feat: presumably completed the first version of the api

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zaaarf 2023-08-18 17:11:15 +02:00
parent fcea6fee70
commit 0dbbe17261
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8 changed files with 175 additions and 8 deletions

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@ -0,0 +1,59 @@
package ftbsc.geb.api;
import java.lang.reflect.Constructor;
import java.util.Map;
import java.util.ServiceLoader;
import java.util.concurrent.ConcurrentHashMap;
/**
* The main event bus class.
* @since 0.1.0
*/
public class GEB {
/**
* The identifier of this bus. Methods
*/
private final String identifier;
/**
* A {@link Map} tying each user-defined event class to its machine-generated implementation.
* In practice, the {@link Class} of the original event is used as key and mapped to each
* class' generated {@link Constructor}.
*/
private final Map<Class<? extends IEvent>, Constructor<? extends IEvent>> eventMapper;
/**
* The public constructor.
* @param identifier a {@link String} uniquely identifying this bus
*/
public GEB(String identifier) {
this.identifier = identifier;
this.eventMapper = new ConcurrentHashMap<>();
for(IEvent event : ServiceLoader.load(IEvent.class)) {
try {
eventMapper.put(event.getOriginalEvent(), event.getClass().getConstructor(event.getClass()));
} catch(NoSuchMethodException ignored) {} //should never happen, this code is machine-generated
}
}
/**
* @return the identifier of this bus
*/
public String getIdentifier() {
return identifier;
}
/**
* Dispatches an event, calling all of its listeners that are subscribed to this bus.
* TODO: make this as efficient as possible
* @param event the event to fire
* @return true if the event was canceled, false otherwise
*/
public boolean handleEvent(IEvent event) {
try {
return eventMapper.get(event.getClass()).newInstance(event).callListeners(this.getIdentifier());
} catch(ReflectiveOperationException ignored) {} //should never happen
return false;
}
}

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@ -1,9 +1,27 @@
package ftbsc.geb.api;
/**
* The common interface for all GEB events.
* @since 0.1.0
*/
public interface IEvent {
default boolean isCanceled() {
/**
* Any custom implementation of this method will be called just before the
* calls to listeners, but its return values will be ignored. You probably
* don't want to touch this.
* @param identifier the identifier of the bus that's calling this
* @return the value {@link GEB#handleEvent(IEvent)} will return for this
*/
default boolean callListeners(String identifier) {
return false;
}
void dispatch();
/**
* Fetches the {@link Class} containing the original implementation of this.
* If you wish to override this, make your override final.
* @return the class of the original, non-extended superclass
*/
default Class<? extends IEvent> getOriginalEvent() {
return IEvent.class;
}
}

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package ftbsc.geb.api;
/**
* The common interface for all cancelable GEB events.
* @since 0.1.0
*/
public interface IEventCancelable extends IEvent {
/**
* Checks whether the event was canceled; any user-defined
* implementation will be ignored.
* @return whether the event was canceled
*/
default boolean isCanceled() {
return false;
}
/**
* Cancels the event. Any user-defined implementation will
* be ignored.
*/
default void setCanceled() {}
}

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@ -1,5 +1,12 @@
package ftbsc.geb.api;
/**
* The common interface for all classes that contain GEB listeners.
* @since 0.1.0
*/
public interface IListener {
boolean active();
/**
* @return whether the listeners in this class should be considered to be active
*/
boolean isActive();
}

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package ftbsc.geb.api.annotations;
import ftbsc.geb.api.GEB;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* This annotation should mark either a static instance of {@link GEB}
* or a static method returning one.
* @since 0.1.0
*/
@Target({ElementType.FIELD, ElementType.METHOD})
@Retention(RetentionPolicy.CLASS)
public @interface BusInstance {}

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@ -1,8 +1,17 @@
package ftbsc.geb.api.annotations;
import ftbsc.geb.api.IEvent;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Marks a class as an Event. It should implement the {@link IEvent} interface.
* It doesn't need to be abstract, but it can never be final.
* @since 0.1.0
*/
@Target(ElementType.TYPE)
public @interface Event {
}
@Retention(RetentionPolicy.CLASS)
public @interface Event {}

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@ -1,14 +1,32 @@
package ftbsc.geb.api.annotations;
import ftbsc.geb.api.IEvent;
import ftbsc.geb.api.IListener;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Marks the method as a listener.
* Its parent must implement the {@link ftbsc.geb.api.IListener} interface.
* The method should only take a single input value, an event.
* Marks the method as a listener. Its parent must implement the {@link IListener} interface.
* The annotated method should only take a single input value, an instance of {@link IEvent};
* it should be either void or boolean; if it's boolean, the return value indicates whether
* the event was canceled.
* @since 0.1.0
*/
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.CLASS)
public @interface Listen {
/**
* @return an integer indicating priority level for the listener, defaulting to 0
*/
int priority() default 0;
/**
* @return an array of {@link String}s specifying which buses they should be listening on;
* an empty array means that they should listen on all buses, ignoring identifiers:
* that's probably what you wanted anyway.
*/
String[] on() default {}; //empty array = listen on all of them
}

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package ftbsc.geb.api.annotations;
import ftbsc.geb.api.IListener;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* This annotation should mark either be a static instance of {@link IListener}
* or a static method returning one.
* @since 0.1.0
*/
@Target({ElementType.FIELD, ElementType.METHOD})
@Retention(RetentionPolicy.CLASS)
public @interface ListenerInstance {}