Outreachy Progress on Lumicall

unnamedLumicall 1.13.0 is released! 😀

Through Lumicall, you can make encrypted calls and send messages using open standards. It uses the SIP protocol to inter-operate with other apps and corporate telephone systems.

During the Outreachy Internship period I worked on the following issues :-

I researched on creating a white label version of Lumicall. Few ideas on how the white label build could be used..

  1. Existing SIP providers can use white label version of Lumicall to expand their business and launch SIP client. This would provide a one stop shop for them!!
  2. New SIP clients/developers can use Lumicall white label version to get the underlying working of making encrypted phone calls using SIP protocol, it will help them to focus on other additional functionalities they would like to include.

Documentation for implementing white labelling – Link 1 and Link 2


Since Lumicall is majorly used to make encrypted calls, there was a need to designate quiet times and the phone will not make an audible ringing tone during that time & if the user has multiple SIP accounts, the user can set the silent mode functionality on one of them, maybe, the Work account.
Documentation for adding silent mode feature  – Link 1 and Link 2


  • Adding 9 Patch Image 

Using Lumicall, users can send SIP messages across. Just to improve the UI a little, I added a 9 patch image in the message screen. A 9 patch image is created using 9 patch tools and are saved as imagename.9.png . The image will resize itself according to the text length and font size.

Documentation for 9 patch image – Link


You can try the new version of Lumicall here ! and know more about Lumicall on a blog by Daniel Pocock.
Looking forward to your valuable feedback !! 😀

Speaking at Open Source Bridge’17

Recently, I and my Co – speaker Pranav Jain, got a chance to speak at Open Source Bridge conference which was held in Portland, Oregon!

Pranav talked about GSoC and I talked about Outreachy , together we talked about Free RTC project Lumicall.
OSB conference was much more than just a ‘conference’. More than content in the talks, it had meaning. I am referring to the amazing keynote session by Nicole Sanchez on Tech Reform. She explained wonderfully the need of the hour, i.e Diversity inclusion is not just ‘inclusion’. Focus should be on what comes after the inclusion, Growth.

We also met several Debian developers and Debian mentor for Outreachy (Hoping to meet my mentors someday!! )

Thanks to OSB, I got to meet Outreachy co-ordinator Sarah Sharp! It was wonderful meeting an Outreachy-person! 😀 We talked and exchanged ideas about the programme. and.. she clicked beautiful pictures of us delivering the talk.

Urvika Gola at Open Source Bridge
Picture Courtesy – Sarah Sharp
Urvika Gola at Open Source Bridge
Picture Courtesy – Sarah Sharp

The talk ended with an unexpected and very precious hand written note written by Audrey Eschright..


Thank you Debian for giving us a chance to speak at Open Source Bridge and to meet wonderful people in Open Source. ❤

Debian goes to Hackathon!

Recently I had the opportunity to be a part of Ultrahack as a mentor which was held in Helsinki, Finland.
Ultrahack is a combination of hackathon and startup accelerators.
As a mentor, my role was to ensure that each team have best possible chances of fulfilling the evaluation criteria for the contest. I also helped teams with the development and pitching.

It was a very exciting place to brainstorm life changing ideas and convert those ideas into working model. I met so many amazing developers who were building cool stuff. There were a few open source developers and student open source developers like me!

Being a Debian contributor, I spread the what Debian is all about. What makes it the best linux distribution. I talked to students about various programmes like GSoC and Outreachy, Debian participates as a mentoring organisation.  I also described my role as a GSoC student under Debian and the free-RTC project I worked under. Many female developers were interested in the Outreachy programme, I described the projects that Debian has currently under the Outreachy programme.

During the hackathon period, I talked to people about the upcoming annual DebConf which takes place. I  informed them that they can still apply as a speaker or for diversity bursaries and about the logo-making competition.

Thank you Debian for always supporting me!



Speaking at FOSSASIA’17 | Seasons of Debian : Summer of Code & Winter of Outreachy

I got an amazing chance to speak at FOSSASIA 2017 held at Singapore on “Seasons of Debian – Summer of Code and Winter of Outreachy“. I gave a combined talk with my co-speaker Pranav Jain, who contributed to Debian through GSoC. We talked about two major open source initiatives – Outreachy and Google Summer of Code and the work we did on a common project – Lumicall under Debian.

WhatsApp Image 2017-03-23 at 11.32.33 PM

The excitement started even before the first day! On 16th March, there was a speakers meetup at Microsoft office in Singapore. There, I got the chance to connect with other speakers and learn about their work The meetup was concluded by Microsoft Office tour! As a student it was very exciting to see first hand the office of a company that I had only dreamt of being at.

On 17th March, i.e the first day of the three days long conference, I met Hong Phuc Dang, Founder of FOSSASIA. She is very kind and just talking to her just made me cheerful!
Meeting so many great developers from different organizations was exciting.

On 18th March, was the day of our talk!  I was a bit nervous to speak in front of amazing developers but, that’s how you grow 🙂 Our talk was preceded by a lovely introduction by Mario Behling.

WhatsApp Image 2017-03-25 at 2.32.01 PM.jpeg


I talked about how Outreachy Programme has made a significant impact in increasing the participation of women in Open Source, with one such woman being me

I also talked about Android Programming concepts which I used in while adding new features into Lumicall. Pranav talked about Debian Organization and how to get started with GSoC by sharing his journey!

After our talk, students approached us asking questions about how to participate in Outreachy and GsOC. I felt that a lot more students were receptive to knowing about this new opportunity.

Our own talk was part of the mini DebConf track. Under this track, there were two other amazing sessions namely, “Debian – The best Linux distribution” and “Open Build Service in Debian”.

The variety of experiences I gained from FOSSASIA was very diverse. I  learned how to speak at a huge platform, learned from other interesting talks, share ideas with smart developers and saw an exciting venue and wonderful city!

I would not be able to experience this without the continuous support of Debian and Outreachy  ! 🙂



Outreachy- Week 8 & 9 Progress

Working with 9-Patch Images, Adapter Classes, Layouts  in Android.

Before starting this new task I never wondered ..”How does that bubble around our chat messages wraps around the width of the text written by us??”.

The image being used as the background of our messages are called 9-Patch images.

They stretch themselves according to the text length and font size!

Android will automatically resize to accommodate the contents , like–

Source- developer.android.com

How great it would be if the clothes we wear could also work the same way.
Fit according to the body-size. I could then still wear my childhood cute nostalgic dresses..

Below, are the 9-Patch image I edited. There are two set of bubble images which are different for incoming and outgoing SIP messages.

bubble_incoming-9           bubble1-9


These images have to be designed a certain way and should be stored as the smallest size and leave 1px to all sides. Details are clearly explained in Android Documentation–


Then,  save the image by concatenating “.9” between the file name and extension.

For example if your image name is bubble.png.  Rename it to bubble.9.png

They should be stored like any other image file in res/drawable folder.

Using 9-patch images these problems are taken care of–

  1. The image proportions are set according to different screen sizes automatically.
    You don’t have to create multiple PNGs of different pixels for multiple screen sizes.
  2. The image resizes itself accroding to the Text size set in the user’s phone.

I had to modify the existing Lumicall SIP Message screen which had simple ListView as the chat message holder and replace it with 9-patch bubble images to make it more interactive 🙂

Voila! What a simple way to provide a simple yet valuable usability feature.


Outreachy- Week 6 & 7 Progress

Working with Date, Calendar, SimpleDateFormat   in Android.

As I mentioned In my last blog, I would talk about how I used Calendar and Date classes for the user to designate silent mode by setting time constraints and weekdays, in Lumicall.

Date class to used to interpret dates as year, month, day, hour, minute, and second values.

I had to compare whether the current time falls between Start Time and End Time specified by the user. So that, silent mode can be enabled within that time frame.

I used Calendar Class to get the current hour in 24-Hour format and minute.

 Calendar now = Calendar.getInstance();

 int hour = now.get(Calendar.HOUR_OF_DAY);  

 int minute = now.get(Calendar.MINUTE);

Now, Since the user enters the Time in EditText Widgets, the values were retrieved as strings.
String hhStart, mmStart, hhEnd, mmEnd store these values from Edit text widgets.

To interpret these strings as a representation of a date and time, we need to parse it

A “Date” class object’s format looks like-

Since, I was only interested in fetching the HH:MM values, i.e the fourth field in the format,

To set and compare only the HH:MM values, Android provides lovely, SimpleDateFormat class to access the particular value we want in the Date object.
To access the year, use letter Y
To access the time zone, use letter z
To access the Hour and minute, we use letter H and m.

SimpleDateFormat simpleDateFormat= new SimpleDateFormat(“HH:mm”, Locale.ENGLISH);

Date currentTime = parseDate(hour + ":" + minute)

Date timeCompareOne = parseDate(hhStart +”:”+mmStart);  

Date timeCompareTwo = parseDate(hhEnd +”:”+mmEnd);

Rest everything in the date object are values set by default. Eg, Year 1970. Which we din’t set / access , hence did not change.

To check if the start time is before the current time. And the endtime is after the current time, 

if(timeCompareOne.before(currentTime) && timeCompareTwo.after(currentTime))


Switch on the silent mode;


Added a try catch block to handle the exception which will arise if the SimpleDateFormat.parse method is unable to parse the given Java String.

public Date parseDate(String date)  
return inputParser.parse(date);
catch (java.text.ParseException e)  
return new Date(0);  

Comparing Time? Done!
Now to check whether the selected weekday in the checkboxes matches the current week day,

Calendar calendar = Calendar.getInstance(); 

int day = calendar.get(Calendar.DAY_OF_WEEK); 

If it’s sunday, value returned by calendar.get(Calendar.DAY_OF_WEEK) is 1, if monday, 2 and so on..
Weekdays compared too! 🙂

Thanks for reading,

Outreachy- Week 4 & 5 Progress

Working with Preferences, AudioManager, RingtoneManager   in Android.

Sometimes the noise can get too much. Imagine all the people around you at work or in a classroom. All of them have at least one cell phones. Even if they were all to make a tiny blip, the noise would be irritating and disruptive.

To avoid devices from interrupting the non-digital life, applications often provide settings that allow users to modify app volumes. My task this week was to  enable/disable silent mode in Lumicall.

To provide settings for your application, instead of using multiple Views, Preference APIs should be used.

Each preference appears as an item in a list and provides the appropriate UI for users to modify the setting.

In Lumicall, when settings menu from the menubar is selected, a preference screen is displayed showing various setting options, where I appended a “Configure Silent Mode” option.

The UI for the preference screen is expected to be in Src->xml folder under the name preferences.xml

Snippet from Lumicall’s preference.xml for Configure Silent Mode preference screen.


In Lumicall, whenever a SIP message comes in, RingtoneManager  Class is used to generate a notification sound & AudioManager Class is used to generate sound for incoming encrypted calls.

The difference between the two is that, AudioManager provides access to volume and ringer mode control. Ringer modes like, Normal, silent and vibration.  Whereas RingtoneManager provides access to ringtones, notification.

So to add a simple -disable/enable silent mode- functionality, I decided to use a CheckboxPreference. For the same goal, a better looking widget would be a SwitchPreference, but It does not work properly with DarkThemes which Lumicall uses. So I decided to use a simple Checkbox instead.

The result of all the settings are  saved as key value pairs in the default  SharedPreferences file which can be retrieved to make changes in the app based on the settings modified by the user.
Every preference has a key and the result associated with it.
To fetch the result from the SharedPreferences file-
boolean silentflag=PreferenceManager.getDefaultSharedPreferences(ctx).getBoolean(org.sipdroid.sipua.ui.Settings.PREF_SILENT_MODE, org.sipdroid.sipua.ui.Settings.DEFAULT_SILENT_MODE);

Note, the arguments in getBoolean function is  (Key, DefaultValue).

Don’t forget to pass the Context object, ctx in the statement. I wasted a lot of time figuring that one out and created a non-optimal-working way which I eventually had to remove cos I figured out how to retrieve the result value.

To add a second method of setting silent mode, i.e where the user can enter his work days/time, I wanted to display an activity with required widgets .
To display an activity on a when a preference is selected, intent tags are used. (See the above snippet)
Note that the target package in the intent tags is not the package name of where the java file of the activity is to be found.It’s the package name which is your applicationID.

Now this activity, like any other activity in android is a combination of an xml and java file.
1. My xml file contains the widgets for user to enter two set of time value in HH:MM format. i.e.the start and end time during which user requires application notifications to be silent it also contains checkboxes for user to select multiple days of the week.

2. The java file associated with this does the following:
2.1 Comparing the Real Time with User’s Specified Start and End time
2.2 Checking the current day of the week with the days marked by the user in the      checkboxes

I have used inbuilt Calendar class and Date class to accomplish this.

All done I felt quite proud but this.. this was something that tested my patience and endurance!
As I continue my work, I will keep sharing!


Please keep reading!

Outreachy- Week 3 Progress

In my previous blog I had tried to explain what White Labelling is and my approach of implementing it in Lumicall.

This week I went ahead with the implementation by using productFlavors feature in Android. I baked my cake!

I’ve created two flavors :

  1. Lumicall (which runs like the default version)
  2. Whitelabel

To switch to the desired version, there is a build variant window on the bottom left of Android Studio, when you open it, you can change your current active flavor from the ones you defined.

So the idea is, there would be different flavors for each client. And all the client specific resources would go under src/(flavorname) folder.

The client specific resources could be:

  1. Application name
  2. Client’s logo (Drawable)
  3. Details about the client’s organization which would go under “about” tab
  4. Colors / Themes (Colors.xml)
  5. Strings (Strings.xml)
  6. Additional Files which include new features

To understand how to modify these resources in the flavored version, Let’s take an example in which we would like to replace the application name from  from Lumicall to, lets say “ClientApp”.

  1. Go to file : /res/values/strings.xml which has the application name <string name=”app_name”>Lumicall</string>
  2. To replace it with client’s app name, You’d have to create a new strings.xml file (Note : Same name as that of the existing ‘strings.xml file’)  in the directory LumicallWhitelabel/src/whitelabel/res/values/strings.xml

    So, in our project, there are two strings.xml file. One is /res/values/strings.xml and one flavored specfic file in LumicallWhitelabel/src/whitelabel/res/values/strings.xml.

    Only add the values which would be different in the flavor version.
    If there are particular things which you’d like to be same, then there is no need of adding them again with the same value in the flavored file.

    -Just define the values you would want to replace. Not the values you would like to be same-

    Gradle will take care of the overwriting while merging the resources when you run the flavored version.

Now, the most important thing is changing the Application ID. In my previous blog I explained the difference between ApplicationID and package name.

I also added  a snippet from my build.gradle file which would suffix “.whitelabel” at the end of the orignal applicationID. So for configuring ApplicationID for each flavor, add applicationIdSuffix’suffix_you_want’.

Link to the the cake : https://github.com/Urvika-gola/LumicallWhitelabel

Thanks for reading,

Outreachy- Week 1,2 Progress

Working with productFlavors  in Android.

Since the past few weeks I have been researching and working on  creating a white label version of Lumicall with my mentors Daniel, Juliana and Bruno.

Lumicall is a free and convenient app for making encrypted phone calls from Android. It uses the SIP protocol to interoperate with other apps and corporate telephone systems. Think of any app that you use to call others using an SIP ID.

What does it mean to make a  “white label” version of Lumicall?
White labelling is the idea of taking the whole or piece of Lumicall’s code by business users and tweaking it according to their requirements and functionality they want.

The white label version would have client’s name, logo, icons, themes etc which reflect their brand. Although, the underlying working of both the applications would be same.

Think of it like getting a cake from the local bakery, putting it into a home baking dish and passing it off as something you made in front of your friends and earning all the praise. Except cake is more appealing than apps.
What whitelabelling does is it takes away the pain of collecting cake ingredients, mixing them in right proportion, baking at the right temperature and uses the experience of one cake base to create more and more fancier, prettier, grander cakes. This lets the cool bakers (or the business users of lumicall) to focus on other aspects of the party like decoration, games and drinks (or monetization, publicity and new features)

Now you would wonder who these cool bakers or business users of lumicall would be?

  • Existing SIP providers can use white label version of Lumicall to expand their business and launch SIP client. This would provide a one stop shop for them!!
  • New SIP clients/developers can use Lumicall white label version to get the underlying working of making encrypted phone calls using SIP protocol, it will help them to focus on other additional functionalities they would like to include.
  • Moreover,  Companies that have existing clients such as shopping apps, social network apps can benefit from integrating lumicall to launch new business ideas

While researching this work that despite the commonalities, there would need to be a unique identifier for any application in the app store.

I found that there is difference between the package name and the applicationID. When I create a new project in Android Studio, the applicationId exactly matches the Java-style package name I chose during setup. However, the application ID and package name are independent of each other beyond this point. The thing to keep in mind is that app stores identify as a changed application ID as a different app altogether.

So if I were to make  N separate copies of the application code for N clients, it would be a maintenance nightmare, If the build system is Gradle, using product flavors is a trick that will make this maintenance easier. Instead of N separate copies, I would simply have N product flavors. Each flavor corresponds to a customized version of my application. Pro, free, whitelabel, Debug  (for development purposes), Release (for production purposes) are the basic flavors I have identified.  

Each flavor would use the same source code and files of the application but resources, icons, manifests etc that are specific to each flavor can be defined again in main/src/flavor_name directory under res folders etc. according to the requirement.

Here is a snippet from my build.gradle file::


Note: You have to define at least two flavors to be able to build multiple variants.
Because once you have flavors, you can only build “flavored” application. You can’t just build “default” configuration anymore. Define an empty flavor, with no applicationIdSuffix at all, and it will use all of the default config section.

This week I’d be moving forward with the implementation of whitelabelling using productFlavors in Lumicall.
I would love to hear from someone who has done this before!
Comment here or email me and I promise you an excellent home-made-store-brought cake!

Wishing you all HAPPY HOLIDAYS! ! 🙂

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