Android: Add private API for jni in QtCore

When interfacing with Java API's on Android we need to write code using
the Java Native Interface (JNI). Writing JNI code requires a lot of
boilerplate code to be written. This patch contains API's to minimize the
amount of work needed to write JNI code.

QJNIEnvironmentPrivate:
 On creation QJNIEnvironmentPrivate will attach the current running
 thread to the Java VM, and expose the java environment.

QJNIObjectPrivate:
 Wrapps around a Java class enabling the user to access the class from C++.

Change-Id: Ib633437ae36ff513d934292e9eeefcdd5b757d29
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>

1 files changed, 264 insertions, 0 deletions

diff --git a/src/corelib/kernel/qjni_p.h b/src/corelib/kernel/qjni_p.h
new file mode 100644
index 0000000000..912b5dbee4
--- /dev/null
+++ b/src/corelib/kernel/qjni_p.h
@@ -0,0 +1,264 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtCore module 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.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#ifndef QJNI_P_H
+#define QJNI_P_H
+
+#include <jni.h>
+#include <QtCore/qglobal.h>
+#include <QtCore/qsharedpointer.h>
+
+QT_BEGIN_NAMESPACE
+
+class Q_CORE_EXPORT QJNIEnvironmentPrivate
+{
+public:
+    QJNIEnvironmentPrivate();
+    ~QJNIEnvironmentPrivate();
+    JNIEnv *operator->();
+    operator JNIEnv*() const;
+
+private:
+    friend class QJNIEnvironment;
+    Q_DISABLE_COPY(QJNIEnvironmentPrivate)
+    JNIEnv *jniEnv;
+};
+
+class Q_CORE_EXPORT QJNIObjectData
+{
+public:
+    QJNIObjectData();
+    ~QJNIObjectData();
+    jobject m_jobject;
+    jclass m_jclass;
+    bool m_own_jclass;
+};
+
+class Q_CORE_EXPORT QJNIObjectPrivate
+{
+public:
+    QJNIObjectPrivate();
+    explicit QJNIObjectPrivate(const char *className);
+    QJNIObjectPrivate(const char *className, const char *sig, ...);
+    explicit QJNIObjectPrivate(jclass clazz);
+    QJNIObjectPrivate(jclass clazz, const char *sig, ...);
+    QJNIObjectPrivate(jobject obj);
+
+    template <typename T>
+    T callMethod(const char *methodName,
+                 const char *sig,
+                 ...) const;
+    template <typename T>
+    T callMethod(const char *methodName) const;
+    template <typename T>
+    QJNIObjectPrivate callObjectMethod(const char *methodName) const;
+    QJNIObjectPrivate callObjectMethod(const char *methodName,
+                                       const char *sig,
+                                       ...) const;
+    template <typename T>
+    static T callStaticMethod(const char *className,
+                              const char *methodName,
+                              const char *sig, ...);
+    template <typename T>
+    static T callStaticMethod(const char *className,
+                              const char *methodName);
+    template <typename T>
+    static T callStaticMethod(jclass clazz,
+                              const char *methodName,
+                              const char *sig, ...);
+    template <typename T>
+    static T callStaticMethod(jclass clazz,
+                              const char *methodName);
+    static QJNIObjectPrivate callStaticObjectMethod(const char *className,
+                                             const char *methodName,
+                                             const char *sig, ...);
+
+    static QJNIObjectPrivate callStaticObjectMethod(jclass clazz,
+                                             const char *methodName,
+                                             const char *sig, ...);
+
+    template <typename T>
+    T getField(const char *fieldName) const;
+    template <typename T>
+    static T getStaticField(const char *className, const char *fieldName);
+    template <typename T>
+    static T getStaticField(jclass clazz, const char *fieldName);
+
+    QJNIObjectPrivate getObjectField(const char *fieldName, const char *sig) const;
+    static QJNIObjectPrivate getStaticObjectField(const char *className,
+                                                  const char *fieldName,
+                                                  const char *sig);
+    static QJNIObjectPrivate getStaticObjectField(jclass clazz,
+                                                  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 void setStaticField(const char *className,
+                               const char *fieldName,
+                               T value);
+    template <typename T>
+    static void setStaticField(const char *className,
+                               const char *fieldName,
+                               const char *sig,
+                               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);
+
+    static QJNIObjectPrivate fromString(const QString &string);
+    QString toString() const;
+
+    static bool isClassAvailable(const char *className);
+    bool isValid() const;
+    jobject object() const { return d->m_jobject; }
+
+    template <typename T>
+    inline QJNIObjectPrivate &operator=(T o)
+    {
+        jobject jobj = static_cast<jobject>(o);
+        if (!isSameObject(jobj)) {
+            d = QSharedPointer<QJNIObjectData>(new QJNIObjectData());
+            QJNIEnvironmentPrivate env;
+            d->m_jobject = env->NewGlobalRef(jobj);
+            d->m_jclass = static_cast<jclass>(env->NewGlobalRef(env->GetObjectClass(jobj)));
+        }
+
+        return *this;
+    }
+
+private:
+    friend class QJNIObject;
+
+    template <typename T>
+    T callMethod(const char *methodName,
+                 const char *sig,
+                 va_list args) const;
+    QJNIObjectPrivate callObjectMethod(const char *methodName,
+                                       const char *sig,
+                                       va_list args) const;
+    template <typename T>
+    static T callStaticMethod(const char *className,
+                              const char *methodName,
+                              const char *sig, va_list args);
+    template <typename T>
+    static T callStaticMethod(jclass clazz,
+                              const char *methodName,
+                              const char *sig, va_list args);
+    static QJNIObjectPrivate callStaticObjectMethod(const char *className,
+                                                    const char *methodName,
+                                                    const char *sig, va_list args);
+
+    static QJNIObjectPrivate callStaticObjectMethod(jclass clazz,
+                                                    const char *methodName,
+                                                    const char *sig, va_list args);
+
+    bool isSameObject(jobject obj) const;
+    bool isSameObject(const QJNIObjectPrivate &other) const;
+
+    friend bool operator==(const QJNIObjectPrivate &, const QJNIObjectPrivate &);
+    friend bool operator!=(const QJNIObjectPrivate&, const QJNIObjectPrivate&);
+    template <typename T> friend bool operator!=(const QJNIObjectPrivate&, T);
+    template <typename T> friend bool operator==(const QJNIObjectPrivate&, T);
+    template <typename T> friend bool operator!=(T, const QJNIObjectPrivate&);
+    template <typename T> friend bool operator==(T, const QJNIObjectPrivate&);
+
+    QSharedPointer<QJNIObjectData> d;
+};
+
+inline bool operator==(const QJNIObjectPrivate&obj1, const QJNIObjectPrivate&obj2)
+{
+    return obj1.isSameObject(obj2);
+}
+
+inline bool operator!=(const QJNIObjectPrivate&obj1, const QJNIObjectPrivate&obj2)
+{
+    return !obj1.isSameObject(obj2);
+}
+
+template <typename T>
+inline bool operator==(const QJNIObjectPrivate &obj1, T obj2)
+{
+    return obj1.isSameObject(static_cast<jobject>(obj2));
+}
+
+template <typename T>
+inline bool operator==(T obj1, const QJNIObjectPrivate &obj2)
+{
+    return obj2.isSameObject(static_cast<jobject>(obj1));
+}
+
+template <typename T>
+inline bool operator!=(const QJNIObjectPrivate &obj1, T obj2)
+{
+    return !obj1.isSameObject(obj2);
+}
+
+template <typename T>
+inline bool operator!=(T obj1, const QJNIObjectPrivate &obj2)
+{
+    return !obj2.isSameObject(obj1);
+}
+
+QT_END_NAMESPACE
+
+#endif // QJNI_P_H