Hello! I posted in response to an earlier related post but had no luck, so I'd like to present my issue more clearly in hopes of someone being able to help.. I am trying to use the JNIHelpers METHODS in order to be able to call Java functions from c++ (i.e. android.os.debug getNativeHeapSize()). I'd like to do this to be able to programmatically probe how much RAM my app is using so that I can manage memory there. I am trying this on a test app first to get all the steps down. Which is seemingly impossible as of right now...
1. I created a new project with the Introjucer with XCode and Android Targets
2. I take the JUCE example, 'HelloWorld' and modify it to have 2 buttons and a display to allocate and free 20M and to someday display the memory available on the Android device. This runs fine until I start trying to incorporate the JNI calls.
3. In my XCode Project, I modified the juceHeader.h and added this after all of the include statements
#if defined(JUCE_ANDROID)
namespace juce
{
#include "modules/juce_core/native/juce_android_JNIHelpers.h"
}
#endif
Both my main.cpp and MainComponent.h files include this file
4. My 'call' to java...
in my mainComponent.cpp file, in my button clicked function, after I deal with what I want done natively, I call Java like so
#if JUCE_ANDROID
std::cout << "About to call to Java" << std::endl;
const LocalRef<jstring> myText ((jstring) android.activity.callObjectMethod (JuceAppActivity.getMemInfo));
std::cout << "myMem from Java: " << myText << std::endl;
#endif
5. I added in my METHOD to the JNIHelpers.h file like so
...
METHOD (scanFile, "scanFile", "(Ljava/lang/String;)V") \
//TESTCODE MINE
METHOD (getMemInfo, "getMemInfo", "()Ljava/lang/String;")
DECLARE_JNI_CLASS (JuceAppActivity, JUCE_ANDROID_ACTIVITY_CLASSPATH);
...
So this function takes no arguments and will return a string to my C++ side of the world.
6. In Eclipse, in my Java source file I have added in this function
public final String getMemInfo ()
{
ActivityManager am = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
int memoryClass = am.getMemoryClass();
MemoryInfo memInfo = new MemoryInfo();
long availableMegs = memInfo.availMem / 1048576L;
return Long.toString(availableMegs);
}
I wanted to make sure first that I could go back and forth with a similar example I found on this forum posted by vipersnake, and was hoping to worry about the already implemented 'getNativeHeapSize' function later-- but I'll take that solution if anyone has got it!!
I know that the ACTIVITY CLASS NAME and PATH are set-- it says so in the Android.mk file. I have double checked all of my file paths and it seems that it is all correct-- I have tried relative an absolute paths. and I still continuously get this error whenever I try running ndk-build. It compiles... but I am having an issue with the paths I think and I don't understand where I could be going wrong...
ndk-build NDK_DEBUG=1 APP_OPTIM=debug
[armeabi] Gdbserver : [arm-linux-androideabi-4.8] libs/armeabi/gdbserver
[armeabi] Gdbsetup : libs/armeabi/gdb.setup
[armeabi-v7a] Gdbserver : [arm-linux-androideabi-4.8] libs/armeabi-v7a/gdbserver
[armeabi-v7a] Gdbsetup : libs/armeabi-v7a/gdb.setup
[armeabi] Compile++ thumb: juce_jni <= MainComponent.cpp
In file included from /Users/claudia/jniTestApp_MEM/JuceLibraryCode/JuceHeader.h:37:0,
from jni/../../../Source/MainComponent.h:24,
from jni/../../../Source/MainComponent.cpp:23:
/Users/claudia/jniTestApp_MEM/JuceLibraryCode/modules/juce_core/native/juce_android_JNIHelpers.h:37:8: error: 'JNIEnv' does not name a type
extern JNIEnv* getEnv() noexcept;
^
/Users/claudia/jniTestApp_MEM/JuceLibraryCode/modules/juce_core/native/juce_android_JNIHelpers.h:44:40: error: expected ')' before 'o'
inline explicit GlobalRef (jobject o) : obj (retain (o)) {}
And the errors just keep going. Does anyone happen to see a step that I may have missed??
Thank you!!!!