Android support (#299)

* AI libs registering shenanigans on android;
* Fixed resolution aspect + mouse event scaling;
* Proper server init/deinit (through android IPC);
Enabled threaded init in CMT;
* Prevented a deadlock in logger on some devices;
* Fixed frozen intro frame after interrupting the video;
Added android progressbar displaying during initial data loading;
* Hacky fix for choppy animations during heroes movement (should look better now, but it's definitely not a good solution);
* Changes/fixes for new android launcher building process;
* Fixed app hang after getting SDL_QUIT when activity was destroyed;
* Functioanal, configurable advmap swiping support;
* VCMI changes cleanup;
Added few missing VCMI_ANDROID guards on swipe mechanics;
* Removed unneeded sleep in server startup code for android;
* Removed android ioapi hack (fixed in newest ndk);
* Removed unused android's library loading logic;
* Added android's swipe option to settings schema;
* Moved NO_STD_TOSTRING to be defined in global.h instead of build files;

lib/CAndroidVMHelper.cpp

@@ -0,0 +1,105 @@
+/*
+ * CAndroidVMHelper.cpp, part of VCMI engine
+ *
+ * Authors: listed in file AUTHORS in main folder
+ *
+ * License: GNU General Public License v2.0 or later
+ * Full text of license available in license.txt file, in main folder
+ *
+ */
+#include "CAndroidVMHelper.h"
+
+static JavaVM * vmCache = nullptr;
+
+/// cached java classloader so that we can find our classes from other threads
+static jobject vcmiClassLoader;
+static jmethodID vcmiFindClassMethod;
+
+void CAndroidVMHelper::cacheVM(JNIEnv * env)
+{
+	env->GetJavaVM(&vmCache);
+}
+
+void CAndroidVMHelper::cacheVM(JavaVM * vm)
+{
+	vmCache = vm;
+}
+
+CAndroidVMHelper::CAndroidVMHelper()
+{
+	auto res = vmCache->GetEnv((void **) &envPtr, JNI_VERSION_1_1);
+	if(res == JNI_EDETACHED)
+	{
+		auto attachRes = vmCache->AttachCurrentThread(&envPtr, nullptr);
+		if(attachRes == JNI_OK)
+		{
+			detachInDestructor = true; // only detach if we actually attached env
+		}
+	}
+	else
+	{
+		detachInDestructor = false;
+	}
+}
+
+CAndroidVMHelper::~CAndroidVMHelper()
+{
+	if(envPtr && detachInDestructor)
+	{
+		vmCache->DetachCurrentThread();
+		envPtr = nullptr;
+	}
+}
+
+JNIEnv * CAndroidVMHelper::get()
+{
+	return envPtr;
+}
+
+jclass CAndroidVMHelper::findClassloadedClass(const std::string & name)
+{
+	auto env = get();
+	return static_cast<jclass>(env->CallObjectMethod(vcmiClassLoader, vcmiFindClassMethod,
+		env->NewStringUTF(name.c_str())));;
+}
+
+void CAndroidVMHelper::callStaticVoidMethod(const std::string & cls, const std::string & method,
+											bool classloaded /*=false*/)
+{
+	auto env = get();
+	auto javaHelper = findClass(cls, classloaded);
+	auto methodId = env->GetStaticMethodID(javaHelper, method.c_str(), "()V");
+	env->CallStaticVoidMethod(javaHelper, methodId);
+}
+
+std::string CAndroidVMHelper::callStaticStringMethod(const std::string & cls, const std::string & method,
+													 bool classloaded /*=false*/)
+{
+	auto env = get();
+	auto javaHelper = findClass(cls, classloaded);
+	auto methodId = env->GetStaticMethodID(javaHelper, method.c_str(), "()Ljava/lang/String;");
+	jstring jres = static_cast<jstring>(env->CallStaticObjectMethod(javaHelper, methodId));
+	return std::string(env->GetStringUTFChars(jres, nullptr));
+}
+
+jclass CAndroidVMHelper::findClass(const std::string & name, bool classloaded)
+{
+	if(classloaded)
+	{
+		return findClassloadedClass(name);
+	}
+	return get()->FindClass(name.c_str());
+}
+
+extern "C" JNIEXPORT void JNICALL Java_eu_vcmi_vcmi_NativeMethods_initClassloader(JNIEnv * baseEnv, jobject * cls)
+{
+	CAndroidVMHelper::cacheVM(baseEnv);
+	CAndroidVMHelper envHelper;
+	auto env = envHelper.get();
+	auto anyVCMIClass = env->FindClass(CAndroidVMHelper::NATIVE_METHODS_DEFAULT_CLASS);
+	jclass classClass = env->GetObjectClass(anyVCMIClass);
+	auto classLoaderClass = env->FindClass("java/lang/ClassLoader");
+	auto getClassLoaderMethod = env->GetMethodID(classClass, "getClassLoader", "()Ljava/lang/ClassLoader;");
+	vcmiClassLoader = (jclass) env->NewGlobalRef(env->CallObjectMethod(anyVCMIClass, getClassLoaderMethod));
+	vcmiFindClassMethod = env->GetMethodID(classLoaderClass, "findClass", "(Ljava/lang/String;)Ljava/lang/Class;");
+}