java - Android: UsageStatsManager not returning correct daily results

Question

I'm attempting to query UsageStats from UsageStatsManager, with the aim of returning all app packages that were used daily and for how long.

The Code:

public static List<UsageStats> getUsageStatsList(Context context){
    UsageStatsManager usm = getUsageStatsManager(context);
    Calendar calendar = Calendar.getInstance();
    long endTime = calendar.getTimeInMillis();
    calendar.add(Calendar.DAY_OF_YEAR, -1);
    long startTime = calendar.getTimeInMillis();

    List<UsageStats> usageStatsList = usm.queryUsageStats(UsageStatsManager.INTERVAL_DAILY,startTime, endTime);
    return usageStatsList;
}

I have an alarm that fires daily just before midnight and query's usagestats and then stores the returned data. At first everything seemed to be working fine and I was getting package results and their active time, however I added a function that would check the results hourly and here is where I made a strange discovery.

The results from UsageStatsManagerseemed to be resetting at different times, instead of at midnight, which is what I would have expected considering I was using INTERVAL_DAILY as a search parameter.

From the data I saved the package 'time' results seem to be resetting at (Rough timings):

• 3am
• Midday
• 3pm
• Midnight

I realize that there is a correlation between when the package timings reset but is this meant to happen?

I've already seen the following thread and it's where I got a lot of my information from: How to use UsageStatsManager?

Consequently: Android UsageStatsManager producing wrong output? In the comments mentions that the data returned from queryUsageStats can't be trusted and random results are being returned.

Am I missing something simple or is UsageStatsManager not functioning correctly?

Answer 1

I too noticed this behaviour in API 21,UsageStats data is not maintained for sufficiently long in API 21. it works fine from API 22, If you check in android /data/system/usagestats, you will find limited entries in API 21, so its not reliable using it in API 21.

For API 21+, You will get the whole day usagestats while querying INTERVAL_DAILY according to UsageStatsManager API. If you want to query within hours of day you should use queryEvents and iterating them by your own logic.

I tried in the following way...

This is the modal class for capturing data for every app:

private class AppUsageInfo {
        Drawable appIcon;
        String appName, packageName;
        long timeInForeground;
        int launchCount;

        AppUsageInfo(String pName) {
            this.packageName=pName;
        }
}

List<AppUsageInfo> smallInfoList; //global var

here is the method, its easy, go with the flow:

void getUsageStatistics() {

UsageEvents.Event currentEvent;
List<UsageEvents.Event> allEvents = new ArrayList<>();
HashMap<String, AppUsageInfo> map = new HashMap <String, AppUsageInfo> ();

long currTime = System.currentTimeMillis();
long startTime currTime - 1000*3600*3; //querying past three hours

UsageStatsManager mUsageStatsManager =  (UsageStatsManager)
                    mContext.getSystemService(Context.USAGE_STATS_SERVICE);

        assert mUsageStatsManager != null;
UsageEvents usageEvents = mUsageStatsManager.queryEvents(usageQueryTodayBeginTime, currTime);

//capturing all events in a array to compare with next element

         while (usageEvents.hasNextEvent()) {
            currentEvent = new UsageEvents.Event();
            usageEvents.getNextEvent(currentEvent);
            if (currentEvent.getEventType() == UsageEvents.Event.MOVE_TO_FOREGROUND ||
                    currentEvent.getEventType() == UsageEvents.Event.MOVE_TO_BACKGROUND) {
                allEvents.add(currentEvent);
                String key = currentEvent.getPackageName();
// taking it into a collection to access by package name
                if (map.get(key)==null)
                    map.put(key,new AppUsageInfo(key));
            }
        }

//iterating through the arraylist 
         for (int i=0;i<allEvents.size()-1;i++){
            UsageEvents.Event E0=allEvents.get(i);
            UsageEvents.Event E1=allEvents.get(i+1);

//for launchCount of apps in time range
             if (!E0.getPackageName().equals(E1.getPackageName()) && E1.getEventType()==1){
// if true, E1 (launch event of an app) app launched
                 map.get(E1.getPackageName()).launchCount++;
             }

//for UsageTime of apps in time range
            if (E0.getEventType()==1 && E1.getEventType()==2
                    && E0.getClassName().equals(E1.getClassName())){
                long diff = E1.getTimeStamp()-E0.getTimeStamp();
                phoneUsageToday+=diff; //gloabl Long var for total usagetime in the timerange
                map.get(E0.getPackageName()).timeInForeground+= diff;
            }
        }
//transferred final data into modal class object
        smallInfoList = new ArrayList<>(map.values());

}