Develop Reference

I need to display a simple AlertDialog within a called class

I'm very new to Android, and have a basic question. I need at certain points to display a user notification in a dialog box, which they can simply acknowledge with the OK button.
I'm using:
myActivity.runOnUiThread(new Runnable() {
public void run() {
AlertDialog alertDialog = new AlertDialog.Builder(myContext).create();
alertDialog.setTitle("Alert");
alertDialog.setMessage("My message");
alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
alertDialog.show();
}
});
This works well in the Main program, but within a called method it needs the Activity and the Context from the main program. Can anybody tell me how to pass these? getApplicationContext() seems to be acceptable, but I can't figure out how to pass the Activity.
Better still of course would be to get the parent Context and Activity within the method, but I can't get that to work either.
I'd be grateful for any help.
-update 10/07/21
Rahul has given me the solution to the problem I posed: how to pass in the Activity and Context.
The problem is that the dialog still doesn't show.
I found a variation online as follows:
AlertDialog.Builder builder = new AlertDialog.Builder(myContext);
builder.setTitle("Alert")
.setMessage("My message")
.setCancelable(false)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.dismiss();
}
});
AlertDialog alert = builder.create();
alert.show();
but this doesn't work either.
I'm puzzled that such a common and simple task needs so much code. In the desktop languages I'm used to it can be done in a single line.
So my titled question stands, but can anyone see where the code is faulty?
Many thanks

You can either pass activity to the class when initializing the object or you can pass activity when calling the function.
Case 1 (Recommended)
Pass Activity when calling the function:
MyObj myObj = new MyObj();
myObj.showDialog(myValue, ActivityName.this);
Where function will look like this:
public void showDialog(int myValue, Activity activity){
...
}
Then you can use this activity instance inside the method.
Case 2
Pass Activity when initializing the object:
MyObj myObj = new MyObj(ActivityName.this);
Where Class will look like this:
class MyObj{
private Activity thisActivity;
public MyObj(Activity activity){
thisActivity = Activity;
}
...
}
Then you can use this activity instance.
When you have activity object available you can replace context object with it.

Second dialog is automatically destroyed when created from within a first dialog's OnClickListener

Basically, I have a login screen where users type their email and password to log in. After they have submitted their data, I check if they have confirmed their email address. If not, I display a dialog with a corresponding message. In that dialog I provide them with a neutral button to request a new confirmation email, if they haven't received one yet. If they clicked on that button, I wanna show another dialog with a message that the email has been successfully sent. The problem is that whenever I create and show the second dialog from within the first dialog's OnClickListener, the second dialog is instantiated, but then destroyed immediately. So my question is, why is this happening and how do I implement this kind of functionality so that whatever fragment is being shown will be retained across rotation?
NotVerifiedEmailDialog.java (first dialog):
public class NotVerifiedEmailDialog extends DialogFragment
{
private static final String TAG = "NotVerifiedEmailDialog";
#NonNull
#Override
public Dialog onCreateDialog(Bundle savedInstanceState)
{
return new AlertDialog.Builder(getActivity())
.setTitle(R.string.email_not_verified)
.setMessage(R.string.email_not_verified_message)
.setPositiveButton(android.R.string.ok, null)
.setNeutralButton(R.string.request_new_email, new DialogInterface.OnClickListener()
{
#Override
public void onClick(DialogInterface dialogInterface, int which)
{
EmailSentDialog dialog = new EmailSentDialog();
dialog.show(getChildFragmentManager(), dialog.getMyTag());
}
})
.create();
}
public String getMyTag()
{
return TAG;
}
}
EmailSentDialog.java (second dialog):
public class EmailSentDialog extends DialogFragment
{
private static final String TAG = "EmailSentDialog";
#NonNull
#Override
public Dialog onCreateDialog(Bundle savedInstanceState)
{
return new AlertDialog.Builder(getActivity())
.setTitle(R.string.success)
.setMessage(R.string.email_sent_message)
.setPositiveButton(android.R.string.ok, null)
.create();
}
public String getMyTag()
{
return TAG;
}
}

Try making the following variable as instance variable. Your dialog object may get destroyed by the previous dialog.
EmailSentDialog dialog;

In case anyone encountered this problem, the solution is to replace getChildFragmentManager() with getParentFragment().getChildFragmentManager(). The former gets a child fragment manager of the first dialog, which is gonna be destroyed, because of the button click (that's why the second dialog is destroyed instantly, because it is tied to the first dialog's child fragment manager), while the latter gets a child fragment manager of the parent fragment (in my case, LoginFragment) and, therefore, is not destroyed immediately.

Clear password field in other activity on exit

I need to clear password field on exit of app,i am exiting the app in other activity and on exit it goes to mainActivity which has login details in which i need to clear password field,how will i do this in other activity ,i tried using setText("") but in vain.
public void backButtonHandler() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(
ReminderActivity.this);
// Setting Dialog Title
alertDialog.setTitle("Leave application?");
// Setting Dialog Message
alertDialog.setMessage("Are you sure you want to leave the application?");
// Setting Positive "Yes" Button
alertDialog.setPositiveButton("YES",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
//I need to clear here all pwd data present in MainActivity in edittext
finish();
}
});
// Setting Negative "NO" Button
alertDialog.setNegativeButton("NO",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// Write your code here to invoke NO event
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}

In your MainActivity do like this:
#Override
public void onResume() {
super.onResume(); // Always call the superclass method first
editText.SetText("");
}
So, it will clear editText value, whenever your MainActivity will get resumed.

Or when you click the login button do
editText.SetText("");
Then it will be cleared before another activity starts

Using setText won't work and may even throw some type of NPE if your activity is no longer in memory.
There are a couple of ways you can do this depending on your requirements:
You can simply clear the text field in the activity/fragment's onStop or onDestroy overrides
If you absolutely have to set the text field from a different activity, then I suggest the following design:
In your Application class, create a nested class that implements ActivityLifeCycleCallbacks. This is a great class to implement as it allows you to monitor the state of all of your activities. It resolved a lot of problems for me
If you have a singleton model, or static String value that binds to your password TextView then you're almost there (other workarounds available if you give us more info).
So let's look at some code:
Design 1:
public void onStop()
{
super.onStop();
myTextField.setText("");
}
Your Application class:
public class MyApplication extends Application
{
...
private static final class MyActivityLifeCycleCallback implements ActivityLifecycleCallbacks
{
#Override
public void onActivityStopped(Activity activity)
{
//Here, I am assuming that your class name is MainActivity
Log.i(TAG, "onActivityStopped:" + activity.getLocalClassName());
if("MainActivity".isEqual(activity.getLocalClassName())
{
myDataModel.getInstance().setPassword("");
//or if your password String member is static
//((MainActivity)activity).myPasswordMember = "";
}
//Or if you want to only clear the password text when RAActivity stops, simply replace "MainActivity" with the RAActivity class name.
}
#Override
public void onActivityDestroyed(Activity activity,
Bundle savedInstanceState)
{
Log.i(TAG, "onActivityDestroyed:" + activity.getLocalClassName());
if(activity.getLocalClassName().contains("MySecondActivity"))
{
//reset your password here - implementation will depend on how you have your data model organized (private, singleton, static, etc.)
}
}
....
}
Remember that this design would work well with some type of a singleton or central data model (think MVC architecture) so that you can propagate the change in data to your components.
Hope it helps
EDIT:
I have added the code according to your comment. But to be honest, I think it's a better idea to simply call the setText("") method in the MainActivity's onStop function like I suggested. This is a simple problem and my second design might be a bit too much. Anyway, the code is updated, so if you like it, mark it as an answer :)
Here's another idea. IF RAActivity calls MainActivity again (probably not) using startActivity, you can simply pass a bundle value to MainActivity that tells it that it's coming from RAActivity. That way, MainActivity can clear the password if it was called from RAActivity. Lots of options.

Android: What is the proper way of connecting dialog buttons with an activity?

Here is what I would like to do:
1) Inside an Activity a dialog is shown. I use DialogFragment and FragmentManager for this, by calling:
dialogFragment.show(fragmentManager, "edit_task_list");
2) Inside the Dialog I have layout with a custom Button. I would like to perform some action when the button is clicked and later close the dialog.
How should I connect everything? I see two options:
1) onclick attribute in the Button and a method inside the Actvity. That was my original plan, but I don't how to get the Dialog from the Activity to dismiss it. Even if this is not the right way, how could this be done? I would like to understand how this works.
2) set on click listener on the button when the Dialog is created in DialogFragment. This will require me to pass some context from the Activity to the DialogFragment, so I would like to avoid it (and keep the DialogFragment as simple as possible).
Which of those options should I take?

Number 2 Doesn't require you to pass any context (and you shouldn't). You define an interface that can act as a contract between fragments and activities and make your activity implement it.
From your dialog and in your button.onClick(), you do something like this (untested code):
if ( getActivity() != null
&& !getActivity().finishing()
&& getActivity() instanceOf YourInterface) {
((YourInterface)getActivity()).onSomeNiceMethod();
dismiss(); // close the dialog (if this is what you want).
}
The interface looks like:
public interface YourInterface {
void onSomeNiceMethod();
}
And your Activity…
public class YourActivity implements YourInterface {
void onSomeNiceMethod() {
// Hey! The Button In The Dialog Has Been Pressed!
}
}

All Activity and Fragment classes have a built-in callback method for you to use when you start another Activity, Fragment, Dialog, or DialogFragment.
void onActivityResult(int requestCode, int resultCode, Intent data)
Since you want to start the Dialog from an Activity, using the Dialog class is better than the DialogFragment class. The latter is better for starting a dialog from a Fragment, because it has two methods for communicating back to the Fragment (get/set TargetFragment())
The Dialog class has the getOwnerActivity() method. This is the Activity you use when creating the Dialog with one of its constructors.
You set a onClickListener on the button in the Dialog class. To pass the result back to the Activity:
getOwnerActivity().onActivityResult(intIdentifyingme, Activity.RESULT_OK,
intent);
dismiss(); // close the dialog
You put additional info you want to send in an Intent.

1) onclick attribute in the Button and a method inside the Actvity.
That was my original plan, but I don't how to get the Dialog from the
Activity to dismiss it. Even if this is not the right way, how could
this be done? I would like to understand how this works.
Basically your Activity has to remember/know which dialog is active at the moment with something like curDialog=dialogFragment;, then when handling the button onclick action you'll know which dialog to dismiss. But this is really not a good idea since basically the Button View would "leak" from your DialogFragment to your Activity, which breaks object encapsulation.
2) set on click listener on the button when the Dialog is created in
DialogFragment. This will require me to pass some context from the
Activity to the DialogFragment, so I would like to avoid it (and keep
the DialogFragment as simple as possible).
As a previous answer mentioned, you don't need to pass any Context to it, especially since you can get the Activity by calling getActivity().
The solution depends on whether or not this dialog would be used by multiple Activities:
Used by a single Activity: #Martin's solution will work just fine
Used by multiple Activity: abstraction can be used such that only the user's decision is passed to a listener. This is a (modified) solution I came up for the same problem:
public class BaseDialogFragment extends DialogFragment {
protected TextView dialogEn;
protected Button dialogYes;
private Button dialogNo;
protected OnSelectListener listener;
public interface OnSelectListener {
public void onSelect(int type, boolean yes);
}
public void setOnSelectListener(OnSelectListener listener) {
this.listener = listener;
}
public BaseDialogFragment() {
super();
}
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.dialog_confirm, container, false);
dialogYes = (Button) v.findViewById(R.id.yes);
dialogNo = (Button) v.findViewById(R.id.no);
dialogEn = (TextView) view.findViewById(R.id.dialog_en);
dialogEn.setText(getArguments().getString("text_en"));
dialogYes.setOnClickListener(this);
dialogNo.setOnClickListener(this);
return v;
}
public void onClick(View v) {
if (listener != null) {
listener.onSelect(getArguments().getInt("type"),
v == dialogYes ? true : false);
}
getDialog().dismiss();
}
}
To use it some additional info needs to be provided:
Bundle bundle = new Bundle();
bundle.putInt("type", type); //type: an unique integer value that helps differentiate result from different dialogs
bundle.putString("text_en", en); //en: String to be displayed
dialog.setArguments(bundle);
dialog.setOnSelectListener(this);
So if the type value above is set to 115, then a dialogYes button click would trigger public void onSelect(int type, boolean yes) method to be called with 115 and true as the 1st & 2nd parameters.

Your first point about the onClick attribute in the xml should be avoided. Because handling a Dialog that way could be really painfull if you respect events like screen rotation or a setup with multiple dialogs. This leads into leaked window errors most of the time and needs unnecessary code overhead to avoid this. Because you have to keep track of the Dialog which is actually shown yourself.
To be able to dismiss the Dialog this way you can use the Tag you setted as you called dialogFragment.show(fragmentManager, "edit_task_list");
DialogFragment frag = (DialogFragment)getFragmentManager().findFragmentByTag("edit_task_list");
if(frag != null)
frag.dismiss();
The proper solution is to use an interface as a callback for the communication between the DialogFragment and the Activity. This keeps the Dialog modular and the code easy. Here is an example from the docs. For this you don't need a Context. You simply pass the interface to the dialog in the onAttach() callback. It has a reference of the Activity as a parameter, which called that Dialog.
// Example interface for the communication
public interface OnArticleSelectedListener {
public void onButtonClicked(/*any Parameters*/);
}
public static class FragmentA extends DialogFragment {
OnArticleSelectedListener mListener;
...
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnArticleSelectedListener) activity; // get the interface of the Activity
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnArticleSelectedListener");
}
}
...
}
Handle the Button click in the Dialog and call dismiss() in it, that the Dialog can dismiss itself. Have a look at this question why to use dismiss() instead of getDialog().dismiss().
yourButton.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v){
if(mListener != null) // check if the listener is still valid
mListener.onButtonClicked(...); // calls the Activity implementation of this callback
dismiss(); // dismiss the Dialog
}
});
In onPause() of the Dialog set the reference of the interface to null. This way you can be sure that the callback will only be used if the Dialog is showing.
Your Activity looks something like this to be able to handle the callback:
public class MyActivity extends Activity implements OnArticleSelectedListener{
...
#Override
public void onButtonClicked(...){
// your implementation here
}
}
I don't know your overall setup but if you would use an AlertDialog a click on the Buttons dismiss the Dialog automatically when the method returns.

Prevent dialog dismissal on screen rotation in Android

I am trying to prevent dialogs built with Alert builder from being dismissed when the Activity is restarted.
If I overload the onConfigurationChanged method I can successfully do this and reset the layout to correct orientation but I lose sticky text feature of edittext. So in solving the dialog problem I have created this edittext problem.
If I save the strings from the edittext and reassign them in the onCofiguration change they still seem to default to initial value not what was entered before rotation. Even if I force an invalidate does seem to update them.
I really need to solve either the dialog problem or the edittext problem.
Thanks for the help.

The best way to avoid this problem nowadays is by using a DialogFragment.
Create a new class which extends DialogFragment. Override onCreateDialog and return your old Dialog or an AlertDialog.
Then you can show it with DialogFragment.show(fragmentManager, tag).
Here's an example with a Listener:
public class MyDialogFragment extends DialogFragment {
public interface YesNoListener {
void onYes();
void onNo();
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
if (!(activity instanceof YesNoListener)) {
throw new ClassCastException(activity.toString() + " must implement YesNoListener");
}
}
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
return new AlertDialog.Builder(getActivity())
.setTitle(R.string.dialog_my_title)
.setMessage(R.string.dialog_my_message)
.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
((YesNoListener) getActivity()).onYes();
}
})
.setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
((YesNoListener) getActivity()).onNo();
}
})
.create();
}
}
And in the Activity you call:
new MyDialogFragment().show(getSupportFragmentManager(), "tag"); // or getFragmentManager() in API 11+
This answer helps explain these other three questions (and their answers):
Android Best way of avoid Dialogs to dismiss after a device rotation
Android DialogFragment vs Dialog
How can I show a DialogFragment using compatibility package?

// Prevent dialog dismiss when orientation changes
private static void doKeepDialog(Dialog dialog){
WindowManager.LayoutParams lp = new WindowManager.LayoutParams();
lp.copyFrom(dialog.getWindow().getAttributes());
lp.width = WindowManager.LayoutParams.WRAP_CONTENT;
lp.height = WindowManager.LayoutParams.WRAP_CONTENT;
dialog.getWindow().setAttributes(lp);
}
public static void doLogout(final Context context){
final AlertDialog dialog = new AlertDialog.Builder(context)
.setIcon(android.R.drawable.ic_dialog_alert)
.setTitle(R.string.titlelogout)
.setMessage(R.string.logoutconfirm)
.setPositiveButton("Yes", new DialogInterface.OnClickListener()
{
#Override
public void onClick(DialogInterface dialog, int which) {
...
}
})
.setNegativeButton("No", null)
.show();
doKeepDialog(dialog);
}

If you're changing the layout on orientation change I wouldn't put android:configChanges="orientation" in your manifest because you're recreating the views anyway.
Save the current state of your activity (like text entered, shown dialog, data displayed etc.) using these methods:
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
}
That way the activity goes through onCreate again and afterwards calls the onRestoreInstanceState method where you can set your EditText value again.
If you want to store more complex Objects you can use
#Override
public Object onRetainNonConfigurationInstance() {
}
Here you can store any object and in onCreate you just have to call getLastNonConfigurationInstance(); to get the Object.

Just add android:configChanges="orientation" with your activity
element in AndroidManifest.xml
Example:
<activity
android:name=".YourActivity"
android:configChanges="orientation"
android:label="#string/app_name"></activity>

A very easy approach is to create the dialogs from the method onCreateDialog() (see note below). You show them through showDialog(). This way, Android handles the rotation for you and you do not have to call dismiss() in onPause() to avoid a WindowLeak and then you neither have to restore the dialog. From the docs:
Show a dialog managed by this activity. A call to onCreateDialog(int, Bundle) will be made with the same id the first time this is called for a given id. From thereafter, the dialog will be automatically saved and restored.
See Android docs showDialog() for more info. Hope it helps somebody!
Note: If using AlertDialog.Builder, do not call show() from onCreateDialog(), call create() instead. If using ProgressDialog, just create the object, set the parameters you need and return it. In conclusion, show() inside onCreateDialog() causes problems, just create de Dialog instance and return it. This should work! (I have experienced issues using showDialog() from onCreate() -actually not showing the dialog-, but if you use it in onResume() or in a listener callback it works well).

This question was answered a long time ago.
Yet this is non-hacky and simple solution I use for myself.
I did this helper class for myself, so you can use it in your application too.
Usage is:
PersistentDialogFragment.newInstance(
getBaseContext(),
RC_REQUEST_CODE,
R.string.message_text,
R.string.positive_btn_text,
R.string.negative_btn_text)
.show(getSupportFragmentManager(), PersistentDialogFragment.TAG);
Or
PersistentDialogFragment.newInstance(
getBaseContext(),
RC_EXPLAIN_LOCATION,
"Dialog title",
"Dialog Message",
"Positive Button",
"Negative Button",
false)
.show(getSupportFragmentManager(), PersistentDialogFragment.TAG);
public class ExampleActivity extends Activity implements PersistentDialogListener{
#Override
void onDialogPositiveClicked(int requestCode) {
switch(requestCode) {
case RC_REQUEST_CODE:
break;
}
}
#Override
void onDialogNegativeClicked(int requestCode) {
switch(requestCode) {
case RC_REQUEST_CODE:
break;
}
}
}

Definitely, the best approach is by using DialogFragment.
Here is mine solution of wrapper class that helps to prevent different dialogs from being dismissed within one Fragment (or Activity with small refactoring). Also, it helps to avoid massive code refactoring if for some reasons there are a lot of AlertDialogs scattered among the code with slight differences between them in terms of actions, appearance or something else.
public class DialogWrapper extends DialogFragment {
private static final String ARG_DIALOG_ID = "ARG_DIALOG_ID";
private int mDialogId;
/**
* Display dialog fragment.
* #param invoker The fragment which will serve as {#link AlertDialog} alert dialog provider
* #param dialogId The ID of dialog that should be shown
*/
public static <T extends Fragment & DialogProvider> void show(T invoker, int dialogId) {
Bundle args = new Bundle();
args.putInt(ARG_DIALOG_ID, dialogId);
DialogWrapper dialogWrapper = new DialogWrapper();
dialogWrapper.setArguments(args);
dialogWrapper.setTargetFragment(invoker, 0);
dialogWrapper.show(invoker.getActivity().getSupportFragmentManager(), null);
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mDialogId = getArguments().getInt(ARG_DIALOG_ID);
}
#NonNull
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
return getDialogProvider().getDialog(mDialogId);
}
private DialogProvider getDialogProvider() {
return (DialogProvider) getTargetFragment();
}
public interface DialogProvider {
Dialog getDialog(int dialogId);
}
}
When it comes to Activity you can invoke getContext() inside onCreateDialog(), cast it to the DialogProvider interface and request a specific dialog by mDialogId. All logic to dealing with a target fragment should be deleted.
Usage from fragment:
public class MainFragment extends Fragment implements DialogWrapper.DialogProvider {
private static final int ID_CONFIRMATION_DIALOG = 0;
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
Button btnHello = (Button) view.findViewById(R.id.btnConfirm);
btnHello.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
DialogWrapper.show(MainFragment.this, ID_CONFIRMATION_DIALOG);
}
});
}
#Override
public Dialog getDialog(int dialogId) {
switch (dialogId) {
case ID_CONFIRMATION_DIALOG:
return createConfirmationDialog(); //Your AlertDialog
default:
throw new IllegalArgumentException("Unknown dialog id: " + dialogId);
}
}
}
You can read the complete article on my blog How to prevent Dialog being dismissed? and play with the source code.

It seems that this is still an issue, even when "doing everything right" and using DialogFragment etc.
There is a thread on Google Issue Tracker which claims that it is due to an old dismiss message being left in the message queue. The provided workaround is quite simple:
#Override
public void onDestroyView() {
/* Bugfix: https://issuetracker.google.com/issues/36929400 */
if (getDialog() != null && getRetainInstance())
getDialog().setDismissMessage(null);
super.onDestroyView();
}
Incredible that this is still needed 7 years after that issue was first reported.

You can combine the Dialog's onSave/onRestore methods with the Activity's onSave/onRestore methods to keep the state of the Dialog.
Note: This method works for those "simple" Dialogs, such as displaying an alert message. It won't reproduce the contents of a WebView embedded in a Dialog. If you really want to prevent a complex dialog from dismissal during rotation, try Chung IW's method.
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
myDialog.onRestoreInstanceState(savedInstanceState.getBundle("DIALOG"));
// Put your codes to retrieve the EditText contents and
// assign them to the EditText here.
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// Put your codes to save the EditText contents and put them
// to the outState Bundle here.
outState.putBundle("DIALOG", myDialog.onSaveInstanceState());
}

I had a similar problem: when the screen orientation changed, the dialog's onDismiss listener was called even though the user didn't dismiss the dialog. I was able to work around this by instead using the onCancel listener, which triggered both when the user pressed the back button and when the user touched outside of the dialog.

In case nothing helps, and you need a solution that works, you can go on the safe side, and each time you open a dialog save its basic info to the activity ViewModel (and remove it from this list when you dismiss dialog). This basic info could be dialog type and some id (the information you need in order to open this dialog). This ViewModel is not destroyed during changes of Activity lifecycle. Let's say user opens a dialog to leave a reference to a restaurant. So dialog type would be LeaveReferenceDialog and the id would be the restaurant id. When opening this dialog, you save this information in an Object that you can call DialogInfo, and add this object to the ViewModel of the Activity. This information will allow you to reopen the dialog when the activity onResume() is being called:
// On resume in Activity
override fun onResume() {
super.onResume()
// Restore dialogs that were open before activity went to background
restoreDialogs()
}
Which calls:
fun restoreDialogs() {
mainActivityViewModel.setIsRestoringDialogs(true) // lock list in view model
for (dialogInfo in mainActivityViewModel.openDialogs)
openDialog(dialogInfo)
mainActivityViewModel.setIsRestoringDialogs(false) // open lock
}
When IsRestoringDialogs in ViewModel is set to true, dialog info will not be added to the list in view model, and it's important because we're now restoring dialogs which are already in that list. Otherwise, changing the list while using it would cause an exception. So:
// Create new dialog
override fun openLeaveReferenceDialog(restaurantId: String) {
var dialog = LeaveReferenceDialog()
// Add id to dialog in bundle
val bundle = Bundle()
bundle.putString(Constants.RESTAURANT_ID, restaurantId)
dialog.arguments = bundle
dialog.show(supportFragmentManager, "")
// Add dialog info to list of open dialogs
addOpenDialogInfo(DialogInfo(LEAVE_REFERENCE_DIALOG, restaurantId))
}
Then remove dialog info when dismissing it:
// Dismiss dialog
override fun dismissLeaveReferenceDialog(Dialog dialog, id: String) {
if (dialog?.isAdded()){
dialog.dismiss()
mainActivityViewModel.removeOpenDialog(LEAVE_REFERENCE_DIALOG, id)
}
}
And in the ViewModel of the Activity:
fun addOpenDialogInfo(dialogInfo: DialogInfo){
if (!isRestoringDialogs){
val dialogWasInList = removeOpenDialog(dialogInfo.type, dialogInfo.id)
openDialogs.add(dialogInfo)
}
}
fun removeOpenDialog(type: Int, id: String) {
if (!isRestoringDialogs)
for (dialogInfo in openDialogs)
if (dialogInfo.type == type && dialogInfo.id == id)
openDialogs.remove(dialogInfo)
}
You actually reopen all the dialogs that were open before, in the same order. But how do they retain their information? Each dialog has a ViewModel of its own, which is also not destroyed during the activity lifecycle. So when you open the dialog, you get the ViewModel and init the UI using this ViewModel of the dialog as always.

Yes, I agree with the solution of using DialogFragment given by #Brais Gabin, just want to suggest some changes to the solution given by him.
While defining our custom class that extends DialogFragment, we require some interfaces to manage the actions ultimately by the activity or the fragment that has invoked the dialog. But setting these listener interfaces in the onAttach(Context context) method may sometimes cause ClassCastException that may crash the app.
So to avoid this exception, we can create a method to set the listener interfaces and call just it after creating the object of the dialog fragment.
Here is a sample code that could help you understand more-
AlertRetryDialog.class
public class AlertRetryDialog extends DialogFragment {
public interface Listener{
void onRetry();
}
Listener listener;
public void setListener(Listener listener)
{
this.listener=listener;
}
#NonNull
#Override
public Dialog onCreateDialog(#Nullable Bundle savedInstanceState) {
AlertDialog.Builder builder=new AlertDialog.Builder(getActivity());
builder.setMessage("Please Check Your Network Connection").setPositiveButton("Retry", new
DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
//Screen rotation will cause the listener to be null
//Always do a null check of your interface listener before calling its method
if(listener!=null&&listener instanceof HomeFragment)
listener.onRetry();
}
}).setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
return builder.create();
}
}
And in the Activity or in the Fragment you call-
AlertRetryDialog alertRetryDialog = new AlertRetryDialog();
alertRetryDialog.setListener(HomeFragment.this);
alertRetryDialog.show(getFragmentManager(), "tag");
And implement the methods of your listener interface in your Activity or the Fragment-
public class YourActivity or YourFragment implements AlertRetryDialog.Listener{
//here's my listener interface's method
#Override
public void onRetry()
{
//your code for action
}
}
Always make sure that you do a null check of the listener interfaces before calling any of its methods to prevent NullPointerException (Screen rotation will cause the listener interfaces to be null).
Please do let me know if you find this answer helpful. Thank You.

Just use
ConfigurationChanges = Android.Content.PM.ConfigChanges.Orientation | Android.Content.PM.ConfigChanges.ScreenSize
and app will know how to handle rotation and screen size.