Implementation of displaying a dynamic data in listview on click of a button

Praveen.Illa

Hi Team,

I am new to Qt QML world, and am struggling to implement a requirement of displaying a dynamic data in listview on click of a button. Can any one help me on this ?

Requirement: On button click, the parameters are passed to C++ code, fetches the dynamic data from backend or middleware and displays it on qml listview.

main.cpp
int main(int argc, char *argv[])
{
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

QGuiApplication app(argc, argv);

QQmlApplicationEngine engine;
const QUrl url(QStringLiteral("qrc:/main.qml"));
/*QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
                 &app, [url](QObject *obj, const QUrl &objUrl) {
    if (!obj && url == objUrl)
        QCoreApplication::exit(-1);
}, Qt::QueuedConnection);
engine.load(url);*/

engine.rootContext()->setContextProperty("xyzModel", new xyzModel());
engine.load(url);

return app.exec();

}

xyzModel.h
class xyzModel : public QAbstractListModel
{
Q_OBJECT
public:
explicit xyzModel();

enum PARAMS {
    DESCRIPTION = 0,
    EDITABLE,
};

// QAbstractItemModel interface
int rowCount(const QModelIndex &parent) const override;
QVariant data(const QModelIndex &index, int role) const override;
QHash<int, QByteArray> roleNames() const override;

// QtableName and tableNo will be sent from the QML
Q_INVOKABLE void xyzTableParams(QString QtableName, int tableNo);

public slots:

private:
QList <xyzTable *> m_list;

};

xyzModel.cpp
void xyzModel::xyzTableParams(QString QtableName, int tableNo)
{
// get_table_data returns a structure from backend or middleware
int status = get_table_data(QtableName.toLatin1().data(), tableNo);

//get_item_count returns number of items from backend or middleware
int mTotalObjectCount = get_item_count();

for(int iLoop = 0; iLoop < mTotalObjectCount; iLoop++)
{
    // get_item_data_address returns the structure from backend or middleware
    xyz_item_data* p_item_data =  get_item_data_address(iLoop);

    xyzTable *xyztableObj = new xyzTable;
    xyztableObj->setdescription(QString((char*)p_item_data->description));
    xyztableObj->seteditable(p_item_data->editable);
    m_list.append(xyztableObj);
}

}

xyzTable.h
class xyzTable
{
public:
xyzTable();

QString description() const;
void setdescription(const QString &description);

unsigned char editable() const;
void seteditable(unsigned char editable);

private:
QString m_description;
unsigned char m_editable;
};

xyzTable.cpp
xyzTable::xyzTable()
{

}

QString xyzTable::description() const
{
return m_description;
}

void xyzTable::setdescription(const QString &description)
{
m_description = description;
}

unsigned char xyzTable::editable() const
{
return m_editable;
}

void xyzTable::seteditable(unsigned char editable)
{
m_editable = editable;
}

main.qml
Window {
width: 640
height: 480
visible: true
title: qsTr("Hello World")

Button {
    id: btnId
    text: "TST_CGF1"
    onClicked: ccnModel.ccnTableParams("TST_CGF1", 2)
}

ListView {
    id: lv
    width: parent.width
    height: 400
    anchors.left: parent.left
    anchors.top: btnId.bottom
    model: ccnModel
    delegate: del
    focus: true
}

Component {
    id: del

    Rectangle {
        width: 300; height: 50; color: "black"
        Row {
            spacing: 10
            anchors.centerIn: parent

            Text {
                color: "white"
                text: Description
                font.pixelSize: 20
            }
            Text {
                color: "white"
                text: Editable
                font.pixelSize: 20
            }
        }
    }
}

Can anyone help me in understanding where am doing wrong or can provide some sudo code how to be shown the dynamic data on list view on click of a button