Adding more actions to the context menu of a spreadsheet app

[tomy]

@mrjj
Thank you. I read other member functions of the class and reached the point below:

void Spreadsheet::sum()
{
    QList<QTableWidgetItem *> items = selectedItems();
    int i = 0, j = 0;
    double d = 0;
    if (!items.isEmpty()) {
        foreach (QTableWidgetItem *item, items)
            d += item->text().toDouble();
        i = QTableWidget::currentRow();
        j = QTableWidget::currentColumn();
        somethingChanged();
    }

    QTableWidgetItem *item = &d;
    qDebug()<<"Row is: "<< ++i << ' ' << "Column is " << ++j;
    ++i;
    QTableWidget::setItem(i, j, item);
}

qDebug() shows well and i and j are pointing to the one below the last cell of the selected area. (The target cell)
There is a problem here:

QTableWidgetItem *item = &d;

if it's correct, I apparently will be able to put d into the target cell using QTableWidget::setItem(i, j, item);

[mrjj]

@tomy said in Adding more actions to the context menu of a spreadsheet app:

QTableWidgetItem *item = &d;

Hi. good work trying.
That seems really wrong.
you say
let QTableWidgetItem * called item points to the memory of the double called d;

You should use a function to set the text.
http://doc.qt.io/qt-5/qtablewidgetitem.html#setText

something like
QTableWidgetItem *item = new QTableWidgetItem ;
item->setText( QString::number(d) );
QTableWidget::setItem(i, j, item);

unless there already IS an item there?
Then you shoul dnot add new, but set text on it.

[tomy]

Hi,
@mrjj

item->setText( QString::number(d) );

This was the key point that I needed! ;)

I wrote two good methods. (Don't you agree? :))
Here they are:

void Spreadsheet::sum()
{
    QList<QTableWidgetItem *> items = selectedItems();
    int i = 0, j = 0;
    double d = 0;
    if (!items.isEmpty()) {
        foreach (QTableWidgetItem *item, items)
            d += item->text().toDouble();
        i = QTableWidget::currentRow();
        j = QTableWidget::currentColumn();
        somethingChanged();
    }

    QTableWidgetItem* item = new QTableWidgetItem;
    item->setText((QString::number(d)));
    ++i;

    while(QTableWidget::item(i, j))
        i++;

     QTableWidget::setItem(i, j, item);
}

//*********************************************

void Spreadsheet::ave()
{
    QList<QTableWidgetItem *> items = selectedItems();
    int i = 0, j = 0;
    double d1 = 0;
    if (!items.isEmpty()) {
        foreach (QTableWidgetItem *item, items)
            d1 += item->text().toDouble();
        i = QTableWidget::currentRow();
        j = QTableWidget::currentColumn();
        somethingChanged();
    }
    double d2 = selectedItems().size();

    QTableWidgetItem* item = new QTableWidgetItem;
    item->setText((QString::number(d1/d2)));
    ++i;

    while(QTableWidget::item(i, j))
        i++;

    QTableWidget::setItem(i, j, item);
}

They work well. You know, I'm aware of C++ programming but not well informed of those numerous methods and classes of Qt, and that is why I face problems. It will gradually be solved. :)

[mrjj]

Hi
Good work.
What happens if you select nothing and then add sum ?
Will it not insert 0 anyway ?
Is that how you want it?

[tomy]

This post is deleted!

[tomy]

@mrjj
I think it's fine now:

QList<QTableWidgetItem *> items = selectedItems();
    int i, j;
    double d;
    
    if (!items.isEmpty())
        foreach (QTableWidgetItem *item, items) {
            d += item->text().toDouble();
        i = QTableWidget::currentRow();
        j = QTableWidget::currentColumn();
        somethingChanged();
    }

      QTableWidgetItem* item = new QTableWidgetItem;
      item->setText((QString::number(d)));
         ++i;

        while(QTableWidget::item(i, j))
        i++;

        QTableWidget::setItem(i, j, item);

It writes nothing when we want to sum nothing.

After these I implemented Max, Min and Count for the context menu.
But the only part of the code that I dislike is this:

foreach (QTableWidgetItem *item, items) {
            ...
        i = QTableWidget::currentRow();
        j = QTableWidget::currentColumn();
        ....
    }

That is, the section that I have to traverse all the cells in the selected area to find the lowest cell's position. It's in a very novice manner. If there isn't a proper function for reaching that position (as the number of the row and column) I may write a function for this avoiding repeating that part in many context menu's functions.

[mrjj]

@tomy said in Adding more actions to the context menu of a spreadsheet app:

part of the code that I dislike is this:

Hmm, wont that always result in the last selected being nominated as the lowest cell pos ?
So it could be expressed as
Q_ASSERT( ! items.isEmpty() );
QTableWidgetItem* last = items.last();
i = item->row();
j = item->column();

[tomy]

@mrjj

Hmm, wont that always result in the last selected being nominated as the lowest cell pos?

It works, but it is a little novice-like.

Q_ASSERT( ! items.isEmpty() );
QTableWidgetItem* last = items.last();
i = item->row();
j = item->column();

Did you mean:

i = last->row();
j = last->column();

I used it and got a runtime error.
So changed it to this:

if(!items.isEmpty()) {
      QTableWidgetItem* last = items.last();
      i = last->row();
      j = last->column();
    }

I tested the actions, sum, ave, count, max and min, they are all working fine.

[mrjj]

@tomy said in Adding more actions to the context menu of a spreadsheet app:

I used it and got a runtime error.

it was the Q_ASSUME :)
but the if(!items.isEmpty()) is better

and yes it was copy paste error.
its last->row/col
as you found out.

[tomy]

Thank you very much. :) ;)

[mrjj]

Good work.
If possible, please mark as solved.