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copied!<p>I think having a service to manage the GPS is the sensible way to go, especially if you have more than one activity which might want location information. I adopted such an approach in my app.</p> <p>Firstly I used an <code>Ibinder</code> in the service and bound to it from the activities with </p> <pre><code>bindService (new Intent(....), mServconn, Context.BIND_AUTO_CREATE); </code></pre> <p>in onStart()</p> <p>and <code>unbindService(mServconn);</code> in onStop() of each activity</p> <p>I had the service use <code>sendBroadcast()</code> to <code>BroadcastReceivers</code> registered in the activities. The location data is passed via extras in the broadcast intent.</p> <p>I used a state machine in the service with 3 states, IDLE, SEEKING and GOT_A_FIX_NOW_SLEEPING. The sleep time is passed in through a 'changeGPSParameters' method exposed in a public method of the service. Another parameter is the required accuracy, i.e. don't broadcast a message until you've had a fix better than the the required accuracy, then you can sleep. Sleep means turn off the GPS until the time has elapsed.</p> <p>The timing is managed by a Runnable and a Handler posts messages to it with code like</p> <pre><code>mHandler.postDelayed(this, mSleepTime ); </code></pre> <p>I find this works well. When no activities are bound to the service then <code>onUnbind()</code> will run in the service. In that method you just have to make sure that you stop the location listener and stop the timer with <code>mHandler.removeCallbacks</code></p> <p>UPDATE</p> <p>Below is a simple example of a Runnable which you can start/stop by means of two buttons in your main.xml which should have a single textview to show the timer state:</p> <pre><code>import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.view.View; import android.widget.TextView; public class TimerLoopActivity extends Activity { private Handler mHandler = new Handler(); private int mSleepTime = 2; //seconds private int mLoopCount = 0; private Runnable mUpdateTimeTask = new Runnable() { public void run() { // Code here for when timer completes mLoopCount++; setTextBoxMsg("Running - count = " + mLoopCount); mHandler.removeCallbacks(this); mHandler.postDelayed(this, mSleepTime * 1000); // keep looping } }; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); setTextBoxMsg("Timer Idle"); } private void setTextBoxMsg(String string) { TextView tv = (TextView) findViewById(R.id.textView1); tv.setText(string); } public void myClickHandler(View target) { switch (target.getId()) { case R.id.startbutton: setTextBoxMsg("Starting timer"); startTimer(); break; case R.id.stopbutton: setTextBoxMsg("Stopping timer"); mLoopCount = 0; stopTimer(); break; } } private void stopTimer() { mHandler.removeCallbacks(mUpdateTimeTask); } private void startTimer() { mHandler.postDelayed(mUpdateTimeTask, mSleepTime * 1000);} } </code></pre> <p>You can adapt this to put it in your service.</p>

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