Accessing Layout Items from inside Widget AppWidgetProvider

Posted by cam4mav on Stack Overflow See other posts from Stack Overflow or by cam4mav
Published on 2010-07-20T11:24:06Z Indexed on 2011/01/07 10:53 UTC
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I am starting to go insane trying to figure this out. It seems like it should be very easy, I'm starting to wonder if it's possible.

What I am trying to do is create a home screen widget, that only contains an ImageButton. When it is pressed, the idea is to change some setting (like the wi-fi toggle) and then change the Buttons image.

I have the ImageButton declared like this in my main.xml

<ImageButton android:id="@+id/buttonOne"
        android:src="@drawable/button_normal_ringer"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center" />

my AppWidgetProvider class, named ButtonWidget

* note that the RemoteViews class is a locally stored variable. this allowed me to get access to the RViews layout elements... or so I thought.

@Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager,
            int[] appWidgetIds) {

    remoteViews = new RemoteViews(context.getPackageName(),
            R.layout.main);

    Intent active = new Intent(context, ButtonWidget.class);
    active.setAction(VIBRATE_UPDATE);
    active.putExtra("msg","TESTING");
    PendingIntent actionPendingIntent = PendingIntent.getBroadcast(context,
            0, active, 0);
    remoteViews.setOnClickPendingIntent(R.id.buttonOne,
            actionPendingIntent);

    appWidgetManager.updateAppWidget(appWidgetIds, remoteViews);


}

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

    // v1.5 fix that doesn't call onDelete Action
    final String action = intent.getAction();
    Log.d("onReceive",action);
    if (AppWidgetManager.ACTION_APPWIDGET_DELETED.equals(action)) {
        final int appWidgetId = intent.getExtras().getInt(
                AppWidgetManager.EXTRA_APPWIDGET_ID,
                AppWidgetManager.INVALID_APPWIDGET_ID);
        if (appWidgetId != AppWidgetManager.INVALID_APPWIDGET_ID) {
            this.onDeleted(context, new int[] { appWidgetId });
        }
    } else {
        // check, if our Action was called
        if (intent.getAction().equals(VIBRATE_UPDATE)) {
            String msg = "null";
            try {
                msg = intent.getStringExtra("msg");
            } catch (NullPointerException e) {
                Log.e("Error", "msg = null");
            }
            Log.d("onReceive",msg);
            if(remoteViews != null){

                Log.d("onReceive",""+remoteViews.getLayoutId());
                remoteViews.setImageViewResource(R.id.buttonOne, R.drawable.button_pressed_ringer);

                Log.d("onReceive", "tried to switch");
            }
            else{
                Log.d("F!", "--naughty language used here!!!--");
            }
        }
        super.onReceive(context, intent);
    }
}

so, I've been testing this and the onReceive method works great, I'm able to send notifications and all sorts of stuff (removed from code for ease of reading)

the one thing I can't do is change any properties of the view elements.

To try and fix this, I made RemoteViews a local and static private variable. Using log's I was able to see that When multiple instances of the app are on screen, they all refer to the one instance of RemoteViews. perfect for what I'm trying to do

The trouble is in trying to change the image of the ImageButton.

I can do this from within the onUpdate method using this.

remoteViews.setImageViewResource(R.id.buttonOne, R.drawable.button_pressed_ringer);

that doesn't do me any good though once the widget is created. For some reason, even though its inside the same class, being inside the onReceive method makes that line not work.

That line used to throw a Null pointer as a matter of fact, until I changed the variable to static. now it passes the null test, refers to the same layoutId as it did at the start, reads the line, but it does nothing.

Its like the code isn't even there, just keeps chugging along.

SO......

Is there any way to modify layout elements from within a widget after the widget has been created!? I want to do this based on the environment, not with a configuration activity launch.

I've been looking at various questions and this seems to be an issue that really hasn't been solved, such as link text and link text

oh and for anyone who finds this and wants a good starting tutorial for widgets, this is easy to follow (though a bit old, it gets you comfortable with widgets) .pdf link text

hopefully someone can help here. I kinda have the feeling that this is illegal and there is a different way to go about this. I would LOVE to be told another approach!!!!

Thanks

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