Added JNI convenience classes in QtPlatformSupport.

This is used for Android.

Change-Id: I049138c140a472b1721390cf4ec2bd88bbe9c471
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>

src/platformsupport/jniconvenience/jniconvenience.pri

@@ -0,0 +1,9 @@
+android {
+    QT += gui-private
+
+    HEADERS += $$PWD/qjnihelpers_p.h \
+               $$PWD/qjniobject_p.h
+
+    SOURCES += $$PWD/qjnihelpers.cpp \
+               $$PWD/qjniobject.cpp
+}

src/platformsupport/jniconvenience/qjnihelpers.cpp

@@ -0,0 +1,115 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** 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
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** 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
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#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

src/platformsupport/jniconvenience/qjnihelpers_p.h

@@ -0,0 +1,191 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** 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
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** 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
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QJNIHELPERS_H
+#define QJNIHELPERS_H
+
+#include <jni.h>
+#include <qglobal.h>
+#include <QString>
+#include <QThreadStorage>
+
+QT_BEGIN_NAMESPACE
+
+template <typename T>
+class QJNILocalRef;
+
+QString qt_convertJString(jstring string);
+QJNILocalRef<jstring> qt_toJString(const QString &string);
+
+
+struct QAttachedJNIEnv
+{
+    QAttachedJNIEnv();
+    ~QAttachedJNIEnv();
+
+    static JavaVM *javaVM();
+
+    JNIEnv *operator->()
+    {
+        return jniEnv;
+    }
+
+    operator JNIEnv*() const
+    {
+        return jniEnv;
+    }
+
+    JNIEnv *jniEnv;
+
+private:
+    static QThreadStorage<int> m_refCount;
+};
+
+
+template <typename T>
+class QJNILocalRef
+{
+public:
+    inline QJNILocalRef() : m_obj(0) { }
+    inline explicit QJNILocalRef(T o) : m_obj(o) { }
+    inline QJNILocalRef(const QJNILocalRef<T> &other) : m_obj(other.m_obj)
+    {
+        if (other.m_obj)
+            m_obj = static_cast<T>(m_env->NewLocalRef(other.m_obj));
+    }
+
+    template <typename X>
+    inline QJNILocalRef(const QJNILocalRef<X> &other) : m_obj(other.m_obj)
+    {
+        if (other.m_obj)
+            m_obj = static_cast<T>(m_env->NewLocalRef(other.m_obj));
+    }
+
+    inline ~QJNILocalRef() { release(); }
+
+    inline QJNILocalRef<T> &operator=(const QJNILocalRef<T> &other)
+    {
+        release();
+        m_obj = other.m_obj; // for type checking
+        if (other.m_obj)
+            m_obj = static_cast<T>(m_env->NewLocalRef(other.m_obj));
+        return *this;
+    }
+
+    template <typename X>
+    inline QJNILocalRef<T> &operator=(const QJNILocalRef<X> &other)
+    {
+        release();
+        m_obj = other.m_obj; // for type checking
+        if (other.m_obj)
+            m_obj = static_cast<T>(m_env->NewLocalRef(other.m_obj));
+        return *this;
+    }
+
+    inline QJNILocalRef<T> &operator=(T o)
+    {
+        release();
+        m_obj = o;
+        return *this;
+    }
+
+    template <typename X>
+    inline QJNILocalRef<T> &operator=(X o)
+    {
+        release();
+        m_obj = o;
+        return *this;
+    }
+
+    inline bool operator !() const { return !m_obj; }
+    inline bool isNull() const { return !m_obj; }
+    inline T object() const { return m_obj; }
+
+private:
+    void release()
+    {
+        if (m_obj) {
+            m_env->DeleteLocalRef(m_obj);
+            m_obj = 0;
+        }
+    }
+
+    QAttachedJNIEnv m_env;
+    T m_obj;
+
+    template <class X> friend class QJNILocalRef;
+};
+
+template <class T, class X>
+bool operator==(const QJNILocalRef<T> &ptr1, const QJNILocalRef<X> &ptr2)
+{
+    return ptr1.m_obj == ptr2.m_obj;
+}
+template <class T, class X>
+bool operator!=(const QJNILocalRef<T> &ptr1, const QJNILocalRef<X> &ptr2)
+{
+    return ptr1.m_obj != ptr2.m_obj;
+}
+
+template <class T, class X>
+bool operator==(const QJNILocalRef<T> &ptr1, X ptr2)
+{
+    return ptr1.m_obj == ptr2;
+}
+template <class T, class X>
+bool operator==(T ptr1, const QJNILocalRef<X> &ptr2)
+{
+    return ptr1 == ptr2.m_obj;
+}
+template <class T, class X>
+bool operator!=(const QJNILocalRef<T> &ptr1, X ptr2)
+{
+    return !(ptr1 == ptr2);
+}
+template <class T, class X>
+bool operator!=(const T *ptr1, const QJNILocalRef<X> &ptr2)
+{
+    return !(ptr2 == ptr1);
+}
+
+QT_END_NAMESPACE
+
+#endif // QJNIHELPERS_H

src/platformsupport/jniconvenience/qjniobject_p.h

@@ -0,0 +1,169 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** 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
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** 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
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QJNIOBJECT_H
+#define QJNIOBJECT_H
+
+#include <qglobal.h>
+#include <jni.h>
+
+QT_BEGIN_NAMESPACE
+
+template <typename T>
+class QJNILocalRef;
+
+/**
+ * Allows to wrap any Java class and partially hide some of the jni calls.
+ *
+ * Usage example:
+ *
+ *    QJNIObject javaString("java/lang/String");
+ *    jchar char = javaString.callMethod<jchar>("charAt", "(I)C", 0);
+ *
+ *    ----
+ *
+ *    jstring string = QJNIObject::callStaticMethod<jstring>("java/lang/String",
+ *                                                           "valueOf",
+ *                                                           "(I)Ljava/lang/String;", 2);
+ *
+ *    ----
+ *
+ *    // Constructor with argument
+ *    jstring someString;
+ *    QJNIObject someObject("java/some/Class", "(Ljava/lang/String;)V", someString);
+ *    someObject.setField<jint>("fieldName", 10);
+ *    someObject.callMethod<void>("doStuff");
+ */
+class QJNIObject
+{
+public:
+    QJNIObject(const char *className);
+    QJNIObject(const char *className, const char *sig, ...);
+    QJNIObject(jclass clazz);
+    QJNIObject(jclass clazz, const char *sig, ...);
+    QJNIObject(jobject obj);
+    virtual ~QJNIObject();
+
+    static bool isClassAvailable(const char *className);
+
+    bool isValid() const { return m_jobject != 0; }
+    jobject object() const { return m_jobject; }
+
+    template <typename T>
+    T callMethod(const char *methodName);
+    template <typename T>
+    T callMethod(const char *methodName, const char *sig, ...);
+    template <typename T>
+    QJNILocalRef<T> callObjectMethod(const char *methodName);
+    template <typename T>
+    QJNILocalRef<T> callObjectMethod(const char *methodName, const char *sig, ...);
+
+    template <typename T>
+    static T callStaticMethod(const char *className, const char *methodName);
+    template <typename T>
+    static T callStaticMethod(const char *className, const char *methodName, const char *sig, ...);
+    template <typename T>
+    static QJNILocalRef<T> callStaticObjectMethod(const char *className, const char *methodName);
+    template <typename T>
+    static QJNILocalRef<T> callStaticObjectMethod(const char *className,
+                                               const char *methodName,
+                                               const char *sig, ...);
+    template <typename T>
+    static T callStaticMethod(jclass clazz, const char *methodName);
+    template <typename T>
+    static T callStaticMethod(jclass clazz, const char *methodName, const char *sig, ...);
+    template <typename T>
+    static QJNILocalRef<T> callStaticObjectMethod(jclass clazz, const char *methodName);
+    template <typename T>
+    static QJNILocalRef<T> callStaticObjectMethod(jclass clazz,
+                                               const char *methodName,
+                                               const char *sig, ...);
+
+    template <typename T>
+    T getField(const char *fieldName);
+    template <typename T>
+    T getField(const char *fieldName, const char *sig);
+    template <typename T>
+    QJNILocalRef<T> getObjectField(const char *fieldName);
+    template <typename T>
+    QJNILocalRef<T> getObjectField(const char *fieldName, const char *sig);
+
+    template <typename T>
+    void setField(const char *fieldName, T value);
+    template <typename T>
+    void setField(const char *fieldName, const char *sig, T value);
+
+    template <typename T>
+    static QJNILocalRef<T> getStaticObjectField(const char *className, const char *fieldName);
+    template <typename T>
+    static QJNILocalRef<T> getStaticObjectField(const char *className,
+                                             const char *fieldName,
+                                             const char *sig);
+    template <typename T>
+    static T getStaticField(const char *className, const char *fieldName);
+    template <typename T>
+    static QJNILocalRef<T> getStaticObjectField(jclass clazz, const char *fieldName);
+    template <typename T>
+    static QJNILocalRef<T> getStaticObjectField(jclass clazz, const char *fieldName, const char *sig);
+    template <typename T>
+    static T getStaticField(jclass clazz, const char *fieldName);
+
+    template <typename T>
+    static void setStaticField(const char *className,
+                               const char *fieldName,
+                               const char *sig,
+                               T value);
+    template <typename T>
+    static void setStaticField(const char *className, const char *fieldName, T value);
+    template <typename T>
+    static void setStaticField(jclass clazz, const char *fieldName, const char *sig, T value);
+    template <typename T>
+    static void setStaticField(jclass clazz, const char *fieldName, T value);
+
+protected:
+    jobject m_jobject;
+    jclass m_jclass;
+    bool m_own_jclass;
+};
+
+QT_END_NAMESPACE
+
+#endif // QJNIOBJECT_H

src/platformsupport/platformsupport.pro

@@ -22,3 +22,4 @@ include(devicediscovery/devicediscovery.pri)
 include(services/services.pri)
 include(themes/themes.pri)
 include(linuxaccessibility/linuxaccessibility.pri)
+include(jniconvenience/jniconvenience.pri)