From random function in cpp to qml - c++

Question

I have a class and I can get data from the constructor to show it in the TableView in qml, but the problem is when I want to show data from anoher function from that class. For example:
main.cpp
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQuickView>
#include <QQmlContext>
#include "myclass.h"
int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);
QQmlApplicationEngine engine;
MyModel *myTable=new MyModel;
engine.rootContext()->setContextProperty("myTable", myTable);
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);
return app.exec();
}
MyModel.h
struct Info
{
QString name;
QString address;
QString values;
QString salary;
};
class MyModel : public QAbstractTableModel
{
Q_OBJECT
public:
MyModel(QObject *parent=nullptr);
.
////some variables declared////
.
Q_INVOKABLE int rowCount(const QModelIndex &parent = QModelIndex()) const override;
Q_INVOKABLE int columnCount(const QModelIndex &parent = QModelIndex()) const override;
Q_INVOKABLE QVariant data(const QModelIndex &index, int role=Qt::DisplayRole) const override;
Q_INVOKABLE QHash<int,QByteArray> roleNames() const override;
private:
QList<Votes> m_model;
MyModel.cpp
MyModel::MyModel(QObject *parent)
: QAbstractTableModel{parent}
{
m_model.append({"name1","add1","value1","salary1"});
m_model.append({"name2", "add2","value2","salary2"});
m_model.append({"name3","add3","value3","salary3"});
} ////I can see this in TableView
void MyModel::mapTable(QVector<QStringList> mapGroup)
{
for(int i=0;i<mapGroup.count();i++)
{
m_model.append ({mapGroup[i][0], mapGroup[i][1], mapGroup[i][2], mapGroup[i][3});
}
} ////I cannot see this in TableView
...
MyModel.qml
import QtQuick 2.0
import QtQuick.Controls 1.4 as CI
CI.TableView
{
model: myTable
CI.TableViewColumn
{
role: "name"
title:"Name"
width: 100
}
CI.TableViewColumn
{
role: "add"
title:"Address"
width: 100
}
CI.TableViewColumn
{
role: "value"
title:"Value"
width: 100
}
CI.TableViewColumn
{
role: "salary"
title:"Salary"
width: 100
}
}
Dialog.qml
...
Rectangle
{
id: tableRec
width: parent.width/1.5
height: parent.height/2
MyModel
{
id: infoTable
width: tableRec.width
height: tableRec.height
anchors.fill: parent
rowDelegate: Rectangle
{
id: rowTable
height: 15
SystemPalette
{
id: myPalette
colorGroup: SystemPalette.Active
}
color:
{
var baseColor = styleData.alternate?myPalette.alternateBase:myPalette.base
return styleData.selected?myPalette.highlight:baseColor
}
}
itemDelegate: Item
{
Text
{
// anchors.centerIn: parent
anchors.verticalCenter: parent.verticalCenter
text: styleData.value
font.pixelSize: Math.round(infoTable.height)/16
}
}
}
How can I pass the data from mapTable function to TableView? I get that it has something to do with QAbstractTableModel, but I cannot make it work.

Answer 1

When you create a custom model based on an inner data model, you have to notify the views that you inserted/removed rows.
The model cannot know when you change its inner model. That's why you have to use beginInsertRows and endInsertRow in your mapTable method.
A quick example:
class MyModel: public QAbstractListModel
{
Q_OBJECT
public:
MyModel(QObject* parent=nullptr): QAbstractListModel (parent)
{
innerModel.append("Bob");
innerModel.append("Patrick");
innerModel.append("Alice");
}
Q_INVOKABLE int rowCount(const QModelIndex &parent = QModelIndex()) const override
{
if (parent.isValid())
return 0;
return innerModel.size();
}
Q_INVOKABLE int columnCount(const QModelIndex &parent = QModelIndex()) const override
{
if (parent.isValid())
return 0;
return 2;
}
Q_INVOKABLE QVariant data(const QModelIndex &index, int role=Qt::DisplayRole) const override
{
qDebug() << index << role;
switch (role)
{
case Qt::DisplayRole:
case Qt::UserRole + 1:
return innerModel.at(index.row());
case Qt::UserRole + 2:
return QString::number(index.row() + 1);
}
return QVariant();
}
Q_INVOKABLE QHash<int,QByteArray> roleNames() const override
{
QHash<int,QByteArray> roles;
roles.insert(Qt::UserRole + 1, "name");
roles.insert(Qt::UserRole + 2, "index");
return roles;
}
Q_INVOKABLE void add(QString const& name)
{
beginInsertRows(QModelIndex(), rowCount(), rowCount());
innerModel.append(name);
endInsertRows();
}
private:
QList<QString> innerModel;
};
Item {
anchors.fill: parent
TextEdit {
width: 100
id: name
anchors.left: parent.left
anchors.top: parent.top
}
Button {
text: "save"
onClicked: theModel.add(name.text)
anchors.left: name.right
anchors.top: parent.top
}
ListView {
anchors.left: parent.left
anchors.right: parent.right
anchors.bottom: parent.bottom
anchors.top: name.bottom
model: theModel
delegate: Text {
text: name
}
}
}
If you comment beginInsertRows(QModelIndex(), rowCount(), rowCount()); and endInsertRows in the method add, you will not be able to see the new rows int the list because the model cannot know when its inner model has changed.