How to manage dividers in a PreferenceFragment?

Question

I started dealing with preferences in a PreferenceFragment. Here\'s what I have:

Answer 1

You can re-style your divider using this theme.

<style name="PreferenceFragment.Material">
    <item name="android:divider">@drawable/preference_list_divider_material</item>
</style>

Answer 2

Although a bit late I`m having same troubles with dividers in preff screen and found this solution: Set custom style to the hosting activity and add to the style:

   <item name="android:listDivider">@null</item>

It actually does the same as setting it trough code but you save one findById and i think it looks clearer set trough styles

Answer 3

For PreferenceFragmentCompat, ListView doesn't work. But this works like a charm:

<style name="PrefsTheme" parent="PreferenceThemeOverlay.v14.Material">
    <item name="android:divider">@null</item>
    <item name="android:dividerHeight">0dp</item>
</style>

Add this to your app theme:

<item name="preferenceTheme">@style/PrefsTheme</item>

Answer 4

Had totally forgot about this question, will post an answer now to help others. I solved by moving my code in the onResume() method of the activity that hosts my PreferenceFragment. I think there are several other points at which you can recall a non-null ListView using findViewById(android.R.id.list).

public boolean mListStyled;

@Override
public void onResume() {
    super.onResume();
    if (!mListStyled) {
        View rootView = getView();
        if (rootView != null) {
            ListView list = (ListView) rootView.findViewById(android.R.id.list);
            list.setPadding(0, 0, 0, 0);
            list.setDivider(null);
            //any other styling call
            mListStyled = true;
        }
    }
}

You can probably get rid of the rootView check, but at the same time you might even want to check for list != null. I didn't face any NPE this way anyway.

So, setDivider(null) takes off the item-item dividers. I managed to add section dividers covering the full width of the screen by:

• Removing padding from list;
• Adding a custom preference in my XML:

n

 <Preference
     android:title="divider"
     android:selectable="false"
     android:layout="@layout/preference_divider"/>

Answer 5

AndroidX makes it simple, but I wish it was better documented.

In XML

To add/remove dividers between preferences in XML, use the following attributes:

<androidx.preference.PreferenceScreen
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <Preference
        ...
        app:allowDividerAbove="true/false"
        app:allowDividerBelow="true/false"
        ... />

</androidx.preference.PreferenceScreen>

Note, a divider will only be shown between two preferences if the top divider has allowDividerBelow set to true and the bottom divider has allowDividerAbove set to true.

In Code

You can also change/remove dividers programmatically using the following methods in onActivityCreated of your PreferenceFragmentCompat:

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    // To remove:
    setDivider(null);

    // To change:
    setDivider(ContextCompat.getDrawable(getActivity(), R.drawable.your_drawable));
    setDividerHeight(your_height);
}

Answer 6

Add this code under the PreferenceFragment :

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        // remove dividers
        View rootView = getView();
        ListView list = (ListView) rootView.findViewById(android.R.id.list);
        list.setDivider(null);

    }