Time Client Application

A client who holds a replica of a time object from a server and displays the time in a clock.

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Publié le 14 février 2024 - Mis à jour le 14 février 2024

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Time Client Application▲

The Time Client Application opens a blue window with a message. When you click once, it displays a clock. When you click again, two clocks, then it repeats. The clock is defined in Clock.qml and uses the Time QML-type, implemented in C++, to set the time of the clock using the time on the server.

I. Before Running the Time Client Application▲

To run this example, Time Server Application must already be running on the same host as this application. It sets up a registry server and hosts an instance of a subclass of the MinuteTimerSimpleSource class. If it is not running, there will be an error message in the window.

II. Defining Remote Objects using a REP-file▲

The REP-file "timemodel.rep" in the parent directory of this application is used to generate the header-files used by both applications. For this application, the generated "rep_timemodel_replica.h" file defines MinuteTimerReplica, the replica of MinuteTimer, and other related classes.

III. The TimeModel Class▲

The TimeModel class in plugin.h and plugin.cpp implements the QML-type Time. It contacts the registry server on localhost using the URL "local:registry", acquires a replica, MinuteTimerReplica, and connects to its signals. The properties are automatically updated.

IV. The QML Types▲

The QML defined in "Clock.qml" draws a watch using the properties hours and minutes.

The application opens a window with the contents "plugins.qml". It changes between displaying different content using a Loader, cycling for each click between "plugins0.qml", "plugins1.qml", and "plugins2.qml".

While "plugins0.qml" displays a blue screen with a message, the custom QML-type Clock is used in "plugins1.qml", with the properties hours and minutes set to the hour and minute properties of Time. The "plugins2.qml" file is similar but displays two clocks.

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import QtQuick
import TimeExample // import types from the plugin

Rectangle {
    width: 200
    height: 400
    color: "blue"
    Clock {
        id: clock1
        anchors.top: parent.top
        Time { // this class is defined in C++ (plugin.cpp)
            id: time
        }

        hours: time.hour
        minutes: time.minute
        valid: time.isValid

    }
}

V. Example project▲

Example project @ code.qt.io