封装LiveData实现跨界面处理消息
livedata的妙用
public final class LiveEventBus {
private final Map>bus;
private LiveEventBus() {
bus =new HashMap<>();
}
private static class SingletonHolder {
private static final LiveEventBusDEFAULT_BUS =new LiveEventBus();
}
public static LiveEventBusget() {
return SingletonHolder.DEFAULT_BUS;
}
public synchronized Observablewith(String key, Class type) {
if (!bus.containsKey(key)) {
bus.put(key, new BusLiveEvent<>());
}
return (Observable)bus.get(key);
}
public Observablewith(String key) {
return with(key, Object.class);
}
public interface Observable {
void setValue(T value);
void postValue(T value);
void postValueDelay(T value, long delay, TimeUnit unit);
void observe(@NonNull LifecycleOwner owner, @NonNull Observer observer);
void observeSticky(@NonNull LifecycleOwner owner, @NonNull Observer observer);
void observeForever(@NonNull Observer observer);
void observeStickyForever(@NonNull Observer observer);
void removeObserver(@NonNull Observer observer);
}
private static class BusLiveEventextends LiveEventimplements Observable {
private class PostValueTaskimplements Runnable {
private ObjectnewValue;
public PostValueTask(@NonNull Object newValue) {
this.newValue = newValue;
}
@Override
public void run() {
setValue((T)newValue);
}
}
private HandlermainHandler =new Handler(Looper.getMainLooper());
@Override
protected Lifecycle.StateobserverActiveLevel() {
return super.observerActiveLevel();
// return Lifecycle.State.STARTED;
}
@Override
public void postValueDelay(T value, long delay, TimeUnit unit) {
mainHandler.postDelayed(new PostValueTask(value), unit.convert(delay, unit));
}
}
}
