qt-everywhere-src-5.15.1/qtandroidextras/examples/androidextras/services/servicebroadcastsamelib/doc/src/qtandroidextras-example-service-broadcastreceiver-samelib.qdoc

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/*!
    \title Android Service with BroadcastReceiver - Same Lib File
    \ingroup examples-qtandroidextras
    \example services/servicebroadcastsamelib
    \brief Demonstrates how to run an Android service in a separate process,
            and how to communicate with Qt using a BroadcastReceiver.

    \image androidservices.png

    This example demonstrates how to create and run an Android service in its
    own process using the same main \c .so lib file, and then exchange data
    between QML/C++ and the Java service using a
    \l{Android: BroadcastReceiver}{BroadcastReceiver}.

    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

    When running the app's process, you can extend either \c QtService or \c Service.
    Extending \c QtService allows Qt to load all the necessary libraries to load
    Qt components correctly and call native methods on Android. However, here
    the service is running in the same process, and with the BroadcastReceiver you
    don't need native calls to exchange messages with Qt, so extending either
    class works.

    Start by creating the Java service class. This is a normal Android \c Service
    that receives a name from QML and replies back with \c {Hello <name>}:

    \quotefromfile services/servicebroadcastsamelib/android/src/org/qtproject/example/qtandroidservice/QtAndroidService.java
    \skipto package
    \printuntil /^\}/

    In the overwritten method
    \l{Android: Service onStartCommand}{onStartCommand()},
    the service receives a name from the calling intent, then sends a broadcast
    to the BroadcastReceiver, which in turn will call the native method
    \c {sendToQt(String message)}. For more information on managing native
    calls in Qt, see \l{Calling QML/C++ Functions from Java Code}.

    \section1 Manage the AndroidManifest.xml File

    To use the service, it must be declared in the \c AndroidManifest.xml
    file:

    \quotefromfile services/servicebroadcastsamelib/android/AndroidManifest.xml
    \skipto <service
    \printuntil </service>

    \section1 Start the Service

    Since the service is run using the same \c .so lib file with different arguments
    for the service, you must handle the arguments. For the main application use:

    \quotefromfile services/servicebroadcastsamelib/main.cpp
    \skipto (argc
    \printline (argc

    Then take the following steps:

    \list 1
        \li Register the native method

        \li Create the BroadcastReceiver in a custom Java class:

            \quotefromfile services/servicebroadcastsamelib/android/src/org/qtproject/example/qtandroidservice/ActivityUtils.java
            \skipto package
            \printuntil /^\}/

        \li Register the BroadcastReceiver:

            \quotefromfile services/common/qtandroidservice.cpp
            \skipto :registerBroadcastReceiver
            \printuntil /^\}/

        \li Call the \l{Android: Service startService}{startService()}
            method, as follows:

            \quotefromfile services/common/qtandroidservice.cpp
            \skipto sendToService
            \printuntil /^\}/

            This function is used to start the Service. If the service is already running,
            it will only send the names without starting a new service instance.

        \li Then, you have to add the necessary \l Connections, as described in
            \l{Qt JNI Messenger}{Qt JNI Messenger Example}.

    \endlist

    Handle the service argument as follows:

    \quotefromfile services/servicebroadcastsamelib/main.cpp
    \skipto else if
    \printuntil app.exec();

    \sa {Android Service with BroadcastReceiver}, {Android Services},
        {Qt for Android}, {Qt Android Extras}
*/