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/****************************************************************************
**
** Copyright (C) 2020 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtAndroidExtras module 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
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** 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
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**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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** 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,
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** $QT_END_LICENSE$
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****************************************************************************/
/*!
\target android service with remote object in same lib
\title Android Service with Qt Remote Objects - Same Lib File
\ingroup examples-qtandroidextras
\example services/serviceremoteobjectssamelib
\brief Demonstrates how to run an Android service in a separate process using
the same lib file, and how to communicate between the service process
and the main process using Qt Remote Objects.
\image androidservices.png
This example demonstrates how to create and run an Android service in
a separate process from the main application process, and then exchange data
between QML/C++ and the Java service using \l{Qt Remote Objects}.
When clicking the \uicontrol {Send to Service} button, the name entered in the QML
view, Qt, in this case, is sent to the Android service. Then, the service
replies back with a message \c {Hello Qt} which is printed in the QML view.
\include examples-run.qdocinc
\section1 Create the Service
To start a service in its own process, you can extend the \c QtService class
for your service. Extending \c QtService allows the service to load the
necessary Qt libraries used for Qt, like \l{Qt Remote Objects} libraries.
Start by creating the Java service class. The following class extends \c QtService
and acts as your service entry point:
\quotefromfile services/serviceremoteobjectssamelib/android/src/org/qtproject/example/qtandroidservice/QtAndroidService.java
\skipto package
\printuntil /^\}/
This class can have any logic you want using Java code. However, you don't need
any logic to communicate with Qt as that will be done using Qt Remote Objects.
\section1 Manage the AndroidManifest.xml File
To be able to use the service, it must be declared in the \c AndroidManifest.xml
file as follows:
\quotefromfile services/serviceremoteobjectssamelib/android/AndroidManifest.xml
\skipto <service
\printuntil </service>
The important parts of this service declaration are the \c arguments and \c lib_name
parts. Those will ensure that the service is run by executing the lib file
of the main activity with the argument \c -service:
\quotefromfile services/serviceremoteobjectssamelib/android/AndroidManifest.xml
\skipto <service
\skipto <!-- Application arguments -->
\printuntil lib_name
\section1 Handle the Application Start
Since the same \c .so lib file is being used for the application and the
service, you need to handle both scenarios in the \c main() function. No
arguments are provided to start the main application, and therefore you must
add the following in the \c main() function:
\quotefromfile services/serviceremoteobjectssamelib/main.cpp
\skipto (argc
\printline (argc
Then calling the following function starts the service:
\quotefromfile services/serviceremoteobjectssamelib/main.cpp
\skipto startService
\printuntil /^\}/
\section1 Handle the Service Start
\l{QAndroidService} is used to create the service process. The main .so lib
file will be called with an argument to start the service if you add the
following code:
\quotefromfile services/serviceremoteobjectssamelib/main.cpp
\skipto else if
\printline else if
\section1 Communication with Qt Remote Objects
To use \l{Qt Remote Objects}, define a \c .rep file:
\quotefromfile services/common/qtandroidservice.rep
\skipto class
\printuntil /^\}/
Define the \c .rep source and replica file in your project \c .pro file as follows:
\quotefromfile services/serviceremoteobjectssamelib/serviceremoteobjectssamelib.pro
\skipto REPC_SOURCE
\printuntil REPC_REPLICA
Then define the class used by Qt Remote Objects, which has a
\c sendToService() slot and a \c messageFromService() signal:
\quotefromfile services/common/qtandroidservice_ro.h
\skipto include
\printuntil /^\};/
Include the class in the previous snippet in \c main.cpp:
\quotefromfile services/serviceremoteobjectssamelib/main.cpp
\skipto _replica.h
\printline _replica.h
Now, inside the service handling part, create the \l{QRemoteObjectHost}
node:
\quotefromfile services/serviceremoteobjectssamelib/main.cpp
\skipto QRemoteObjectHost
\printuntil enableRemoting
Then, in the application handling part, create the client node and connect it
to the source node created in the service and connect it to the QML view:
\quotefromfile services/serviceremoteobjectssamelib/main.cpp
\skipto QRemoteObjectNode
\printuntil sendToService
Then, add a \l Connections element to watch for the incoming messages from
the service:
\quotefromfile services/common/main.qml
\skipto Connections
\printuntil /^\ {4}\}/
And set the \c onClicked for the sending button to:
\quotefromfile services/common/main.qml
\skipto onClicked
\printline onClicked
\sa {Android Service with Qt Remote Objects}, {Android Services},
{Qt for Android}, {Qt Android Extras}
*/
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