How to correctly dismiss a DialogFragment? - android

The docs say this for the dismiss() method from the Dialog class:
Dismiss this dialog, removing it from the screen. This method can be invoked
safely from any thread. Note that you should not override this method to do
cleanup when the dialog is dismissed, instead implement that in onStop().
In my code, all I do is call getDialog().dismiss() to dismiss it. But I am not doing anything else or even using onStop(). So I am asking exactly how to correctly dismiss a DialogFragment to avoid any memory leaks, etc..

tl;dr: The correct way to close a DialogFragment is to use dismiss() directly on the DialogFragment.
Details: The documentation of DialogFragment states
Control of the dialog (deciding when to show, hide, dismiss it) should be done through the API here, not with direct calls on the dialog.
Thus, you should not use getDialog().dismiss(), since that would invoke dismiss() on the dialog. Instead, you should use the dismiss() method of the DialogFragment itself:
public void dismiss()
Dismiss the fragment and its dialog. If the fragment was added to the back stack, all back stack state up to and including this entry will be popped. Otherwise, a new transaction will be committed to remove the fragment.
As you can see, this takes care not only of closing the dialog but also of handling the fragment transactions involved in the process.
You only need to use onStop if you explicitly created any resources that require manual cleanup (closing files, closing cursors, etc.). Even then, I would override onStop of the DialogFragment rather than onStop of the underlying Dialog.

I think a better way to close a DialogFragment is this:
Fragment prev = getSupportFragmentManager().findFragmentByTag("fragment_dialog");
if (prev != null) {
DialogFragment df = (DialogFragment) prev;
df.dismiss();
}
This way you dont have to hold a reference to the DialogFragment and can close it from everywhere.

Why don't you try using only this code:
dismiss();
If you want to dismiss the Dialog Fragment by its own. You can simply put this code inside the dialog fragment where you want to dismiss the Dialog.
For example:
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dismiss();
}
});
This will close the recent Dialog Fragment that is shown on the screen.
Hope it helps for you.

I gave an upvote to Terel's answer. I just wanted to post this for any Kotlin users:
supportFragmentManager.findFragmentByTag(TAG_DIALOG)?.let {
(it as DialogFragment).dismiss()
}

Kotlin Version of Terel answer
(fragmentManager.findFragmentByTag(TAG) as? DialogFragment)?.dismiss()

You should dismiss you Dialog in onPause() so override it.
Also before dismissing you can check for null and is showing like below snippet:
#Override
protected void onPause() {
super.onPause();
if (dialog != null && dialog.isShowing()) {
dialog.dismiss();
}
}

There are references to the official docs (DialogFragment Reference) in other answers, but no mention of the example given there:
void showDialog() {
mStackLevel++;
// DialogFragment.show() will take care of adding the fragment
// in a transaction. We also want to remove any currently showing
// dialog, so make our own transaction and take care of that here.
FragmentTransaction ft = getFragmentManager().beginTransaction();
Fragment prev = getFragmentManager().findFragmentByTag("dialog");
if (prev != null) {
ft.remove(prev);
}
ft.addToBackStack(null);
// Create and show the dialog.
DialogFragment newFragment = MyDialogFragment.newInstance(mStackLevel);
newFragment.show(ft, "dialog");
}
This removes any currently shown dialog, creates a new DialogFragment
with an argument, and shows it as a new state on the back stack. When
the transaction is popped, the current DialogFragment and its Dialog
will be destroyed, and the previous one (if any) re-shown. Note that
in this case DialogFragment will take care of popping the transaction
of the Dialog is dismissed separately from it.
For my needs I changed it to:
FragmentManager manager = getSupportFragmentManager();
Fragment prev = manager.findFragmentByTag(TAG);
if (prev != null) {
manager.beginTransaction().remove(prev).commit();
}
MyDialogFragment fragment = new MyDialogFragment();
fragment.show(manager, TAG);

CustomFragment dialog = (CustomDataFragment) getSupportFragmentManager().findFragmentByTag("Fragment_TAG");
if (dialog != null) {
dialog.dismiss();
}

Adding to the other answers, when having a DialogFragment that is full screen calling dismiss() won't pop the DialogFragment from the fragment backstack. A workaround is to call onBackPressed() on the parent activity.
Something like this:
CustomDialogFragment.kt
closeButton.onClick {
requireActivity().onBackPressed()
}

I found that when my fragment was defined in the navigation graph with a <fragment> tag (for a full screen dialogfragment), the dialogfragment would not dismiss with the dismiss() command. Instead, I had to pop the back stack:
findNavController(getActivity(), R.id.nav_host_fragment).popBackStack();
However, if the same dialogfragment was defined in the navigation graph with a <dialog> tag, dismiss() works fine.

Just call dismiss() from the fragment you want to dismiss.
imageView3.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
dismiss();
}
});

Consider the below sample code snippet which demonstrates how to dismiss a dialog fragment safely:
DialogFragment dialogFragment = new DialogFragment();
/**
* do something
*/
// Now you want to dismiss the dialog fragment
if (dialogFragment.getDialog() != null && dialogFragment.getDialog().isShowing())
{
// Dismiss the dialog
dialogFragment.dismiss();
}
Happy Coding!

Here is a simple AppCompatActivity extension function, which closes opened Dialog Fragment:
fun AppCompatActivity.whenDialogOpenDismiss(
tag: String
) {
supportFragmentManager.findFragmentByTag(tag)?.let {
if(it is DialogFragment) it.dismiss() }
}
Of course you can call it from any activity directly.
If you need to call it from a Fragment just make the same extension function about Fragment class

Related

Dismissing dialog and showing new one shortly shows underlying fragment before opening new dialog

I currently have one fragment that shows dialogfragment, and when I press the button on dialogfragment, I want to show another dialogfragment. In my first dialog fragment I have following method:
fun showSecondDialog() {
dismiss()
SecondDialog().showDialog(targetFragment!!)
}
showDialog() looks like this:
fun showDialog(fragment: Fragment) {
val fragmentManager = fragment.fragmentManager
val ft = fragmentManager!!.beginTransaction()
val prev = fragmentManager.findFragmentByTag(getName())
if (prev != null) {
ft.remove(prev)
}
ft.addToBackStack(null)
setTargetFragment(fragment, 0)
show(ft, getName())
}
The problem is, that dismissing dialog works immediately, but before the new dialog is shown there is a gap, where my underlying fragment is fully visible and this causes an undesirable flicker.
How to show second dialog immediately, or how to know when it's opened, so I could close the first one?
I am also having this same problem, but you can try a workaround like this if it works according to your requirement :
fun showSecondDialog() {
SecondDialog().showDialog(targetFragment!!)
Handler().postDelayed({ dismiss() }, 1000)
}
Google recommends all the fragment inflate, replace, dismiss...should be done in the parent activity and no fragment should know anything about any other fragment. That way fragments can be reused like they were initially designed to.

what is correct approach to perform UI related task when a dialog gets dismissed

I have a dialog with onDismiss handler:
public class TextReaderDialog extends DialogFragment {
...
public void onDismiss() {
}
I show this dialog and add some styles to a part of text from the fragment:
TextReaderDialog d = new TextReaderDialog();
d.show(getFragmentManager(), "sample");
Spannable spannableText = new SpannableString(tv.getText());
spannableText.setSpan(new BackgroundColorSpan(Color.LTGRAY), startOffset, startOffset + w.word.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
tv.setText(spannableText);
Whenever a dialog is dismissed, I want to remove styles from the text. How can I do that? What is the correct way to do that?
The simplest way to go about this would be to add a method to your fragment like so:
public void dismissStyles(){
//do your style dismissing here
}
Now, I assume in the dialog you are overriding DialogFragment.onDismiss(DialogInterface dialog). As long as that is the case, once you have completed that method, in your dialog's onDismiss function, you can do something to the effect of:
#Override
public void onDismiss(DialogInterface dialog) {
super.onDismiss(dialog);
MyFragment fragment = (MyFragment) activity
.getFragmentManager()
.findFragmentByID(R.id.containerOfYourFragment);
if(fragment != null){
fragment.dismissStyles();
}
}
Here, activity should be the current activity that your fragment and dialog are hosted in. You can pass this to the dialog in a constructor, or depending on where the dialog is located. You could also just pass the current fragment to the dialog in the constructor as well, and then it would simply be called by myFragment.dismissStyles();.

DialogFragment dismiss() does not pop backstack

I have a simple DialogFragment that calls dismiss when exits, according to the documentation:
public void dismiss()
Dismiss the fragment and its dialog. If the fragment was added to the
back stack, all back stack state up to and including this entry will
be popped. Otherwise, a new transaction will be committed to remove
the fragment.
however, I found that the fragment is still on the backstack after calling dismiss() so I have to click back button to clear it. Does anyone know why ?
here's my code:
public void onCreate(Bundle b) {
super.onCreate(b);
setContentView(R.layout.test_layout);
class MyDialogFragment extends DialogFragment implements OnClickListener{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.hello_world, container, false);
Button b = (Button)v.findViewById(R.id.btn);
b.setOnClickListener(this);
return v;
}
#Override
public void onClick(View v) {
dismiss();
}
}
getFragmentManager().beginTransaction().add(android.R.id.content, new MyDialogFragment(), "test").addToBackStack("b").commit();
}
#Override
public void onBackPressed() {
if (getFragmentManager().getBackStackEntryCount() > 0 ){
getFragmentManager().popBackStack();
} else {
super.onBackPressed();
}
}
}
I also found out that if I don't override onBackPressed(), the back button simple doesn't work, no matter how many fragments I add to the activity, the back button always exits the activity right away.
I can confirm what #Luksprog said in his comment: the dialog must be started through show(FragmentTransaction, String).
Note after looking the source: make sure to call addToBackStack(String) on the supplied transaction or else it still won't work.
That it's a wrong way to create a DialogFragment.
Never ever use the FragmentManager to show a DialogFragment. To be shown there are a method called show(FragmentTransacion, String).
In java:
MyDialogFragment mDialogFragment = new MyDialogFragment();
mDialogFragment.show(getFragmentManager(), "MyDialogFragment");
For another hand, to dismiss the dialog just do this:
mDialogFragment.dismiss()
Another think that I would like to highlight is that the MyDialogFragment class is defined inner onCreate method :'(
Please, define the class outside the method or in another file if you want :)
Good Look!
dismiss()
findNavController().navigate(FirstBottomSheetDialogDirections.actionFirstSheetToSecondSheet())
This code is always the wrong thing to do: dismiss() is an asynchronous operation that doesn't actually dismiss anything immediately. That is unlike the navigate() which does immediately update the NavController's state, stacking the new dialog destination on top of the previous one.
This means that when the asynchronous dismiss actually happens, it correctly removes the dialog and, because it is a navigation stack, removes everything on top of it - including your second dialog. However, due to a bug in the DialogFragmentNavigator, we don't actually dismiss that second dialog, which is why it appears to work, despite everything actually already being internally out of sync (thus causing the later crash).
The correct way to pop a destination and navigate to a new destination as an atomic, immediate operation is to use popUpTo and popUpToInclusive. Therefore you can fix the sample app by removing the call to dismiss() and updating the action to pop the first dialog as part of the navigate call:
<action
android:id="#+id/action_firstSheet_to_secondSheet"
app:destination="#id/secondSheet"
app:popUpTo="#id/firstSheet"
app:popUpToInclusive="true"/>
This correctly pops the first dialog off the back stack and then navigates to the new dialog destination.
please refer this link : https://issuetracker.google.com/issues/191073055

Can I show() a FragmentDialog after dismiss()?

I have a FragmentDialog sppearing in front of a GoogleMap that I want to temporarily hide so that the user can select something on the background, and then bring it back in front again. Regular hide()/show() won't work since it's not "embedded" fragment, but a FragmentDialog cannot be hidden. I tried to use dismiss() and then show() using the same instance, since that should recreate the dialog, but it doesn't seem to work for some reason. Here's my code:
if (onHoldDialog != null) {
onHoldDialog.setPointText(mapMarker.getTitle());
FragmentTransaction ft = getFragmentManager().beginTransaction();
Fragment prev = getFragmentManager().findFragmentByTag("dialog");
if (prev != null) {
ft.remove(prev);
}
ft.addToBackStack(null);
onHoldDialog.show(ft, "dialog");
}
Is my method wrong? Are FragmentDialog instances only "one-use"? Can I copy it to another instance?
The problem I had was I overrode onDismiss in my DialogFragment subclass, but I didn't call super.onDismiss. Once I called the super's method, the problem was fixed.
In general, remember to call the super method of an overridden method in fragments and activities.

DialogFragment and back button

Is there any possibility to intercept the key button in DialogFragment? sorry for the naive question.. the onBackPressed of my FragmentActivity is never called.
thanks in advance
if (imageFile.exists()) {
ShowPicDialog newFragment = ShowPicDialog.newInstance();
FragmentTransaction ft = manager.beginTransaction();
Fragment prev = manager.findFragmentByTag("picDialog");
if (prev != null) {
ft.remove(prev);
}
ft.addToBackStack("picDialog");
newFragment.getArguments().putString("path", imageFile.getAbsolutePath());
newFragment.show(ft, "picDialog");
}
sorry I added the snip of code I use to show the dialog.
It's hard to say for sure what the issue is, since you haven't posted any code. But my first guess is that you haven't added the DialogFragment to the back stack by calling the addToBackStack method of the FragmentTransaction that you're using to add your fragment to the activity.
There are examples right in the Android documentation pages that give examples of a good pattern for using a DialogFragment in your Activity.
Since you are displaying a Dialog, the created Dialog will receive the key events, not the parent Activity. So, set a Dialog.OnKeyListener when you create the Dialog's fragment, and call setCancelable(false) on the Dialog to prevent the back key from dismissing it. You can then handle the back key in your OnKeyListener's onkey method.
Best way to Handle DialogFragment with back button:
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
return new Dialog(getActivity(), getTheme()){
#Override
public void onBackPressed() {
// On backpress, do your stuff here.
}
};
}
Rahul Pundhir's answer works great if you aren't using the builder pattern. If you are using the Builder pattern on your dialog you can instead do this:
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog alertDialog = new AlertDialog.Builder(getContext())
.setTitle(...)
.setPositiveButton(...)
.setNegativeButton(...)
.setMessage(...)
.create();
alertDialog.setOnKeyListener((dialog, keyCode, event) -> {
if (keyCode == KeyEvent.KEYCODE_BACK
&& event.getAction() == KeyEvent.ACTION_UP) {
// TODO do the "back pressed" work here
return true;
}
return false;
});
return alertDialog;
}
This works by mimicking how the system calls onBackPressed() in the first place (ignoring the tracking and listening for ACTION_UP). See the source on Dialog

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