[Qt-interest] QTableWidgetItem with Validator (only numbers) and Range

[David Soler]

Hi!

Well I think it could be done easily using QItemDelegate in order to do:

- When user clicks to edit a cell of the table, the program invoke your 
delegate class that construct the QDoubleSpinBox with your preferences.

So at most you'll have to do:

- make a subclass of QItemDelegate
- Use the tableWidget->setItemDelegateForColumn(your_delegate) (or 
setItemDelegateForRow or something)..

The "problem" is that your delegate will act in all cells of the column (or 
row) of the table.

A custom delegate that i use is, for example, a date editor in tables:

#include "dateDelegate.h"

dateDelegate::dateDelegate(QObject *parent) : QItemDelegate(parent)
{
}

dateDelegate::~dateDelegate()
{
}

//here i create my editor

QWidget * dateDelegate::createEditor(QWidget *parent, const 
QStyleOptionViewItem &option, const QModelIndex &index) const
{
   QDateEdit *dateedit = new QDateEdit(parent);
   dateedit->setDate(QDate::currentDate());
   dateedit->setCalendarPopup(true);
   connect(dateedit, SIGNAL(dateChanged(const QDate &)), this, 
SLOT(commitAndCloseEditor(const QDate &)));
   return dateedit;
}

// here i put a string (kk) from the table converted to a QDate for may editor  
(_DATA function does that)

void dateDelegate::setEditorData(QWidget *editor, const QModelIndex &index) 
const
{
   CGlobal *g = CGlobal::getInstance();
   QString kk = index.model()->data(index, Qt::DisplayRole).toString();
   QDate d = g->_DATA(kk);

   QDateEdit *dedit = qobject_cast<QDateEdit*>(editor);
   dedit->setDate(d);
}

// here i convert the date of the editor to a string to be viewed in the cell 
of the table when it isn't in edit mode

void dateDelegate::setModelData(QWidget *editor, QAbstractItemModel *model, 
const QModelIndex &index) const
{
   QDateEdit *dedit = qobject_cast<QDateEdit*>(editor);
   model->setData(index, dedit->date().toString("dd/MM/yyyy"));
}

//Inform that the data of the cell has changed
void dateDelegate::commitAndCloseEditor(const QString & str)
{
     QDateEdit *editor = qobject_cast<QDateEdit*>(sender());
     emit commitData(editor);
     emit closeEditor(editor);
}


Hope it helps!

bye!


-- 
David
beavies at gmail.com
On Saturday 02 May 2009 20:25:34 Matthias Pospiech wrote:
> I want to have cells in a QTableWidget that accept only numbers in a
> specified range. Think of a QDoubleSpinBox without the buttons.
>
> I could not see from the docs that such functionality is built into the
> QTableWidgetItem. So I tried to add a QDoubleSpinBox instead of a QString
> for the constructor, but that fails.
>
>             QDoubleSpinBox * spinbox = new QDoubleSpinBox(this);
>             spinbox->setRange(0,20000);
>             spinbox->setDecimals(2);
>             spinbox->setValue(power);
>             newItem = new QTableWidgetItem(spinbox);
>
> instead of
>
>             newItem = new QTableWidgetItem(QString("%1").arg(power));
>
> So, how do I add the functionality of the QDoubleSpinBox into the
> QTableWidgetItem. The docs say something about subclassing, but I have
> no idea how that should possibly look like. Exept that I could reinvent
> the wheel and copy most of  QDoubleSpinBox  code  into  a subclassed
> class of QTableWidgetItem...
>
> Seems to me like a standard problem. Maybe someone has a solution for me?
>
> Matthias
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