Use Optional for simpler code

This commit is contained in:
Stypox 2023-01-11 15:08:10 +01:00
parent 28109fef38
commit 944e295ae7
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1 changed files with 77 additions and 83 deletions

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@ -91,16 +91,16 @@ import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Optional;
import java.util.function.Consumer;
import icepick.Icepick;
import icepick.State;
import io.reactivex.rxjava3.android.schedulers.AndroidSchedulers;
import io.reactivex.rxjava3.core.Observable;
import io.reactivex.rxjava3.core.Single;
import io.reactivex.rxjava3.core.SingleTransformer;
import io.reactivex.rxjava3.disposables.CompositeDisposable;
import io.reactivex.rxjava3.disposables.Disposable;
import io.reactivex.rxjava3.functions.Consumer;
import io.reactivex.rxjava3.schedulers.Schedulers;
/**
@ -702,7 +702,7 @@ public class RouterActivity extends AppCompatActivity {
}
public static class PersistentFragment extends Fragment {
private WeakReference<AppCompatActivity> context;
private WeakReference<AppCompatActivity> weakContext;
private final CompositeDisposable disposables = new CompositeDisposable();
private int running = 0;
@ -711,21 +711,23 @@ public class RouterActivity extends AppCompatActivity {
running++;
} else {
running--;
if (running <= 0 && getActivityContext() != null) {
getActivityContext().getSupportFragmentManager()
.beginTransaction().remove(this).commit();
if (running <= 0) {
getActivityContext().ifPresent(context -> context.getSupportFragmentManager()
.beginTransaction().remove(this).commit());
}
}
}
public interface ResultRunnable {
void run(AppCompatActivity context);
}
@Override
public void onAttach(@NonNull final Context activityContext) {
super.onAttach(activityContext);
context = new WeakReference<>((AppCompatActivity) activityContext);
weakContext = new WeakReference<>((AppCompatActivity) activityContext);
}
@Override
public void onDetach() {
super.onDetach();
weakContext = null;
}
@SuppressWarnings("deprecation")
@ -741,12 +743,13 @@ public class RouterActivity extends AppCompatActivity {
disposables.clear();
}
private AppCompatActivity getActivityContext() {
return context == null ? null : context.get();
}
private boolean activityGone() {
return getActivityContext() == null || getActivityContext().isFinishing();
/**
* @return the activity context, if there is one and the activity is not finishing
*/
private Optional<AppCompatActivity> getActivityContext() {
return Optional.ofNullable(weakContext)
.flatMap(context -> Optional.ofNullable(context.get()))
.filter(context -> !context.isFinishing());
}
// guard against IllegalStateException in calling DialogFragment.show() whilst in background
@ -754,60 +757,56 @@ public class RouterActivity extends AppCompatActivity {
// the network request to return) when it internally calls FragmentTransaction.commit()
// after the FragmentManager has saved its states (isStateSaved() == true)
// (ref: https://stackoverflow.com/a/39813506)
private void runOnVisible(final ResultRunnable runnable) {
if (activityGone()) {
inFlight(false);
return;
}
if (getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.STARTED)) {
getActivityContext().runOnUiThread(() -> {
runnable.run(getActivityContext());
inFlight(false);
});
} else {
getLifecycle().addObserver(new DefaultLifecycleObserver() {
@Override
public void onResume(@NonNull final LifecycleOwner owner) {
getLifecycle().removeObserver(this);
if (activityGone()) {
inFlight(false);
return;
private void runOnVisible(final Consumer<AppCompatActivity> runnable) {
getActivityContext().ifPresentOrElse(context -> {
if (getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.STARTED)) {
context.runOnUiThread(() -> {
runnable.accept(context);
inFlight(false);
});
} else {
getLifecycle().addObserver(new DefaultLifecycleObserver() {
@Override
public void onResume(@NonNull final LifecycleOwner owner) {
getLifecycle().removeObserver(this);
getActivityContext().ifPresentOrElse(context ->
context.runOnUiThread(() -> {
runnable.accept(context);
inFlight(false);
}),
() -> inFlight(false)
);
}
getActivityContext().runOnUiThread(() -> {
runnable.run(getActivityContext());
inFlight(false);
});
});
// this trick doesn't seem to work on Android 10+ (API 29)
// which places restrictions on starting activities from the background
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q
&& !context.isChangingConfigurations()) {
// try to bring the activity back to front if minimised
final Intent i = new Intent(context, RouterActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(i);
}
});
// this trick doesn't seem to work on Android 10+ (API 29)
// which places restrictions on starting activities from the background
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q
&& !getActivityContext().isChangingConfigurations()) {
// try to bring the activity back to front if minimised
final Intent i = new Intent(getActivityContext(), RouterActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(i);
}
}
}, () -> {
// this branch is executed if there is no activity context
inFlight(false);
});
}
<T> SingleTransformer<T, T> pleaseWait() {
return single -> single
// 'abuse' ambWith() here to cancel the toast for us when the wait is over
.ambWith(Single.create(emitter -> {
if (!activityGone()) {
getActivityContext().runOnUiThread(() -> {
// Getting the stream info usually takes a moment
// Notifying the user here to ensure that no confusion arises
final Toast t = Toast.makeText(
getActivityContext().getApplicationContext(),
getString(R.string.processing_may_take_a_moment),
Toast.LENGTH_LONG);
t.show();
emitter.setCancellable(t::cancel);
});
}
}));
<T> Single<T> pleaseWait(final Single<T> single) {
// 'abuse' ambWith() here to cancel the toast for us when the wait is over
return single.ambWith(Single.create(emitter -> getActivityContext().ifPresent(context ->
context.runOnUiThread(() -> {
// Getting the stream info usually takes a moment
// Notifying the user here to ensure that no confusion arises
final Toast toast = Toast.makeText(context,
getString(R.string.processing_may_take_a_moment),
Toast.LENGTH_LONG);
toast.show();
emitter.setCancellable(toast::cancel);
}))));
}
@SuppressLint("CheckResult")
@ -816,7 +815,7 @@ public class RouterActivity extends AppCompatActivity {
disposables.add(ExtractorHelper.getStreamInfo(currentServiceId, currentUrl, true)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.compose(pleaseWait())
.compose(this::pleaseWait)
.subscribe(result ->
runOnVisible(ctx -> {
final FragmentManager fm = ctx.getSupportFragmentManager();
@ -833,23 +832,18 @@ public class RouterActivity extends AppCompatActivity {
disposables.add(ExtractorHelper.getStreamInfo(currentServiceId, currentUrl, false)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.compose(pleaseWait())
.compose(this::pleaseWait)
.subscribe(
info -> {
if (!activityGone()) {
PlaylistDialog.createCorrespondingDialog(
getActivityContext(),
List.of(new StreamEntity(info)),
playlistDialog ->
runOnVisible(ctx -> {
// dismiss listener to be handled by FragmentManager
final FragmentManager fm =
ctx.getSupportFragmentManager();
playlistDialog.show(fm, "addToPlaylistDialog");
})
);
}
},
info -> getActivityContext().ifPresent(context ->
PlaylistDialog.createCorrespondingDialog(context,
List.of(new StreamEntity(info)),
playlistDialog -> runOnVisible(ctx -> {
// dismiss listener to be handled by FragmentManager
final FragmentManager fm =
ctx.getSupportFragmentManager();
playlistDialog.show(fm, "addToPlaylistDialog");
})
)),
throwable -> runOnVisible(ctx -> handleError(ctx, new ErrorInfo(
throwable,
UserAction.REQUESTED_STREAM,