Listen for when your app is allowed or denied to listen for notifications

ListenerStatusObserver.java

    /**
     * This is just a simple ContentObserver class used to listen for
     * changes to the list of enabled notification listeners.
     * You'll need to create an instance of this class and call observe()
     * to listen for changes and unobserve() when you no longer need it.
     */
    class ListenerStatusObserver extends ContentObserver {
        /**
         * Note: Settings.Secure.ENABLED_NOTIFICATION_LISTENERS is hidden from
         * the public API so you'll want to replace it with the actual string
         * which is "enabled_notification_listeners"
         */

        public ListenerStatusObserver() {
            super(new Handler());
        }

        public void observe() {
            ContentResolver cr = getContentResolver();
            cr.registerContentObserver(Settings.Secure.getUriFor(
                    Settings.Secure.ENABLED_NOTIFICATION_LISTENERS), false, this);
            update();
        }

        public void unobserve() {
            getContentResolver().unregisterContentObserver(this);
        }

        @Override
        public void onChange(boolean selfChange) {
            update();
        }

        public void update() {
            final String flat = Settings.Secure.getString(getContentResolver(),
                    Settings.Secure.ENABLED_NOTIFICATION_LISTENERS);
            boolean enabled = false;
            if (flat != null && !"".equals(flat)) {
                final String[] names = flat.split(":");
                for (int i = 0; i < names.length; i++) {
                    if (names[i].contains(getPackageName())) {
                        enabled = true;
                    }
                }
            }
            // Do whatever you want based on the value of enabled
            Toast.makeText(NotificationListener.this, TAG + " enabled=" + enabled, Toast.LENGTH_SHORT).show();
        }
    }

Hey. How can I set enable to a specific or all the applications that ask for notification access?