Better understanding of the ModelView archtecture

[scarleton]

I did understand your wrong. In that case, I guess you can use a file system watcher (also in the model): http://doc.qt.nokia.com/4.6/qfilesystemwatcher.html

Again, a file system watcher is not viable, because as I stated before: outside forces can and DO change the state. Using a file system watcher would mean a service running 24/7 and this is a bit over kill. The safest and cleaned way to accurately show the user the state is to check the state on demand. So, the question remains:

Q: In a Qt Model, how does one have one column that is dynamic upon display.

[tbscope]

Q: In a Qt Model, how does one have one column that is dynamic upon display.

A model is (or should be) dynamic by design. You don't need to do anything else but set the new data in the correct place.

[boudie]

Normally, you implement your own data() method that returns the value for a given ModelIndex. It could look something like this:

QVariant CalculatorTapeModel::data(const QModelIndex &index, int role) const
{
	if (!index.isValid()) return QVariant();
 
 
	if (role == Qt::TextAlignmentRole)
	{
                ...   alignment code   ...
	}
 
 
	if (role == Qt::DisplayRole)
	{
                *** This is where you should check the state of your dynamic items ***
                ...   return data for requested item   ...
	}
}

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


	if (role == Qt::TextAlignmentRole)
	{
                ...   alignment code   ...
	}


	if (role == Qt::DisplayRole)
	{
                *** This is where you should check the state of your dynamic items ***
                ...   return data for requested item   ...
	}
}

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