Android: setting up a google map class. bit of advice required.

Question

Hey there,

Ok so this is what i've got.

Button anandabutton = (Button) findViewById(R.id.anandaAddressButton);
anandabutton.setOnClickListener(new View.OnClickListener() {

    public void onClick(View view) {
        Intent myIntent = new Intent(view.getContext(),MapClass.class);
        startActivityForResult(myIntent,0);

    }

});

This method opens up my MapClass class which at the moment I just have set to show the location of one place.

But I have a load of buttons and rather than making a lot of different mapClass classes for each button, I am wondering can I just use the one class and depending on what button 'id' is pressed, it will check an 'if statement' and then put in the correct coordinates into the method to display the map. It would be a lot neater than coding up like 20-30 classes.

I'm not sure if i've explained that right so if not let me know.

Thanks for any help.

This is my map class now...

public class MapClass extends MapActivity {

MapView mapView;
MapController mc;
GeoPoint p;

@Override
public void onCreate(Bundle savedInstanceState)
{

    super.onCreate(savedInstanceState);
    setContentView(R.layout.map);

    int button = getIntent().getExtras().getInt("button", -1);
    switch(button){
    case DundrumSelector.BUTTON1:
        handleCoordinates("53.288719","-6.241179");
        break;
    case DundrumSelector.BUTTON2:
        handleCoordinates("53.288719","-6.241179");
        break;
    }
}




private void handleCoordinates(String l, String b){


    mapView = (MapView) findViewById(R.id.mapView);
    LinearLayout zoomLayout = (LinearLayout)findViewById(R.id.zoom);
    View zoomView = mapView.getZoomControls();

    zoomLayout.addView(zoomView,
            new LinearLayout.LayoutParams(
                LayoutParams.WRAP_CONTENT, 
                LayoutParams.WRAP_CONTENT)); 
        mapView.displayZoomControls(true);

    mc = mapView.getController();
    String coordinates[] = {l, b};
    double lat = Double.parseDouble(coordinates[0]);
    double lng = Double.parseDouble(coordinates[1]);

    p = new GeoPoint(
            (int) (lat*1E6),
            (int) (lng*1E6));

    mc.animateTo(p);
    mc.setZoom(17);
    mapView.invalidate();


}

and then my other activity is

public static final int BUTTON1 = R.id.anandaAddressButton;

Button anandabutton = (Button) findViewById(R.id.anandaAddressButton);
anandabutton.setOnClickListener(new View.OnClickListener() {

    public void onClick(View view) {
        Intent myIntent = new Intent(view.getContext(),MapClass.class);
        myIntent.putExtra("button", BUTTON1);
        startActivityForResult(myIntent,0);

    }

});

For some reason when I try and click on any other item in the list other than BUTTON1 the program crashes. Ive had to take out BUTTON2, BUTTON3 etc because it just keeps crashing if i try and go into their view. but when i comment out this onClick method they all work fine?

Do either of you guys have any openions? Do u understand my problem? Thanks.

Answer 1

If I understand you correctly, you want to always start the same Intent, but on the receiver side on the intent, that is the activity that is started, you want to use different methods depending on which button has been pressed.

I would suggest to add a constant to the Intent depending on the button you pressed, and the in the MapClass you check which constant it is and you react according to do that:

public void onClick(View view) {
        Intent myIntent = new Intent(view.getContext(),MapClass.class);
        myIntent.putExtra("button", BUTTON1);
        startActivityForResult(myIntent,0);
 }

BUTTON1 and BUTTON2 are constant int which you have do define in your Acitivty class correspondig to the buttons you want to add.

In the MapClass in the onCreate() method you do the following:

int button = getIntent().getExtras().getIntExtra("button", -1);
switch(button) {
   case BUTTON1:
   //do something
   break;
   case BUTTON2:
   //do method for button 2
   break;
   default:
   //do another thing
   break;
}

To also cover your edit:

if only the coordinates change the i would do something linke this:

int button = getIntent().getExtras().getIntExtra("button", -1);
switch(button) {
   case BUTTON1:
   handleCoordinates("53.288719","-6.241179");
   break;
   case BUTTON2:
  handleCoordinates("23.288719","23.241179"
   break;
   default:
   //do another thing
   break;
}



private void handleCoordinates(String l, String b) {
mapView = (MapView) findViewById(R.id.mapView);
    LinearLayout zoomLayout = (LinearLayout)findViewById(R.id.zoom);
    View zoomView = mapView.getZoomControls();

    zoomLayout.addView(zoomView,
            new LinearLayout.LayoutParams(
                LayoutParams.WRAP_CONTENT, 
                LayoutParams.WRAP_CONTENT)); 
        mapView.displayZoomControls(true);

    mc = mapView.getController();
    String coordinates[] = {l, b};
    double lat = Double.parseDouble(coordinates[0]);
    double lng = Double.parseDouble(coordinates[1]);

    p = new GeoPoint(
            (int) (lat*1E6),
            (int) (lng*1E6));

    mc.animateTo(p);
    mc.setZoom(17);
    mapView.invalidate();
}

Answer 2

To complement on Sebi's answer and the question you asked in the comments, what you want to do is create one handler (could be in your onCreate() method):

OnClickListener buttonListener = new OnClickListener(){
    public void onClick(View v) {
        if(!(v instanceof Button))
           //throw error, not supposed to happen
        Button b = (Button)v;
        int id = b.getId();
        int code; //used to know when your activity comes back (if you need to)
        int lat;
        int long;
        switch(id) {
           case button1.getId():
              //set code, lat and long for button1
           case button2.getId():
              //set code, lat and long for button2
        ...
        }
        Bundle bdl = new Bundle();
        bdl.putDouble("latitude", lat);
        bdl.putDouble("longitude", long);
        Intent myIntent = new Intent(view.getContext(),MapClass.class);
        myIntent.putExtras(bdl);
        startActivityForResult(myIntent,code);
}
button1.setOnClickListener(buttonListener);
button2.setOnClickListener(buttonListener);
...