XiaoxintongSystemOS/app/src/main/java/com/uiuios/aios/base/BaseFragment.java

package com.uiuios.aios.base;

import android.os.Bundle;
import android.view.View;

import androidx.annotation.CallSuper;
import androidx.annotation.CheckResult;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

import com.trello.rxlifecycle4.LifecycleProvider;
import com.trello.rxlifecycle4.LifecycleTransformer;
import com.trello.rxlifecycle4.RxLifecycle;
import com.trello.rxlifecycle4.android.FragmentEvent;
import com.trello.rxlifecycle4.android.RxLifecycleAndroid;

import io.reactivex.rxjava3.core.Observable;
import io.reactivex.rxjava3.subjects.BehaviorSubject;

public abstract class BaseFragment extends Fragment implements LifecycleProvider<FragmentEvent> {
    public final BehaviorSubject<FragmentEvent> lifecycleSubject = BehaviorSubject.create();

    protected boolean isViewInitiated;
    protected boolean isVisibleToUser;
    protected boolean isDataInitiated;

    @Override
    @NonNull
    @CheckResult
    public final Observable<FragmentEvent> lifecycle() {
        return lifecycleSubject.hide();
    }

    @Override
    @NonNull
    @CheckResult
    public final <T> LifecycleTransformer<T> bindUntilEvent(@NonNull FragmentEvent event) {
        return RxLifecycle.bindUntilEvent(lifecycleSubject, event);
    }

    @Override
    @NonNull
    @CheckResult
    public final <T> LifecycleTransformer<T> bindToLifecycle() {
        return RxLifecycleAndroid.bindFragment(lifecycleSubject);
    }

    @Override
    @CallSuper
    public void onAttach(android.app.Activity activity) {
        super.onAttach(activity);
        lifecycleSubject.onNext(FragmentEvent.ATTACH);
    }

    @Override
    @CallSuper
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        lifecycleSubject.onNext(FragmentEvent.CREATE);
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        isViewInitiated = true;
        prepareFetchData();
    }

    @Override
    public void setUserVisibleHint(boolean isVisibleToUser) {
        super.setUserVisibleHint(isVisibleToUser);
        this.isVisibleToUser = isVisibleToUser;
        prepareFetchData();
    }

    public abstract void fetchData();

    public boolean prepareFetchData() {
        return prepareFetchData(false);
    }

    public boolean prepareFetchData(boolean forceUpdate) {
        if (isVisibleToUser && isViewInitiated && (!isDataInitiated || forceUpdate)) {
            fetchData();
            isDataInitiated = true;
            return true;
        }
        return false;
    }

    @Override
    @CallSuper
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        lifecycleSubject.onNext(FragmentEvent.CREATE_VIEW);
    }

    @Override
    @CallSuper
    public void onStart() {
        super.onStart();
        lifecycleSubject.onNext(FragmentEvent.START);
    }

    @Override
    @CallSuper
    public void onResume() {
        super.onResume();
        lifecycleSubject.onNext(FragmentEvent.RESUME);
    }

    @Override
    @CallSuper
    public void onPause() {
        lifecycleSubject.onNext(FragmentEvent.PAUSE);
        super.onPause();
    }

    @Override
    @CallSuper
    public void onStop() {
        lifecycleSubject.onNext(FragmentEvent.STOP);
        super.onStop();
    }

    @Override
    @CallSuper
    public void onDestroyView() {
        lifecycleSubject.onNext(FragmentEvent.DESTROY_VIEW);
        super.onDestroyView();
    }

    @Override
    @CallSuper
    public void onDestroy() {
        lifecycleSubject.onNext(FragmentEvent.DESTROY);
        super.onDestroy();
    }

    @Override
    @CallSuper
    public void onDetach() {
        lifecycleSubject.onNext(FragmentEvent.DETACH);
        super.onDetach();
    }
}