[WIP] Provide common LifecycleObservers

EventBus/build.gradle

@@ -1,11 +1,22 @@
+buildscript {
+    repositories {
+        maven { url "https://plugins.gradle.org/m2/" }
+    }
+
+    dependencies {
+        classpath "net.ltgt.gradle:gradle-apt-plugin:0.13"
+    }
+}
+
 apply plugin: 'java'
 apply plugin: 'maven'
 apply plugin: 'signing'
 apply plugin: 'idea'
+apply plugin: 'net.ltgt.apt-idea'
 
 archivesBaseName = 'eventbus'
 group = 'org.greenrobot'
-version = '3.1.1'
+version = '3.2.0-SNAPSHOT'
 sourceCompatibility = 1.7
 
 def isSnapshot = version.endsWith('-SNAPSHOT')
@@ -18,6 +29,7 @@ if(isSnapshot) {
 
 repositories {
     mavenCentral()
+    google()
 }
 
 // Still unsupported, see http://issues.gradle.org/browse/GRADLE-784
@@ -32,6 +44,8 @@ dependencies {
     provided 'com.google.android:android-test:4.1.1.4'
     provided 'com.google.android:annotations:4.1.1.4'
     provided 'com.google.android:support-v4:r7'
+    provided "android.arch.lifecycle:runtime:1.0.3"
+    apt "android.arch.lifecycle:compiler:1.0.0"
     // deployerJars 'org.apache.maven.wagon:wagon-webdav-jackrabbit:2.4'
     deployerJars 'org.apache.maven.wagon:wagon-webdav:1.0-beta-2'
 }

EventBus/src/org/greenrobot/eventbus/EventBus.java

@@ -15,6 +15,9 @@
  */
 package org.greenrobot.eventbus;
 
+import android.arch.lifecycle.LifecycleObserver;
+import android.arch.lifecycle.LifecycleOwner;
+
 import java.lang.reflect.InvocationTargetException;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -127,6 +130,45 @@ public EventBus() {
         executorService = builder.executorService;
     }
 
+    /**
+     * Adds an observer to the given {@link LifecycleOwner}s lifecycle to automatically register
+     * EventBus during an onCreated event and unregister during an onDestroy event.
+     * <p>
+     * Requires dependency on Android Architecture Components Lifecycle package.
+     *
+     * @see #register(Object)
+     * @see #unregister(Object)
+     */
+    public void observeCreateDestroy(LifecycleOwner lifecycleOwner) {
+        createAndAddObserver(lifecycleOwner, "org.greenrobot.eventbus.android.lifecycle.EventBusCreateDestroyObserver");
+    }
+
+    /**
+     * Adds an observer to the given {@link LifecycleOwner}s lifecycle to automatically register
+     * EventBus during an onStart event and unregister during an onStop event.
+     * <p>
+     * Requires dependency on Android Architecture Components Lifecycle package.
+     *
+     * @see #register(Object)
+     * @see #unregister(Object)
+     */
+    public void observeStartStop(LifecycleOwner lifecycleOwner) {
+        createAndAddObserver(lifecycleOwner, "org.greenrobot.eventbus.android.lifecycle.EventBusStartStopObserver");
+    }
+
+    private void createAndAddObserver(LifecycleOwner lifecycleOwner, String className) {
+        try {
+            Class<?> observer = Class.forName(className);
+            LifecycleObserver instance = (LifecycleObserver) observer
+                    .getDeclaredConstructor(LifecycleOwner.class, EventBus.class)
+                    .newInstance(lifecycleOwner, this);
+            lifecycleOwner.getLifecycle().addObserver(instance);
+        } catch (Exception e) {
+            throw new EventBusException("Failed to create LifecycleObserver. " +
+                    "Do you have a dependency on Android Architecture Components Lifecycles?", e);
+        }
+    }
+
     /**
      * Registers the given subscriber to receive events. Subscribers must call {@link #unregister(Object)} once they
      * are no longer interested in receiving events.

EventBus/src/org/greenrobot/eventbus/android/lifecycle/EventBusCreateDestroyObserver.java

@@ -0,0 +1,31 @@
+package org.greenrobot.eventbus.android.lifecycle;
+
+import android.arch.lifecycle.Lifecycle.Event;
+import android.arch.lifecycle.LifecycleObserver;
+import android.arch.lifecycle.LifecycleOwner;
+import android.arch.lifecycle.OnLifecycleEvent;
+
+import org.greenrobot.eventbus.EventBus;
+
+
+public class EventBusCreateDestroyObserver implements LifecycleObserver {
+
+    private final LifecycleOwner lifecycleOwner;
+    private final EventBus eventBus;
+
+    public EventBusCreateDestroyObserver(LifecycleOwner lifecycleOwner, EventBus eventBus) {
+        this.lifecycleOwner = lifecycleOwner;
+        this.eventBus = eventBus;
+    }
+
+    @OnLifecycleEvent(Event.ON_CREATE)
+    void register() {
+        eventBus.register(lifecycleOwner);
+    }
+
+    @OnLifecycleEvent(Event.ON_DESTROY)
+    void unregister() {
+        eventBus.unregister(lifecycleOwner);
+    }
+
+}

EventBus/src/org/greenrobot/eventbus/android/lifecycle/EventBusStartStopObserver.java

@@ -0,0 +1,31 @@
+package org.greenrobot.eventbus.android.lifecycle;
+
+import android.arch.lifecycle.Lifecycle.Event;
+import android.arch.lifecycle.LifecycleObserver;
+import android.arch.lifecycle.LifecycleOwner;
+import android.arch.lifecycle.OnLifecycleEvent;
+
+import org.greenrobot.eventbus.EventBus;
+
+
+public class EventBusStartStopObserver implements LifecycleObserver {
+
+    private final LifecycleOwner lifecycleOwner;
+    private final EventBus eventBus;
+
+    public EventBusStartStopObserver(LifecycleOwner lifecycleOwner, EventBus eventBus) {
+        this.lifecycleOwner = lifecycleOwner;
+        this.eventBus = eventBus;
+    }
+
+    @OnLifecycleEvent(Event.ON_START)
+    void register() {
+        eventBus.register(lifecycleOwner);
+    }
+
+    @OnLifecycleEvent(Event.ON_STOP)
+    void unregister() {
+        eventBus.unregister(lifecycleOwner);
+    }
+
+}