Help with getting my custom model working

[thomaspu]

Also, I believe that what you're trying to do is having a collection of connectionData structure inside your model, each one representing a row. Is that true? In this case you must not do it as you tried but instead setup an underlying data structure (e.g. a list of connection data) without using setData() and using them to feed the view through data()...

Yes, I was going for a list of items stored in a QList and each item in the QList represents an item in my ListView. This is what I currently have:

class ConnectionListModel : public QAbstractListModel
{
	Q_OBJECT
 
enum sessionTypesEnum {
	secureShell,
	remoteFileBrowser
};
 
struct connectionData {
	QString name;
	QString hostAddress;
	QString username;
	QString password;
	int port;
	sessionTypesEnum sessionType;
};
 
public:
    ConnectionListModel(QObject *parent = 0);
 
    ~ConnectionListModel();
 
	 //Required items to make this model work
	 int rowCount(const QModelIndex &parent = QModelIndex()) const;
	 QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;
 
	 //required items to be able to edit items
	 bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole);
	 Qt::ItemFlags flags(const QModelIndex &index) const;
 
 
	 //Required to be able to resize the model (add & remove shit)
	 bool insertRows(int row, int count, const QModelIndex &parent = QModelIndex());
	 bool removeRows(int row, int count, const QModelIndex &parent = QModelIndex());
 
	private:
		QList<connectionData> connectionList;
};
 
ConnectionListModel::ConnectionListModel(QObject *parent)
 : QAbstractListModel(parent)
{
}
 
 
ConnectionListModel::~ConnectionListModel()
{
}
 
int ConnectionListModel::rowCount(const QModelIndex &parent) const
{
	return connectionList.count();
}
 
Qt::ItemFlags ConnectionListModel::flags(const QModelIndex &index) const
{
	if (!index.isValid())
		return Qt::ItemIsEnabled;
 
	return QAbstractItemModel::flags(index) | Qt::ItemIsEditable;
}
 
QVariant ConnectionListModel::data(const QModelIndex &index, int role) const
{
	if ( ! index.isValid())
		return QVariant();
 
	int row = index.row();
	if ( row < 0 || row >= connectionList.count() ) //Is the row invalid?
		return QVariant();
 
	if (role == Qt::DisplayRole)
	{
		switch( index.column() ){
			case 0: return connectionList[row].name;
			case 1: return connectionList[row].hostAddress;
			case 2: return connectionList[row].username;
			case 3: return connectionList[row].password;
			case 4: return connectionList[row].port;
			case 5: return connectionList[row].sessionType;
			return QVariant();
		}
	}
	else
		return QVariant();
}
 
bool ConnectionListModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
	if (index.isValid() && role == Qt::DisplayRole)
	{
		int row = index.row();
		//Lets cast our QVariant so we can get the data out
 
		const connectionData *newData = qvariant_cast<connectionData>( value );
 
		//get a pointer to the list item so we can change its contents
		connectionList[row].name			= newData.name;
		connectionList[row].hostAddress	= newData.hostAddress;
		connectionList[row].username		= newData.username;
		connectionList[row].password		= newData.password;
		connectionList[row].port			= newData.port;
		connectionList[row].sessionType	= newData.sessionType;
 
		emit dataChanged(index, index);
		return true;
	}
	return false;
}
 
 
bool ConnectionListModel::insertRows(int row, int count, const QModelIndex &parent)
{
	beginInsertRows(parent, row, row +count-1);
	//Not finished!
	endInsertRows();
}
 
bool ConnectionListModel::removeRows(int row, int count, const QModelIndex &parent)
{
	beginRemoveRows(parent, row, row+count+1);
//Not finished!
	endRemoveRows();
}

class ConnectionListModel : public QAbstractListModel
{
	Q_OBJECT

enum sessionTypesEnum {
	secureShell,
	remoteFileBrowser
};

struct connectionData {
	QString name;
	QString hostAddress;
	QString username;
	QString password;
	int port;
	sessionTypesEnum sessionType;
};

public:
    ConnectionListModel(QObject *parent = 0);

    ~ConnectionListModel();

	 //Required items to make this model work
	 int rowCount(const QModelIndex &parent = QModelIndex()) const;
	 QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;

	 //required items to be able to edit items
	 bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole);
	 Qt::ItemFlags flags(const QModelIndex &index) const;

			 
	 //Required to be able to resize the model (add & remove shit)
	 bool insertRows(int row, int count, const QModelIndex &parent = QModelIndex());
	 bool removeRows(int row, int count, const QModelIndex &parent = QModelIndex());
	 
	private:
		QList<connectionData> connectionList;
};

ConnectionListModel::ConnectionListModel(QObject *parent)
 : QAbstractListModel(parent)
{
}


ConnectionListModel::~ConnectionListModel()
{
}

int ConnectionListModel::rowCount(const QModelIndex &parent) const
{
	return connectionList.count();
}

Qt::ItemFlags ConnectionListModel::flags(const QModelIndex &index) const
{
	if (!index.isValid())
		return Qt::ItemIsEnabled;

	return QAbstractItemModel::flags(index) | Qt::ItemIsEditable;
}

QVariant ConnectionListModel::data(const QModelIndex &index, int role) const
{
	if ( ! index.isValid())
		return QVariant();

	int row = index.row();
	if ( row < 0 || row >= connectionList.count() ) //Is the row invalid?
		return QVariant();
	
	if (role == Qt::DisplayRole)
	{
		switch( index.column() ){
			case 0: return connectionList[row].name;
			case 1: return connectionList[row].hostAddress;
			case 2: return connectionList[row].username;
			case 3: return connectionList[row].password;
			case 4: return connectionList[row].port;
			case 5: return connectionList[row].sessionType;
			return QVariant();
		}
	}
	else
		return QVariant();
}

bool ConnectionListModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
	if (index.isValid() && role == Qt::DisplayRole)
	{
		int row = index.row();
		//Lets cast our QVariant so we can get the data out
		
		const connectionData *newData = qvariant_cast<connectionData>( value );

		//get a pointer to the list item so we can change its contents
		connectionList[row].name			= newData.name;
		connectionList[row].hostAddress	= newData.hostAddress;
		connectionList[row].username		= newData.username;
		connectionList[row].password		= newData.password;
		connectionList[row].port			= newData.port;
		connectionList[row].sessionType	= newData.sessionType;
		
		emit dataChanged(index, index);
		return true;
	}
	return false;
}


bool ConnectionListModel::insertRows(int row, int count, const QModelIndex &parent)
{
	beginInsertRows(parent, row, row +count-1);
	//Not finished!
	endInsertRows();
}

bool ConnectionListModel::removeRows(int row, int count, const QModelIndex &parent)
{
	beginRemoveRows(parent, row, row+count+1);
//Not finished!
	endRemoveRows();
}

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The problem that I have though is that the qvariant_cast<connectionData> doesn't work. I'm not really sure how to pass in the connectionData object using a QVariant.

Paul

[jacek]

The problem that I have though is that the qvariant_cast<connectionData> doesn't work. I'm not really sure how to pass in the connectionData object using a QVariant.

As fullmetalcoder wrote, use Q_DECLARE_METATYPE.

[thomaspu]

OK, I declared my custom datatype outside the class and now that seems to work so that I can set items that are in my QList<connectionData> list.

class ConnectionListModel : public QAbstractListModel
{
	Q_OBJECT
 
public:
	struct connectionData {
		QString name;
		QString hostAddress;
		QString username;
		QString password;
		int port;
		sessionTypesEnum sessionType;
	};
 
    ConnectionListModel(QObject *parent = 0);
    ~ConnectionListModel();
 
	private:
		QList<connectionData> connectionList;
};
Q_DECLARE_METATYPE(ConnectionListModel::connectionData);

class ConnectionListModel : public QAbstractListModel
{
	Q_OBJECT

public:
	struct connectionData {
		QString name;
		QString hostAddress;
		QString username;
		QString password;
		int port;
		sessionTypesEnum sessionType;
	};

    ConnectionListModel(QObject *parent = 0);
    ~ConnectionListModel();
	 
	private:
		QList<connectionData> connectionList;
};
Q_DECLARE_METATYPE(ConnectionListModel::connectionData);

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But now I'm lost as to how to add data to it. I understand that I have to do my own insertRows function. Is the purpose of the insertRows function just to insert a row, but not add the data to it?

In other words, to insert a row, I'd be expected to do something like this to the model:

conenctionData addMe;
//set items in addMe
myModel.insertRows(1, 1, QModelIndex ????);  // <-what do i do here?
myModel.setData(QModelIndex ???, addMe);

conenctionData addMe;
//set items in addMe
myModel.insertRows(1, 1, QModelIndex ????);  // <-what do i do here?
myModel.setData(QModelIndex ???, addMe);

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Paul

[jacek]

myModel.insertRows(1, 1, QModelIndex ????); // <-what do i do here?

You can use the default value for the last parameter (i.e. QModelIndex()). Your items don't have a parent, since you have a flat list. If you had a tree, then you would have to specify it to add items below the root.

myModel.setData(QModelIndex ???, addMe);

Here you need a model index that points to that empty row, you have added in previous line. You can get it using the index() method:

myModel.setData( myModel.index( 0 ), addMe);

myModel.setData( myModel.index( 0 ), addMe);

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[thomaspu]

I'm making slow progress here. Understanding this stuff is frustrating. Now I can put stuff in the model (I think) but it doesn't show up in my associated view. I think I've got the setData() dataChanged signal all messed up. It keeps giving me comipler errors.

bool ConnectionListModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
	if (index.isValid() && role == Qt::DisplayRole)
	{
		int row = index.row();
		//Lets cast our QVariant so we can get the data out
 
		connectionData newData = value.value<connectionData>();
 
		//get a pointer to the list item so we can change its contents
		connectionList[row].name			= newData.name;
		connectionList[row].hostAddress	= newData.hostAddress;
		connectionList[row].username		= newData.username;
		connectionList[row].password		= newData.password;
		connectionList[row].port			= newData.port;
		connectionList[row].sessionType	= newData.sessionType;
 
		emit dataChanged( index(row, 0), index(row, 0));
		return true;
	}
	return false;
}

bool ConnectionListModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
	if (index.isValid() && role == Qt::DisplayRole)
	{
		int row = index.row();
		//Lets cast our QVariant so we can get the data out
		
		connectionData newData = value.value<connectionData>();

		//get a pointer to the list item so we can change its contents
		connectionList[row].name			= newData.name;
		connectionList[row].hostAddress	= newData.hostAddress;
		connectionList[row].username		= newData.username;
		connectionList[row].password		= newData.password;
		connectionList[row].port			= newData.port;
		connectionList[row].sessionType	= newData.sessionType;
		
		emit dataChanged( index(row, 0), index(row, 0));
		return true;
	}
	return false;
}

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What am I doing wrong now?
Paul