Question

Within a public class that doesn’t extend any other class I’m doing some evaluation stuff and I would like to return a Dialog if something needs to be communicated to the user.

I’m using an AsyncTask to run a method of an instance of this class from the main UI:

private OnlineActivities onlineActivities = new OnlineActivities();

new DoOnlineActivity().execute(getApplicationContext());

private class DoOnlineStuff extends AsyncTask<Context, Integer, Dialog> {
    @Override
    protected Dialog doInBackground(Context... params) {
        return onlineActivities.start(params[0]);
    }

    @Override
    protected void onProgressUpdate(Integer... progress) {
        Log.v(RuntimeVars.getMyName(), "AsyncOnlineTask in progess");
    }

    @Override
    protected void onPostExecute(Dialog result) {
        if (result != null)
            result.show();
    }
}

Now, the public Dialog start() method of OnlineActivities.java creates a dialog using the Context that was assigned via it’s parameter.

When the Dialog is returned to onPostExecute I receive the following exception

11-14 23:53:43.303: ERROR/AndroidRuntime(1320): FATAL EXCEPTION: main
11-14 23:53:43.303: ERROR/AndroidRuntime(1320): android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at android.view.ViewRoot.setView(ViewRoot.java:509)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:177)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at android.app.Dialog.show(Dialog.java:241)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at info.myProject.messaging.ConversationList$DoOnlineActivity.onPostExecute(ConversationList.java:245)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at info.myProject.messaging.ConversationList$DoOnlineActivity.onPostExecute(ConversationList.java:1)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at android.os.AsyncTask.finish(AsyncTask.java:417)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at android.os.AsyncTask.access$300(AsyncTask.java:127)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:429)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at android.os.Handler.dispatchMessage(Handler.java:99)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at android.os.Looper.loop(Looper.java:123)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at android.app.ActivityThread.main(ActivityThread.java:4627)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at java.lang.reflect.Method.invokeNative(Native Method)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at java.lang.reflect.Method.invoke(Method.java:521)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
11-14 23:53:43.303: ERROR/AndroidRuntime(1320):     at dalvik.system.NativeStart.main(Native Method)

I suppose I cannot use the context like this. But what would be the alternative? How can I outsource some basic stuff I always need to do, even some general Dialogs?

Do I need to use custom intents instead?

Answer 1

I got a part of it to work. The problem was the usage of getApplicationContext(). The Android SDK states

Return the context of the single, global Application object of the current process.

I suppose this context differs from the context of the actual activity.

So, the Dialog gets displayed when I use this instead of getApplicationContext():

private OnlineActivities onlineActivities = new OnlineActivities();

new DoOnlineActivity(this).execute();

private class DoOnlineStuff extends AsyncTask<Void, Integer, Dialog> {
    Context ctx;
    Dialog dialog;

    public DoOnlineActivity(Context ctx){
        this.ctx = ctx;
    }

    @Override
    protected Dialog doInBackground(Void... params) {
        return onlineActivities.start(ctx);
    }

    @Override
    protected void onProgressUpdate(Integer... progress) {
        Log.v(RuntimeVars.getMyName(), "AsyncOnlineTask in progess");
    }

    @Override
    protected void onPostExecute(Dialog result) {
        if (result != null) {
            dialog = result;
            dialog.show();
        }
    }
}

BUT: Now the button I created within the Dialog won’t do anything. I guess the OnClickListener() within my Dialog isn’t responsive in the context of my main ui:

final View layout = View.inflate(ctx, R.layout.dialog_phonenumber_request, null);
((TextView) layout.findViewById(R.id.label)).setText(ctx.getString(R.string.dialog_insert_self_phonenumber_request_text1));

final EditText savedPhoneNumber = ((EditText) layout.findViewById(R.id.phonenum));
AlertDialog.Builder builder = new AlertDialog.Builder(ctx);
builder.setIcon(0);
builder.setTitle(ctx.getString(R.string.dialog_insert_self_phonenumber_request_title));

builder.setPositiveButton(ctx.getString(R.string.save),
    new Dialog.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
            String toSavePhoneNumber = savedPhoneNumber.getText().toString().trim();

            Database thisDBHandler = new Database(ctx);
            thisDBHandler.open();
            thisDBHandler.insertSetting(RuntimeVars.getDBPhoneNumberName(), toSavePhoneNumber);
            thisDBHandler.close();
        }
    }
);
builder.setView(layout);
return builder.create();

So the last step should be to tell the OnClickListener() which context to use. But how can this be done? new Dialog.OnClickListener() won’t take any parameter about the context?

Thanks!
S.