A work blog around Android

Getting the instance of a system service without an application context in Android

July 29, 2017 omerjerk Comments 0 Comment

I have been working on a project where I am supposed to execute some Java code, which uses Android APIs, outside the application environment. This means I don’t have access to any Android component i.e. Activity, Service, Broadcast Receiver etc. I was supposed to get the display’s width and height. Hence arose the need for hacking a way to achieve what is mentioned in the title, i.e. getting the instance of a system service without having an application context. Normally, you…

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Create touch events programmatically in Android

November 7, 2016 omerjerk Comments 0 Comment

Creating a touch event in Android is pretty easy. Although, is the easy way the best? Let’s find out! The simplest way is to use the “input” binary which you can use to create touch events all over the screen (via the shell user). The command to create a simple tap event is as simple as – adb shell input tap x y. However, there’s a latency of more than 1 second while executing this command. If we’re making some…

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Take screenshot programmatically without root in Android

March 3, 2016 omerjerk Comments 0 Comment

Here’s another post related to Android hacking. One can find a lot of ways over the internet which will tell you how take the screenshot of your own app, and that’s like pretty easy too. That’s also allowed by the Android framework. Note that here I’m not talking about the screenshots you take (as a user) by pressing Power + Volume down keys (that screenshot is taken by the SystemUI which has extra privileges). Let’s talk about the case if…

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Execute Java code as a root user in Android

October 16, 2015 omerjerk Comments 0 Comment

You can find a lot of ways on StackOverflow about executing shell commands as root in Android, and it goes as follows :

Process process = Runtime.getRuntime().exec("su");
os = new DataOutputStream(process.getOutputStream());
os.writeBytes(commandToExecute + "\n");
os.writeBytes("exit\n");
os.flush();
process.waitFor();

Process process = Runtime.getRuntime().exec("su");

os = new DataOutputStream(process.getOutputStream());

os.writeBytes(commandToExecute + "\n");

os.writeBytes("exit\n");

os.flush();

process.waitFor();

What if you want to execute some Java code which uses Android APIs as a root user ? This is not as straightforward as executing a shell command with root. The idea is to compile the Java class with a static main method just like a normal apk is compiled. First of all, we need to…

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GSoC 2015 – The Processing Foundation

August 15, 2015 omerjerk Comments 0 Comment

GSoC 2015 has come to an end. I was lucky to have such an intelligent mentor, Andres Colubri. I worked on maintaining the Android mode of Processing. My GSoC project was around the following main goals : Update the Android Mode to work with the updated processing base code. Move PApplet from Activity to Fragment so that it can be embedded inside other apps. Create a video library for the Android Mode of Processing. Let’s start with the first sub task….

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Using variadic templates in C++

January 3, 2015 omerjerk Comments 0 Comment

I’ve lately been working on C++ and my main task was to improve the design of the code and make it as generic as possible, removing the redundant code and so. To achieve this aim Templates and void pointers helped me a lot. In the following post I’m going to explain about variadic templates in C++. Let’s me first give a brief intro about what templates actually are before moving on to variadic templates. Quoting from Wikipedia “Templates are a…

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How to install an app to /system partition ?

August 18, 2014 omerjerk Comments 0 Comment

Note : This article is for you if you’re making an app for rooted android devices. The normal behaviour being that the android’s package manager installs the apk file to /data partition. But for accessing hidden APIs and having extra privileges one may want the app to be installed in /system partition. For pre-kitkat devices the extra privileges folder is /system/app whereas for kitkat and post-kitkat devices the extra privileges folder is /system/priv-app. The trick to install your app to /system…

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Getting video stream from Android’s display

July 15, 2014 omerjerk Comments 6 comments

This is something that has been tried to be achieved in various ways. What other people usually do is to take screenshots at regular intervals and stitch them together to make a video out of it. What I’m doing here is pretty different an much better than that approach. And so I also present a way to capture video frames from Android’s default display and do further processing as one pleases. I’ll broadly use two main APIs viz. MediaCodec (added in…

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Make HTTP requests from SIM300 GSM module

April 11, 2014 omerjerk Comments 4 comments

SIM300 is a GSM module by Simcom. And believe me it’s no less than a piece of shit. I was unlucky enough to have my hands on it. I spent 3-4 days figuring out and testing the correct sequence of AT commands that must be used to make HTTP request via this module. In the following post I’m going to explain how to use it with the Arduino to send and receive data to a web server over HTTP. Let’s start…

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My work at Cube26

April 5, 2014 omerjerk Comments 0 Comment

Cube26 has it’s innovations in the areas of Image Processing, Machine Vision, Machine Learning. They basically focus on gesture and image based controlling of the device. At this time Cube26 has partnerships with 6 Indian phone manufacturers including Micromax, Intex and Spice. I’m in the Android development team of Cube26. At the time of writing this blog I’m working on the release of Micromax A290. We currently don’t have access to the whole source but some parts of the OS. Below…

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