DiscoveryHandler.java

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/*
 * Copyright (C) 2013 Yujin Robot.
 *
 * 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.github.rosjava.android_extras.ros_master_browser;

import java.net.Inet4Address;
import java.net.Inet6Address;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;

import android.os.AsyncTask;
import android.widget.TextView;
import com.github.rosjava.zeroconf_jmdns_suite.jmdns.DiscoveredService;
import com.github.rosjava.zeroconf_jmdns_suite.jmdns.ZeroconfDiscoveryHandler;

public class DiscoveryHandler implements ZeroconfDiscoveryHandler {

        /*********************
         * Tasks
         ********************/
        private class ServiceAddedTask extends AsyncTask<DiscoveredService, String, Void> {
                
            protected Void doInBackground(DiscoveredService... services) {
            android.util.Log.i("zeroconf", "Service added ");
                if ( services.length == 1 ) {
                        DiscoveredService service = services[0];
                                String result = "[+] Service added: " + service.name + "." + service.type + "." + service.domain + ".";
                                publishProgress(result);
                } else {
                    publishProgress("Error - ServiceAddedTask::doInBackground received #services != 1");
                }
                return null;
            }

            protected void onProgressUpdate(String... progress) {
                uiLog(progress);
                }
        }

        private class ServiceResolvedTask extends AsyncTask<DiscoveredService, String, DiscoveredService> {
                
            protected DiscoveredService doInBackground(DiscoveredService... services) {
            android.util.Log.i("zeroconf", " Resolved");
                if ( services.length == 1 ) {
                        DiscoveredService discovered_service = services[0];
                        String result = "[=] Service resolved: " + discovered_service.name + "." + discovered_service.type + "." + discovered_service.domain + ".\n";
                        result += "    Port: " + discovered_service.port;
                        for ( String address : discovered_service.ipv4_addresses ) {
                                result += "\n    Address: " + address;
                        }
                        for ( String address : discovered_service.ipv6_addresses ) {
                                result += "\n    Address: " + address;
                        }
                        publishProgress(result);
                        return discovered_service;
                } else {
                    publishProgress("Error - ServiceAddedTask::doInBackground received #services != 1");
                }
                return null;
            }

            protected void onProgressUpdate(String... progress) {
                uiLog(progress);
                }
            
            protected void onPostExecute(DiscoveredService discovered_service) {
                // add to the content and notify the list view if its a new service
                // this is a bit horrible - ServiceInfo/DiscoveredService objects can't add 
                // extra addresses, so we just discard one if it doesn't have a complete list of ip's
                // (quite often we get just an ipv4 address come in, or just an ipv6 address
                // but also a service info with both).
                if ( discovered_service != null ) {
                                Iterator<DiscoveredService> it = discovered_services.iterator();
                                Boolean exists = false;
                                Boolean modified_address_list = false;
                                while ( it.hasNext() )
                                {
                                        DiscoveredService s = it.next();
                                        if ( s.name.equals(discovered_service.name) ) {
                                        for ( String address : discovered_service.ipv4_addresses ) {
                                                if ( !s.ipv4_addresses.contains(address) ) {
                                s.ipv4_addresses.add(address);
                                modified_address_list = true;
                                                        break;
                                                }
                                        }
                                        for ( String address : discovered_service.ipv6_addresses ) {
                                                if ( !s.ipv6_addresses.contains(address) ) {
                                s.ipv6_addresses.add(address);
                                                        modified_address_list = true;
                                                        break;
                                                }
                                        }
                                        exists = true;
                                                break;
                                        }
                                }
                                if ( exists ) {
                                        if ( modified_address_list ) {
                        discovery_adapter.notifyDataSetChanged();
                                        }
                                } else {
                                        discovered_services.add(discovered_service);
                                        discovery_adapter.notifyDataSetChanged();
                                }
                }
            }
        }
        
        private class ServiceRemovedTask extends AsyncTask<DiscoveredService, String, DiscoveredService> {
                
            protected DiscoveredService doInBackground(DiscoveredService... services) {
                if ( services.length == 1 ) {
                        DiscoveredService discovered_service = services[0];
                    String result = "[-] Service removed: " + discovered_service.name + "." + discovered_service.type + "." + discovered_service.domain + ".";
                    // Address and port information is not usually transferred here, you'd have
                    // to look it up on stored objects here in this program if you wanted to work out
                    // which was removed.
                        publishProgress(result);
                        return discovered_service;
                } else {
                    publishProgress("Error - ServiceAddedTask::doInBackground received #services != 1");
                }
                return null;
            }

            protected void onProgressUpdate(String... progress) {
                uiLog(progress);
                }
            
            protected void onPostExecute(DiscoveredService discovered_service) {
                // remove service from storage and notify list view
                if ( discovered_service != null ) {
                                int index = 0;
                                for ( DiscoveredService s : discovered_services ) {
                                        if ( s.name.equals(discovered_service.name) ) {
                                                break;
                                        } else {
                                                ++index;
                                        }
                                }
                                if ( index != discovered_services.size() ) {
                                        discovered_services.remove(index);
                                        discovery_adapter.notifyDataSetChanged();
                                } else {
                                        android.util.Log.i("zeroconf", "Tried to remove a non-existant service");
                                }
                }
            }
        }

        /*********************
         * Variables
         ********************/
        private ArrayList<DiscoveredService> discovered_services;
    private DiscoveryAdapter discovery_adapter;
        private TextView text_view;

        /*********************
         * Constructors
         ********************/
        public DiscoveryHandler(TextView tv, DiscoveryAdapter discovery_adapter, ArrayList<DiscoveredService> discovered_services) {
                this.text_view = tv;
                this.discovery_adapter = discovery_adapter;
                this.discovered_services = discovered_services;
        }

        /*********************
         * Callbacks
         ********************/
        public void serviceAdded(DiscoveredService service) {
                new ServiceAddedTask().execute(service);
        }
        
        public void serviceRemoved(DiscoveredService service) {
                new ServiceRemovedTask().execute(service);
        }
        
        public void serviceResolved(DiscoveredService service) {
                new ServiceResolvedTask().execute(service);
        }

        /*********************
         * Utility
         ********************/
        private void uiLog(String... messages) {
        for (String msg : messages ) {
            android.util.Log.i("zeroconf", msg);
            text_view.append(msg + "\n");
        }
        int line_count = text_view.getLineCount(); 
        int view_height = text_view.getHeight();
        int pixels_per_line = text_view.getLineHeight();
        int pixels_difference = line_count*pixels_per_line - view_height;
        if ( pixels_difference > 0 ) {
                text_view.scrollTo(0, pixels_difference);
        }
        }
}