[SOLVED] Accessing properties in QML Delegate for imported C++ objects / ListView

[serdef]

Hello,

I am making a parameter edit screen with QML, QT 5.3. I am importing a C++ map of objects as a Listview model, and it almost works : All rectangles appear, but no text in it.
I get these QML errors. "ReferenceError: prop_name is not defined" "ReferenceError: prop_description is not defined"
It seems the list exist, was constructed correctly with the right number of items, but I cannot access the properties. Probably I am still doing something wrong, but I can't find what, from all information I find online, I think my effort could work, but it does not. I implemented a workaround to get the data from a C++ map into a variant list, and this seems ok, but probably I still made a mistake. I don't see it.

I'd appreciate if you experts had a look, and tell me your opinion, how can I make this work ?
Is this the wrong approach ?

You can see the code fragments below, ParamScreen.qml is included in
marpgui.qml :

@// main initialisation :

QMap<QString, MaQParam *> marpParamMap;
QVariantList marpParamList;

MARPGUI::MARPGUI(JSONRPCUDP* param_jsonrpcserver)
{
MARP_jsonrpcserver = param_jsonrpcserver;
GUIRootContext = viewer.rootContext();
qmlRegisterType<MaQParam>("MaQParam", 1, 0, "MaQParam");
GUIRootContext->setContextProperty("marpParamList", QVariant::fromValue(marpParamList));
viewer.setMainQmlFile(QStringLiteral("qml/QT_UDP_QML/MARPGUI.qml"));
viewer.showExpanded();
GUIRootObject = viewer.rootObject();
}

//--- maqparam.h

#ifndef MAQPARAM_H
#define MAQPARAM_H

#include <QObject>

class MaQParam : public QObject
{
Q_OBJECT
public:
explicit MaQParam(QObject *parent=0, QString par_name="unknown",QString par_value="0",QString par_min="0",QString par_max="100", QString par_description="no comment");
Q_PROPERTY(QString prop_name READ getname NOTIFY nameChanged)
Q_PROPERTY(QString prop_value MEMBER m_value )
Q_PROPERTY(QString prop_min MEMBER m_min )
Q_PROPERTY(QString prop_max MEMBER m_max )
Q_PROPERTY(QString prop_description MEMBER m_description)
QString getname(void);
signals:
void nameChanged();
public slots:

private:
QString m_name;
QString m_value;
QString m_min;
QString m_max;
QString m_description;
};

#endif // MAQPARAM_H

//--- maqparam.c

#include "maqparam.h"

/*
MaQParam::MaQParam(QObject *parent) : QObject(parent)
{
}
*/

MaQParam :: MaQParam(QObject *parent, QString par_name,QString par_value,QString par_min,QString par_max, QString par_description) : QObject(parent)
{
m_name = par_name;
m_value = par_value;
m_min = par_min;
m_max = par_max;
m_description = par_description;
}

QString MaQParam::getname(void)
{
return(m_name);
}

// ParamScreen.qml

import QtQuick 2.2
import QtQuick.Dialogs 1.1
import QtGraphicalEffects 1.0
import QtQuick.Controls 1.2
import QtQuick.Controls.Styles 1.2
import QtQuick.Layouts 1.1
import MaQParam 1.0

Rectangle {
x: 0
y: 0
anchors.fill: parent
gradient: Gradient {
GradientStop {
id: gradientStop3
position: 0
color: "#5d62cb"
}

    GradientStop {
        position: 1
        color: "#d7d9fa"
    }
}

Button {
    id: closeparamlist_button
    x: 300
    y: 325
    width: 50
    text: qsTr("Close")
    onClicked : parent.z = -1;
}


RowLayout {
    id: parameditrowlayout
    anchors.fill: parent

    Component {
        id: paramlijstDelegate
        Row {
            id: paramlijst
            Rectangle {
                width: 250
                height: 60
                color: "dark blue"
                radius : 5
                MouseArea{
                       id: paramlistMouseArea
                       anchors.fill: parent
                       }

                Column {
                    width: parent.width
                    anchors.horizontalCenter: parent.horizontalCenter
                    Text { width: parent.width; anchors.horizontalCenter: parent.horizontalCenter; font.pointSize : 16 ; horizontalAlignment:Text.AlignHCenter; text: prop_name; color: paramlijst.ListView.view.paramlijst_color   }
                    Text { width: parent.width;  anchors.horizontalCenter: parent.horizontalCenter; font.pointSize : 16 ; horizontalAlignment:Text.AlignHCenter; text: prop_description; color: paramlijst.ListView.view.paramlijst_color   }
                }
            }

        }
    }



    ListView {
        width : 260
        height : 360
        anchors.top : parameditrowlayout.top
        anchors.left: parameditrowlayout.left
        property color paramlijst_color: "white"
        //model: paramlijstModel
        model: marpParamList
        delegate: paramlijstDelegate
        anchors.margins: 20
        clip: true
        spacing: 5

    }
    Item{
        id: editWindow
        anchors.top : parameditrowlayout.top
        anchors.left: parameditrowlayout.left + parameditrowlayout.width/2
        width : 350
        ParamEdit{
            id: paramedit

        }

    }

}

}

// adding new parameters happens with this code (if a parameter exists it is updated instead of added)

   MaQParam * pQParam;
    pQParam = new MaQParam((QObject *)0,nameStr,valueStr,minStr,maxStr,descriptionStr);
    marpParamMap.insert(nameStr,pQParam);
    marpParamList.clear();
    foreach (MaQParam * curQParam,marpParamMap.values())

    {
        marpParamList.append( QVariant::fromValue(curQParam));
    }
    GUIRootContext->setContextProperty("marpParamList", QVariant::fromValue(marpParamList));

...
@

[Vincent007]

Maybe you should "qabstractitemmodel":http://qt-project.org/doc/qt-5/qtquick-modelviewsdata-cppmodels.html#qabstractitemmodel

[serdef]

Hi,
I found the solution, it was something really simple i had overlooked :
It should access the properties through model.modelData
so use model.modelData.prop_name instead of prop_name

It works now, the delegate becomes :
@Component {
id: paramlijstDelegate
Row {
id: paramlijst
Rectangle {
width: 250
height: 60
color: "#353535"
radius : 5
MouseArea{
id: paramlistMouseArea
anchors.fill: parent
}

                Column {
                    width: parent.width
                    anchors.horizontalCenter: parent.horizontalCenter
                    Text { width: parent.width; anchors.horizontalCenter: parent.horizontalCenter; font.pointSize : 18 ; horizontalAlignment:Text.AlignHCenter; text : model.modelData.prop_name; color: "#00B4FF"   }
                    Text { width: parent.width;  anchors.horizontalCenter: parent.horizontalCenter; font.pointSize : 14 ; horizontalAlignment:Text.AlignHCenter; text:  model.modelData.prop_value; color: "#FFFFFF" }
                }
            }

        }
    }

@

[serdef]

Thanks Vincent, for the suggestion to use qabstractitemmodel.
It looks suitable. When I find the time, I'll try this too, it may be more efficient.