Question

I am creating an app which is going to have as a background USA map. I want to click on the map and wherever I click I want to create a small red dot. But it should not be created outside of the map borders. Can I use GridView? Thanks.

Answer 1

You can just create a Linear Layout with a USA map as the background and then set an onTouchListener to that Linear Layout, inside the onTouch just add a red dot on the x and y coordinates that the person clicked. Something like this:

public class MyAppActivity extends Activity {    

LinearLayout mLayout;
double x, y;    

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);       

    mLayout = (LinearLayout) findViewById(R.id.yourID); 
    mLayout.setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {

            x = event.getX();
            y = event.getY();
            //Draw a ball using the x and y coordinates. You can make a separate class to do that.

            return false;
    });        

 }
}

and your xml could look something like:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/yourID"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/yourUSABackGround"
    >




</LinearLayout>

Hope that helps.