QTableWidget problem

[MarkoSan]

Hi to all!

I need to develop an subclassed table widget, which will look something like that:

+===================================+
+ Coca Cola                         +
+    1,50 EUR    002   3,00    EUR  +
+ Sprite                            +
+    1,30 EUR    010   13,00   EUR  +
+ Cheeseburger with salad           +
+    3,80 EUR    004   15,20   EUR  +
+ Beefstake with potato and salad   +
+   24,67 EUR    012   296,04  EUR  +
+===================================+
+              TOTAL:  327,24  EUR  +
+===================================+

+===================================+
+ Coca Cola                         +
+    1,50 EUR    002   3,00    EUR  +
+ Sprite                            +
+    1,30 EUR    010   13,00   EUR  +
+ Cheeseburger with salad           +
+    3,80 EUR    004   15,20   EUR  +
+ Beefstake with potato and salad   +
+   24,67 EUR    012   296,04  EUR  +
+===================================+
+              TOTAL:  327,24  EUR  +
+===================================+

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The point is that every row consists of two lines, the upper one will hold merchandize name (solo column) and the lower one will consists of following fields in order:

• price/merchandize unit (eur formatted, including euro sign
• number of merchandize unit (formatted with leading 0)
• price/unit*number of merchandize units (eur formatted, including euro sign)
• at the end there will be total field

Does someone has any idea how to achieve that?!

[wysota]

Have you already tried anything?

[MarkoSan]

No, I need a few hints how to make two lines in a cell. Then I will begin.

[wysota]

Add a newline character to the string displayed.

[MarkoSan]

Ok, I am not total idiot. I need a cell, which is constructed from:

• upper string line
• and lower line, which is constructed from
  • price/unit string line and eur icon - left formatted
  • quantity string line (with leading zeros)
  • price/unit*quantity string line and eur icon - right formatted

I cannot solve this with newline character.

[aamer4yu]

Well, why cant u have the brand name as column ? why need it as row ??

I am not sure of this will work... but hers my idea..
U can use delegates to have each cell as a widget. This widget has two rows... first the name, second the pprice, quantity etc.

hope it helps

[MarkoSan]

I am limited with table's width, it is critical to minimize table's width because the neighbour widget must take the largest size possible because of data representation.

[jpn]

So, what prevents you from using multiple columns? You'll get nice alignment out of the box. Besides, I'd use tree view instead of table view.

[THRESHE]

You can create a layout on a widget wich has the strings that you said and icons and then set this widget as a cell widget. Though it can be slow...

The other way is to implement a delegate and draw your cell there

[MarkoSan]

So, what prevents you from using multiple columns? You'll get nice alignment out of the box. Besides, I'd use tree view instead of table view.

Tree view is clumsy for touch screen user interaction. I've tried it before and because of fu... users I had to recode tree view into representation I want to do now in Qt. The same solution worked in Clarion for Windows.

You can create a layout on a widget wich has the strings that you said and icons and then set this widget as a cell widget. Though it can be slow...

The other way is to implement a delegate and draw your cell there

So. thanks for guideline, I will get to read docs about delegates ASAP.

[MarkoSan]

Well, now I have developec merchandize order class. What do I need to do to get the requested form in delegate? Reimplement the paintEvent()?? Or what?

[MarkoSan]

Well, I am slowly managing to get somewhere with my problem. Now, how do I translate the table cell (which has QString, qreal, qint16 and another qreal) from the first post into QVariant type? And how do I transfrom this cell into single QString?

[wysota]

If you use QTableWidget then you have to iterate all the cells and translate them manually. With a model based approach you could embed that functionality in the model.

[MarkoSan]

I've taken a look at Pixelator example and built my own model based on ImageModel class. Now, how do I embedd this functionality into my class, which code is:

#ifndef CSHOPPINGCARTMODEL_H_
#define CSHOPPINGCARTMODEL_H_
 
// qt includes
#include <QAbstractTableModel>
#include <QList>
#include <QString>
#include <QSize>
 
// custom includes
//#include "CMerchandizeOrder.h"
//#include "globals.h"
 
typedef struct
{
    qint16 iMerchandizeID;
    QString strMerchandizeName;
    qreal rMerchandizePrice;
    qint16 iMerchandizeQuantity;
    qreal rSubtotal;
} structOrder;
 
typedef QList<structOrder> structOrders;
 
class CShoppingCartModel : public QAbstractTableModel
{
    Q_OBJECT
 
public:
    CShoppingCartModel(QObject* parent=0);
    void setData(const structOrders& merchandizeOrders);
 
    int rowCount(const QModelIndex& parent=QModelIndex()) const;
    int columnCount(const QModelIndex& parent=QModelIndex()) const;
 
    QVariant data(const QModelIndex &index, int role=Qt::DisplayRole) const;
    QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const;
 
private:
    structOrders m_ModelData;
};
 
#endif /*CSHOPPINGCARTMODEL_H_*/

#ifndef CSHOPPINGCARTMODEL_H_
#define CSHOPPINGCARTMODEL_H_

// qt includes
#include <QAbstractTableModel>
#include <QList>
#include <QString>
#include <QSize>

// custom includes
//#include "CMerchandizeOrder.h"
//#include "globals.h"

typedef struct
{
    qint16 iMerchandizeID;
    QString strMerchandizeName;
    qreal rMerchandizePrice;
    qint16 iMerchandizeQuantity;
    qreal rSubtotal;
} structOrder;

typedef QList<structOrder> structOrders;

class CShoppingCartModel : public QAbstractTableModel
{
    Q_OBJECT

public:
    CShoppingCartModel(QObject* parent=0);
    void setData(const structOrders& merchandizeOrders);

    int rowCount(const QModelIndex& parent=QModelIndex()) const;
    int columnCount(const QModelIndex& parent=QModelIndex()) const;

    QVariant data(const QModelIndex &index, int role=Qt::DisplayRole) const;
    QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const;
    
private:
    structOrders m_ModelData;
};

#endif /*CSHOPPINGCARTMODEL_H_*/

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and it's implementation:

#include "CShoppingCartModel.h"
 
CShoppingCartModel::CShoppingCartModel(QObject* parent)
    : QAbstractTableModel(parent)
{
}
 
void CShoppingCartModel::setData(const structOrders& merchandizeOrder)
{
    m_ModelData=merchandizeOrder;
    reset();
}
 
int CShoppingCartModel::rowCount(const QModelIndex& /* parent */) const
{
    return m_ModelData.size();
}
 
int CShoppingCartModel::columnCount(const QModelIndex& /* parent */) const
{
    return 1;
}
 
QVariant CShoppingCartModel::data(const QModelIndex& index, int role) const
{
    // invalid order setup
    structOrder invalidOrder;
    invalidOrder.iMerchandizeID=0;
    invalidOrder.iMerchandizeQuantity=0;
    invalidOrder.rMerchandizePrice=0.00;
    invalidOrder.rSubtotal=0.00;
    invalidOrder.strMerchandizeName=QString("");
 
/*
    if (!index.isValid() || role!=Qt::DisplayRole)
        return invalidOrder;
    //return qGray(modelImage.pixel(index.column(), index.row()));
    return m_ModelData.at(index.column());
*/
    return QVariant();
}
 
QVariant CShoppingCartModel::headerData(int /* section */,
                                        Qt::Orientation /* orientation */,
                                        int role) const
{
    if (role==Qt::SizeHintRole)
        return QSize(1, 1);
    return QVariant();
}

#include "CShoppingCartModel.h"

CShoppingCartModel::CShoppingCartModel(QObject* parent)
    : QAbstractTableModel(parent)
{
}

void CShoppingCartModel::setData(const structOrders& merchandizeOrder)
{
    m_ModelData=merchandizeOrder;
    reset();
}

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

int CShoppingCartModel::columnCount(const QModelIndex& /* parent */) const
{
    return 1;
}

QVariant CShoppingCartModel::data(const QModelIndex& index, int role) const
{
    // invalid order setup
    structOrder invalidOrder;
    invalidOrder.iMerchandizeID=0;
    invalidOrder.iMerchandizeQuantity=0;
    invalidOrder.rMerchandizePrice=0.00;
    invalidOrder.rSubtotal=0.00;
    invalidOrder.strMerchandizeName=QString("");
    
/*
    if (!index.isValid() || role!=Qt::DisplayRole)
        return invalidOrder;
    //return qGray(modelImage.pixel(index.column(), index.row()));
    return m_ModelData.at(index.column());
*/
    return QVariant();
}

QVariant CShoppingCartModel::headerData(int /* section */,
                                        Qt::Orientation /* orientation */,
                                        int role) const
{
    if (role==Qt::SizeHintRole)
        return QSize(1, 1);
    return QVariant();
}

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As you can see, I do not know how to return whole record as QVariant.

[wysota]

As you can see, I do not know how to return whole record as QVariant.

Why would you want to do that?

BTW. Don't call reset() from setData(). emit dataChanged() instead.

[MarkoSan]

Well, from the beggining of this thread you saw I need a table with 1 column and orders.size() columns. For data cell I will implement my own delegate, which will represent one cell containing of:

+=====================================================================+
+ SPRITE 0,33L (QString)                                              +
+ 2,55 EUR (qreal)             3x (qint16)           7,65 EUR (qreal) +
+---------------------------------------------------------------------+
+ PIZZA PARMA (QString)                                               +
+ 12,23 EUR (qreal)            2x (qint16)          24,46 EUR (qreal) +
+=====================================================================+
                                             TOTAL: 32,11 EUR (qreal)

+=====================================================================+
+ SPRITE 0,33L (QString)                                              +
+ 2,55 EUR (qreal)             3x (qint16)           7,65 EUR (qreal) +
+---------------------------------------------------------------------+
+ PIZZA PARMA (QString)                                               +
+ 12,23 EUR (qreal)            2x (qint16)          24,46 EUR (qreal) +
+=====================================================================+
                                             TOTAL: 32,11 EUR (qreal)

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So as I understood, every cell is QVariant and every QVariant then will contain the values form QList of

typedef struct
{
    qint16 iMerchandizeID;
    QString strMerchandizeName;
    qreal rMerchandizePrice;
    qint16 iMerchandizeQuantity;
    qreal rSubtotal;
} structOrder;

typedef struct
{
    qint16 iMerchandizeID;
    QString strMerchandizeName;
    qreal rMerchandizePrice;
    qint16 iMerchandizeQuantity;
    qreal rSubtotal;
} structOrder;

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So, I need a mechanismus to serialize all this info into one QVariant. Am I wrong?

[wysota]

Yes, you are wrong You need a custom delegate that will render the data fetched from a single item using different item roles (like the text, icon, etc. - your custom roles included).

And to be honest, I'd do it completely differently. I'd have a table with three columns and simply span appropriate rows across all columns.

[MarkoSan]

Yes, you are wrong You need a custom delegate that will render the data fetched from a single item using different item roles (like the text, icon, etc. - your custom roles included).

So, I can use existing model classes, existing view classes and I only reimplement delegate class?

And to be honest, I'd do it completely differently. I'd have a table with three columns and simply span appropriate rows across all columns.

The problem is that this table must be wide as little as possible, because on 17" touch monitor I am very limited with its width. About 90% of desktop (from 17") there is a some operation window. But because your ideas helped me a lot, can you provide me some screenshot, what did you mean by quote?

[wysota]

So, I can use existing model classes, existing view classes and I only reimplement delegate class?

Yes, that's correct. QStandardItemModel has everything you might need.

The problem is that this table must be wide as little as possible, because on 17" touch monitor I am very limited with its width. About 90% of desktop (from 17") there is a some operation window. But because your ideas helped me a lot, can you provide me some screenshot, what did you mean by quote?

I don't have a screenshot. I meant to use QTableView::setSpan().

[MarkoSan]

But, which delegate should I use, QItemDelegate or QAbstractItemDelegate? At this moment, I am totaly confused ...