Develop Reference

Can you build React Native apps (Android app) on Ubuntu?

As I can see here you need OS X to build apps with React Native. That is probably because they used it at first to create only iOS apps. Now it's possible to create Android apps with React Native but they still require OS X as development platform which doesn't make sense to me. Is there any way to create Android apps using React Native on Ubuntu OS or any other Linux?

Update 2: I've been developing React native apps on Ubuntu for some time now, without any issues.
Update 1: It's almost possible on linux and windows now. Check this doc page: link
Old answer:
It's already almost working, from the issue shared in kzzzf's answer:
Everything works on Linux except:
react-native run-android can't open a new shell window, you need to
use react-native start. Will be fixed in next release. Debugging in
Chrome currently relies on an AppleScript to launch Chrome. There's a
PR to replace that.

Building on linux and windows is not officially supported although there are people in the community already sending pull requests that will allow to do so (main obstacle is the fact of using apple-script and calling to shell scripts from node - from react-packager and from react-cli).
Main task for tracking those efforts is here: https://github.com/facebook/react-native/issues/2693

While it's not officially supported on Linux yet, and there are certainly some hoops to jump through, I have created a docker container that allows me to build and run android apps from Ubuntu.
The dockerfile is still a work in progress but it's available on github: https://github.com/gilesp/docker/tree/master/react_native
There's a couple of shell scripts to make local development easier - I mainly use the react-bash script to give me a shell prompt in the container for running react-native run-android etc.
It works well enough that I can have a phone connected via USB on my host machine, the react native stuff running in the container and have my edits to the code (I mainly edit using emacs on the host) appear immediately on the device.
I'm currently working on CI builds for android as there are some more hoops to jump through to create the bundled version of the javascript for deployment.

It should be possible by now. For an up to date guide on "can i build for platform X on system Y", see:
https://facebook.github.io/react-native/docs/getting-started.html

Building Android application inside android OS

Im curious to know the what steps/tools need to build an android app from source code to apk inside android (i.e. inside an android powered smartphone).
Im actually curious how AIDE works. They give a whole integrated development environment as an android app. Without any root privilege, it compiles==>builds==>generates apk==>deploys/installs apk to host machine (i.e the smartphone).
Im guessing I need ANT/Gradle , keytool , jarsigner(to sign apk).
But:
What tools?
In what sequence?
How? :)
I dont know is it a good place to ask? If not, any suggestion of stackexchange network or any blog will be appriciated.

You don't need any extra tools, if you have AIDE installed...
Just wrap up your Android project code, hit the 'Build' button & it Compiles everything to a working Android App (.apk) :)

All you need is just AIDE .
IT HAS ALL REQUIRED TOOLS LIKE GRADLE, AAPT, SIGNER ETC
Just chill and start using AIDE, if you have problem with free version, try Pro. Am using Pro without any problem since 3 years

Use Sublime Text 2 to develop Phonegap applications for Android

I've been using eclipse to develop Android apps with phonegap until, a few weeks ago, I decided to try Sublime Text 2. I found it to be so much better than the eclipse editor so I would like to keep using it. Only thing I'm missing is a quick way to test the app on the device inside Sublime.
Luckily, someone else also had the same idea and developed a plugin for this:
https://github.com/Korcholis/Andrew
Sadly, I cannot get it to work, I installed ant and pointed the plugin to adb but then nothing happens when I try to create a new project (and there is no error message in the console).
I also found this other plugin:
https://bitbucket.org/ucomesdag/sublime-android
But I have no idea on how to install and run it.
Did someone else found a way to do this?

A quick update into 2014.
As of PhoneGap Cordova 3.0, it is no longer required to develop Android apps via eclipse. You are free to use any code editor or IDE you wish as app building is done independently from eclipse via a simple command line.
cordova run android to package the .apk and install on any active devices detected by adb or
cordova build android to package the .apk only.
In your case, you can keep using Sublime and pop in the cordova run android command whenever you ready to go on a test run.

While I agree with Insane Coder that you should stick with supported IDEs to develop for Android, according to this link and existing Sublime Text 2 Ant support, you could build and develop your android project with this IDE (It will just take some time to set it all up... as opposed to using a supported IDE like IntelliJ or Eclipse).
Using PackageControl, look for "Ant". That will install syntax highlighting for Ant. Another plugin that enables the build command (ctrl+b) to work for Ant files, "Super Ant". You should be able to code for android in sublime text 2 with those installed.
On another note... Do you use windows? The Andrew project you link to, seems to have Windows compatibility issues. Apparently related to locating the "SDK" (he says sdk in Andrew's github page but, probably he means JDK?) in your hard drive. Which is probably a hassle because Windows typically installs stuff to "Program Files" and in code, that turns into "Progra~1" because of the space. In the link I give you there is another approach to it, so when you install the JDK set a folder that has no spaces in its name, like c:\java\jdk1.6.0_02 or something else that strikes your fancy. The problem you could be having with Andrew is that it isn't finding the jdk in your hard disk.

SL4A Android x86 installation

I am currently developing a Android Application. I couldn't install the Android Python APKs like the sl4a.apk and the PythonInterpreter.apk on my Android x86 emulator. I read that it is possible to recompile the APKs with NDK but I have not found a closer decription, yet. Has anybody experience with this and could provide a small tutorial?
Best Regards

Try the official Android emulator. If the APKs include native libraries, chances are those are compiled for ARM only. Google's emulator emulates the ARM instruction set.
To make sure, rename the APK to ZIP and look inside. The structure of the lib folder, if any, will give you an idea.

you just install an APK package available here: http://code.google.com/p/android-scripting/downloads/detail?name=beanshell_for_android_r3.apk&can=2&q=
SL4A then you will have to start, edit your script, the APK package is available here: http://code.google.com/p/android-scripting/downloads/detail?name=sl4a_r4.apk&can=2&q=
Then you just google uses the SDK to emulate your scripts on a PC
you also just edit directly with a text editor on Android for example "920 text editor"
sorry for the Google translation
++ BeHuman

To install SL4A, you will need to enable the "Unknown sources" option in your device's "Application" settings, download the .apk and install it either by accessing http://code.google.com/p/android-scripting/ from your computer and click the qr-code or directly from your phone and click the qr-code and then run the downloaded .apk file.
After installing SL4A:
press the Home button
press Add button
go to Interpreters
press Home button again
press Add again
pick Python Interpreter and install it
and after that a new screen will appear with an Install button on the top, press it and it will download Python 2.6.2, at the moment, for you. Optionally there is a button so that you can download a few more Python modules.
To build your new files you have a great little tutorial here: http://jokar-johnk.blogspot.com/2011/02/how-to-make-android-app-with-sl4a.html
Just follow all of these steps and you will be able to make working .apk files written in Python for your Android phone.

Getting started with JUCE for Android

I need to start building an Android app that uses the JUCE libraries. I'm reading the web site and trying to figure stuff out.
I tried installing JUCE on an Ubuntu 11.04 system, and when I built the IntroJucer app, the menus don't work right (they flash open when I click with the mouse but then disappear). Can a JUCE app for Android be built on Mac OS X, or even Windows?
If you are using JUCE to build Android apps, please give me any advice you can.

Yes, a Juce app can be written for Android using either OS X (XCode 4) or Windows (Microsoft Visual Studio 2008 and higher). You also have the option of using the Eclipse IDE on either platform.
At the time you posted, Juce was undergoing a major overhaul and the IntroJucer might not have been as stable as it needed to be, especially on systems other than OS X or Windows. You should look into it again. IntroJucer is not required to build a Juce Application (although it can make things easier).
I suggest you first build the Juce Demo application for your platform. If Ubuntu is giving you trouble, try OS X or Windows first. Once you have the Juce Demo running you can move on to IntroJucer. If that works, then try compiling Juce Demo for Android. Your questions can be answered in the Android Juce Forum:
http://rawmaterialsoftware.com/viewforum.php?f=13

Here is what I have figured out now that I have been working with this stuff for a bit.
All of this is based on the most recent "stable" release of JUCE, which is about ten months old as I write this. It is quite possible that things have changed (for the better!) in more bleeding-edge releases of JUCE, and when I get a chance I will try a newer JUCE.
The best platform is Mac OS X. When I tried Linux I had some issues with Eclipse not working; I still prefer Linux so I'm going to go back and try again, but on Windows and Mac I had no Eclipse troubles.
Start by installing the Android SDK, and running the updater to grab all the updates. Also install the Android NDK, and Eclipse. In Eclipse, install the ADT plugin.
JUCE sets up an Ant build file that will build all the C++ code for you, automatically. You need to not mess with this. I had a problem where there was a task called "setup" and Ant didn't know how to resolve it; the solution was to delete the "setup" task and not touch anything else. When I was trying to figure out how to solve this issue, I found suggestions here on StackOverflow to run this command: android update project --path . DO NOT DO THIS for JUCE. This re-writes your build.xml file and the special JUCE stuff to build the C++ code disappears; then you build and you get a tiny .APK file (about 10 KB) that contains only the Java setup code and no compiled C++, and does not work. So, just to be clear, the solution to the "setup" build problem is to delete that build task and touch nothing else, and not to completely replace your build.xml file.
The JUCE build process relies on a Bash shell script to do some work. On Mac OS X this works great; on Windows, the build fails with an error from CreateProcess() because CreateProcess() doesn't understand Bash shell scripts. It should be possible to edit this and make it work, but out of the box it works perfectly on Mac OS X.
For testing your code on an Android device, you must sign your code. Eclipse makes it easy to build either signed or unsigned .APK file, but the unsigned file is nearly useless. The only thing you can do with an unsigned .APK is run it in the emulator.
Once I had all the above stuff correct, I had no problems with building the JUCE app for Android.