私は視覚障害者向けの Android ナビゲーション アプリケーションに取り組んでいます。したがって、当然、画面に地図を表示する必要はありません。私のコードは今のところ、URL を作成してから html ドキュメントを解析することでパスを取得します。私はこれをライブにしたいです。つまり、彼/彼女が道を外れたり、間違った方向に進んだりしたときにケースを処理したいのですが、私のアプリで彼に警告したいのです。
Google マップの機能を使用して、そのようなことは可能ですか? 可能であれば、その機能の詳細を教えてください。または、そのような機能が存在しない場合は、既存の機能を使用して問題を解決するために何らかの方法で使用することは可能ですか.
これは私の現在のコードです：
public class GPSTracking extends Activity implements
TextToSpeech.OnInitListener
{
protected static final int RESULT_SPEECH_start = 1;
protected static final int RESULT_SPEECH_end = 2;
protected static final int RESTART_ALL = 3;
//total distance travelled till last turn
Float totalDistance;
//distance to be travelled from present point to the next point
Float obtainedDistance;
//upper button
Button btnShowLocation;
//bottom button
Button btnShowLocationNo;
//to narate what user should do.
TextToSpeech tts;
//used to get name of current location
Geocoder geocoder;
//used to find positioning feature
GPS gps;
//start and position of the journey
String startPosition=null, endPosition=null;
//strings containing the path.
String[] string = null;
//vibrate the mobile
Vibrator viberator;
//indexing the present value of string which contains the path
int i = 0;
//to maintain proper order of events
int steps=0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//button on top
btnShowLocation = (Button) findViewById(R.id.trueButton);
//button on the lower side
btnShowLocationNo = (Button) findViewById(R.id.falseButton);
//initialising the text to speech
tts = new TextToSpeech(this, this);
//initialising the vibrator.
viberator = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
//to know what the current location
btnShowLocation.setOnClickListener(new View.OnClickListener() {
//to avoid start of multiple threads
boolean mytaskStarted=false;
String str=null;
@Override
public void onClick(View v) {
if(steps==0){
//to make sure values are reset
totalDistance=(float)0;
obtainedDistance=(float)0;
mytaskStarted=false;
string=null;
str=null;
i=0;
//only ask for initial position if not set
if(startPosition == null){
speakOut("Please enter the start position");
//takes the input using speech to text
intentGenerator(RESULT_SPEECH_start);
}
else{
//to enter the destination
speakOut("press the button again");
steps=1;
}
}
else if(steps==1){
//to enter the destination
speakOut("Please enter the destination");
intentGenerator(RESULT_SPEECH_end);
}
else if(steps==2){
//for a impatient user
speakOut("please wait");
//to avoid start of many asynchronous task
if(!mytaskStarted){
mytaskStarted=true;
//asynchronous task to find the path to be followed
new GetPath().execute();
}
}
else if(steps==3){
if (string != null && i < string.length) {
if(gps!=null && gps.isGpsEnabled()){
speakOut(i + 1 + " " + string[i]);
if(i>0 && i<string.length-1 && (string[i]+" ").lastIndexOf(" m ")>-1){
str=(string[i]+" ").substring(0,(string[i]+" ").lastIndexOf(" m ")+3);
obtainedDistance=Float.parseFloat(str.substring(1+str.substring(0,str.substring(0,str.lastIndexOf(" ")).lastIndexOf(" ")).lastIndexOf(" "),str.substring(0,str.lastIndexOf(" ")).lastIndexOf(" ")));
//increment only when present distance greater than distance in present string so that one will know when to turn.
if(((totalDistance+obtainedDistance)-gps.getApprximateDistance())<10)
{
i++;
totalDistance=totalDistance+obtainedDistance;
}
}
else if(i>0 && i<string.length-1 && (string[i]+" ").lastIndexOf(" km ")>-1){
str=(string[i]+" ").substring(0,(string[i]+" ").lastIndexOf(" km ")+4);
obtainedDistance=Float.parseFloat(str.substring(1+str.substring(0,str.substring(0,str.lastIndexOf(" ")).lastIndexOf(" ")).lastIndexOf(" "),str.substring(0,str.lastIndexOf(" ")).lastIndexOf(" ")));
obtainedDistance*=1000;
//increment only when present distance greater than distance in present string so that one will know when to turn.
if(((totalDistance+obtainedDistance)-gps.getApprximateDistance())<10)
{
i++;
totalDistance=totalDistance+obtainedDistance;
}
}
else if(i==0 ){
i++;
}
}
else if(gps!=null){
gps.resetDistance();
gps.stopUsingGPS();
//if gps not working.
speakOut(i + 1 + " " + string[i]);
i++;
}
else{
speakOut(i + 1 + " " + string[i]);
i++;
}
} else if (string != null && i >= string.length) {
i = 0;
}
}
}
});
//to get present location
btnShowLocation.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
if(gps==null){
gps = new GPS(AndroidGPSTrackingActivity.this);
}
if (gps.canGetLocation()) {
double longitude = gps.getLongitude();
double latitude = gps.getLatitude();
Geocoder geocoder = new Geocoder(getApplicationContext(), Locale.getDefault());
try {
//obtain the address of present location
List<Address> listAddresses = geocoder.getFromLocation(latitude, longitude, 1);
if(null!=listAddresses&&listAddresses.size()>0){
if (listAddresses.size() > 0) {
StringBuilder result = new StringBuilder();
for(int i = 0; i < listAddresses.size(); i++){
Address address = listAddresses.get(i);
int maxIndex = address.getMaxAddressLineIndex();
for (int x = 0; x <= maxIndex; x++ ){
if(address.getAddressLine(x)!=null){
result.append(address.getAddressLine(x));
result.append(",");
}
}
if(address.getLocality()!=null){
result.append(address.getLocality());
result.append("\n\n");
}
}
//if position accurate
if(gps.isGpsEnabled()){
speakOut(result.toString()+" is Your current location");
startPosition=result.toString();
Toast.makeText(
getApplicationContext(),startPosition,
Toast.LENGTH_LONG).show();
} else if(gps.isNetworkEnabled()){
speakOut(result.toString()+" is Your current approximate location. You have to give input of your present location on your own.");
Toast.makeText(
getApplicationContext(),result.toString(),
Toast.LENGTH_LONG).show();
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
} else {
gps.showSettingsAlert();
startPosition=null;
speakOut(" please turn on gps");
}
return false;
}
});
//to know what the previous direction string
btnShowLocationNo.setOnClickListener(new View.OnClickListener() {
int j=0;
@Override
public void onClick(View arg0) {
if(string!=null && j<string.length){
speakOut(j + 1 + " " + string[j]);
j++;
}
else if(string!=null && j>=string.length){
j=0;
}
}
});
//to reset all values for fresh start
btnShowLocationNo.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
// TODO Auto-generated method stub
speakOut("Values reset");
steps=0;
string=null;
i=0;
startPosition=null;
gps.stopUsingGPS();
gps=null;
endPosition=null;
return false;
}
});
}
//function to handle he text obtained from speech to text.
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode) {
//set the start
case RESULT_SPEECH_start:
if (resultCode == RESULT_OK && null != data) {
ArrayList<String> text = data
.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS);
Toast.makeText(getApplicationContext(), text.get(0),
Toast.LENGTH_SHORT).show();
startPosition = text.get(0);
steps=1;
//speakOut("please press button again");
}
else{
steps=0;
}
break;
//to set the end
case RESULT_SPEECH_end:
if (resultCode == RESULT_OK && null != data) {
ArrayList<String> text = data
.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS);
Toast.makeText(getApplicationContext(), text.get(0),
Toast.LENGTH_SHORT).show();
endPosition = text.get(0);
steps=2;
}
else{
steps=1;
}
break;
}
}
//function to generate intent to take speech input
public void intentGenerator(int code) {
Intent intent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, "en-US");
try {
startActivityForResult(intent, code);
} catch (ActivityNotFoundException a) {
Toast.makeText(getApplicationContext(),
"Opps! Your device doesn't support Speech to Text",
Toast.LENGTH_SHORT).show();
speakOut("Opps! Your device doesn't support Speech to Text");
}
}
//mobile gives instruction.
private void speakOut(String text) {
tts.speak(text, TextToSpeech.QUEUE_FLUSH, null);
while (tts.isSpeaking()) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
//asynchronous task to get the path. THIS IS USED TO AVOID OVERLOAD THE MAIN THRED AND AVOID FORCE CLOSE OF THE APPLICATION
private class GetPath extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... params) {
try {
string=null;
String html="";
//forming url
URL net = new URL(("http://maps.google.com/maps?saddr="+startPosition+" &daddr= "+endPosition).replaceAll(" ","%20"));
URLConnection netConnection = null;
netConnection = net.openConnection();
//to take the input from google maps
BufferedReader in = null;
in = new BufferedReader(new InputStreamReader(netConnection.getInputStream()));
String inputLine;
while ((inputLine = in.readLine()) != null) {
html+=inputLine;
}
//jsoup parser to parse the document obtained from google maps
Document doc = Jsoup.parse(html);
//obtain necessary part of the document
Elements el = doc.getElementsByClass("dir-mrgnr");
//to remove html tags
String str = el.text();
str = str.replaceAll("[0-9]+[.] ", "\n");
string = str.split("\n");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onProgressUpdate(Void... values) {
// TODO Auto-generated method stub
super.onProgressUpdate(values);
}
@Override
protected void onPostExecute(Void result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
//so that on press of button again mobile can read the directions to users
steps=3;
}
}
@Override
public void onDestroy() {
//shutdown
if (tts != null) {
tts.stop();
tts.shutdown();
}
super.onDestroy();
}
@Override
protected void onStart() {
gps = new GPS(AndroidGPSTrackingActivity.this);
super.onStart();
}
@Override
protected void onStop() {
if (tts != null) {
tts.stop();
tts.shutdown();
}
if(gps!=null){
gps.stopUsingGPS();
}
super.onStop();
}
@Override
public void onInit(int status) {
//initialising the text to speech
if (status == TextToSpeech.SUCCESS) {
int result = tts.setLanguage(Locale.US);
if (result == TextToSpeech.LANG_MISSING_DATA
|| result == TextToSpeech.LANG_NOT_SUPPORTED) {
Log.e("TTS", "Language is not supported");
} else {
btnShowLocation.setEnabled(true);
}
} else {
Log.e("TTS", "Initilization Failed");
}
}
}