public class Scene


A scene represents the collection of values that various properties in the View hierarchy will have when the scene is applied. A Scene can be configured to automatically run a Transition when it is applied, which will animate the various property changes that take place during the scene change.

Summary

Public constructors

Scene(@NonNull ViewGroup sceneRoot)

Constructs a Scene with no information about how values will change when this scene is applied.

Scene(@NonNull ViewGroup sceneRoot, @NonNull View layout)

Constructs a Scene which, when entered, will remove any children from the sceneRoot container and add the layout object as a new child of that container.

Public methods

void

Enters this scene, which entails changing all values that are specified by this scene.

void

Exits this scene, if it is the current scene on the scene's scene root.

static @Nullable Scene

Gets the current Scene set on the given ViewGroup.

static @NonNull Scene
getSceneForLayout(
    @NonNull ViewGroup sceneRoot,
    @LayoutRes int layoutId,
    @NonNull Context context
)

Returns a Scene described by the resource file associated with the given layoutId parameter.

@NonNull ViewGroup

Gets the root of the scene, which is the root of the view hierarchy affected by changes due to this scene, and which will be animated when this scene is entered.

void

Scenes that are not defined with layout resources or hierarchies, or which need to perform additional steps after those hierarchies are changed to, should set an enter action, and possibly an exit action as well.

void

Scenes that are not defined with layout resources or hierarchies, or which need to perform additional steps after those hierarchies are changed to, should set an enter action, and possibly an exit action as well.

Public constructors

Scene

Added in 1.0.0
public Scene(@NonNull ViewGroup sceneRoot)

Constructs a Scene with no information about how values will change when this scene is applied. This constructor might be used when a Scene is created with the intention of being dynamically configured, through setting setEnterAction and possibly setExitAction.

Parameters
@NonNull ViewGroup sceneRoot

The root of the hierarchy in which scene changes and transitions will take place.

Scene

Added in 1.0.0
public Scene(@NonNull ViewGroup sceneRoot, @NonNull View layout)

Constructs a Scene which, when entered, will remove any children from the sceneRoot container and add the layout object as a new child of that container.

Parameters
@NonNull ViewGroup sceneRoot

The root of the hierarchy in which scene changes and transitions will take place.

@NonNull View layout

The view hierarchy of this scene, added as a child of sceneRoot when this scene is entered.

Public methods

enter

Added in 1.0.0
public void enter()

Enters this scene, which entails changing all values that are specified by this scene. These may be values associated with a layout view group or layout resource file which will now be added to the scene root, or it may be values changed by an setEnterAction enter action}, or a combination of the these. No transition will be run when the scene is entered. To get transition behavior in scene changes, use one of the methods in androidx.transition.TransitionManager instead.

exit

Added in 1.0.0
public void exit()

Exits this scene, if it is the current scene on the scene's scene root. The current scene is set when entering a scene. Exiting a scene runs the exit action if there is one.

getCurrentScene

Added in 1.1.0
public static @Nullable Scene getCurrentScene(@NonNull ViewGroup sceneRoot)

Gets the current Scene set on the given ViewGroup. A scene is set on a ViewGroup only if that ViewGroup is the scene root.

Parameters
@NonNull ViewGroup sceneRoot

The ViewGroup on which the current scene will be returned

Returns
@Nullable Scene

The current Scene set on this ViewGroup. A value of null indicates that no Scene is currently set.

getSceneForLayout

Added in 1.0.0
public static @NonNull Scene getSceneForLayout(
    @NonNull ViewGroup sceneRoot,
    @LayoutRes int layoutId,
    @NonNull Context context
)

Returns a Scene described by the resource file associated with the given layoutId parameter. If such a Scene has already been created for the given sceneRoot, that same Scene will be returned. This caching of layoutId-based scenes enables sharing of common scenes between those created in code and those referenced by TransitionManager XML resource files.

Parameters
@NonNull ViewGroup sceneRoot

The root of the hierarchy in which scene changes and transitions will take place.

@LayoutRes int layoutId

The id of a standard layout resource file.

@NonNull Context context

The context used in the process of inflating the layout resource.

Returns
@NonNull Scene

The scene for the given root and layout id

getSceneRoot

Added in 1.0.0
public @NonNull ViewGroup getSceneRoot()

Gets the root of the scene, which is the root of the view hierarchy affected by changes due to this scene, and which will be animated when this scene is entered.

Returns
@NonNull ViewGroup

The root of the view hierarchy affected by this scene.

setEnterAction

Added in 1.0.0
public void setEnterAction(@Nullable Runnable action)

Scenes that are not defined with layout resources or hierarchies, or which need to perform additional steps after those hierarchies are changed to, should set an enter action, and possibly an exit action as well. An enter action will cause Scene to call back into application code to do anything else the application needs after transitions have captured pre-change values and after any other scene changes have been applied, such as the layout (if any) being added to the view hierarchy. After this method is called, Transitions will be played.

Parameters
@Nullable Runnable action

The runnable whose run() method will be called when this scene is entered

See also
setExitAction
Scene

setExitAction

Added in 1.0.0
public void setExitAction(@Nullable Runnable action)

Scenes that are not defined with layout resources or hierarchies, or which need to perform additional steps after those hierarchies are changed to, should set an enter action, and possibly an exit action as well. An exit action will cause Scene to call back into application code to do anything the application needs to do after applicable transitions have captured pre-change values, but before any other scene changes have been applied, such as the new layout (if any) being added to the view hierarchy. After this method is called, the next scene will be entered, including a call to setEnterAction if an enter action is set.