de.wolfgang_popp.shoppinglist.activity.SettingsFragment.java Source code

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Here is the source code for de.wolfgang_popp.shoppinglist.activity.SettingsFragment.java

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/*
 * ShoppingList - A simple shopping list for Android
 *
 * Copyright (C) 2016  Wolfgang Popp
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package de.wolfgang_popp.shoppinglist.activity;

import android.content.SharedPreferences;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.preference.EditTextPreference;
import android.preference.Preference;
import android.preference.PreferenceCategory;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;
import android.support.annotation.NonNull;
import android.support.v13.app.FragmentCompat;
import android.support.v4.content.ContextCompat;
import android.widget.Toast;

import de.wolfgang_popp.shoppinglist.R;

/**
 * @author Wolfgang Popp.
 */
public class SettingsFragment extends PreferenceFragment
        implements SharedPreferences.OnSharedPreferenceChangeListener {

    public static final String KEY_FILE_LOCATION = "FILE_LOCATION";
    private static final int REQUEST_CODE_EXT_STORAGE = 32537;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.preferences);
        PreferenceManager.getDefaultSharedPreferences(getActivity()).registerOnSharedPreferenceChangeListener(this);

        // show the current value in the settings screen
        for (int i = 0; i < getPreferenceScreen().getPreferenceCount(); i++) {
            initSummary(getPreferenceScreen().getPreference(i));
        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        PreferenceManager.getDefaultSharedPreferences(getActivity())
                .unregisterOnSharedPreferenceChangeListener(this);
    }

    private void initSummary(Preference p) {
        if (p instanceof PreferenceCategory) {
            PreferenceCategory cat = (PreferenceCategory) p;
            for (int i = 0; i < cat.getPreferenceCount(); i++) {
                initSummary(cat.getPreference(i));
            }
        } else {
            updatePreferences(p);
        }
    }

    private void updatePreferences(Preference p) {
        if (p instanceof EditTextPreference) {
            EditTextPreference editTextPref = (EditTextPreference) p;
            p.setSummary(editTextPref.getText());
        }
    }

    private void requestExternalStoragePermission() {
        int result = ContextCompat.checkSelfPermission(getActivity(), "android.permission.WRITE_EXTERNAL_STORAGE");
        if (result == PackageManager.PERMISSION_DENIED) {
            FragmentCompat.requestPermissions(this, new String[] { "android.permission.WRITE_EXTERNAL_STORAGE" },
                    REQUEST_CODE_EXT_STORAGE);
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
            @NonNull int[] grantResults) {
        if (requestCode == REQUEST_CODE_EXT_STORAGE) {
            if (grantResults.length == 0 || grantResults[0] == PackageManager.PERMISSION_DENIED) {
                Toast.makeText(getActivity(), "permisson denied", Toast.LENGTH_SHORT).show();
                PreferenceManager.getDefaultSharedPreferences(getActivity()).edit().putString(KEY_FILE_LOCATION, "")
                        .commit();
            }
        }
    }

    @Override
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
        if (key.equals(KEY_FILE_LOCATION)) {
            Preference p = findPreference(key);
            updatePreferences(p);
            if (!sharedPreferences.getString(KEY_FILE_LOCATION, "").equals("")) {
                requestExternalStoragePermission();
            } else {
                p.setSummary("");
            }

        }
    }
}