Android – Why the activity is called twice

androidbroadcastreceiverbuttondialog

So, I'll explain my situation.
I have a Service which is catching the events from the power Button. In the service i have a broadcast receiver which takes Intent.ACTION_SCREEN_OFF and Intent.ACTION_SCREEN_ON.

// BroadcastReceiver for handling ACTION_SCREEN_OFF.
public BroadcastReceiver mReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        // Check action just to be on the safe side.
        if ((intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) ||
                (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) ) {

            if((System.currentTimeMillis() - delta) < DOUBLE_CLICK_INTERVAL) 
            {
                count++;
                Log.e("AAAAAAAA", "count= "+count);
            }else{
                count = 0;
            }

            if(count == 4){
                Log.e("AAAAAAAA", "EVENT TRIGGERED!!!!!");
                Intent alarmIntent = new Intent("com.myaction.action.EVENT_TRIGGERED");
                sendBroadcast(alarmIntent);
            }

            delta = System.currentTimeMillis();
        }
    }
};

I register the receiver in onCreate and i unregister it in onDestroy().
I have another BroadcastReceiver (this is registered in the manifest) which catch my action (EVENT_TRIGGERED). The broadcast receiver launch an activity that wraps a dialog.

public class AlarmBroadReceiver extends BroadcastReceiver {


@Override
public void onReceive(Context context, Intent intent) {

    Log.e("BROADCAST", "----------GOT THE EVENT---------");

    Intent newActivityDialog = new Intent(context, NotifyDialog.class);
    newActivityDialog .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    context.startActivity(newActivityDialog );

}}

The Activity called by the broadcast is the following:

public class NotifyDialog extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    Log.e("DIALOGACTIVITY", "ON CREATE");
    final Window win = getWindow();
    win.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
                  | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD); 
    win.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
                  | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);




}



@Override
protected void onStart() {
    // TODO Auto-generated method stub
    super.onStart();
    Log.e("DIALOGACTIVITY", "ON START");
    displayAlert();
}





@Override
protected void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
    Log.e("DIALOGACTIVITY", "ON RESUME");
}





@Override
protected void onPause() {
    // TODO Auto-generated method stub
    super.onPause();
    Log.e("DIALOGACTIVITY", "ON PAUSE");
}


@Override
protected void onDestroy() {
    // TODO Auto-generated method stub
    super.onDestroy();
    Log.e("DIALOGACTIVITY", "ON DESTROY");
}





private void displayAlert()
{
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage("Random question?").setCancelable(
            false).setPositiveButton("Yes",
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    //do somethin

                    dialog.cancel();
                    finish();
                }
            }).setNegativeButton("No",
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    dialog.cancel();
                    finish();
                }
            });
    AlertDialog alert = builder.create();
    alert.show();
}}

When i push (several times) the power button, my action is broadcast and caught by the proper receiver which launch the activity. My problem is that the activiy is called twice and i dont get the reason, the log gives an idea of what happen:

11-04 16:20:22.339: E/AAAAAAAA(19451): count= 1
11-04 16:20:22.562: E/AAAAAAAA(19451): count= 2
11-04 16:20:22.886: E/AAAAAAAA(19451): count= 3
11-04 16:20:22.983: E/AAAAAAAA(19451): count= 4
11-04 16:20:22.983: E/AAAAAAAA(19451): EVENT TRIGGERED!!!!!
11-04 16:20:23.073: E/AAAAAAAA(19451): count= 5
11-04 16:20:23.077: E/MAMT FESC(19451): ----------GOT SOMETHING---------
11-04 16:20:23.085: E/DIALOGACTIVITY(19451): ON CREATE
11-04 16:20:23.085: E/DIALOGACTIVITY(19451): ON START
11-04 16:20:23.112: E/DIALOGACTIVITY(19451): ON RESUME
11-04 16:20:23.499: E/DIALOGACTIVITY(19451): ON PAUSE
11-04 16:20:23.499: E/DIALOGACTIVITY(19451): ON DESTROY
11-04 16:20:23.554: E/WindowManager(19451): Activity com.notfall.NotifyEmergencyCall has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@482c8228 that was originally added here
11-04 16:20:23.554: E/WindowManager(19451): android.view.WindowLeaked: Activity com.notfall.NotifyEmergencyCall has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@482c8228 that was originally added here
11-04 16:20:23.554: E/WindowManager(19451):     at android.view.ViewRoot.<init>(ViewRoot.java:247)
11-04 16:20:23.554: E/WindowManager(19451):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:181)
11-04 16:20:23.554: E/WindowManager(19451):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:124)
11-04 16:20:23.554: E/WindowManager(19451):     at android.view.Window$LocalWindowManager.addView(Window.java:424)
11-04 16:20:23.554: E/WindowManager(19451):     at android.app.Dialog.show(Dialog.java:241)
11-04 16:20:23.554: E/WindowManager(19451):     at com.notfall.NotifyEmergencyCall.displayAlert(NotifyEmergencyCall.java:115)
11-04 16:20:23.554: E/WindowManager(19451):     at com.notfall.NotifyEmergencyCall.onStart(NotifyEmergencyCall.java:54)
11-04 16:20:23.554: E/WindowManager(19451):     at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1129)
11-04 16:20:23.554: E/WindowManager(19451):     at android.app.Activity.performStart(Activity.java:3781)
11-04 16:20:23.554: E/WindowManager(19451):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2636)
11-04 16:20:23.554: E/WindowManager(19451):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
11-04 16:20:23.554: E/WindowManager(19451):     at android.app.ActivityThread.access$2300(ActivityThread.java:125)
11-04 16:20:23.554: E/WindowManager(19451):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
11-04 16:20:23.554: E/WindowManager(19451):     at android.os.Handler.dispatchMessage(Handler.java:99)
11-04 16:20:23.554: E/WindowManager(19451):     at android.os.Looper.loop(Looper.java:123)
11-04 16:20:23.554: E/WindowManager(19451):     at android.app.ActivityThread.main(ActivityThread.java:4627)
11-04 16:20:23.554: E/WindowManager(19451):     at java.lang.reflect.Method.invokeNative(Native Method)
11-04 16:20:23.554: E/WindowManager(19451):     at java.lang.reflect.Method.invoke(Method.java:521)
11-04 16:20:23.554: E/WindowManager(19451):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
11-04 16:20:23.554: E/WindowManager(19451):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
11-04 16:20:23.554: E/WindowManager(19451):     at dalvik.system.NativeStart.main(Native Method)
11-04 16:20:23.554: E/DIALOGACTIVITY(19451): ON CREATE
11-04 16:20:23.558: E/DIALOGACTIVITY(19451): ON START
11-04 16:20:23.620: E/DIALOGACTIVITY(19451): ON RESUME
11-04 16:20:23.636: E/DIALOGACTIVITY(19451): ON PAUSE
11-04 16:20:23.815: E/DIALOGACTIVITY(19451): ON RESUME
11-04 16:20:24.105: E/AAAAAAAA(19451): count= 1
11-04 16:21:19.589: E/DIALOGACTIVITY(19451): ON PAUSE
11-04 16:21:19.667: E/DIALOGACTIVITY(19451): ON DESTROY

My guess is the window leak is caused by the double call to the activity. And as you can see the broadcast is sent and received only once. Sorry for the long mail but i had to explain the whole situation in order to you guys understand why the activity is called twice. Thanks guys.

Daniel

Best Answer

I'm not sure why your activity is getting started twice, but you can remove the leak by clearing up the dialog. Make the dialog a member variable of the Activity, and dismiss and null it onStop if it exists.

Related Solutions

Android – How to save an activity state using the save instance state

You need to override onSaveInstanceState(Bundle savedInstanceState) and write the application state values you want to change to the Bundle parameter like this:

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
  super.onSaveInstanceState(savedInstanceState);
  // Save UI state changes to the savedInstanceState.
  // This bundle will be passed to onCreate if the process is
  // killed and restarted.
  savedInstanceState.putBoolean("MyBoolean", true);
  savedInstanceState.putDouble("myDouble", 1.9);
  savedInstanceState.putInt("MyInt", 1);
  savedInstanceState.putString("MyString", "Welcome back to Android");
  // etc.
}

The Bundle is essentially a way of storing a NVP ("Name-Value Pair") map, and it will get passed in to onCreate() and also onRestoreInstanceState() where you would then extract the values from activity like this:

@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
  super.onRestoreInstanceState(savedInstanceState);
  // Restore UI state from the savedInstanceState.
  // This bundle has also been passed to onCreate.
  boolean myBoolean = savedInstanceState.getBoolean("MyBoolean");
  double myDouble = savedInstanceState.getDouble("myDouble");
  int myInt = savedInstanceState.getInt("MyInt");
  String myString = savedInstanceState.getString("MyString");
}

Or from a fragment.

@Override
public void onViewStateRestored(@Nullable Bundle savedInstanceState) {
    super.onViewStateRestored(savedInstanceState);
    // Restore UI state from the savedInstanceState.
    // This bundle has also been passed to onCreate.
    boolean myBoolean = savedInstanceState.getBoolean("MyBoolean");
    double myDouble = savedInstanceState.getDouble("myDouble");
    int myInt = savedInstanceState.getInt("MyInt");
    String myString = savedInstanceState.getString("MyString");
}

You would usually use this technique to store instance values for your application (selections, unsaved text, etc.).

Android – Activity restart on rotation Android

Using the Application Class

Depending on what you're doing in your initialization you could consider creating a new class that extends Application and moving your initialization code into an overridden onCreate method within that class.

public class MyApplicationClass extends Application {
  @Override
  public void onCreate() {
    super.onCreate();
    // TODO Put your application initialization code here.
  }
}

The onCreate in the application class is only called when the entire application is created, so the Activity restarts on orientation or keyboard visibility changes won't trigger it.

It's good practice to expose the instance of this class as a singleton and exposing the application variables you're initializing using getters and setters.

NOTE: You'll need to specify the name of your new Application class in the manifest for it to be registered and used:

<application
    android:name="com.you.yourapp.MyApplicationClass"

Reacting to Configuration Changes [UPDATE: this is deprecated since API 13; see the recommended alternative]

As a further alternative, you can have your application listen for events that would cause a restart – like orientation and keyboard visibility changes – and handle them within your Activity.

Start by adding the android:configChanges node to your Activity's manifest node

 <activity android:name=".MyActivity"
      android:configChanges="orientation|keyboardHidden"
      android:label="@string/app_name">

or for Android 3.2 (API level 13) and newer:

<activity android:name=".MyActivity"
      android:configChanges="keyboardHidden|orientation|screenSize"
      android:label="@string/app_name">

Then within the Activity override the onConfigurationChanged method and call setContentView to force the GUI layout to be re-done in the new orientation.

@Override
public void onConfigurationChanged(Configuration newConfig) {
  super.onConfigurationChanged(newConfig);
  setContentView(R.layout.myLayout);
}

Best Answer

Related Solutions

Android – How to save an activity state using the save instance state

Android – Activity restart on rotation Android

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