QAbstractTableModel EDITABLE ERASES current value when editable is invoked

[jvk]

I created a TableModel which extends QAbstractTableModel and whenever I double click inside a cell to edit it, if it has a current value, that value gets erased, I've tried overwriting the double click signal and resetting the value, but that didn't help.

I've included all the files I'm using.

model.h
http://pastebin.com/V7VJAuCJ

model.cpp
http://pastebin.com/zPjSViFQ

MainWindow.h
http://pastebin.com/kGGp06zH

MainWindow.cpp
http://pastebin.com/wuRaQ3eE


Model.cpp



#include <QtGui>

#include "model.h"
#include <QDebug>

/*!
Constructs a table model with at least one row and one column.
*/

TableModel::TableModel(int rows, int columns, QObject *parent)
: QAbstractTableModel(parent)
{
QStringList newList;

for (int column = 0; column < qMax(1, columns); ++column) {
newList.append("");
}

for (int row = 0; row < qMax(1, rows); ++row) {
rowList.append(newList);
}
}


/*!
Returns the number of items in the row list as the number of rows
in the model.
*/

int TableModel::rowCount(const QModelIndex &/*parent*/) const
{
return rowList.size();
}

/*!
Returns the number of items in the first list item as the number of
columns in the model. All rows should have the same number of columns.
*/

int TableModel::columnCount(const QModelIndex &/*parent*/) const
{
return rowList[0].size();
}

/*!
Returns an appropriate value for the requested data.
If the view requests an invalid index, an invalid variant is returned.
Any valid index that corresponds to a string in the list causes that
string to be returned for the display role; otherwise an invalid variant
is returned.
*/

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

if (role == Qt::DisplayRole)
return rowList[index.row()][index.column()];
else
return QVariant();
}

/*!
Returns the appropriate header string depending on the orientation of
the header and the section. If anything other than the display role is
requested, we return an invalid variant.
*/

QVariant TableModel::headerData(int section, Qt::Orientation orientation,
int role) const
{
if (role != Qt::DisplayRole)
return QVariant();

if (orientation == Qt::Horizontal)
return QString("Column %1").arg(section);
else
return QString("Row %1").arg(section);
}

/*!
Returns an appropriate value for the item's flags. Valid items are
enabled, selectable, and editable.
*/

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

return Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsEditable;
}

/*!
Changes an item in the model, but only if the following conditions
are met:

* The index supplied is valid.
* The role associated with editing text is specified.

The dataChanged() signal is emitted if the item is changed.
*/

bool TableModel::setData(const QModelIndex &index,
const QVariant &value, int role)
{
if (!index.isValid() || role != Qt::EditRole)
return false;

qDebug()<< value.toString();
rowList[index.row()][index.column()] = value.toString();
emit dataChanged(index, index);
return true;
}

/*!
Inserts a number of rows into the model at the specified position.
*/

bool TableModel::insertRows(int position, int rows, const QModelIndex &parent)
{
int columns = columnCount();
beginInsertRows(parent, position, position + rows - 1);

for (int row = 0; row < rows; ++row) {
QStringList items;
for (int column = 0; column < columns; ++column)
items.append("");
rowList.insert(position, items);
}

endInsertRows();
return true;
}

/*!
Inserts a number of columns into the model at the specified position.
Each entry in the list is extended in turn with the required number of
empty strings.
*/

bool TableModel::insertColumns(int position, int columns, const QModelIndex &parent)
{
int rows = rowCount();
beginInsertColumns(parent, position, position + columns - 1);

for (int row = 0; row < rows; ++row) {
for (int column = position; column < columns; ++column) {
rowList[row].insert(position, "");
}
}

endInsertColumns();
return true;
}

/*!
Removes a number of rows from the model at the specified position.
*/

bool TableModel::removeRows(int position, int rows, const QModelIndex &parent)
{
beginRemoveRows(parent, position, position + rows - 1);

for (int row = 0; row < rows; ++row) {
rowList.removeAt(position);
}

endRemoveRows();
return true;
}

/*!
Removes a number of columns from the model at the specified position.
Each row is shortened by the number of columns specified.
*/

bool TableModel::removeColumns(int position, int columns, const QModelIndex &parent)
{
int rows = rowCount();
beginRemoveColumns(parent, position, position + columns - 1);

for (int row = 0; row < rows; ++row) {
for (int column = 0; column < columns; ++column) {
rowList[row].removeAt(position);
}
}

endRemoveColumns();
return true;
}





model.h




#ifndef MODEL_H
#define MODEL_H

#include <QAbstractTableModel>
#include <QStringList>
#include <QVariant>

class TableModel : public QAbstractTableModel
{
Q_OBJECT

public:
TableModel(int rows = 1, int columns = 1, QObject *parent = 0);

int rowCount(const QModelIndex &parent = QModelIndex()) const;
int columnCount(const QModelIndex &parent = QModelIndex()) const;
QVariant data(const QModelIndex &index, int role) const;
QVariant headerData(int section, Qt::Orientation orientation,
int role = Qt::DisplayRole) const;

Qt::ItemFlags flags(const QModelIndex &index) const;
bool setData(const QModelIndex &index, const QVariant &value,
int role = Qt::EditRole);

bool insertRows(int position, int rows, const QModelIndex &parent = QModelIndex());
bool insertColumns(int position, int columns, const QModelIndex &parent = QModelIndex());
bool removeRows(int position, int rows, const QModelIndex &parent = QModelIndex());
bool removeColumns(int position, int columns, const QModelIndex &parent = QModelIndex());

private:
QList<QStringList> rowList;
};

#endif

[ChrisW67]

Your model data() function returns a null QVariant for the EditRole and that is the value that Qt gives to the default editor.