displays entries that have added dialog to their NavEntry.metadata within a Dialog instance.
SinglePaneSceneStrategy

A SceneStrategy that always creates a 1-entry Scene simply displaying the last entry in the list.

A strategy that tries to calculate a Scene given a list of NavEntry.

If the list of NavEntry does not result in a Scene for this strategy, null will be returned instead to delegate to another strategy.

Summary

Public methods
abstract Scene<@NonNull T>
calculateScene(
    @NonNull SceneStrategyScope<@NonNull T> receiver,
    @NonNull List<@NonNull NavEntry<@NonNull T>> entries
)

Given a SceneStrategyScope, calculate whether this SceneStrategy should take on the task of rendering one or more of the entries in the scope.
default @NonNull Scene<@NonNull T>
calculateScene(
    @NonNull SceneStrategyScope<@NonNull T> receiver,
    @NonNull Scene<@NonNull T> scene
)

Given a SceneStrategyScope, calculate whether this SceneStrategy should take on the task of rendering along with the given Scene in the scope.
default @NonNull SceneStrategy<@NonNull T>
then(@NonNull SceneStrategy<@NonNull T> sceneStrategy)

Chains this SceneStrategy with another sceneStrategy to return a combined SceneStrategy.

Public methods

calculateScene

Added in 1.0.0
abstract Scene<@NonNull T> calculateScene(
    @NonNull SceneStrategyScope<@NonNull T> receiver,
    @NonNull List<@NonNull NavEntry<@NonNull T>> entries
)

Given a SceneStrategyScope, calculate whether this SceneStrategy should take on the task of rendering one or more of the entries in the scope.

By returning a non-null Scene, your Scene takes on the responsibility of rendering the set of entries you declare in Scene.entries. If you return null, the next available SceneStrategy will be called.

Parameters
@NonNull List<@NonNull NavEntry<@NonNull T>> entries

The entries on the back stack that should be considered valid to render via a returned Scene.

calculateScene

Added in 1.1.0-alpha02
default @NonNull Scene<@NonNull T> calculateScene(
    @NonNull SceneStrategyScope<@NonNull T> receiver,
    @NonNull Scene<@NonNull T> scene
)

Given a SceneStrategyScope, calculate whether this SceneStrategy should take on the task of rendering along with the given Scene in the scope.

This will always return a non-null Scene where if a SceneStrategy does not want to use the given scene it should just return it.

Parameters
@NonNull Scene<@NonNull T> scene

The scene that should be considered valid to render via a returned Scene.

then

Added in 1.0.0
default @NonNull SceneStrategy<@NonNull T> then(@NonNull SceneStrategy<@NonNull T> sceneStrategy)

Chains this SceneStrategy with another sceneStrategy to return a combined SceneStrategy. For the returned SceneStrategy, the calculateScene that takes entries will be use the first non-null result from the calculation, while the calculateScene that takes scenes will be called for every SceneStrategy in the chain.

For SceneStrategys that wish to be calculated with another scene, the calling SceneStrategy is first and the given SceneStrategy receives the result of the calculation. This means that the result is cumulative, with each consecutive SceneStrategy using the result of the previous one.