Instantiating gui object issue

Dn588

Yes i'm sure i'm using the correct name. which base class are you talking about?
this code is copied from another project example. What does it mean when in the constructor QWidget is initialized to parent? What is the parent of QWidget?
Thanks again
Deon

code for orderForm implimentation file:
@
#include "orderform.h"
#include "order.h"
#include <QFormLayout>

//constructor
OrderForm::OrderForm(QWidget *parent):QWidget(parent){
setUpGui();
}

//sets up the GUI
void OrderForm::setUpGui(){
m_nameEdit = new QLineEdit();
m_dateEdit = new QDateEdit();
m_quantitySpin = new QSpinBox();
m_quantitySpin->setRange(1,1000);
m_priceSpin = new QDoubleSpinBox();
m_priceSpin->setRange(1.0,1000.00);
m_totalEdit = new QLineEdit();
m_totalEdit->setReadOnly(true);
m_submitButton = new QPushButton("OK");
m_cancelButton = new QPushButton("Cancel");

QGridLayout* gridLayout = new QGridLayout();
gridLayout->addWidget(m_submitButton,0,0);
gridLayout->addWidget(m_cancelButton,0,1);

QFormLayout *formLayout = new QFormLayout();
formLayout->addRow(tr("&Name"), m_nameEdit);
formLayout->addRow(tr("&Date Added"), m_dateEdit);
formLayout->addRow(tr("&Quantity"), m_quantitySpin);
formLayout->addRow(tr("&Unit Price"), m_priceSpin);
formLayout->addRow(tr("&Total Price"), m_totalEdit);
formLayout->addRow(gridLayout);

connect(m_submitButton, SIGNAL(clicked()), this, SLOT(submit()));
connect(m_cancelButton, SIGNAL(clicked()), this, SLOT(close()));
connect(m_quantitySpin, SIGNAL(editingFinished()), this, SLOT(calculateCost()));
connect(m_priceSpin, SIGNAL(editingFinished()), this, SLOT(calculateCost()));

this->setLayout(formLayout);
this->setWindowTitle("Manual Order Form");

}

// sets an order
void OrderForm::setOrder(Order prod){
m_Order = prod;
viewOrder();
}

//create a new order
void OrderForm::submit(){
m_Order.setName(m_nameEdit->text());
m_Order.setDateAdded(m_dateEdit->date());
m_Order.setQuantity(m_quantitySpin->value());
m_Order.setPrice(m_priceSpin->value());
}

//view an order
void OrderForm::viewOrder(){
m_nameEdit->setText(m_Order.name());
m_dateEdit->setDate(m_Order.dateAdded());
m_quantitySpin->setValue(m_Order.quantity());
m_priceSpin->setValue(m_Order.price());
calculateCost();
}
//calculate the cost of an order
void OrderForm::calculateCost(){
double total = double(m_quantitySpin->value()* m_priceSpin->value());
m_totalEdit->setText(QString::number(total, 'f', 2));
}

@

SGaist

Your class is not called orderForm but OrderForm, that's why it fails. Casing is important.

Have look "here":http://qt-project.org/doc/qt-5/qwidget.html#QWidget to get an explanation about the parent of QWidget

Dn588

Thanks SGaist stupid error on my side... What do you mean by the base constructor isn't called in the constructor? I get the program to run but there's no gui output

SGaist

Since both are QWidget:

Clean way:
@
OrderForm::OrderForm(QWidget *parent):
QWidget(parent){

}@

Only if you don't expect to parent your widget in the constructor:
@
ordergui::ordergui() {
}@

Edit: corrected the wording

Dn588

Thanks again... So I obviously didn't understand the explanation on the previous link you posted. What I understood from there was that if QWidget* parent = 0; it will be a window otherwise it would be a widget on a window?

Dn588

When I do that I get an error saying QWidget is not a direct base type of ordergui...

Also why was that not done in this example?

http://qt-project.org/doc/qt-4.8/mainwindows-application.html

SGaist

I've updated the wording of my last post (was a bit tired)

Since you have that error, it means that ordergui doesn't inherit from QWidget. It should inherit from QMainWindow.

Since you don't see anything do you call show somewhere in you main.cpp ?

Dn588

Yes I call show from main.cpp but for some reason I don't get any output, any idea what i'm doing wrong?

main.cpp:

@
#include <QtGui>
#include <QApplication>
#include "ordergui.h"

int main(int argc, char *argv[]) {
QApplication app(argc, argv);
ordergui order;

order.show();
return app.exec();

}
@

mranger90

could it be becuase you orderForm is created on the stack before being sent to setCentralWidget ? It then goes out of scope and is not available.
You should allocate it off the heap with "new".

Dn588

I just tried that but still no luck...

Xander84

Just wondering, how can you even call setCentralWidget without a pointer to QWidget? :)
@
void QMainWindow::setCentralWidget(QWidget * widget)
@
you should get a compile error here:
@
orderForm obj;
setCentralWidget(obj);
@

Dn588

Hi Xander. Sorry yes I changed it to OrderForm* obj but for some reason there's no output. Also when I try to close the running program I have to force quit

Xander84

[quote author="Dn588" date="1397930234"]Hi Xander. Sorry yes I changed it to OrderForm* obj but for some reason there's no output. Also when I try to close the running program I have to force quit[/quote]
Then you have most like created another (invisible) top level windows, if you have to "kill" the app.
you can try setting the parent of your central widget, I though the setCentralWidget would reparent it, but maybe not:
@
setCentralWidget(new orderForm(this));
@
maybe that works.

Dn588

No still no visible output and I still have to force quit...

Xander84

Is it possible that you can upload your whole project code somewhere? I don't know if you can publish your code or how large your codebase is beside what you already posted, but an logic error like this is hard to debug over the forums.. :/

Dn588

My Code:

@
order.h

#ifndef ORDER_H
#define ORDER_H

#include <QString>
#include <QDate>

class Order {

public:
//getters
QString name() const {return m_name;}
QDate dateAdded() const { return m_added; }
int quantity() const {return m_quantity; }
double price() const {return m_price;}

//return a string representation of an order
QString toString() const;

//setters
void setName(const QString &name) {m_name = name;}
void setDateAdded(const QDate &added) {m_added = added;}
void setQuantity(int qty) {m_quantity = qty;}
void setPrice(double unitPrice) {m_price = unitPrice;}

private:
//data members
QString m_name;
QDate m_added;
int m_quantity;
double m_price;

};

#endif // #ifndef ORDER_H

order.cpp

#include "order.h"
#include <QString>

//returns the string representation of an order
QString Order::toString() const {
return QString("%1 %2 (%3)at $ %4 total: %5").arg(m_name)
.arg(m_added.toString("yyyyMMdd")).arg(m_quantity)
.arg(m_price).arg(m_quantity*m_price);
}

OrderForm.h
#ifndef ORDERFORM_H
#define ORDERFORM_H

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

class OrderForm : public QWidget {
Q_OBJECT

public:
//constructor
OrderForm(QWidget* parent);
//view a given order
void setOrder(Order prod);

private slots:
//create a new order
void submit();
//calculate the cost of an order
void calculateCost();

private:
//private data members
QLineEdit* m_nameEdit;
QDateEdit* m_dateEdit;
QSpinBox* m_quantitySpin;
QDoubleSpinBox* m_priceSpin;
QLineEdit* m_totalEdit;
QPushButton* m_submitButton;
QPushButton* m_cancelButton;

Order m_Order;

//to view an order
void viewOrder();
//sets up the GUI
void setUpGui();

};

#endif // #ifndef ORDERFORM_H

OrderForm.cpp

#include "orderform.h"
#include "order.h"
#include <QFormLayout>

//constructor
OrderForm::OrderForm(QWidget *parent) : QWidget(parent) {
setUpGui();
}

//sets up the GUI
void OrderForm::setUpGui(){
m_nameEdit = new QLineEdit();
m_dateEdit = new QDateEdit();
m_quantitySpin = new QSpinBox();
m_quantitySpin->setRange(1,1000);
m_priceSpin = new QDoubleSpinBox();
m_priceSpin->setRange(1.0,1000.00);
m_totalEdit = new QLineEdit();
m_totalEdit->setReadOnly(true);
m_submitButton = new QPushButton("OK");
m_cancelButton = new QPushButton("Cancel");

QGridLayout* gridLayout = new QGridLayout();
gridLayout->addWidget(m_submitButton,0,0);
gridLayout->addWidget(m_cancelButton,0,1);

QFormLayout *formLayout = new QFormLayout();
formLayout->addRow(tr("&Name"), m_nameEdit);
formLayout->addRow(tr("&Date Added"), m_dateEdit);
formLayout->addRow(tr("&Quantity"), m_quantitySpin);
formLayout->addRow(tr("&Unit Price"), m_priceSpin);
formLayout->addRow(tr("&Total Price"), m_totalEdit);
formLayout->addRow(gridLayout);

connect(m_submitButton, SIGNAL(clicked()), this, SLOT(submit()));
connect(m_cancelButton, SIGNAL(clicked()), this, SLOT(close()));
connect(m_quantitySpin, SIGNAL(editingFinished()), this, SLOT(calculateCost()));
connect(m_priceSpin, SIGNAL(editingFinished()), this, SLOT(calculateCost()));

this->setLayout(formLayout);
this->setWindowTitle("Manual Order Form");

}

// sets an order
void OrderForm::setOrder(Order prod){
m_Order = prod;
viewOrder();
}

//create a new order
void OrderForm::submit(){
m_Order.setName(m_nameEdit->text());
m_Order.setDateAdded(m_dateEdit->date());
m_Order.setQuantity(m_quantitySpin->value());
m_Order.setPrice(m_priceSpin->value());
}

//view an order
void OrderForm::viewOrder(){
m_nameEdit->setText(m_Order.name());
m_dateEdit->setDate(m_Order.dateAdded());
m_quantitySpin->setValue(m_Order.quantity());
m_priceSpin->setValue(m_Order.price());
calculateCost();
}
//calculate the cost of an order
void OrderForm::calculateCost(){
double total = double(m_quantitySpin->value()* m_priceSpin->value());
m_totalEdit->setText(QString::number(total, 'f', 2));
}

ordergui.h

#ifndef ORDERGUI_H
#define ORDERGUI_H
#include <QMainWindow>
#include <QTextEdit>

class ordergui : public QMainWindow {
Q_OBJECT
public:
ordergui();
public slots:
void add_order_clicked();
void view_orders_clicked();
private:
void createMenu();
void createActions();
QTextEdit* m_text;
QMenu* orderMenu;
QAction* add_order;
QAction* view_orders;
};

#endif // ORDERGUI_H

ordergui.cpp

#include <QTGui>
#include "ordergui.h"
#include "OrderForm.h"

ordergui::ordergui() {
m_text = new QTextEdit;
setCentralWidget(m_text);
createActions();
createMenu();
}

void ordergui::createActions() {
add_order = new QAction(("Add Order"), this);
connect(add_order, SIGNAL(triggered()), this, SLOT(add_order_clicked()));

view_orders = new QAction(("View Order"), this);
connect(view_orders, SIGNAL(triggered()), this, SLOT(view_orders_clicked()));

}

void ordergui::createMenu() {
orderMenu = menuBar()->addMenu("Order");
orderMenu->addAction(add_order);
orderMenu->addAction(view_orders);
orderMenu->exec();
}

void ordergui::add_order_clicked() {
//OrderForm* obj = new OrderForm;
setCentralWidget(new OrderForm(this));
}

void ordergui::view_orders_clicked() {
setCentralWidget(m_text);
}

main.cpp

#include <QtGui>
#include <QApplication>
#include "ordergui.h"

int main(int argc, char *argv[]) {
QApplication app(argc, argv);
ordergui order1;

order1.show();
return app.exec&#40;&#41;;

}

@

[edit: modified the code to allow proper tagging SGaist]

Xander84

HI, sorry I tried to copy your messed up code here but it's almost impossible because it puts everything into one line and the quotations are also messed up etc.

If you put it in proper code tags or just zip and upload your project somewhere I will try finding your error, but not like this if I have to cleanup all the code just to recreate your whole project. :D

Dn588

Hi Xander thanks for taking a look
I uploaded it to dropbox, hope that's ok?

download link:

https://www.dropbox.com/s/i2hz6per5o78lry/Order-exercise.rar

Xander84

Ok i had to add some stuff to the pro file and include QtWidgets in OrderForm.h to compile the project, I think you are using Qt 4 or why don't you need that?

Anyway I didn't change the code and it works!? lol
maybe a little weird to start the app with a menu only, but when i click on "Add Order" i see this:
!http://i.imgur.com/2ADRudL.png(order form)!
isn't that what you want, I am a little confused now because it seems to work or what is not working!?

I noticed some other bugs, but i'm waiting for your response on this first.

Dn588

Yes I am using QT 4