Package org.openpatch.scratch.internal

Class StageAccess

java.lang.Object

org.openpatch.scratch.internal.StageAccess

public abstract class StageAccess
extends Object

How an extension package reaches something on Stage that is not part of its public face.

TiledMap has to put a map's tiles into the stage's stamp queues, and it lives in its own package. Without this, the queue-taking stamp method would have to be public on Stage, where it would sit in every learner's autocomplete while taking a type - Stamp - that they have no way to build. The same trick as StageHooks, in the other direction: that one lets the render loop into a stage, this one lets an extension in.

Stage installs an implementation when the class is loaded, which has always happened by the time anything can call get() - reaching it requires a stage to pass in.

Constructor Summary

Constructors

Constructor	Description
StageAccess()

Method Summary

Modifier and Type	Method	Description
static StageAccess	get()	Returns the installed accessor.
static void	install(StageAccess access)	Installs the implementation.
abstract void	stamp(Stage stage, Queue<Stamp> stamps, Layer layer)	Stamps images permanently onto one of a stage's layers.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

StageAccess

public StageAccess()

Method Details

install

public static void install(StageAccess access)

Installs the implementation. Called by Stage; the first one wins, so this cannot be swapped out from outside the library.

Parameters:

access - the implementation to install

get

public static StageAccess get()

Returns the installed accessor.

Returns:

the accessor

Throws:

IllegalStateException - if no stage has been loaded, which should be impossible from anywhere that has a stage to hand

stamp

public abstract void stamp(Stage stage,
 Queue<Stamp> stamps,
 Layer layer)

Stamps images permanently onto one of a stage's layers.

Parameters:

stage - the stage to stamp onto

stamps - the images to stamp

layer - which layer to stamp them onto