Disable an editable cell

[SailinShoes]

I have qtablewidget with delegates. If a cell does not receive a value, e.g. the cell is empty and the user tries to open its editor, it crashes? How do I avoid the crash? I would like to be able to disable the cell if there is no value.

[spirit]

you can make value checking in createEditor of your delegate and if value is empty retun 0.

[wysota]

What does the debugger say about the crash? Can you show us the backtrace?

Anyway, you can disable editing a cell by returning proper flags from your model (i.e. don't return ItemIsEditable for the item).

[SailinShoes]

Sorry...my mistake...it does not crash...but the editor opens with the minimum value of the spinbox.

ok...I set item->setFlags(Qt::ItemIsSelectable) to disable the cell if there is no value. It works, But...is it not possible to set item->setFlags(Qt::ItemIsEditable) if a value shows up later on? That does not work?

[wysota]

You can change the flags at any time.

[SailinShoes]

Well...I am doing something wrong?

This is the table constructor...

.
.
.
	pItemTorque = new QTableWidgetItem;
	pItemTorque->setTextAlignment(Qt::AlignHCenter);
	setItem(ROW_TORQUE, SECOND_COLUMN, pItemTorque);
.
.
.

.
.
.
	pItemTorque = new QTableWidgetItem;
	pItemTorque->setTextAlignment(Qt::AlignHCenter);
	setItem(ROW_TORQUE, SECOND_COLUMN, pItemTorque);
.
.
.

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...and this is the method that is called to populate the cell...

void PSetConfigurationTable::setTorque(QString torque)
{
 
	QTableWidgetItem *torqueItem = item( 0, 1 );
 
	if(torque.isEmpty())
	{
 
		torqueItem->setFlags(Qt::ItemIsSelectable);
 
	}
	else
	{
 
		torqueItem->setFlags(Qt::ItemIsEditable);
 
	}
 
        torqueItem->setData(Qt::EditRole, QVariant(torque));
 
}

void PSetConfigurationTable::setTorque(QString torque)
{
	
	QTableWidgetItem *torqueItem = item( 0, 1 );
	
	if(torque.isEmpty())
	{
		
		torqueItem->setFlags(Qt::ItemIsSelectable);
		
	}
	else
	{
		
		torqueItem->setFlags(Qt::ItemIsEditable);
		
	}

        torqueItem->setData(Qt::EditRole, QVariant(torque));
	
}

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It is ok if the cell is editable if a value is set. If a value is not set the cell is just selectable...and if a value comes along the setFlags(Qt::ItemIsEditable) does not work...in fact the app. goes down. What am i doing wrong?

[wysota]

You probably want to set more than one flag at once...

item->setFlags(Qt::ItemIsEnabled|Qt::ItemIsSelectable|Qt::ItemIsEditable);

item->setFlags(Qt::ItemIsEnabled|Qt::ItemIsSelectable|Qt::ItemIsEditable);

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[SailinShoes]

I am not sure where and how the flags should be set? I think I have tried every combination of setflags for every state the parameter value can be in, but can't get it to work properly?

[wysota]

What do you do, what do you get and what do you expect?