Generic AlertDialogFragment with Builder Pattern
En mi proyecto, que ya se utiliza AlertDialog.Builder
ya mucho antes de descubrir que es problemático. Sin embargo, no quería cambiar tanto código en ninguna parte de mi aplicación. Además, en realidad soy fanático de pasar OnClickListeners
como clases anónimas donde se necesitan (es decir, cuando se usa setPositiveButton()
, setNegativeButton()
etc.) en lugar de tener que implementar miles de métodos de devolución de llamada para comunicarse entre un fragmento de diálogo y el fragmento del titular, que puede, en mi opinión, lleva a un código muy confuso y complejo. Especialmente, si tiene múltiples diálogos diferentes en un fragmento y luego necesita distinguir en las implementaciones de devolución de llamada entre qué diálogo se muestra actualmente.
Por lo tanto, combiné diferentes enfoques para crear una AlertDialogFragment
clase auxiliar genérica que se puede usar exactamente como AlertDialog
:
SOLUCIÓN
( TENGA EN CUENTA que estoy usando expresiones lambda de Java 8 en mi código, por lo que es posible que tenga que cambiar partes del código si aún no está usando expresiones lambda ).
/**
* Helper class for dialog fragments to show a {@link AlertDialog}. It can be used almost exactly
* like a {@link AlertDialog.Builder}
* <p />
* Creation Date: 22.03.16
*
* @author felix, http://flx-apps.com/
*/
public class AlertDialogFragment extends DialogFragment {
protected FragmentActivity activity;
protected Bundle args;
protected String tag = AlertDialogFragment.class.getSimpleName();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
activity = getActivity();
args = getArguments();
}
@NonNull
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
Dialog dialog = setDialogDefaults(new AlertDialog.Builder(getActivity())).create();
if (args.containsKey("gravity")) {
dialog.getWindow().getAttributes().gravity = args.getInt("gravity");
}
dialog.setOnShowListener(d -> {
if (dialog != null && dialog.findViewById((android.R.id.message)) != null) {
((TextView) dialog.findViewById(android.R.id.message)).setMovementMethod(LinkMovementMethod.getInstance());
}
});
return dialog;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return super.onCreateView(inflater, container, savedInstanceState);
}
@Override
public void onDismiss(DialogInterface dialog) {
super.onDismiss(dialog);
if (args.containsKey("onDismissListener")) {
Parcelable onDismissListener = args.getParcelable("onDismissListener");
if (onDismissListener != null && onDismissListener instanceof ParcelableOnDismissListener) {
((ParcelableOnDismissListener) onDismissListener).onDismiss(this);
}
}
}
/**
* Sets default dialog properties by arguments which were set using {@link #builder(FragmentActivity)}
*/
protected AlertDialog.Builder setDialogDefaults(AlertDialog.Builder builder) {
args = getArguments();
activity = getActivity();
if (args.containsKey("title")) {
builder.setTitle(args.getCharSequence("title"));
}
if (args.containsKey("message")) {
CharSequence message = args.getCharSequence("message");
builder.setMessage(message);
}
if (args.containsKey("viewId")) {
builder.setView(getActivity().getLayoutInflater().inflate(args.getInt("viewId"), null));
}
if (args.containsKey("positiveButtonText")) {
builder.setPositiveButton(args.getCharSequence("positiveButtonText"), (dialog, which) -> {
onButtonClicked("positiveButtonListener", which);
});
}
if (args.containsKey("negativeButtonText")) {
builder.setNegativeButton(args.getCharSequence("negativeButtonText"), (dialog, which) -> {
onButtonClicked("negativeButtonListener", which);
});
}
if (args.containsKey("neutralButtonText")) {
builder.setNeutralButton(args.getCharSequence("neutralButtonText"), (dialog, which) -> {
onButtonClicked("neutralButtonListener", which);
});
}
if (args.containsKey("items")) {
builder.setItems(args.getStringArray("items"), (dialog, which) -> {
onButtonClicked("itemClickListener", which);
});
}
// @formatter:off
// FIXME this a pretty hacky workaround: we don't want to show the dialog if onClickListener of one of the dialog's button click listener were lost
// the problem is, that there is no (known) solution for parceling a OnClickListener in the long term (only for state changes like orientation change,
// but not if the Activity was completely lost)
if (
(args.getParcelable("positiveButtonListener") != null && !(args.getParcelable("positiveButtonListener") instanceof ParcelableOnClickListener)) ||
(args.getParcelable("negativeButtonListener") != null && !(args.getParcelable("negativeButtonListener") instanceof ParcelableOnClickListener)) ||
(args.getParcelable("neutralButtonListener") != null && !(args.getParcelable("neutralButtonListener") instanceof ParcelableOnClickListener)) ||
(args.getParcelable("itemClickListener") != null && !(args.getParcelable("itemClickListener") instanceof ParcelableOnClickListener))
) {
new DebugMessage("Forgot onClickListener. Needs to be dismissed.")
.logLevel(DebugMessage.LogLevel.VERBOSE)
.show();
try {
dismissAllowingStateLoss();
} catch (NullPointerException | IllegalStateException ignored) {}
}
// @formatter:on
return builder;
}
public interface OnDismissListener {
void onDismiss(AlertDialogFragment dialogFragment);
}
public interface OnClickListener {
void onClick(AlertDialogFragment dialogFragment, int which);
}
protected void onButtonClicked(String buttonKey, int which) {
ParcelableOnClickListener parcelableOnClickListener = getArguments().getParcelable(buttonKey);
if (parcelableOnClickListener != null) {
parcelableOnClickListener.onClick(this, which);
}
}
// region Convenience Builder Pattern class almost similar to AlertDialog.Builder
// =============================================================================================
public AlertDialogFragment builder(FragmentActivity activity) {
this.activity = activity;
this.args = new Bundle();
return this;
}
public AlertDialogFragment addArguments(Bundle bundle) {
args.putAll(bundle);
return this;
}
public AlertDialogFragment setTitle(int titleStringId) {
return setTitle(activity.getString(titleStringId));
}
public AlertDialogFragment setTitle(CharSequence title) {
args.putCharSequence("title", title);
return this;
}
public AlertDialogFragment setMessage(int messageStringId) {
return setMessage(activity.getString(messageStringId));
}
public AlertDialogFragment setMessage(CharSequence message) {
args.putCharSequence("message", message);
return this;
}
public AlertDialogFragment setPositiveButton(int textStringId, OnClickListener onClickListener) {
return setPositiveButton(activity.getString(textStringId), onClickListener);
}
public AlertDialogFragment setPositiveButton(CharSequence text, AlertDialogFragment.OnClickListener onClickListener) {
args.putCharSequence("positiveButtonText", text);
args.putParcelable("positiveButtonListener", createParcelableOnClickListener(onClickListener));
return this;
}
public AlertDialogFragment setNegativeButton(int textStringId, AlertDialogFragment.OnClickListener onClickListener) {
return setNegativeButton(activity.getString(textStringId), onClickListener);
}
public AlertDialogFragment setNegativeButton(CharSequence text, AlertDialogFragment.OnClickListener onClickListener) {
args.putCharSequence("negativeButtonText", text);
args.putParcelable("negativeButtonListener", createParcelableOnClickListener(onClickListener));
return this;
}
public AlertDialogFragment setNeutralButton(int textStringId, AlertDialogFragment.OnClickListener onClickListener) {
return setNeutralButton(activity.getString(textStringId), onClickListener);
}
public AlertDialogFragment setNeutralButton(CharSequence text, AlertDialogFragment.OnClickListener onClickListener) {
args.putCharSequence("neutralButtonText", text);
args.putParcelable("neutralButtonListener", createParcelableOnClickListener(onClickListener));
return this;
}
public AlertDialogFragment setOnDismissListener(OnDismissListener onDismissListener) {
if (onDismissListener == null) {
return this;
}
Parcelable p = new ParcelableOnDismissListener() {
@Override
public void onDismiss(AlertDialogFragment dialogFragment) {
onDismissListener.onDismiss(dialogFragment);
}
};
args.putParcelable("onDismissListener", p);
return this;
}
public AlertDialogFragment setItems(String[] items, AlertDialogFragment.OnClickListener onClickListener) {
args.putStringArray("items", items);
args.putParcelable("itemClickListener", createParcelableOnClickListener(onClickListener));
return this;
}
public AlertDialogFragment setView(int viewId) {
args.putInt("viewId", viewId);
return this;
}
public AlertDialogFragment setGravity(int gravity) {
args.putInt("gravity", gravity);
return this;
}
public AlertDialogFragment setTag(String tag) {
this.tag = tag;
return this;
}
public AlertDialogFragment create() {
setArguments(args);
return AlertDialogFragment.this;
}
public AlertDialogFragment show() {
create();
try {
super.show(activity.getSupportFragmentManager(), tag);
}
catch (IllegalStateException e1) {
/**
* this whole part is used in order to attempt to show the dialog if an
* {@link IllegalStateException} was thrown (it's kinda comparable to
* {@link FragmentTransaction#commitAllowingStateLoss()}
* So you can remove all those dirty hacks if you are sure that you are always
* properly showing dialogs in the right moments
*/
new DebugMessage("got IllegalStateException attempting to show dialog. trying to hack around.")
.logLevel(DebugMessage.LogLevel.WARN)
.exception(e1)
.show();
try {
Field mShownByMe = DialogFragment.class.getDeclaredField("mShownByMe");
mShownByMe.setAccessible(true);
mShownByMe.set(this, true);
Field mDismissed = DialogFragment.class.getDeclaredField("mDismissed");
mDismissed.setAccessible(true);
mDismissed.set(this, false);
}
catch (Exception e2) {
new DebugMessage("error while showing dialog")
.exception(e2)
.logLevel(DebugMessage.LogLevel.ERROR)
.show();
}
FragmentTransaction transaction = activity.getSupportFragmentManager().beginTransaction();
transaction.add(this, tag);
transaction.commitAllowingStateLoss(); // FIXME hacky and unpredictable workaround
}
return AlertDialogFragment.this;
}
@Override
public int show(FragmentTransaction transaction, String tag) {
throw new NoSuchMethodError("Please use AlertDialogFragment.show()!");
}
@Override
public void show(FragmentManager manager, String tag) {
throw new NoSuchMethodError("Please use AlertDialogFragment.show()!");
}
protected ParcelableOnClickListener createParcelableOnClickListener(AlertDialogFragment.OnClickListener onClickListener) {
if (onClickListener == null) {
return null;
}
return new ParcelableOnClickListener() {
@Override
public void onClick(AlertDialogFragment dialogFragment, int which) {
onClickListener.onClick(dialogFragment, which);
}
};
}
/**
* Parcelable OnClickListener (can be remembered on screen rotation)
*/
public abstract static class ParcelableOnClickListener extends ResultReceiver implements AlertDialogFragment.OnClickListener {
public static final Creator<ResultReceiver> CREATOR = ResultReceiver.CREATOR;
ParcelableOnClickListener() {
super(null);
}
@Override
public abstract void onClick(AlertDialogFragment dialogFragment, int which);
}
/**
* Parcelable OnDismissListener (can be remembered on screen rotation)
*/
public abstract static class ParcelableOnDismissListener extends ResultReceiver implements AlertDialogFragment.OnDismissListener {
public static final Creator<ResultReceiver> CREATOR = ResultReceiver.CREATOR;
ParcelableOnDismissListener() {
super(null);
}
@Override
public abstract void onDismiss(AlertDialogFragment dialogFragment);
}
// =============================================================================================
// endregion
}
USO
// showing a normal alert dialog with state loss on configuration changes (like device rotation)
new AlertDialog.Builder(getActivity())
.setTitle("Are you sure? (1)")
.setMessage("Do you really want to do this?")
.setPositiveButton("Yes", (dialog, which) -> Toast.makeText(getContext(), "Yes clicked", Toast.LENGTH_SHORT).show())
.setNegativeButton("Cancel", null)
.show();
// showing a dialog fragment using the helper class with no state loss on configuration changes
new AlertDialogFragment.builder(getActivity())
.setTitle("Are you sure? (2)")
.setMessage("Do you really want to do this?")
.setPositiveButton("Yes", (dialog, which) -> Toast.makeText(getContext(), "Yes clicked", Toast.LENGTH_SHORT).show())
.setNegativeButton("Cancel", null)
.show();
Estoy publicando esto aquí no solo para compartir mi solución, sino también porque quería pedirles a las personas su opinión: ¿Es este enfoque legítimo o problemático hasta cierto punto?
Dialog
oAlertDialog.Builder::create()::show()
creará un cuadro de diálogo que desaparecerá cuando gire la pantalla.