PreferenceActivity: getFragmentManager() has been deprecated

Asked 31/10, 2018 at 7:45 Answered 31/10, 2018 at 18:5

Solved android android-fragments android-preferences deprecation-warning androidx

When testing a android.preference.PreferenceActivity, I get the following warning:

warning: [deprecation] getFragmentManager() in Activity has been deprecated

That is how I obtain a handle to the current PreferenceFragment:

FragmentManager fm = this.mActivity.getFragmentManager();
this.currentFragment = (PreferenceFragment) fm.getFragments().get(1);

Using FragmentActivity.getSupportFragmentManager() is obviously not an option.

I've found PreferenceFragmentCompat, which would replace the deprecated PreferenceFragment.

But is there any androidx replacement for the PreferenceActivity?

Andros answered 31/10, 2018 at 7:45 Comment(1)

Good question, it may be bug in documentation of Android Class. You should post a bug on Google Issues Tracker. Obviously using getSupportFragmentManager is not an option. – Dying 31/10, 2018 at 8:4

What I've came up with is an AppCompatActivity, which inflates androidx PreferenceFragment. I've kept the previous EXTRA_SHOW_FRAGMENT, so that switching to a specific PreferenceFragment still would work. EXTRA_NO_HEADERS has not yet been considered:

/**
 * Preference {@link AppCompatActivity}.
 * @see <a href="https://developer.android.com/reference/androidx/preference/Preference Fragment">PreferenceFragment</a>
**/
public final class PreferenceCompatActivity extends AppCompatActivity {

    /** the class-name of the main {@link androidx.preference.PreferenceFragment} */
    public static final String MAIN_FRAGMENT = "com.acme.fragment.PreferencesFragment";

    /** framework {@link Intent} extra */
    public static final String EXTRA_SHOW_FRAGMENT = ":android:show_fragment";

    /** framework {@link Intent} extra */
    public static final String EXTRA_NO_HEADERS = ":android:no_headers";

    /** the currently displayed {@link PreferenceFragment} */
    private PreferenceFragment currentFragment;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        String fragmentName = MAIN_FRAGMENT;
        Intent intent = getIntent();
        if (intent.getStringExtra(EXTRA_SHOW_FRAGMENT) != null) {
            fragmentName = intent.getStringExtra(EXTRA_SHOW_FRAGMENT);
        }
        this.switchToFragment(fragmentName, null);
    }

    private void switchToFragment(String fragmentName, @Nullable Bundle args) {
        PreferenceFragment fragment;
        switch(fragmentName) {
            // case "": {break;}
            default: {
                fragment = new PreferencesFragment();
            }
        }
        getFragmentManager().beginTransaction().replace(android.R.id.content, fragment).commit();
        this.currentFragment = fragment;
    }

    @VisibleForTesting(otherwise = VisibleForTesting.NONE)
    public PreferenceFragment getCurrentFragment() {
        return this.currentFragment;
    }

    ...
}

Update: Meanwhile there's PreferenceFragmentCompat, which support this by default.

Andros answered 31/10, 2018 at 18:5 Comment(0)

The Fragment-related UI classes that ship as part of the device firmware have been deprecated in Android 28. It is recommended to move to the support library classes for Activitys and Fragments.

There are already other posts about this:

Mikael answered 31/10, 2018 at 8:7 Comment(0)

/**
 * Preference {@link AppCompatActivity}.
 * @see <a href="https://developer.android.com/reference/androidx/preference/Preference Fragment">PreferenceFragment</a>
**/
public final class PreferenceCompatActivity extends AppCompatActivity {

    /** the class-name of the main {@link androidx.preference.PreferenceFragment} */
    public static final String MAIN_FRAGMENT = "com.acme.fragment.PreferencesFragment";

    /** framework {@link Intent} extra */
    public static final String EXTRA_SHOW_FRAGMENT = ":android:show_fragment";

    /** framework {@link Intent} extra */
    public static final String EXTRA_NO_HEADERS = ":android:no_headers";

    /** the currently displayed {@link PreferenceFragment} */
    private PreferenceFragment currentFragment;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        String fragmentName = MAIN_FRAGMENT;
        Intent intent = getIntent();
        if (intent.getStringExtra(EXTRA_SHOW_FRAGMENT) != null) {
            fragmentName = intent.getStringExtra(EXTRA_SHOW_FRAGMENT);
        }
        this.switchToFragment(fragmentName, null);
    }

    private void switchToFragment(String fragmentName, @Nullable Bundle args) {
        PreferenceFragment fragment;
        switch(fragmentName) {
            // case "": {break;}
            default: {
                fragment = new PreferencesFragment();
            }
        }
        getFragmentManager().beginTransaction().replace(android.R.id.content, fragment).commit();
        this.currentFragment = fragment;
    }

    @VisibleForTesting(otherwise = VisibleForTesting.NONE)
    public PreferenceFragment getCurrentFragment() {
        return this.currentFragment;
    }

    ...
}

Update: Meanwhile there's PreferenceFragmentCompat, which support this by default.

Andros answered 31/10, 2018 at 18:5 Comment(0)

Recommended topics

Hot tags