How to make a simple table and calculate col sums?

[teele]

I'm newbie with qt and i'd like to make a simple table with a few rows for double typed numbers.

Then i'd like to calculate the sums of each column and show the results on the bottom row.

Yes, i have the book c++ programming with qt4, but the examples are quite complicated for this simple task.

I found a basic table here

http://www.qtsoftware.com/developer/...ntry&id=192313

but how to implement the calculable rows in it in a non-complicated way?

Any hints are well appreciated.

teele

[spirit]

very simple example
h

#ifndef TEST_H
#define TEST_H
 
#include <QMainWindow>
 
class QTableWidget;
class QTableWidgetItem;
 
class Test: public QMainWindow
{
	Q_OBJECT
 
public:
	Test(QWidget *parent = 0);
 
private slots:
	void recalculateSums(QTableWidgetItem *);
 
private:
	QTableWidget *m_table;
};
 
#endif//TEST_H

#ifndef TEST_H
#define TEST_H

#include <QMainWindow>

class QTableWidget;
class QTableWidgetItem;

class Test: public QMainWindow
{
	Q_OBJECT

public:
	Test(QWidget *parent = 0);

private slots:
	void recalculateSums(QTableWidgetItem *);

private:
	QTableWidget *m_table;
};

#endif//TEST_H

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cpp

#include <QtGui>
#include "test.h"
 
Test::Test(QWidget *parent)
	: QMainWindow(parent)
{
	m_table = new QTableWidget(10, 10);	
 
	for (int row = 0; row < m_table->rowCount(); ++row) {
		for (int column = 0; column < m_table->columnCount(); ++column) {
			QTableWidgetItem *tableItem = new QTableWidgetItem;
			tableItem->setText(QString::number(row));
			m_table->setItem(row, column, tableItem);
		}
	}
 
	const int lastRow = m_table->rowCount();
	m_table->setRowCount(lastRow + 1);
	for (int column = 0; column < m_table->columnCount(); ++column)
		m_table->setItem(lastRow, column, new QTableWidgetItem);
 
	QTableWidgetItem *item = new QTableWidgetItem;
	item->setText(tr("Sum"));	
	m_table->setVerticalHeaderItem(lastRow, item);
 
	setCentralWidget(m_table);
 
	connect(m_table, SIGNAL(itemChanged(QTableWidgetItem *)), SLOT(recalculateSums(QTableWidgetItem *)));
}
 
void Test::recalculateSums(QTableWidgetItem *item)
{
	const int lastRow = m_table->rowCount() - 1;
	if (item && item->row() == lastRow)
		return;
 
	for (int column = 0; column < m_table->columnCount(); ++column) {
		int sum = 0;
		for (int row = 0; row < lastRow; ++row) {
			QTableWidgetItem *tableItem = m_table->item(row, column);
			sum += tableItem->text().toInt();			
		}
		m_table->item(lastRow, column)->setText(QString::number(sum));
	}
}

#include <QtGui>
#include "test.h"

Test::Test(QWidget *parent)
	: QMainWindow(parent)
{
	m_table = new QTableWidget(10, 10);	

	for (int row = 0; row < m_table->rowCount(); ++row) {
		for (int column = 0; column < m_table->columnCount(); ++column) {
			QTableWidgetItem *tableItem = new QTableWidgetItem;
			tableItem->setText(QString::number(row));
			m_table->setItem(row, column, tableItem);
		}
	}

	const int lastRow = m_table->rowCount();
	m_table->setRowCount(lastRow + 1);
	for (int column = 0; column < m_table->columnCount(); ++column)
		m_table->setItem(lastRow, column, new QTableWidgetItem);

	QTableWidgetItem *item = new QTableWidgetItem;
	item->setText(tr("Sum"));	
	m_table->setVerticalHeaderItem(lastRow, item);

	setCentralWidget(m_table);

	connect(m_table, SIGNAL(itemChanged(QTableWidgetItem *)), SLOT(recalculateSums(QTableWidgetItem *)));
}

void Test::recalculateSums(QTableWidgetItem *item)
{
	const int lastRow = m_table->rowCount() - 1;
	if (item && item->row() == lastRow)
		return;

	for (int column = 0; column < m_table->columnCount(); ++column) {
		int sum = 0;
		for (int row = 0; row < lastRow; ++row) {
			QTableWidgetItem *tableItem = m_table->item(row, column);
			sum += tableItem->text().toInt();			
		}
		m_table->item(lastRow, column)->setText(QString::number(sum));
	}
}

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[teele]

Thank you, Spirit!

The code runs fine. Now i have to study it carefully to get in the qt world.

teele

[zizoumgs]

Thank spirit , For newbie like me your code very, very helpful

[aprado]

Hello, sorry for reviving this thread but i had the same question and it helped me =)

I have another question.. How can i insert this table as a widget inside a mainwindow? For exemple:

I have a main window and i want to click in the option "file" and then "table", when i click table i want to show this table in the main area of my mainwindow with a close button inside.


Other question i have is:

How can i use the callendar? For exemple.. i want to get the current time and show it in the screen as a calendar.

Thanks for the help!!