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/****************************************************************************
**
** Copyright (C) 2021 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** 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 The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of The Qt Company Ltd nor the names of its
** contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
//! [Working with lists]
QStringList getTrackTitles(const QJniObject &album) {
QStringList stringList;
QJniObject list = album.callObjectMethod("getTitles",
"()Ljava/util/List;");
if (list.isValid()) {
const int size = list.callMethod<jint>("size");
for (int i = 0; i < size; ++i) {
QJniObject title = list.callObjectMethod("get", "(I)Ljava/lang/Object;", i);
stringList.append(title.toString());
}
}
return stringList;
}
//! [Working with lists]
//! [QJniObject scope]
void functionScope()
{
QString helloString("Hello");
jstring myJString = 0;
{
QJniObject string = QJniObject::fromString(helloString);
myJString = string.object<jstring>();
}
// Ops! myJString is no longer valid.
}
//! [QJniObject scope]
//! [C++ native methods]
static void fromJavaOne(JNIEnv *env, jobject thiz, jint x)
{
Q_UNUSED(env);
Q_UNUSED(thiz);
qDebug() << x << "< 100";
}
static void fromJavaTwo(JNIEnv *env, jobject thiz, jint x)
{
Q_UNUSED(env);
Q_UNUSED(thiz);
qDebug() << x << ">= 100";
}
void foo()
{
// register the native methods first, ideally it better be done with the app start
JNINativeMethod methods[] {{"callNativeOne", "(I)V", reinterpret_cast<void *>(fromJavaOne)},
{"callNativeTwo", "(I)V", reinterpret_cast<void *>(fromJavaTwo)}};
QJniEnvironment env;
env.registerNativeMethods("my/java/project/FooJavaClass", methods, 2);
// Call the java method which will calls back to the C++ functions
QJniObject::callStaticMethod<void>("my/java/project/FooJavaClass", "foo", "(I)V", 10); // Output: 10 < 100
QJniObject::callStaticMethod<void>("my/java/project/FooJavaClass", "foo", "(I)V", 100); // Output: 100 >= 100
}
//! [C++ native methods]
//! [Java native methods]
class FooJavaClass
{
public static void foo(int x)
{
if (x < 100)
callNativeOne(x);
else
callNativeTwo(x);
}
private static native void callNativeOne(int x);
private static native void callNativeTwo(int x);
}
//! [Java native methods]
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