/****************************************************************************
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** This file is part of the Qt Toolkit.
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** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
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****************************************************************************/

#include "qjnihelpers_p.h"

#include <qpa/qplatformnativeinterface.h>
#include <qguiapplication.h>

QT_BEGIN_NAMESPACE

QString qt_convertJString(jstring string)
{
    QAttachedJNIEnv env;
    int strLength = env->GetStringLength(string);
    QString res;
    res.resize(strLength);
    env->GetStringRegion(string, 0, strLength, (jchar*)res.utf16());
    return res;
}

QJNILocalRef<jstring> qt_toJString(const QString &string)
{
    QAttachedJNIEnv env;
    return QJNILocalRef<jstring>(env->NewString(reinterpret_cast<const jchar*>(string.constData()),
                                                string.length()));
}


static JavaVM *g_javaVM = 0;

static JavaVM *getJavaVM()
{
    if (!g_javaVM){
        QPlatformNativeInterface *nativeInterface = QGuiApplication::platformNativeInterface();
        g_javaVM = static_cast<JavaVM*>(nativeInterface->nativeResourceForIntegration("JavaVM"));
    }
    return g_javaVM;
}

QThreadStorage<int> QAttachedJNIEnv::m_refCount;

QAttachedJNIEnv::QAttachedJNIEnv()
{
    JavaVM *vm = javaVM();
    if (vm->GetEnv((void**)&jniEnv, JNI_VERSION_1_6) == JNI_EDETACHED) {
        if (vm->AttachCurrentThread(&jniEnv, 0) < 0) {
            jniEnv = 0;
            return;
        }
    }

    if (!m_refCount.hasLocalData())
        m_refCount.setLocalData(1);
    else
        m_refCount.setLocalData(m_refCount.localData() + 1);
}

QAttachedJNIEnv::~QAttachedJNIEnv()
{
    if (!jniEnv)
        return;

    int newRef = m_refCount.localData() - 1;
    m_refCount.setLocalData(newRef);

    if (newRef == 0)
        javaVM()->DetachCurrentThread();

    jniEnv = 0;
}

JavaVM *QAttachedJNIEnv::javaVM()
{
    return getJavaVM();
}

QT_END_NAMESPACE