I have two existing native libraries that I would like to integrate into an Android project. One has a working Android.mk file and the other has a working CMakeList.txt file. Is there a clean way to link both to Gradle?
Using CMake's ExternalProject[1] is the only idea I have at the moment.
[1] https://cmake.org/cmake/help/v3.0/module/ExternalProject.html
The solution that I arrived at was to add an additional Gradle module to build the ndk-build project. In Gradle terms the project would become a multi-project/multi-module build and is discussed further here [1]. I was also able to express the dependency in Gradle and the project built without issue.
My initial thought of using CMake's ExternalBuild failed under Gradle, but would build fine when invoking CMake from the command line. This probably had something to do with my lack of knowledge in Gradle and CMake.
[1] https://speakerdeck.com/bmuschko/state-of-the-art-gradle-multi-module-builds
I might have what you need. There is an all c++ sample that involves no JAVA UI which is actually a big thing because now your main (entry point) is in a c++ file - you can do OOP and depend on 3rd party libraries without much hassle.
Check out my repo: https://github.com/skanti/Android-Manual-Build-Command-Line
Related
I'm porting a project from NDK build to Android Studio.
Currently the project has a precompiled header attached (with NDK build), which speeds up compilation time a lot.
I'm looking for a way to add precompiled header (.pch) to my external native build within Android Studio project. I'm using CMake.
I am in the same situation and I have found several user-made script to do that.
I would recommend this one:
https://github.com/larsch/cmake-precompiled-header
In order to make it work for the latest ndk-tools which uses clang, copy paste the content of this pull request:
https://gist.github.com/leeor/316168500765cf51ae97
into the PrecompiledHeader.cmake file (replace everything in this file, except if you want to keep GCC/ MSVC compatibility, then just you will have to merge the two files which shouldn't be hard).
It should work, except some special CMAKE_CXX_FLAGS that triggers an error in the export_all_flags function, and that I don't know how to fix yet. I'll keep you updated with my progress.
I have an Android app that uses OpenCV's Java wrapper for image processing. To add OpenCV to the project, I had to add the following line to gradle.properties:
android.useDeprecatedNdk=true
This had been working fine without any warnings or errors (that I know of) up until I updated my Android Studio and Gradle after a long time (I'm using Gradle 2.2.2 and Android Studio 2.2.2 now). Now when I build my app, I get the following warnings on the messages window:
Warning:Native C/C++ source code is found, but it seems that NDK
option is not configured. Note that if you have an Android.mk, it is
not used for compilation. The recommended workaround is to remove the
default jni source code directory by adding:
Warning:Deprecated NDK integration enabled by useDeprecatedNdk flag in
gradle.properties will be removed from Android Gradle plugin soon.
Even though the build is successful at this time, as the second warning informs, this is highly likely to cause some trouble in the future, so I want to resolve them as soon as possible before things go sideways.
Does anyone know how to get resolve these warnings? Or are there any other way to import OpenCV to an Android project, other than adding all the compiled code (the .so files) and setting the flag I mentioned earlier? Any help on this will be appreciated.
I would suggest to migrate over to using the native support with cmake. You could check the link which provides a step-by-step tutorial to add OpenCV using cmake via the following link.
You're code should stay the same without any changes, only necessary action is to figure out how to include them within the build process using CMakeLists.txt.
In the project pane, right click your app (in my React Native project it's the "app" catalog), and select "Link C++ project with gradle".
Now you must find the Android.mk file - it should be already generated in your_app/app/build/intermediates/ndk/debug/
I am currently working on an Android app that is using a library that is using the NDK. The library and the app are maintained in separate repositories and are worked on as separate projects. The library is compiled on its own with Gradle and the ndk-build script. The aar output and .so files are then included in the main application.
My question is:
Is there a way to use ndk-gdb (or some alternative) to debug the library while running in the main app?
I have the source code for both projects, and if need be I could combine the projects for use with ndk-gdb, but this is very messy and requires a lot of additional work that would not be version controlled.
I have created a Non-Qt C++ (CMake) project using Qt, and I am able to build it using MinGW, MSVC compiler.
So in short, when I am opening my test project I can select the generators under Run CMake Window. I have issue with other platforms.
When I am trying to Add a kit for Android, there are no generators available in the list. I tried the same thing on Macbook, there also the same problem.
I need help on this issue, I couldn't get the proper steps to build the CMake based project for Android/iOS using QtCreator.
P.S. Installed CMake version is 3.2.1 and Qt Version is 5.5, I have installed Android SDK, NDK , and and Java
I would love to tell you "just check this box in the options dialog and it will work", but, unfortunately, there is no generator that you can use to build an Android/iOS project from a CMakeLists.txt file.
I found alternatives, in all cases, I don't think your have a chance to port a whole huge CMake-based project that used to work on Windows (with lots of libraries and 3rd party libraries) work on Android in less than a few days of work....;-)
Personnaly, I wrote a small CMake function generating the .pro file manually from my CMake scripts. It started small but is now huge and it's difficult to share it with you. But, basically, I started from this post on a Qt forum. It creates a simple .pro file that does not work that bad and then you can extend it for your own needs. I like this solution because I have full control on generated .pro file (mine can now build on PC, Android and iOS...but I had a hard time to have this fully work).
Apparently, there's also a way to add a Qt-android CMake support using this open source stuff: https://github.com/LaurentGomila/qt-android-cmake. But I never tried it. You may want to have a look to it. If it works, it may be more convenient that writting your own script generating .pro files. Apparently, it builds an Android apk using androidqtdeploy but without using QtCreator. There's also an iOS support.
Finally, the best may be to have CMake propose a QtCreator "generator" (it would generate .pro files, like CMake generates sln/vcproj files when using Visual Studio generator or makefiles for g++ generator....), but there is no such generator supported. I reported this to CMake team some time ago hoping they could fix that. I understood that there was and would be no plan to do that because CMake targets only "compilers" as "generators" and "QtCreator" is not really a "compiler", it's a "IDE" using external "compilers" to build (MinGW, MSVC, CLang, Android's NDK g++...). It's a shame because CMake known all your project information and could easily generate a .pro file....so, as, CMake is opensource, one may extend CMake with a custom QtCreator file generator...and share it with the whole world,it would be wonderful!
Hope this will help you!
I am new in android. I see a lot of android libraries out there like github.com but when I download them none of them are a *.jar file like this one:
NumberProgressBar
It seems that all these libraries are for android studio NOT eclipse (Am I correct? This is important).
My question is: How do I use these libraries in eclipse?
I tried to import the downloaded library as an android project and then mark it as "is library" and then add to my project, but that did not work.
That library is designed to be built with Gradle for Android (with or without Android Studio), producing an AAR.
Eclipse does not have native AAR support. I have published a recipe and a Ruby script to convert an AAR into a library project that Eclipse can use, though I have not tested it much.
Or, you can download the source code and attempt to reorganize it into an Eclipse-style library project.
I just downloaded it and add it as library project and everything looks fine. How do you do it, it's extremely simple. Let us know in which step you have a problem so we can figure out what is wrong.
You have to build the library first.
For your example, read the Readme file, section 'Build'.