com.facebook.litho.annotations

Annotation Type LayoutSpec

@Retention(value=RUNTIME)
public @interface LayoutSpec

A class that is annotated with this annotation will be used to create a component lifecycle that is made up of other components.

A class that is annotated with LayoutSpec must implement a method with the OnCreateLayout annotation. It may also implement methods with the following annotations: - OnLoadStyle - OnEvent

If you wish to create a component that mounts its own content, then use MountSpec instead.

For example: @LayoutSpec public class MyComponentSpec { @OnCreateLayout ComponentLayout onCreateLayout(LayoutContext c, @Prop MyProp prop) { return Row.create(c) .alignItems(FLEX_START) .child(someChild1) .child(someChild2) .build(); } }

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
java.lang.Class<?>[]	events
boolean	isPublic
boolean	isPureRender
java.lang.Class<?>[]	triggers
java.lang.String	value

Element Detail

value

public abstract java.lang.String value

Default:

""

isPublic

public abstract boolean isPublic

Returns:

Boolean indicating whether the generated class should be public. If not, it will be package-private.

Default:

true

isPureRender

public abstract boolean isPureRender

Returns:

Boolean indicating Whether the component implements a pure render function. If this is true and the Component didn't change during an update of the ComponentTree measurements and LayoutOutputs will be reused instead of being calculated again.

Default:

false

events

public abstract java.lang.Class<?>[] events

Returns:

List of event POJOs this component can dispatch. Used to generate event dispatch methods.

Default:

{}

triggers

public abstract java.lang.Class<?>[] triggers

Returns:

List of trigger POJOs this component can dispatch. Used to generate trigger creation methods.

Default:

{}