Question

I’m creating an app widget that queries data from a database, and uses a content observer to update a label once this data changes. The problem is that when the widget is created, I update the label to the correct value. When the data changes, the content observer correctly registers this, but I can’t get the widget to update. The code looks like this:

//called after the configuration activity is done
public static void updateAppWidget(Context context, AppWidgetManager appWidgetManager,
         int appWidgetId){
    m_appWidgetManager = appWidgetManager;
    SharedPreferences prefs = context.getSharedPreferences(PREFS_NAME, 0);
    m_account = prefs.getString("account" + appWidgetId, "unknown");
    m_label = prefs.getString("label" + appWidgetId, "unknown");
    m_context = context;
    if (!m_accounts.contains(m_account)){
        m_accounts.add(m_account);
        m_context.getContentResolver().registerContentObserver(GmailContract.Labels.getLabelsUri(m_account), true,new MyContentObserver(new Handler()));
    }
    updateViews();

}

In the ContentObserver, I only overwrite the following function:

@Override
public void onChange(boolean selfChange) {
        GmailUnreadCounterActivity.updateViews();
        super.onChange(selfChange);
    }

the updateViews function looks like this (when called from updateAppWidget, it works perfectly, when called from the contentobserver, the widget isn’t updated, despite the value changing)

public static void updateViews(){
    System.out.println("Number of widgets:" + m_appWidgetIds.length);
    for (int i = 0; i < m_appWidgetIds.length; i++){
        SharedPreferences prefs = m_context.getSharedPreferences(PREFS_NAME, 0);
        m_account = prefs.getString("account" + m_appWidgetIds[i], "unknown");
        m_label = prefs.getString("label" + m_appWidgetIds[i], "unknown");
        Cursor c = m_context.getContentResolver().query(GmailContract.Labels.getLabelsUri(m_account),null,null,null,null);
        while (c.moveToNext()) {
            if (c.getString(c.getColumnIndex(GmailContract.Labels.CANONICAL_NAME)).equals(m_label)){
                String line = String.valueOf(c.getInt(c.getColumnIndex(GmailContract.Labels.NUM_UNREAD_CONVERSATIONS)));
                remoteViews = new RemoteViews(m_context.getPackageName(), R.layout.main);
                remoteViews.setTextViewText(R.id.unread_count,
                        line);
                AppWidgetManager.getInstance(m_context).updateAppWidget(m_appWidgetIds[i], remoteViews);
            }
        }
    }   
}

Answer 1

How do you get m_appWidgetIds?

Why do you want to keep it in a for loop and update all the instances. Instead of that use

updateAppWidget (ComponentName provider, RemoteViews views) 

This will update all the instances of widget.

Use the following code to get the ComponentName
ComponentName provider = new ComponentName(context, YourAppWidgetProvider.class);