Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. QML and Qt Quick
  4. How to use property change signal if used with setContextProperty()?
Forum Updated to NodeBB v4.3 + New Features

How to use property change signal if used with setContextProperty()?

Scheduled Pinned Locked Moved QML and Qt Quick
5 Posts 3 Posters 1.4k Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • H Offline
    H Offline
    HorstJ
    wrote on last edited by
    #1

    Hi everyone,

    I have problems writing my first qml/c++ app. Maybe someone can lend me a helping hand?

    My app should show some health states including network settings. Reading the "ipAddress" is no problem, but I get a parser error on "eth0.onIpAddressChanged", saying the eth0 is unknown. Couldn't be that much, but I havn't found the problem/a solution yet.

    Thanks in advance,
    Horst

    cpp:
    @class netData : public QObject {
    Q_OBJECT
    Q_PROPERTY(QString ipAddress READ getIpAddress WRITE setIpAddress NOTIFY ipAddressChanged)

    QString getIpAddress(void) const;
    void setIpAddress(QString address);

    signals:
    void ipAddressChanged(QString addr);
    }@

    main.cpp:
    @...
    context->setContextProperty("eth0", myNetData );@

    qml:
    @Rectangle {
    width: 360
    height: 360

    Text {
        color: "#000000"
        height: 20
        x: 10
        y: 10
        id: text1
        text: "ipAddr: " + eth0.ipAddress
        font.weight: Font.Bold
        font.pixelSize: 11
        verticalAlignment: Text.AlignVCenter
    }
    
    eth0.onIpAddressChanged: {
       text1.text = "ipAddr: " + addr;
    }
    

    }@

    1 Reply Last reply
    0
    • sierdzioS Offline
      sierdzioS Offline
      sierdzio
      Moderators
      wrote on last edited by
      #2

      You need to use that block (JS connect style) in a JavaScript block, for example in Component.onCompleted:
      @
      Rectangle {
      // ...

      function addressChange() {
      text1.text = "ipAddr: " + eth0.ipAddress;
      }

      Component.onCompleted: {
      eth0.ipAddressChanged.connect(addressChange);
      }
      @

      (Z(:^

      1 Reply Last reply
      0
      • T Offline
        T Offline
        Torgeir
        wrote on last edited by
        #3

        What sierdzio said, or you may use a Connections element:

        @Connections {
        target: eth0
        onIpAddressChanged: text1.text = "ipAddr:" + addr
        }
        @

        1 Reply Last reply
        0
        • H Offline
          H Offline
          HorstJ
          wrote on last edited by
          #4

          Thanks both of you!

          Is it possible to use the connection element like this:
          @
          Connections {
          target: eth0
          onIpAddressChanged: text1.text = "ipAddr:" + addr
          onIpSubnetChanged: text1.text = "Subnet:" + mask
          }@

          1 Reply Last reply
          0
          • T Offline
            T Offline
            Torgeir
            wrote on last edited by
            #5

            yes, if the netData class has a signal ipSubnetChanged with parameter named mask, that should work nicely.

            1 Reply Last reply
            0

            • Login

            • Login or register to search.
            • First post
              Last post
            0
            • Categories
            • Recent
            • Tags
            • Popular
            • Users
            • Groups
            • Search
            • Get Qt Extensions
            • Unsolved