ByteBufferWrapper tweaks

operator() gets called in a Java GC thread. A JNIEnv* saved in the
constructor (which is called from the UI thread) is not valid in other
threads (although for now, Dalvik notices, warns, and works around
it). So don't bother keeping the JNIEnv*. Instead fetch one when
needed. Move the method implementations from inline in the header to
libotouch's android.cxx.

Change-Id: I7de6fc54bb8d9a59146576d6e8c325fe917393ee

sal/inc/sal/ByteBufferWrapper.hxx

@@ -21,25 +21,14 @@ namespace org { namespace libreoffice { namespace touch {
 class ByteBufferWrapper
 {
 private:
-  JNIEnv *env;
-  jobject object;
+    jobject object;
 
 public:
-  ByteBufferWrapper(JNIEnv *e, jobject o) :
-    env(e)
-  {
-    object = env->NewGlobalRef(o);
-  }
-
-  sal_uInt8* pointer()
-  {
-    return (sal_uInt8 *) env->GetDirectBufferAddress(object);
-  }
-
-  void operator()(sal_uInt8 * /* p */)
-  {
-    env->DeleteGlobalRef(object);
-  }
+    ByteBufferWrapper(JNIEnv *env, jobject o);
+
+    sal_uInt8* pointer();
+
+    void operator()(sal_uInt8 *p);
 };
 
 }; }; };

touch/Library_libotouch.mk

@@ -33,6 +33,10 @@ $(eval $(call gb_Library_add_exception_objects,libotouch,\
 
 ifeq ($(OS),ANDROID)
 
+$(eval $(call gb_Library_use_libraries,libotouch,\
+	lo-bootstrap \
+))
+
 $(eval $(call gb_Library_add_exception_objects,libotouch,\
 	touch/source/android/android \
 ))

touch/source/android/android.cxx

@@ -10,9 +10,43 @@
 #include <jni.h>
 
 #include <sal/ByteBufferWrapper.hxx>
+#include <osl/detail/android-bootstrap.h>
 
 using org::libreoffice::touch::ByteBufferWrapper;
 
+static JNIEnv *get_env()
+{
+    JavaVMAttachArgs args = {
+        JNI_VERSION_1_2,
+        NULL,
+        NULL
+    };
+
+    JavaVM *jvm = lo_get_javavm();
+    JNIEnv *env = NULL;
+
+    jvm->AttachCurrentThread(&env, &args);
+    return env;
+}
+
+__attribute__ ((visibility("default")))
+ByteBufferWrapper::ByteBufferWrapper(JNIEnv *env, jobject o)
+{
+    object = env->NewGlobalRef(o);
+}
+
+__attribute__ ((visibility("default")))
+sal_uInt8* ByteBufferWrapper::pointer()
+{
+    return (sal_uInt8 *) get_env()->GetDirectBufferAddress(object);
+}
+
+__attribute__ ((visibility("default")))
+void ByteBufferWrapper::operator()(sal_uInt8 * /* p */)
+{
+    get_env()->DeleteGlobalRef(object);
+}
+
 extern "C"
 __attribute__ ((visibility("default")))
 jlong