OpenTracks/src/main/java/de/dennisguse/opentracks/settings/DefaultsSettingsFragment.java

package de.dennisguse.opentracks.settings;

import android.content.SharedPreferences;
import android.os.Bundle;

import androidx.fragment.app.DialogFragment;
import androidx.preference.ListPreference;
import androidx.preference.Preference;
import androidx.preference.PreferenceFragmentCompat;

import de.dennisguse.opentracks.R;
import de.dennisguse.opentracks.fragments.ChooseActivityTypeDialogFragment;

public class DefaultsSettingsFragment extends PreferenceFragmentCompat implements ChooseActivityTypeDialogFragment.ChooseActivityTypeCaller {

    // Used to forward update from ChooseActivityTypeDialogFragment; TODO Could be replaced with LiveData.
    private ActivityTypePreference.ActivityPreferenceDialog activityPreferenceDialog;

    private final SharedPreferences.OnSharedPreferenceChangeListener sharedPreferenceChangeListener = (sharedPreferences, key) -> {
        if (PreferencesUtils.isKey(R.string.stats_units_key, key)) {
            getActivity().runOnUiThread(this::updateUnits);
        }
    };

    @Override
    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
        addPreferencesFromResource(R.xml.settings_defaults);
    }

    @Override
    public void onStart() {
        super.onStart();
        ((SettingsActivity) getActivity()).getSupportActionBar().setTitle(R.string.settings_defaults_title);
    }

    @Override
    public void onResume() {
        super.onResume();
        PreferencesUtils.registerOnSharedPreferenceChangeListener(sharedPreferenceChangeListener);
        updateUnits();
    }

    @Override
    public void onPause() {
        super.onPause();
        PreferencesUtils.unregisterOnSharedPreferenceChangeListener(sharedPreferenceChangeListener);
    }

    @Override
    public void onDisplayPreferenceDialog(Preference preference) {
        DialogFragment dialogFragment = null;
        if (preference instanceof ActivityTypePreference) {
            activityPreferenceDialog = ActivityTypePreference.ActivityPreferenceDialog.newInstance(preference.getKey());
            dialogFragment = activityPreferenceDialog;
        }

        if (dialogFragment != null) {
            dialogFragment.setTargetFragment(this, 0);
            dialogFragment.show(getParentFragmentManager(), getClass().getSimpleName());
            return;
        }

        super.onDisplayPreferenceDialog(preference);
    }

    private void updateUnits() {
        UnitSystem unitSystem = PreferencesUtils.getUnitSystem();

        ListPreference statsRatePreferences = findPreference(getString(R.string.stats_rate_key));

        int entriesId;
        switch (unitSystem) {
            case METRIC:
                entriesId = R.array.stats_rate_metric_options;
                break;
            case IMPERIAL:
            case NAUTICAL_IMPERIAL:
                entriesId = R.array.stats_rate_imperial_options;
                break;
            default:
                throw new RuntimeException("Not implemented");
        }

        String[] entries = getResources().getStringArray(entriesId);
        statsRatePreferences.setEntries(entries);

        HackUtils.invalidatePreference(statsRatePreferences);
    }

    @Override
    public void onChooseActivityTypeDone(String iconValue) {
        if (activityPreferenceDialog != null) {
            activityPreferenceDialog.updateUI(iconValue);
        }
    }
}