Develop Reference

Integrate Flutter into an existing project

I'd like to add Flutter into an existing Android application. The initial projet is really huge so I cannot use flutter create, I went on the FAQ but there's a lack of documentation for this.
Here is the exception I get from Gradle :
Could not resolve all files for configuration ':app:officialGooglePlayStoreDebugCompileClasspath'.
Failed to transform file 'flutter-x86.jar' to match attributes {artifactType=android-classes} using transform JarTransform
Transform output file /Users/mch/project/app_flutter/build/app/intermediates/flutter/flutter-x86.jar does not exist.
Apparently flutter-x86.jar cannot be generated. I tried to copy-paste it from another flutter project but the compilation just fail as well.

You should still run flutter create and then swap out the contents of the generated android and ios folders (via a submodule or whatever) with your existing projects. You will need to then manually port over all the flutter specific gradle tasks and config that are in the template projects to your projects in order for it to work.
You will also need to make sure that you add code to initialize the Flutter application and Plugin Registry, etc.
You will hit a lot of limitations though when trying to add Flutter to an existing app. #1 is that you will only be able to have one Flutter Activity, ViewController, View, etc in an application as a general rule.
It's something that will eventually work really well, and I'm not trying to dissuade you, but just be aware before starting.

Creating multiple new project apks from one parent project ionic

This question may seems old to some you guys or may be silly or may interesting , but i really want to know this.I build an application in ionic but now as i want to make such automated system like i can make multiple application's apks from the existing parent code with different package names and version codes.I want to make such a script that when i run it on command line i will be able to build a new apk from the parent code just by changing logo and package name , version code , version name.As the functionality will remain same only base url , package name , version code need to get changed . so i want this process to reduce my efforts in generating new apks manually.
I done some R&D and found some links but i am not able to understand them clearly , as i never use ant or maven earlier , After seing such links i believe that this can be possible . So , i just want to get sure of this and want to take idea from all the experts here in stackoverflow.I really want to learn this amazing thing.
links are as follows :-
Create an Android project from existing one
How to compile APK from command line?
http://www.simpligility.com/2010/11/release-version-management-for-your-android-application/
Found This But it is Unanswered :-
Generate multiple APK's with same code base using ANT
I found this But i do not know how ruby works and how to use this in ionic framework:-
http://iambrucewang.blogspot.in/2012/03/create-multiple-android-apps-from-one.html
I am using Linux mint and eclipse as IDE .
Please enlighten me with your expertise knowledge.I will be very grateful to you all.
Regards

First of all: Don't use Ecplise anymore as an Android IDE. The Eclipse Support for Android is outdated and Android Studio will bring you joy.
Regarding your question: You are asking about build types (i.e. develop, release, ...) and build flavors (paid, free, whatever, ...).
You can define these two in the gradle file (don't use Ant anymore. For Android it's as outdated as Ecplise). For example you define two flavors: logoOne and logoTwo. For each flavor you can either use different implementations for classes who need to do different things OR you can also define BuildConfig Fields with more or less hardcoded information.
More about this here:
https://developer.android.com/studio/build/build-variants.html
or on youtube here:
https://www.youtube.com/watch?v=cD7NPxuuXYY
This will generate seperate APKs for each build variant (= combination of buildtype and buildflavor)

Android library project custom Ant build

I have a library project that serves as the backend for a number of other projects. It does the web connection and parsing etc. Then I have other front end projects that build on this.
For development and server environments I wrote an ANT build script that replaces certain values in the code bases on the build type.
So I have two targets buildDev and buildProd.
Is there a way for me to have the values set correctly while building the dependent (non-library projects). E.g. if I do ant debug on the project it builds the backend with ant buildDev and if I do ant release it does it with ant buildProd.
I'm pretty sure that's not possible, so what are the alternatives.
For the curious, the custom builds just replaces a file that has static variables that are assigned different values based on the type of build. Nothing too complex.

In ant, there are a variety of different tasks that can be used to edit properties in a file.
I'm sure you're aware of property files, so if you use the documentation here:
http://ant.apache.org/manual/index.html
It could probably help you.
If you set your variables in an ant-style property file, then for certain builds you could have separate files for separate builds, and then therefore have the variables set correctly.
If you're talking about having variables set in your source, try the copy task:
http://ant.apache.org/manual/index.html
Filterchains on a copy task will allow you to replace certain lines of code out of a file. So if you have a variable named server_ip or something like that, you can use a filterchain to change that value and re-copy that source file back into your tree.
I hope this answers your questions. If not, be gentle. I'm kinda new at answering stuff and I got slightly chewed out on an Android post haha.

I found the solution. The default Android Ant build.xml passes the release name to the child library project script while calling it. The following lines and the code that follows details it.
<!-- figure out which target must be used to build the library projects.
If emma is enabled, then use 'instrument' otherwise, use 'debug' -->
<condition property="project.libraries.target" value="instrument" else="${build.target}">
<istrue value="${build.is.instrumented}" />
</condition>
Then it's just a matter of having the same targets in all the interdependent projects.

Android ant build changing global variable

I have an ant build setup for my Android project, and I've been reading guides and tutorials all over stackoverflow and online, but cannot seem to understand how to make this work. Basically in my code I have a variable, "isDebugVersion" (which will print out logs, and a few other things). When I build with ant, I want that variable in my code to be set to "false". I'm looking around and I cannot find the custom_rules.xml examples even though it's listed in the build.xml file.
So the variable is in com.example.application.Globals, and it's listed as isDebugVersion. Can someone please give me an example for how to manipulate this variable using an ant build script?

You can a file named custom_rules.xml to the root folder of your project.
Inside define any property you want.
Note that what you are trying to achieve could be simpler using BuildConfig.DEBUG. This file is in the gen folder of your project, close to R.java. It is generated during the build and the constant DEBUG will be set to false during debug builds and to true in release.
So if you type ant release, you will get false. With eclipse or ant debug, you will get true.
You could also learn how to use RoboGuice, it has an interesting logging solution.
You can use this constant for all purposes like changing the google map api key from debug to release key. For an example, follow this thread.

Optimize the project code

I have been working on one project which is too complex and contain very much space with so many images and Java files as well.
Somewhere I have read about the proguard which optimizes the code.
I have used it, but it's still does not have an effect on my final APK file.
It might be I have made a mistake somewhere. I have the following this like http://developer.android.com/guide/developing/tools/proguard.html.
How can I optimize my code?

You can add it to the default.properties. I've been adding manually without having a problem so far.
If you add the line:
proguard.config=proguard.cfg
As said it will only use ProGuard when exporting signed application (Android Tools => Export Signed Application)
If you start the project with the SDK before Android 2.3 the proguard.cfg file will not be created (next to default.properties as in 2.3>).
To enable automatic creation of it, just simply update to the SDK of Android 2.3 and create a new project with existing sources (which are the sources of the project you currently have).
Automagically the proguard.cfg fill will be created.
Without optimizations the compiler produces very dumb code - each command is compiled in a very straightforward manner, so that it does the intended thing.
The Debug builds have optimizations disabled by default, because without the optimizations the produced executable matches the source code in a straightforward manner.

Please refer this one
From documentation:
ProGuard is integrated into the Android build system, so you do not have to invoke it manually. ProGuard runs only when you build your application in release mode, so you do not have to deal with obfuscated code when you build your application in debug mode.