Listener method

EventSys has two modes of listener method invocation, first is generating a class which implements EventListener, example, if the listener is called MyListener and the listener methods is listen:

Obs: Classes was decompiled with IntelliJ Built-in FernFlower

public class listen$0 implements EventListener<MvEvent> {
    private final MyListener $instance;

    public listen$0(MyListener $instance) {
        this.$instance = $instance;
    }

    @Override
    public void onEvent(Event event, Object pluginContainer) {
        this.$instance.listen((MvEvent)event);
    }

    @Override
    public EventPriority getPriority() {
        return EventPriority.NORMAL;
    }

    @Override
    public int getPhase() {
        return -1;
    }

    @Override
    public boolean getIgnoreCancelled() {
        return false;
    }
}

For destruction, the class generator generates the destruction on onEvent method:

public class listen$0 implements EventListener<MyGenericEvent<Integer>> {
    private final MyListener $instance;

    public listen$0(MyListener $instance) {
        this.$instance = $instance;
    }

    @Override
    public void onEvent(Event event, Object pluginContainer) {
        MyListener var10000 = this.$instance;
        MyGenericEvent var10001 = (MyGenericEvent)event;
        GetterProperty var10002 = event.getGetterProperty(Integer.class, "obj");
        if (var10002 != null) {
            if (var10002 != null) {
                var10000.listen2(var10001, (Integer)var10002.getValue());
            }
        }
    }

    @Override
    public EventPriority getPriority() {
        return EventPriority.NORMAL;
    }

    @Override
    public int getPhase() {
        return -1;
    }

    @Override
    public boolean getIgnoreCancelled() {
        return false;
    }
}

Annotation properties are also inlined on the generated class, example, given following class:

@Listener(ignoreCancelled = true, priority = EventPriority.HIGHEST)
public void listen3(MyGenericEvent<Integer> event, @Name("obj") Integer i) {
    System.out.println("Value: " + i);
}

Generator would generate a class like that:

public class listen$0 implements EventListener<MyGenericEvent<Integer>> {
    private final MyListener $instance;

    public listen$0(MyListener $instance) {
        this.$instance = $instance;
    }

    @Override
    public void onEvent(Event event, Object pluginContainer) {
        MyListener var10000 = this.$instance;
        MyGenericEvent var10001 = (MyGenericEvent)event;
        GetterProperty var10002 = event.getGetterProperty(Integer.class, "obj");
        if (var10002 != null) {
            if (var10002 != null) {
                var10000.listen3(var10001, (Integer)var10002.getValue());
            }
        }
    }

    @Override
    public EventPriority getPriority() {
        return EventPriority.HIGHEST;
    }

    @Override
    public int getPhase() {
        return -1;
    }

    @Override
    public boolean getIgnoreCancelled() {
        return true;
    }
}

The second way is using Java 7 MethodHandle (and yes, destruction is supported).

Event classes

Given following event class:

public interface MyTestEvent extends Event {

    @NotNullValue
    String getName();

    int getAmount();

    void setAmount(int amount);

    default void applyToAmount(IntUnaryOperator operator) {
        this.setAmount(operator.applyAsInt(this.getAmount()));
    }
}

Generator would generate an event class like that:

public class MyTestEventImpl implements MyTestEvent {
    private int amount;
    private final String name;
    private final Map<String, Property> #properties = new HashMap();
    private final Map<String, Property> immutable#properties;

    public MyTestEventImpl(@Name("amount") int amount, @Name("name") String name) {
        this.immutable#properties = Collections.unmodifiableMap(this.#properties);
        Objects.requireNonNull(name);
        this.amount = amount;
        this.name = name;
        this.#properties.put("amount", new IntGSProperty.Impl(this::getAmount, this::setAmount));
        this.#properties.put("name", new GetterProperty.Impl(String.class, this::getName));
    }

    public int getAmount() {
        return this.amount;
    }

    public void setAmount(int amount) {
        this.amount = amount;
    }

    public String getName() {
        return this.name;
    }

    public <T> T getExtension(Class<T> extensionClass) {
        return null;
    }

    @Override
    public Map<String, Property> getProperties() {
        return this.immutable#properties;
    }
    
    // Note: A lot of bridge methods are generated to call DefaultImpls of PropertyHolder class
}

Note that EventGenerator uses specialized versions of Property for primitive types, and generates Objects.requireNonNull for @NotNullValue annotated properties.

Generic events

For generic events, the type information of event should be provided to event class.

Given following event interface:

public interface MyGenericEvent<T> extends Event {

    @NotNullValue
    T getObj();

}

And following factory:

<T> MyGenericEvent<T> createMyGenericEvent(@TypeParam TypeInfo<MyGenericEvent<T>> type, @Name("obj") T obj);

Following event class will be generated to createMyGenericEvent(new AbstractTypeInfo<MyGenericEvent<String>>(){}, "A"):

public class MyGenericEventImpl implements MyGenericEvent {
    private final Object obj;
    private final Map<String, Property> #properties = new HashMap();
    private final Map<String, Property> immutable#properties;
    private final TypeInfo<MyGenericEvent> eventTypeInfo;

    public MyGenericEventImpl(@TypeParam @Name("eventTypeInfo") TypeInfo<MyGenericEvent> eventTypeInfo, @Name("obj") Object obj) {
        this.immutable#properties = Collections.unmodifiableMap(this.#properties);
        Objects.requireNonNull(obj);
        Objects.requireNonNull(eventTypeInfo);
        this.eventTypeInfo = eventTypeInfo;
        this.obj = obj;
        this.#properties.put("obj", new Impl(Object.class, this::getObj));
    }

    public Object getObj() {
        return this.obj;
    }

    @Override
    public TypeInfo<? extends Event> getEventTypeInfo() {
        return this.eventTypeInfo;
    }

    // toString()

    public <T> T getExtension(Class<T> extensionClass) {
        return null;
    }

    @Override
    public Map<String, Property> getProperties() {
        return this.immutable#properties;
    }
}

Yes, you need to provide a TypeInfo<...> for event construction, you can also construct the event without the type information, but dispatch methods will only dispatch for listeners which listen to event without the type or with bound type, for example, if you construct MyGenericEvent without type information and dispatch it without TypeInfo, only listeners which listen to MyGenericEvent and MyGenericEvent<Object> will be invoked. If you dispatch the event with TypeInfo event will be also be dispatched correctly.

Since 1.3

If you use generic events, PropertyHolder.lookup will be called instead of PropertyHolder.getGetterProperty in event destruction.

Lazy generation

Events can be also lazily generated by factories, this means that event classes will not be generated before the factory is generated, they will be generated on-demand, there are currently two modes of lazy generation:

Reflection + PropertySorter
InvokeDynamic + Bootstrap with fallback

The first call the EventGenerator to generate event class and uses PropertySorter class to sort event arguments to follow constructor property order and call it using Constructor instance (Reflectively).

The second delegate the call to FactoryBootstrap, which implements the generation and sorting logic (and a simple cache).

The second mode is the default mode

Reflection factory

public MyGenericEvent createMyGenericEvent(TypeInfo eventTypeInfo, Object obj) {
    Class eventClass = this.eventGenerator.createEventClass(TypeInfo.of(MyGenericEvent.class), Collections3.listOf(new Object[0]), Collections3.listOf(new Object[0]));
    Constructor ctr = eventClass.getDeclaredConstructors()[0];
    Object[] sorted = PropertiesSort.sort(ctr, new String[]{"eventTypeInfo", "obj"}, new Object[]{(Object)eventTypeInfo, obj});
    return (MyGenericEvent)ctr.newInstance(sorted);
}

Bytecode:

public com.github.koresframework.eventsys.test.event.MyGenericEvent createMyGenericEvent(com.github.jonathanxd.iutils.type.TypeInfo, java.lang.Object);
descriptor: (Lcom/github/jonathanxd/iutils/type/TypeInfo;Ljava/lang/Object;)Lcom/github/projectsandstone/eventsys/test/event/MyGenericEvent;
flags: ACC_PUBLIC
Code:
  stack=6, locals=6, args_size=3
     0: aload_0
     1: getfield      #16                 // Field eventGenerator:Lcom/github/projectsandstone/eventsys/gen/event/EventGenerator;
     4: ldc           #33                 // class com/github/projectsandstone/eventsys/test/event/MyGenericEvent
     6: invokestatic  #39                 // Method com/github/jonathanxd/iutils/type/TypeInfo.of:(Ljava/lang/Class;)Lcom/github/jonathanxd/iutils/type/TypeInfo;
     9: iconst_0
    10: anewarray     #4                  // class java/lang/Object
    13: invokestatic  #45                 // Method com/github/jonathanxd/iutils/collection/Collections3.listOf:([Ljava/lang/Object;)Ljava/util/List;
    16: iconst_0
    17: anewarray     #4                  // class java/lang/Object
    20: invokestatic  #45                 // Method com/github/jonathanxd/iutils/collection/Collections3.listOf:([Ljava/lang/Object;)Ljava/util/List;
    23: invokeinterface #51,  4           // InterfaceMethod com/github/projectsandstone/eventsys/gen/event/EventGenerator.createEventClass:(Lcom/github/jonathanxd/iutils/type/TypeInfo;Ljava/util/List;Ljava/util/List;)Ljava/lang/Class;
    28: astore_3
    29: aload_3
    30: invokevirtual #57                 // Method java/lang/Class.getDeclaredConstructors:()[Ljava/lang/reflect/Constructor;
    33: iconst_0
    34: aaload
    35: astore        4
    37: aload         4
    39: iconst_2
    40: anewarray     #59                 // class java/lang/String
    43: dup
    44: iconst_0
    45: ldc           #60                 // String eventTypeInfo
    47: aastore
    48: dup
    49: iconst_1
    50: ldc           #61                 // String obj
    52: aastore
    53: iconst_2
    54: anewarray     #4                  // class java/lang/Object
    57: dup
    58: iconst_0
    59: aload_1
    60: checkcast     #4                  // class java/lang/Object
    63: aastore
    64: dup
    65: iconst_1
    66: aload_2
    67: aastore
    68: invokestatic  #67                 // Method com/github/projectsandstone/eventsys/reflect/PropertiesSort.sort:(Ljava/lang/reflect/Constructor;[Ljava/lang/String;[Ljava/lang/Object;)[Ljava/lang/Object;
    71: astore        5
    73: aload         4
    75: aload         5
    77: invokevirtual #73                 // Method java/lang/reflect/Constructor.newInstance:([Ljava/lang/Object;)Ljava/lang/Object;
    80: areturn
  LocalVariableTable:
    Start  Length  Slot  Name   Signature
       71      10     5 sorted   [Ljava/lang/Object;
       35      46     4   ctr   Ljava/lang/reflect/Constructor;
       28      53     3 eventClass   Ljava/lang/Class;
        0      81     2   obj   Ljava/lang/Object;
        0      81     1 eventTypeInfo   Lcom/github/jonathanxd/iutils/type/TypeInfo;
        0      81     0  this   Lcom/github/projectsandstone/eventsys/test/factory/MyFactory$Impl;
  LineNumberTable:
    line 3: 0
    line 4: 29
    line 5: 37
    line 6: 73
MethodParameters:
  Name                           Flags
  eventTypeInfo
  obj

Bootstrap factory

public MyGenericEvent createMyGenericEvent(TypeInfo eventTypeInfo, Object obj) {
    return this.eventGenerator.create<invokedynamic>(this.eventGenerator, TypeInfo.of(MyGenericEvent.class), Collections3.listOf(new Object[0]), Collections3.listOf(new Object[0]), new String[]{"eventTypeInfo", "obj"}, new Object[]{(Object)eventTypeInfo, obj});
}

Bytecode:

public com.github.koresframework.eventsys.test.event.MyGenericEvent createMyGenericEvent(com.github.jonathanxd.iutils.type.TypeInfo, java.lang.Object);
descriptor: (Lcom/github/jonathanxd/iutils/type/TypeInfo;Ljava/lang/Object;)Lcom/github/projectsandstone/eventsys/test/event/MyGenericEvent;
flags: ACC_PUBLIC
Code:
  stack=9, locals=3, args_size=3
     0: aload_0
     1: getfield      #16                 // Field eventGenerator:Lcom/github/projectsandstone/eventsys/gen/event/EventGenerator;
     4: ldc           #24                 // class com/github/projectsandstone/eventsys/test/event/MyGenericEvent
     6: invokestatic  #30                 // Method com/github/jonathanxd/iutils/type/TypeInfo.of:(Ljava/lang/Class;)Lcom/github/jonathanxd/iutils/type/TypeInfo;
     9: iconst_0
    10: anewarray     #4                  // class java/lang/Object
    13: invokestatic  #36                 // Method com/github/jonathanxd/iutils/collection/Collections3.listOf:([Ljava/lang/Object;)Ljava/util/List;
    16: iconst_0
    17: anewarray     #4                  // class java/lang/Object
    20: invokestatic  #36                 // Method com/github/jonathanxd/iutils/collection/Collections3.listOf:([Ljava/lang/Object;)Ljava/util/List;
    23: iconst_2
    24: anewarray     #38                 // class java/lang/String
    27: dup
    28: iconst_0
    29: ldc           #39                 // String eventTypeInfo
    31: aastore
    32: dup
    33: iconst_1
    34: ldc           #40                 // String obj
    36: aastore
    37: iconst_2
    38: anewarray     #4                  // class java/lang/Object
    41: dup
    42: iconst_0
    43: aload_1
    44: checkcast     #4                  // class java/lang/Object
    47: aastore
    48: dup
    49: iconst_1
    50: aload_2
    51: aastore
    52: invokedynamic #51,  0             // InvokeDynamic #0:create:(Lcom/github/projectsandstone/eventsys/gen/event/EventGenerator;Lcom/github/jonathanxd/iutils/type/TypeInfo;Ljava/util/List;Ljava/util/List;[Ljava/lang/String;[Ljava/lang/Object;)Lcom/github/projectsandstone/eventsys/test/event/MyGenericEvent;
    57: areturn
  LocalVariableTable:
    Start  Length  Slot  Name   Signature
        0      58     2   obj   Ljava/lang/Object;
        0      58     1 eventTypeInfo   Lcom/github/jonathanxd/iutils/type/TypeInfo;
        0      58     0  this   Lcom/github/projectsandstone/eventsys/test/factory/MyFactory$Impl;
  LineNumberTable:
    line 2: 0
MethodParameters:
  Name                           Flags
  eventTypeInfo
  obj

BootstrapMethods:
  0: #87 invokestatic com/github/projectsandstone/eventsys/bootstrap/FactoryBootstrap.factoryBootstrap:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;[Ljava/lang/Object;)Ljava/lang/invoke/CallSite;
    Method arguments:

Performance

Both have similar performance (and is very good).

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INTERNALS.md

INTERNALS.md

Listener method

Event classes

Generic events

Lazy generation

Reflection factory

Bootstrap factory

Performance

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Listener method

Event classes

Generic events

Lazy generation

Reflection factory

Bootstrap factory

Performance