Java tutorial
/* * Copyright (C) 2013 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.radar.niyo.contacts; import com.radar.niyo.BuildConfig; import com.radar.niyo.R; import android.Manifest; import android.app.Activity; import android.app.SearchManager; import android.content.Intent; import android.content.pm.PackageManager; import android.net.Uri; import android.os.Build; import android.os.Bundle; import android.support.v4.app.FragmentActivity; import android.util.Log; import android.widget.ArrayAdapter; import android.widget.Toast; import java.util.List; /** * FragmentActivity to hold the main {@link ContactsListFragment}. On larger screen devices which * can fit two panes also load {@link ContactDetailFragment}. */ public class ContactsListActivity extends FragmentActivity implements ContactsListFragment.OnContactsInteractionListener { // Defines a tag for identifying log entries private static final String TAG = "ContactsListActivity"; private ContactDetailFragment mContactDetailFragment; // If true, this is a larger screen device which fits two panes private boolean isTwoPaneLayout; // True if this activity instance is a search result view (used on pre-HC devices that load // search results in a separate instance of the activity rather than loading results in-line // as the query is typed. private boolean isSearchResultView = false; private static final int PERMISSIONS_REQUEST_READ_CONTACTS = 100; public static final String LOG_TAG = ContactsListActivity.class.getSimpleName(); @Override protected void onCreate(Bundle savedInstanceState) { Log.d(LOG_TAG, "onCreate started"); if (BuildConfig.DEBUG) { Utils.enableStrictMode(); } super.onCreate(savedInstanceState); // Set main content view. On smaller screen devices this is a single pane view with one // fragment. One larger screen devices this is a two pane view with two fragments. setContentView(R.layout.activity_main); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && checkSelfPermission(Manifest.permission.READ_CONTACTS) != PackageManager.PERMISSION_GRANTED) { Log.d(LOG_TAG, "permission to READ_CONTACTS is NOT granted yet. asking..."); requestPermissions(new String[] { Manifest.permission.READ_CONTACTS }, PERMISSIONS_REQUEST_READ_CONTACTS); //After this point you wait for callback in onRequestPermissionsResult(int, String[], int[]) overriden method } else { Log.d(LOG_TAG, "permission to READ_CONTACTS is granted"); showContacts(); } } private void showContacts() { Log.d(LOG_TAG, "showContacts started"); // Check if two pane bool is set based on resource directories isTwoPaneLayout = getResources().getBoolean(R.bool.has_two_panes); // Check if this activity instance has been triggered as a result of a search query. This // will only happen on pre-HC OS versions as from HC onward search is carried out using // an ActionBar SearchView which carries out the search in-line without loading a new // Activity. if (Intent.ACTION_SEARCH.equals(getIntent().getAction())) { // Fetch query from intent and notify the fragment that it should display search // results instead of all contacts. String searchQuery = getIntent().getStringExtra(SearchManager.QUERY); ContactsListFragment mContactsListFragment = (ContactsListFragment) getSupportFragmentManager() .findFragmentById(R.id.contact_list); // This flag notes that the Activity is doing a search, and so the result will be // search results rather than all contacts. This prevents the Activity and Fragment // from trying to a search on search results. isSearchResultView = true; mContactsListFragment.setSearchQuery(searchQuery); // Set special title for search results String title = getString(R.string.contacts_list_search_results_title, searchQuery); setTitle(title); } if (isTwoPaneLayout) { // If two pane layout, locate the contact detail fragment mContactDetailFragment = (ContactDetailFragment) getSupportFragmentManager() .findFragmentById(R.id.contact_detail); } } @Override public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { if (requestCode == PERMISSIONS_REQUEST_READ_CONTACTS) { if (grantResults[0] == PackageManager.PERMISSION_GRANTED) { // Permission is granted showContacts(); } else { Toast.makeText(this, "Until you grant the permission, we canot display the names", Toast.LENGTH_SHORT).show(); } } } public static Intent getCreationIntent(Activity context) { Intent result = new Intent(context, ContactsListActivity.class); return result; } /** * This interface callback lets the main contacts list fragment notify * this activity that a contact has been selected. * * @param contactUri The contact Uri to the selected contact. */ @Override public void onContactSelected(Uri contactUri) { if (isTwoPaneLayout && mContactDetailFragment != null) { // If two pane layout then update the detail fragment to show the selected contact mContactDetailFragment.setContact(contactUri); } else { // Otherwise single pane layout, start a new ContactDetailActivity with // the contact Uri Intent intent = new Intent(this, ContactDetailActivity.class); intent.setData(contactUri); startActivity(intent); } } /** * This interface callback lets the main contacts list fragment notify * this activity that a contact is no longer selected. */ @Override public void onSelectionCleared() { if (isTwoPaneLayout && mContactDetailFragment != null) { mContactDetailFragment.setContact(null); } } @Override public boolean onSearchRequested() { // Don't allow another search if this activity instance is already showing // search results. Only used pre-HC. return !isSearchResultView && super.onSearchRequested(); } }