Custom list preference dialog layout in Preference Screen, with custom list items

I want to create a custom list dialog when I click on a ListPreference in Settings Activity.

ListPreference in root_preferences.xml:

  <ListPreference
        android:icon="@drawable/pref_language"
        app:defaultValue="en"
        app:entries="@array/language_entries"
        app:entryValues="@array/language_values"
        app:iconSpaceReserved="false"
        app:key="@string/prefkey_language"
        app:summary="%s"
        app:title="@string/language_title" />

I want it to have rounded corners, and I also want custom listitem views (e.g. images instead of the default radiobuttons).

Actual result:

Expected result:

Can I do this in a way that I use ListPreference, but replace @array entries with an adapter?

Is there any other way to achieve this without needing to get rid of the PreferenceScreen?

Meanwhile, I have found a solution. It's probably not the cleanest one, but it works for me. If anyone knows a better solution, don't hesitate to let us know.

1. Create a class that extends DialogPreference. Create as many classes as many custom dialogs you want to have, e.g. LanguagePreference, UnitPreference, etc.

   public class LanguagePreference extends DialogPreference implements Preference.OnPreferenceChangeListener {
   
      public LanguagePreference(Context context, AttributeSet attrs) {
          super(context, attrs);
          setOnPreferenceChangeListener(this);
      }
   
      @Override
      public boolean onPreferenceChange(Preference preference, Object newValue) {
          // do something
          return true;
      }
   }
   

2. Now you can use these in root_preferences.xml.

    <PreferenceCategory app:title="@string/category">
        <com.company.yourapp.preferences.LanguagePreference
            android:icon="@drawable/pref_language"
            app:title="@string/language" />
   
        <com.company.yourapp.preferences.UnitPreference
            android:icon="@drawable/pref_unit"
            app:title="@string/unit" />
    </PreferenceCategory>
   

3. Create a class that extends DialogFragment (may be abstract). Remove default background and title in onViewCreated().

   public abstract class RoundedPreferenceDialog extends DialogFragment {
   
       @Override
       public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
           if (getDialog() != null && getDialog().getWindow() != null) {
               getDialog().getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));  // remove default background so that dialog can be rounded
               getDialog().getWindow().requestFeature(Window.FEATURE_NO_TITLE);  // remove default title
           }
           super.onViewCreated(view, savedInstanceState);
       }
   }
   

4. Extend classes from RoundedPreferenceDialog, e.g. LanguagePreferenceDialog, UnitPreferenceDialog.

   public class LanguagePreferenceDialog extends RoundedPreferenceDialog {
   
      public static LanguagePreferenceDialog newInstance() {
          return new LanguagePreferenceDialog();
      }
   
      @Override
      public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
          View view = inflater.inflate(R.layout.dialogpreference_language, container, false);
   
          // init UI, list adapter, listeners
   
          return view;
      }
   }
   

5. Override onDisplayPreferenceDialog in SettingsFragment. Create a condition for each custom dialog you have.

    @Override
    public void onDisplayPreferenceDialog(Preference preference) {
        if (preference instanceof LanguagePreference) {         // rounded language dialog
            LanguagePreferenceDialog.newInstance().show(getParentFragmentManager(), null);
        } else if (preference instanceof UnitPreference) {      // rounded unit dialog
            UnitPreferenceDialog.newInstance().show(getParentFragmentManager(), null);
        } else {
            super.onDisplayPreferenceDialog(preference);
        }
    }
   

6. Now you can display a custom dialog instead of the default one. You just have to customize it the way you want. To make it rounded, set the background of the root layout to a custom rounded layout.

dialogpreference_language.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:id="@+id/dialogLayout"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:background="@drawable/bg_dialog_rounded">

   <!-- titleTextView, languageListView, cancelButton, etc. -->
</RelativeLayout>

bg_dialog_rounded.xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <corners android:radius="@dimen/dialog_radius" />
    <solid android:color="@color/white" />
</shape>

7. Set the style of the list items in your listitem layout file, e.g. listitem_language.xml, which is inflated in the adapter. (ImageView+TextView in the example below.)

Final result: