*本篇文章已授权微信公众号 guolin_blog （郭霖）独家发布
一. 概述
RxLifecycle是一个轻量级,侵入性低的RxJava注销管理库.他不会改变原有项目Activity的继承结构,轻松实现RxJava在Android平台下的自动注销,甚至你在自定义view的时候使用RxJava都能轻松完整自动注销功能.如果你的项目在开发中期想要引入RxJava相关的自动注销库,这个库将是你不错的选择,原因就在他的入侵性低.
项目地址: 欢迎star
https://github.com/dhhAndroid/RxLifecycle
gradle 依赖:
compile 'com.dhh:rxlifecycle:1.0'
二. 使用方法
把RxLifecycle注入到Activity,请放心,RxLifecycle库并不会引用with()传进去的上下文引用,所以不用反注销,不会造成内存泄漏,这块的逻辑类似Glide的处理方式,在原理解析部分会讲到.以下两种注入方式,实现一种即可:
如果你有一个BaseActivity,仅需在BaseActivity的onCreate方法里注入RxLifecycle:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
RxLifecycle.injectRxLifecycle(this);
}
既然你有一个BaseActivity,可以将RxLifecycle代码封装一下:
private <T> LifecycleTransformer<T> bindToLifecycle() {
return RxLifecycle.with(this).bindToLifecycle();
}
private <T> LifecycleTransformer<T> bindOnDestroy() {
return RxLifecycle.with(this).bindOnDestroy();
}
private <T> LifecycleTransformer<T> bindUntilEvent(ActivityEvent event) {
return RxLifecycle.with(this).bindUntilEvent(event);
}
//use
@Override
protected void onStart() {
super.onStart();
Observable.just(1)
//use
.compose(bindToLifecycle())
.subscribe();
}
或者你已经有了继承Application的操作,你也可以这样注入RxLifecycle:
public class RxLifecycleAPP extends Application {
@Override
public void onCreate() {
super.onCreate();
registerActivityLifecycleCallbacks(new ActivityLifecycleCallbacks() {
@Override
public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
RxLifecycle.injectRxLifecycle(activity);
}
//other mothods
});
}
}
注意:
1. 以上两种注入RxLifecycle的方式,实现一种就可以了,同时实现也没有问题,如果你乐意!
2. 如果你不在Activity的"onPause"生命周期及其以后的生命周期里订阅一个Observable,注入RxLifecycle的步骤可以省略不做.如果在Activity的"onPause"生命周期及其以后的生命周期里订阅一个Observable,并且使用RxLifecycle.with(this).bindToLifecycle(),必须进行RxLifecycle注入步奏.在原理解析部分会说明导致这种问题的原因.代码示例:
@Override
protected void onPause() {
super.onPause();
Observable.just("dhhAndroid")
//其他方式绑定不用预先注入
.compose(RxLifecycle.with(this).<String>bindOnDestroy())
.subscribe();
Observable.just(1)
//在onPause及其以后生命周期,使用bindToLifecycle()必须先注入RxLifecycle
.compose(RxLifecycle.with(this).<Integer>bindToLifecycle())
.subscribe();
}
3. 为了简化和保险,可以忽略第二条,全部注入,第二条就当我在瞎BB......
在Activity和Fragment中使用:
仅仅需要在你原先的Observable事件流上用compose操作符加上如下代码:
Observable.timer(10, TimeUnit.SECONDS)
//自动判断生命周期
.compose(RxLifecycle.with(this).<Long>bindToLifecycle())
.subscribe();
Observable.timer(10, TimeUnit.SECONDS)
//当activity onStop 注销
.compose(RxLifecycle.with(this).<Long>bindUntilEvent(ActivityEvent.onStop))
.subscribe();
Observable.just("dhhAndroid")
//当activity onDestroy 注销
.compose(RxLifecycle.with(this).<String>bindOnDestroy())
.subscribe();
RxLifecycle.with(),with方法可以接收的参数类型有Activity,Context(说明:这个Context必须能强转成Activity),View(暂不支持V7包下的AppCompatXXXView),Fragment,V4.Fragment等.
在自定义view用使用
如果你在自定义view的时候里面使用的RxJava,以及View内部有retrofit+RxJava的网络访问,已经RxJava操作的耗时数据转换,同样支持一行代码管理RxJava自动注销,确保你的view不是继承自AppCompatXXXView,暂不支持.用法和在activity和fragment里一样:
public class MyView extends View {
//other...
public void doSomething(){
Observable.timer(10, TimeUnit.SECONDS)
//自动判断生命周期
.compose(RxLifecycle.with(this).<Long>bindToLifecycle())
.subscribe();
Observable.timer(10, TimeUnit.SECONDS)
//当activity onStop 注销
.compose(RxLifecycle.with(this).<Long>bindUntilEvent(ActivityEvent.onStop))
.subscribe();
Observable.just("dhhAndroid")
//当activity onDestroy 注销
.compose(RxLifecycle.with(this).<String>bindOnDestroy())
.subscribe();
....
}
}
在其他层使用
在MVP架构或者其他地方使用RxLifecycle时,仅需确保所使用的地方能获取到一个能转化成Activity的Context即可. 项目里我写了一个with重载方法可传入任意对象,只要能转化成Context,或者通过反射能获取到所传对象的成员变量有能转化成Context(Activity),也可实现RxJava生命周期自动绑定,但考虑到性能问题暂未开放(private方法).你可以根据这用思路,结合自己项目进行扩展.代码如下:
private static LifecycleManager with(Object object) {
if (object instanceof Context) {
return with((Context) object);
}
for (Field field : object.getClass().getDeclaredFields()) {
try {
field.setAccessible(true);
Object value = field.get(object);
if (value instanceof Context) {
return with((Context) value);
}
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
throw new ClassCastException(object.getClass().getSimpleName() + " can\'t convert Context !");
}
三 . 原理解析(开始秀操作了,别打我)
首先聊一下写这个库的初衷,首先RxJava的确是一个优秀的异步操作库,这也就导致了在Android平台上使用时,内存泄漏的问题.所以要在适当的时候(一般是RxJava代码依托的Activity视图onDestroy的时候),注销掉Observable的事件任务.那么我们先聊聊RxJava的注销都有那些方式,以及什么条件能触发注销.
1.生成Subscription,在Activity的onDestroy时注销:
private Subscription mSubscription;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSubscription = Observable.just(1).subscribe();
}
@Override
protected void onDestroy() {
super.onDestroy();
if(mSubscription!=null&&!mSubscription.isUnsubscribed()) {
mSubscription.unsubscribe();
}
}
这中方式算是传统方式,比较笨重,如果界面中有多个网络请求,或者RxBus接收数据的话,这样注销太累了.
2. 条件触发,取消订阅关系,取消Observable事件流任务.
这里面条件触发的就很多了,比如take系列的操作符,都是在满足条件的时候开始订阅,或者取消订阅. 以及在 subscriber的onNext()方法中满足某些条件都能取消订阅,还有一个另类的方法,就是是Observable的事件流执行过程中抛异常,也可以达到注销的目的,实例代码:
Observable.just(1, 23, 434, 5454, 343, 346, 56, 67, 4, -1)
//取前五个就注销
.take(5)
//直到条件满足,注销
.takeUntil(new Func1<Integer, Boolean>() {
@Override
public Boolean call(Integer integer) {
return integer > 66666;
}
})
//直到另外一个Observable发送数据就注销,本库主要用的这个操作符
.takeUntil(Observable.just(1))
.first(new Func1<Integer, Boolean>() {
@Override
public Boolean call(Integer integer) {
return integer == 111;
}
})
.map(new Func1<Integer, Integer>() {
@Override
public Integer call(Integer integer) {
if (integer < 0) {
//抛异常注销,这种用法在我另外一个库RxProgressManager使用到
throw new RuntimeException("数据不能小于0");
}
return integer;
}
})
.subscribe(new Subscriber<Integer>() {
@Override
public void onCompleted() {
}
@Override
public void onError(Throwable e) {
}
@Override
public void onNext(Integer integer) {
if (integer == 666) {
//当满足条件注销
unsubscribe();
}
}
});
本库主要利用takeUntil(otherObservable)实现,takeUntil操作符演示图:
takeUntil
一旦otherObservable发送数据原Observable就取消订阅.所以我们要做的就是将Activity的生命周期信息通过Observable包装成otherObservable,然后跟随生命周期发送信息,到达到我们需要的生命周期的时候(比如onDestroy)取消订阅.幸好RxJava已经为我们实现了这种功能的Subject,Subject extends Observable implement Observer,是一种Observable与 subscriber之间的桥梁:
public abstract class Subject<T, R> extends Observable<R> implements Observer<T> {
protected Subject(OnSubscribe<R> onSubscribe) {
super(onSubscribe);
}
public abstract boolean hasObservers();
public final SerializedSubject<T, R> toSerialized() {
if (getClass() == SerializedSubject.class) {
return (SerializedSubject<T, R>)this;
}
return new SerializedSubject<T, R>(this);
}
}
RxJava已经默认实现了几种XXXSubject,其他的我就不介绍了,只介绍本文要用到的 BehaviorSubject ,他的特点是当有subscriber订阅BehaviorSubject时,BehaviorSubject都将这个subscriber订阅之前发射的最后一个数据一并发给他,如果BehaviorSubject已经执行onCompleted或者onError,那么将会把onCompleted或者onError通知发送给这个Subscriber.
BehaviorSubject
// observer will receive all 4 events (including "default").
BehaviorSubject<Object> subject = BehaviorSubject.create("default");
subject.subscribe(observer);
subject.onNext("one");
subject.onNext("two");
subject.onNext("three");
// observer will receive the "one", "two" and "three" events, but not "default" and "zero"
BehaviorSubject<Object> subject = BehaviorSubject.create("default");
subject.onNext("zero");
subject.onNext("one");
subject.subscribe(observer);
subject.onNext("two");
subject.onNext("three");
// observer will receive only onCompleted
BehaviorSubject<Object> subject = BehaviorSubject.create("default");
subject.onNext("zero");
subject.onNext("one");
subject.onCompleted();
subject.subscribe(observer);
// observer will receive only onError
BehaviorSubject<Object> subject = BehaviorSubject.create("default");
subject.onNext("zero");
subject.onNext("one");
subject.onError(new RuntimeException("error"));
subject.subscribe(observer);
那么我们在Activity或Fragment中就可以这样(由于Fragment依托于Activity,我在本项目里,Fragment的生命周期认为是和Activity一样的,没有处理Fragment比Activity多的生命周期回调):
public class MainActivity extends AppCompatActivity {
private final BehaviorSubject<ActivityEvent> lifecycleSubject = BehaviorSubject.create();
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
lifecycleSubject.onNext(ActivityEvent.onCreate);
super.onCreate(savedInstanceState);
Observable.just(1)
.takeUntil(lifecycleSubject.first(new Func1<ActivityEvent, Boolean>() {
@Override
public Boolean call(ActivityEvent event) {
return event==ActivityEvent.onDestory;
}
}))
.subscribe();
}
@Override
public void onStart() {
lifecycleSubject.onNext(ActivityEvent.onStart);
super.onStart();
}
@Override
public void onResume() {
lifecycleSubject.onNext(ActivityEvent.onResume);
super.onResume();
}
@Override
public void onPause() {
lifecycleSubject.onNext(ActivityEvent.onPause);
super.onPause();
}
@Override
public void onStop() {
lifecycleSubject.onNext(ActivityEvent.onStop);
super.onStop();
}
@Override
public void onDestroy() {
lifecycleSubject.onNext(ActivityEvent.onDestory);
super.onDestroy();
}
}
ActivityEvent是一个枚举,列举出了Activity的生命周期:
public enum ActivityEvent {
onCreate,
onStart,
onResume,
onPause,
onStop,
onDestory,
}
这样我们通过lifecycleSubject将Activity的生命周期一一发出,用takeUntil将其作为otherObservable连接到原Observable上,在通过first操作符,直到接收到我们指定的生命周期(上面指定的是onDestroy),原Observable若没注销,就会注销.first操作符演示图如下(和takeFirst操作符类似):
first
takeFirst
这样我们已经完成了通过Activity生命周期注销RxJava的核心原理,那么我们是不是可以将这个固定操作封装成我们自己的操作符?当然是可以了, RxJava提供了两种自定义操作符类型,一种是Observable.Operator,通过lift()操作符将自定义操作符连接到Observable上,这种操作符是对数据做转换的,不适用我们的应用场景,我们是要对Observable做变换,我们需要使用第二种自定义操作符Observable.Transformer,它是对上游的Observable做变换:
public class LifecycleTransformer<T> implements Observable.Transformer<T, T> {
private Observable<ActivityEvent> lifecycleObservable;
private ActivityEvent activityEvent;
LifecycleTransformer(Observable<ActivityEvent> lifecycleObservable, ActivityEvent activityEvent) {
this.lifecycleObservable = lifecycleObservable;
this.activityEvent = activityEvent;
}
@Override
public Observable<T> call(Observable<T> sourceObservable) {
return sourceObservable.takeUntil(getLifecycleObservable());
}
@NonNull
private Observable<?> getLifecycleObservable() {
lifecycleObservable.takeFirst(new Func1<ActivityEvent, Boolean>() {
@Override
public Boolean call(ActivityEvent event) {
return activityEvent == event;
}
});
}
}
这个时候我们就可以使用 compose操作符将我们自定义的LifecycleTransformer连接到原来的Observable上:
Observable.just(1)
.compose(new LifecycleTransformer<Integer>(lifecycleSubject,ActivityEvent.onDestory))
.subscribe();
实现的功能和上面写法一模一样,那么我们定义一个接口LifecycleManager用于生成这些LifecycleTransformer:
public interface LifecycleManager {
Observable<ActivityEvent> getLifecycle();
<T> LifecycleTransformer<T> bindUntilEvent(ActivityEvent activityEvent);
<T> LifecycleTransformer<T> bindToLifecycle();
<T> LifecycleTransformer<T> bindOnDestroy();
}
接口里一共提供了4个方法:
- getLifecycle():用于获取提供生命周期的Observable,也就是上文提到的 lifecycleSubject(就是BehaviorSubject)
- bindUntilEvent(ActivityEvent activityEvent):根据传入的生命周期,生成指定的LifecycleTransformer,就是将原Observable绑定到指定Activity生命周期.
- bindToLifecycle() : 这个是根据原Observable订阅与那个生命周期,转化到它应该在那个生命周期注销,比如在onCreate订阅就在OnDestroy注销,在onStart订阅就在onStop注销,在onResume订阅就在onPause注销,这个适用于在界面可见的时候开始干什么事,界面不可见的时候停止干什么事情,比如轮播图.
- bindOnDestroy():直接绑定到当Activity界面销毁的时候Observable注销,这个是bindUntilEvent(ActivityEvent activityEvent)的一种情况,因为用的比较多,我就多写了这个.
下面介绍一下这个 bindToLifecycle()如何实现,直接上代码:
public class LifecycleTransformer<T> implements Observable.Transformer<T, T> {
private Observable<ActivityEvent> lifecycleObservable;
LifecycleTransformer(Observable<ActivityEvent> lifecycleObservable) {
this.lifecycleObservable = lifecycleObservable.share();
}
@Override
public Observable<T> call(Observable<T> sourceObservable) {
return sourceObservable.takeUntil(getLifecycleObservable());
}
@NonNull
private Observable<?> getLifecycleObservable() {
return Observable.combineLatest(lifecycleObservable.first().map(ACTIVITY_LIFECYCLE),
lifecycleObservable.skip(1), new Func2<ActivityEvent, ActivityEvent, Boolean>() {
@Override
public Boolean call(ActivityEvent activityEvent, ActivityEvent event) {
return activityEvent == event;
}
})
.takeFirst(new Func1<Boolean, Boolean>() {
@Override
public Boolean call(Boolean aBoolean) {
return aBoolean;
}
});
}
// 用于生命周期转化
private static final Func1<ActivityEvent, ActivityEvent> ACTIVITY_LIFECYCLE =
new Func1<ActivityEvent, ActivityEvent>() {
@Override
public ActivityEvent call(ActivityEvent lastEvent) {
switch (lastEvent) {
case onCreate:
return ActivityEvent.onDestory;
case onStart:
return ActivityEvent.onStop;
case onResume:
return ActivityEvent.onPause;
case onPause:
return ActivityEvent.onStop;
case onStop:
return ActivityEvent.onDestory;
case onDestory:
throw new IllegalStateException("Cannot injectRxLifecycle to Activity lifecycle when outside of it.");
default:
throw new UnsupportedOperationException("Binding to " + lastEvent + " not yet implemented");
}
}
};
}
首先构造方法里,这次我们只需要拿到lifecycleSubject(lifecycleObservable)即可,不用在传入ActivityEvent,通过share操作符,是这个lifecycleObservable可以有多个Subscriber.由于这个lifecycleObservable 其实就是BehaviorSubject,上文已经介绍,当有订阅者时,他会把他被订阅之前最后一个事件发给这个订阅者,我们通过first操作符,就可以拿到原Observable订阅的时候是在那个生命周期订阅的,然后通过map操作符将订阅发生的生周期转化出应该注销的生命周期,这样注销的生命周期我们就有了,这样就和构造方法传入两个参数的逻辑基本一样了.
再通过combineLatest操作符将转化生命周期的Observable(lifecycleObservable.first().map(ACTIVITY_LIFECYCLE))和发射生命周期的Observable(lifecycleObservable.skip(1))联合起来,再通过takeFirst过滤出指定生命周期的后发送数据,从而注销原Observable.
将以上种构造方法合并到一个LifecycleTransformer里后代码如下:
public class LifecycleTransformer<T> implements Observable.Transformer<T, T> {
private Observable<ActivityEvent> lifecycleObservable;
private ActivityEvent activityEvent;
LifecycleTransformer(Observable<ActivityEvent> lifecycleObservable) {
this.lifecycleObservable = lifecycleObservable.share();
}
LifecycleTransformer(Observable<ActivityEvent> lifecycleObservable, ActivityEvent activityEvent) {
this.lifecycleObservable = lifecycleObservable;
this.activityEvent = activityEvent;
}
@Override
public Observable<T> call(Observable<T> sourceObservable) {
return sourceObservable.takeUntil(getLifecycleObservable());
}
@NonNull
private Observable<?> getLifecycleObservable() {
if (activityEvent != null) {
lifecycleObservable.takeFirst(new Func1<ActivityEvent, Boolean>() {
@Override
public Boolean call(ActivityEvent event) {
return activityEvent == event;
}
});
}
return Observable.combineLatest(lifecycleObservable.first().map(ACTIVITY_LIFECYCLE),
lifecycleObservable.skip(1), new Func2<ActivityEvent, ActivityEvent, Boolean>() {
@Override
public Boolean call(ActivityEvent activityEvent, ActivityEvent event) {
return activityEvent == event;
}
})
.takeFirst(new Func1<Boolean, Boolean>() {
@Override
public Boolean call(Boolean aBoolean) {
return aBoolean;
}
});
}
// 用于生命周期转化
private static final Func1<ActivityEvent, ActivityEvent> ACTIVITY_LIFECYCLE =
new Func1<ActivityEvent, ActivityEvent>() {
@Override
public ActivityEvent call(ActivityEvent lastEvent) {
switch (lastEvent) {
case onCreate:
return ActivityEvent.onDestory;
case onStart:
return ActivityEvent.onStop;
case onResume:
return ActivityEvent.onPause;
case onPause:
return ActivityEvent.onStop;
case onStop:
return ActivityEvent.onDestory;
case onDestory:
throw new IllegalStateException("Cannot injectRxLifecycle to Activity lifecycle when outside of it.");
default:
throw new UnsupportedOperationException("Binding to " + lastEvent + " not yet implemented");
}
}
};
}
也是由于这个 生命周期转化的问题,导致在onPause及其以后的生命周期里订阅一个Observable的时候,需要事先注入RxLifecycle,下文会讲到.
那么我们接下来要做的事情就是获取和Activity一一对应的LifecycleManager了.
这一块我借鉴的是Glide的做法:Glide.with(activity):
我们知道当Fragment通过FragmentManager加入到Activity中后,具有和activity基本相同的生命周期(忽略其他),那么我们通过这个Fragment发送activity的使命周期事件,同样能达到预期的效果,再让这个Fragment实现 LifecycleManager 接口不就行了,上一波代码:
public class LifecycleFragment extends Fragment implements LifecycleManager {
private final BehaviorSubject<ActivityEvent> lifecycleSubject;
public LifecycleFragment() {
lifecycleSubject = BehaviorSubject.create();
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
lifecycleSubject.onNext(ActivityEvent.onCreate);
super.onCreate(savedInstanceState);
}
@Override
public void onStart() {
lifecycleSubject.onNext(ActivityEvent.onStart);
super.onStart();
}
@Override
public void onResume() {
lifecycleSubject.onNext(ActivityEvent.onResume);
super.onResume();
}
@Override
public void onPause() {
lifecycleSubject.onNext(ActivityEvent.onPause);
super.onPause();
}
@Override
public void onStop() {
lifecycleSubject.onNext(ActivityEvent.onStop);
super.onStop();
}
@Override
public void onDestroy() {
lifecycleSubject.onNext(ActivityEvent.onDestory);
super.onDestroy();
}
@Override
public Observable<ActivityEvent> getLifecycle() {
return lifecycleSubject.asObservable();
}
@Override
public <T> LifecycleTransformer<T> bindUntilEvent(final ActivityEvent activityEvent) {
return new LifecycleTransformer<>(lifecycleSubject, activityEvent);
}
@Override
public <T> LifecycleTransformer<T> bindToLifecycle() {
return new LifecycleTransformer<>(lifecycleSubject);
}
@Override
public <T> LifecycleTransformer<T> bindOnDestroy() {
return bindUntilEvent(ActivityEvent.onDestory);
}
}
这样我们就可以通过这个**LifecycleFragment ** 既能获取到Activity的生命周期,又能获取到 各种 LifecycleTransformer.
这个时候我们就需要获取这个和Activity一一对应的**LifecycleFragment **即 LifecycleManager:
public class RxLifecycle {
private static final String FRAGMENT_TAG = "lifecycle_tag";
public static LifecycleManager with(Activity activity) {
FragmentManager fm = activity.getFragmentManager();
Fragment fragment = fm.findFragmentByTag(FRAGMENT_TAG);
if (fragment == null) {
fragment = new LifecycleFragment();
fm.beginTransaction().add(fragment, FRAGMENT_TAG).commitAllowingStateLoss();
fm.executePendingTransactions();
}
return (LifecycleManager) fragment;
}
通过FragmentManager 将一个空的LifecycleFragment 附加TAG添加到Activity中,如果再次调用同过TAG拿到.这样我们就拿到了LifecycleManager,就可以获取各种LifecycleTransformer了.
这时候我们就要想那个在onPause以后以后订阅的Observable使用bindToLifecycle 为什么要先注入RxLifecycle的问题:
若果你在onPause之前,这个Activity都没有使用过RxLifecycle,这个是个这个界面并没有加入这个空的LifecycleFragment,导致在onPause的时候首次调用会出现LifecycleFragment回调的生命周期是onCreate->onStart->onPause->onStop(没有onResume,是因为这个Fragment在创建的时候界面已经不可见了,所以不会回调这个),所以在使用bindToLifecycle()的时候,生命周期的转化会出问题.自行补脑吧,不详细分析了.
所以我不得不加入一个预先注入的方法,在Activity的onCreate方法调用:
/**
* @param context ensure context can be cast {@link Activity}
*/
public static void injectRxLifecycle(Context context) {
with(context);
}
其实最后调用的还是 with(activity)的方法,就是先把这个LifecycleFragment和Activity绑定.保证在调用bindToLifecycle()的时候,生命周期转化正常.如果你有更好的处理方法,请及时告知我,万分感谢!
上文说到,这个RxLifecycle库,也可以在自定义view中使用,其实也简单,就是通过view.getContext(),获取上下文,那view是放在Activity上,那个这个上下文必然是Activity,然而实事还是打脸了,V7包下的AppCompatXXXView,获取的上下文是一个TintContextWrapper,不能强转成Activity,我的内心是崩溃的,哪位大佬知道怎么班,快告诉我,膝盖送上!
RxLifecycle类全部代码:
public class RxLifecycle {
private static final String FRAGMENT_TAG = "lifecycle_tag";
/**
* @param context ensure context can be cast {@link Activity}
*/
public static void injectRxLifecycle(Context context) {
with(context);
}
public static LifecycleManager with(Activity activity) {
if (activity instanceof FragmentActivity) {
return with((FragmentActivity) activity);
}
FragmentManager fm = activity.getFragmentManager();
Fragment fragment = fm.findFragmentByTag(FRAGMENT_TAG);
if (fragment == null) {
fragment = new LifecycleFragment();
fm.beginTransaction().add(fragment, FRAGMENT_TAG).commitAllowingStateLoss();
fm.executePendingTransactions();
}
return (LifecycleManager) fragment;
}
private static LifecycleManager with(FragmentActivity activity) {
android.support.v4.app.FragmentManager fm = activity.getSupportFragmentManager();
android.support.v4.app.Fragment fragment = fm.findFragmentByTag(FRAGMENT_TAG);
if (fragment == null) {
fragment = new LifecycleV4Fragment();
fm.beginTransaction().add(fragment, FRAGMENT_TAG).commitNowAllowingStateLoss();
}
return (LifecycleManager) fragment;
}
public static LifecycleManager with(Fragment fragment) {
return with(fragment.getActivity());
}
public static LifecycleManager with(android.support.v4.app.Fragment fragment) {
return with(fragment.getActivity());
}
/**
* @param context ensure context can be cast {@link Activity}
*/
public static LifecycleManager with(Context context) {
if (context instanceof AppCompatActivity) {
return with((FragmentActivity) context);
}
if (context instanceof Activity) {
return with((Activity) context);
}
throw new ClassCastException(context.getClass().getSimpleName() + " can\'t cast Activity !");
}
public static LifecycleManager with(View view) {
return with(view.getContext());
}
private static void injectRxLifecycle(Object object) {
if (object instanceof View) {
with((View) object);
} else {
with(object);
}
}
private static LifecycleManager with(Object object) {
if (object instanceof Context) {
return with((Context) object);
}
for (Field field : object.getClass().getDeclaredFields()) {
try {
field.setAccessible(true);
Object value = field.get(object);
if (value instanceof Context) {
return with((Context) value);
}
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
throw new ClassCastException(object.getClass().getSimpleName() + " can\'t convert Context !");
}
}
About me
- email: dhhmvp@163.com
- github: https://github.com/dhhAndroid
