Java tutorial
/* * Copyright (C) 2014 Andrew Comminos * * 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 com.terracom.mumbleclient.servers; import android.annotation.TargetApi; import android.app.Activity; import android.app.AlertDialog; import android.app.ProgressDialog; import android.content.Context; import android.content.DialogInterface; import android.os.AsyncTask; import android.os.Build; import android.os.Build.VERSION; import android.os.Bundle; import android.support.v4.app.Fragment; import android.view.KeyEvent; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.view.WindowManager; import android.view.inputmethod.EditorInfo; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ArrayAdapter; import android.widget.EditText; import android.widget.GridView; import android.widget.ProgressBar; import android.widget.TextView; import android.widget.TextView.OnEditorActionListener; import android.widget.Toast; import com.terracom.jumble.model.Server; import com.terracom.mumbleclient.R; import com.terracom.mumbleclient.Settings; import com.terracom.mumbleclient.db.DatabaseProvider; import com.terracom.mumbleclient.db.QRPushToTalkDatabase; import com.terracom.mumbleclient.db.PublicServer; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.Comparator; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.Locale; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; /** * Displays a list of public servers that can be connected to, sorted, and favourited. * @author terracom * */ public class PublicServerListFragment extends Fragment implements OnItemClickListener, PublicServerAdapter.PublicServerAdapterMenuListener { private FavouriteServerListFragment.ServerConnectHandler mConnectHandler; private DatabaseProvider mDatabaseProvider; private List<PublicServer> mServers; private GridView mServerGrid; private ProgressBar mServerProgress; private PublicServerAdapter mServerAdapter; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setHasOptionsMenu(true); } @Override public void onAttach(Activity activity) { super.onAttach(activity); try { mConnectHandler = (FavouriteServerListFragment.ServerConnectHandler) activity; mDatabaseProvider = (DatabaseProvider) activity; } catch (ClassCastException e) { throw new ClassCastException( activity.toString() + " must implement ServerConnectHandler and DatabaseProvider!"); } } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); fillPublicList(); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragment_public_server_list, container, false); mServerGrid = (GridView) view.findViewById(R.id.server_list_grid); mServerGrid.setOnItemClickListener(this); if (mServerAdapter != null) mServerGrid.setAdapter(mServerAdapter); mServerProgress = (ProgressBar) view.findViewById(R.id.serverProgress); mServerProgress.setVisibility(mServerAdapter == null ? View.VISIBLE : View.GONE); return view; } @Override public void onPrepareOptionsMenu(Menu menu) { super.onPrepareOptionsMenu(menu); menu.findItem(R.id.menu_match_server).setVisible(VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB); // Executors only supported on Honeycomb + } @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { super.onCreateOptionsMenu(menu, inflater); inflater.inflate(R.menu.fragment_public_server_list, menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { if (isFilled()) { switch (item.getItemId()) { case R.id.menu_match_server: showMatchDialog(); break; case R.id.menu_sort_server_item: showSortDialog(); return true; case R.id.menu_search_server_item: showFilterDialog(); return true; } } return super.onOptionsItemSelected(item); } @Override public void favouriteServer(final Server server) { final Settings settings = Settings.getInstance(getActivity()); final EditText usernameField = new EditText(getActivity()); usernameField.setHint(settings.getDefaultUsername()); AlertDialog.Builder adb = new AlertDialog.Builder(getActivity()); adb.setTitle(R.string.addFavorite); adb.setView(usernameField); adb.setPositiveButton(R.string.add, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { if (usernameField.getText().length() > 0) { server.setUsername(usernameField.getText().toString()); } else { server.setUsername(settings.getDefaultUsername()); } QRPushToTalkDatabase database = mDatabaseProvider.getDatabase(); database.addServer(server); } }); adb.setNegativeButton(android.R.string.cancel, null); adb.show(); } public void setServers(List<PublicServer> servers) { mServers = servers; mServerProgress.setVisibility(View.GONE); mServerAdapter = new PublicServerAdapter(getActivity(), servers, this); mServerGrid.setAdapter(mServerAdapter); } public boolean isFilled() { return mServerAdapter != null; } private void showMatchDialog() { AlertDialog.Builder adb = new AlertDialog.Builder(getActivity()); adb.setTitle(R.string.server_match); adb.setMessage(R.string.server_match_description); adb.setPositiveButton(R.string.search, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { findOptimalServer(); } }); adb.setNegativeButton(android.R.string.cancel, null); adb.show(); } private void findOptimalServer() { MatchServerTask matchServerTask = new MatchServerTask(); matchServerTask.execute(Locale.getDefault().getCountry()); } private void showSortDialog() { AlertDialog.Builder alertBuilder = new AlertDialog.Builder(getActivity()); alertBuilder.setTitle(R.string.sortBy); alertBuilder.setItems(new String[] { getString(R.string.name), getString(R.string.country) }, new SortClickListener()); alertBuilder.show(); } private void showFilterDialog() { View dialogView = ((LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE)) .inflate(R.layout.dialog_server_search, null); final EditText nameText = (EditText) dialogView.findViewById(R.id.server_search_name); final EditText countryText = (EditText) dialogView.findViewById(R.id.server_search_country); final AlertDialog dlg = new AlertDialog.Builder(getActivity()).setTitle(R.string.search).setView(dialogView) .setPositiveButton(R.string.search, new DialogInterface.OnClickListener() { public void onClick(final DialogInterface dialog, final int which) { String queryName = nameText.getText().toString().toUpperCase(Locale.US); String queryCountry = countryText.getText().toString().toUpperCase(Locale.US); mServerAdapter.filter(queryName, queryCountry); dialog.dismiss(); } }).create(); nameText.setImeOptions(EditorInfo.IME_ACTION_SEARCH); nameText.setOnEditorActionListener(new OnEditorActionListener() { @Override public boolean onEditorAction(final TextView v, final int actionId, final KeyEvent event) { String queryName = nameText.getText().toString().toUpperCase(Locale.US); String queryCountry = countryText.getText().toString().toUpperCase(Locale.US); mServerAdapter.filter(queryName, queryCountry); dlg.dismiss(); return true; } }); countryText.setImeOptions(EditorInfo.IME_ACTION_SEARCH); countryText.setOnEditorActionListener(new OnEditorActionListener() { @Override public boolean onEditorAction(final TextView v, final int actionId, final KeyEvent event) { String queryName = nameText.getText().toString().toUpperCase(Locale.US); String queryCountry = countryText.getText().toString().toUpperCase(Locale.US); mServerAdapter.filter(queryName, queryCountry); dlg.dismiss(); return true; } }); // Show keyboard automatically nameText.setOnFocusChangeListener(new View.OnFocusChangeListener() { @Override public void onFocusChange(View v, boolean hasFocus) { if (hasFocus) { dlg.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE); } } }); dlg.show(); } @Override public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) { mConnectHandler.connectToPublicServer(mServerAdapter.getItem(arg2)); } private void fillPublicList() { new PublicServerFetchTask() { protected void onPostExecute(List<PublicServer> result) { super.onPostExecute(result); if (result == null) { // Handle error Toast.makeText(getActivity(), R.string.error_fetching_servers, Toast.LENGTH_SHORT).show(); return; } if (isVisible()) // Prevents NPEs when fragment is detached. setServers(result); }; }.execute(); } private class SortClickListener implements DialogInterface.OnClickListener { private static final int SORT_NAME = 0; private static final int SORT_COUNTRY = 1; private Comparator<PublicServer> nameComparator = new Comparator<PublicServer>() { @Override public int compare(PublicServer lhs, PublicServer rhs) { return lhs.getName().compareTo(rhs.getName()); } }; private Comparator<PublicServer> countryComparator = new Comparator<PublicServer>() { @Override public int compare(PublicServer lhs, PublicServer rhs) { if (rhs.getCountry() == null) return -1; else if (lhs.getCountry() == null) return 1; return lhs.getCountry().compareTo(rhs.getCountry()); } }; @Override public void onClick(DialogInterface dialog, int which) { ArrayAdapter<PublicServer> arrayAdapter = mServerAdapter; if (which == SORT_NAME) { arrayAdapter.sort(nameComparator); } else if (which == SORT_COUNTRY) { arrayAdapter.sort(countryComparator); } } } /** * Finds an empty server in the user's country code with low latency. * By default, it will show a ProgressDialog while it performs this and an AlertDialog allowing the user to connect. */ @TargetApi(Build.VERSION_CODES.HONEYCOMB) private class MatchServerTask extends AsyncTask<String, Void, ServerInfoResponse> { /** * Query until we find up to SEARCH_RANGE empty servers that meet the zero user and location requirements. * Once we have that, then we'll sort them based on latency. * TODO make this a user-changeable option. */ public static final int SEARCH_RANGE = 20; private Comparator<ServerInfoResponse> mLatencyComparator = new Comparator<ServerInfoResponse>() { @Override public int compare(ServerInfoResponse lhs, ServerInfoResponse rhs) { return lhs.getLatency() == rhs.getLatency() ? 0 : lhs.getLatency() < rhs.getLatency() ? -1 : 1; } }; private class MatchServerInfoTask extends ServerInfoTask { @Override protected void onPostExecute(ServerInfoResponse serverInfoResponse) { mResponseCount++; if (serverInfoResponse == null) { // TODO handle bad responses } else if (serverInfoResponse.getCurrentUsers() == 0 && serverInfoResponse.getVersion() == com.terracom.jumble.Constants.PROTOCOL_VERSION) { mGoodResponses.add(serverInfoResponse); } // Once we have a good sample of results, shut down the ping threads. if (mResponseCount >= mResponsesToSend) { synchronized (mLock) { mLock.notify(); } mPingExecutor.shutdownNow(); } } } private ExecutorService mPingExecutor = Executors.newFixedThreadPool(5); // Run 5 concurrent pings at a time private Object mLock = new Object(); private List<ServerInfoResponse> mGoodResponses = Collections .synchronizedList(new ArrayList<ServerInfoResponse>()); private volatile int mResponseCount = 0; private int mResponsesToSend = SEARCH_RANGE; private ProgressDialog mProgressDialog; @Override protected void onPreExecute() { super.onPreExecute(); mProgressDialog = ProgressDialog.show(getActivity(), null, getString(R.string.server_match_progress)); mProgressDialog.setCancelable(true); mProgressDialog.setCanceledOnTouchOutside(true); mProgressDialog.setOnCancelListener(new DialogInterface.OnCancelListener() { @Override public void onCancel(DialogInterface dialog) { cancel(true); } }); } @Override protected ServerInfoResponse doInBackground(String... params) { final String country = params.length > 0 ? params[0] : null; // If a country is provided, search within country Collection<PublicServer> servers; if (country != null) { servers = new LinkedList<PublicServer>(); for (PublicServer server : mServers) { if (country.equals(server.getCountryCode())) { servers.add(server); } } } else { servers = mServers; } // For countries with 0 servers, immediately return null. if (servers.size() == 0) return null; // If there are less servers than the value of our range, deal with it. mResponsesToSend = Math.min(SEARCH_RANGE, servers.size()); Iterator iterator = servers.iterator(); while (iterator.hasNext() && mGoodResponses.size() < mResponsesToSend) { PublicServer server = (PublicServer) iterator.next(); new MatchServerInfoTask().executeOnExecutor(mPingExecutor, server); } try { synchronized (mLock) { mLock.wait(); } } catch (InterruptedException e) { e.printStackTrace(); } Collections.sort(mGoodResponses, mLatencyComparator); if (mGoodResponses.size() > 0) return mGoodResponses.get(0); else return null; } @Override protected void onPostExecute(ServerInfoResponse response) { super.onPostExecute(response); final PublicServer publicServer = response == null ? null : (PublicServer) response.getServer(); mProgressDialog.hide(); AlertDialog.Builder adb = new AlertDialog.Builder(getActivity()); if (publicServer != null) { adb.setTitle(R.string.server_match_found); adb.setMessage(getString(R.string.server_match_info, publicServer.getName(), publicServer.getHost(), publicServer.getPort(), response.getCurrentUsers(), response.getMaximumUsers(), response.getVersionString(), publicServer.getCountry(), response.getLatency())); adb.setPositiveButton(R.string.connect, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { mConnectHandler.connectToPublicServer(publicServer); } }); } else { adb.setTitle(R.string.server_match_not_found); adb.setMessage(R.string.server_match_expand_country); adb.setPositiveButton(R.string.expand, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { MatchServerTask matchTask = new MatchServerTask(); matchTask.execute(); } }); } adb.setNegativeButton(android.R.string.cancel, null); adb.show(); } } }