How to transfer data entered in a QWizard to other classes?

[dcopeto]

Hi!

I'm using a QWizard to get some user configurations at the beggining of my program but i can't seem to find a way to fill in my database class with the data the user enters in the wizard pages! How can this be done?


thanks a lot for the help,
david

[Lykurg]

Hi,

have a look at the docs, there you can find your questions answered: Class Wizard Example (http://doc.trolltech.com/4.5/dialogs-classwizard.html). Especially "void ClassWizard::accept()".

Or in your code is somewhere
MyWizard wiz;
wiz.exec()
wiz.getMyFancyData(); // where you have to implement these function in your wizard class...

Lykurg

[dcopeto]

Thanks for the reply :)


Yeah in the meantime i found that too and my problem changed:
From what i understood, one recovers the data using something like


QString sessionName = field("session.name").toString();

which is ok. My problem is that i want to recover data from a QTableWidget!:confused: Any ideas on how to do this?


thanks for your help,
david

[Lykurg]

The "field" way is only one possibility. Since the QWizard is a normal class you can simply add a private member which points to the table. Use this pointer in the "save" function to get the data.

[dcopeto]

Maybe i didn't give you enough details because i'm having trouble finding out to do that...:crying:


This is what i have in my startwizard.h

class startWizard : public QWizard
{
Q_OBJECT

public:
enum{Page_Intro, Page_New, Page_Load, Page_Configs, Page_LoadDetails, Page_NewDetails};
startWizard(QWidget *parent = 0);

void accept();

};

(...)

class configsPage : public QWizardPage
{
Q_OBJECT

public:
configsPage(QWidget *parent = 0);
int nextId();

private:
(...)
QTableWidget *tableDisplay;

(...)
};


In the ConfigsPage of the wizard i create the table for the user to see what he's adding/configuring and then i want to be able to recover the data he just entered to my database object in the main application.

In your previous reply you meant placing a QTableWidget pointer in the startWizard class, pointing to the table that gets the stuff in ConfigsPage class? even that i'm having trouble with...

I still don't see how can i go on from there? I mean to have access to the database I must make the wizard have access to the database somehow...:confused:


thanks a lot for the help,
david

[wysota]

Move the table widget pointer to your QWizard subclass and then access the pointer when you want to retrieve the data.

[Lykurg]

class startWizard : public QWizard
{
Q_OBJECT
public:
enum{Page_Intro, Page_New, Page_Load, Page_Configs, Page_LoadDetails, Page_NewDetails};
startWizard(QWidget *parent = 0);
void accept();
private:
configsPage *m_configsPage;
};

startWizard::startWizard(QWidget *parent) : QWizard(parent) {
//...
m_configsPage = new configsPage(this);
addPage(m_configsPage);
//...
}

void startWizard::accept() {
//...
m_configsPage->table() //<- here's your pointer...
//...
}
(...)

class configsPage : public QWizardPage
{
Q_OBJECT

public:
configsPage(QWidget *parent = 0);
int nextId();
const QTableWidget* table() const {return tableDisplay;}

private:
(...)
QTableWidget *tableDisplay;

(...)
};

[dcopeto]

THANK YOU!:D

That took care of my table access and now I have also managed to 'reach' the dataBase from the wizard by passing a pointer to the database to it!

thanks again,
david

[wysota]

You don't have to transfer pointers to the database (assuming you are using QSqlDatabase). You can always retrieve the connection by calling it by name. See docs of QSqlDatabase.

[dcopeto]

Hey! thanks for the suggestion! I'm not using sqlDatabase, I'm using my own storing class, because it's not a lot of stuff, anyway can you tell me when does it 'payoff' to use a sql database instead of a custom class? I'm not really into it so it's probable that I'm writing garbage right this moment... :o


thanks,
david

[BillGates]

hi

maybe i didnt understand very well the method that Lykurg wrote in code, but, will other Pages of the wizard be able to access m_configsPage->table() ?

Is it possible to pass objects instead of int/Qstrings using ::field() and registerField(..) ?

[wysota]

You can pass anything that will fit into QVariant.

[BillGates]

Thanks for reply wysota !

Im sorry to ask, but is there any example somewhere ? I am a noob.
I searched on the net and even here but all I could find were widgets with properties that were int or string.

As I understand it it must be something like :

registerField("name", myWidget, "myProperty", SIGNAL(selectionChanged()));

so i conclude that i must declare my own widget and my own propery. Is this correct ?
My purpose is to make variables like a QList accessible to any/all wizardPage subclass.

[wysota]

A QList of what? That's a template class, you know... And while you are at it, what is the reason for doing that? You can always expose the list using your wizard class's public interface.

[BillGates]

yes, i know its a template, pardon me, a QList<QString> . I didnt think it mattered much.
I dont understand what you mean by "your wizard class public interface" ? Maybe I am missing something?

[wysota]

yes, i know its a template, pardon me, a QList<QString> . I didnt think it mattered much.
Well, it does, because QStringList is already registered to be used with QVariant.


I dont understand what you mean by "your wizard class public interface" ? Maybe I am missing something?
I mean two methods in your wizard class's "public" section - one for setting the value and the other for getting it. Look at the code Lykurg has written, "table()" is the getter method and "setTable(QTableWidget*)" would be a setter method.

Still you didn't answer what you want to do with this all so maybe there are tons of better way to do what you want.

[BillGates]

I want for the QTableWidget *tableDisplay from the first QWizardPAGE to be accesible to the second, the third and so on Pages. So that i can use them for default values, exacty what the field() does.
The only problem is that I am not competent enough; I dont know how to pass my own variables through registerField().
If I have a QStringList created in Page1, i would like to access it in Page2 and Page3..


in void myPage2::initializePage() {

myObject list = field("some_field_registered_from_page1") <-- something like this...

}

[wysota]

I want for the QTableWidget *tableDisplay from the first QWizardPAGE to be accesible to the second, the third and so on Pages. So that i can use them for default values, exacty what the field() does.
It's not what the field() does. To me it seams you need a model in your wizard. Then you can set this model to a QTableView (or QListView) in the first wizard page and also access the model from other pages. field() should represent a single value, not all possible values.

[BillGates]

Umh... so how would i access the model from the QWizard class from inside the Pages ? Pass it to their constructor ?

[wysota]

You can do it any way you see fit. C++ allows for many solutions to this problem. For instance each page has a pointer to the wizard object it is part of.

[BillGates]

"For instance each page has a pointer to the wizard object it is part of. "

you mean wizard() ?



class myWizard : public QWizard
{
Q_OBJECT

public:
whatever* m_member;
}


in the myWizard constructor i do :
addPage( new myPage1( ) );





myPage1::mypage1(QWidget *parent) : QWizardPage(parent) {

wizard()->m_member ? (is this supposed to work?) (apparently it doesnt) (thats basically what i want :D )

}



Can I reimplement ::next ? http://doc.trolltech.com/4.5/qwizard.html#next [slot] (doesnt say virtual, but I'm no c++ expert)

I do realise your time is more precious than mine, so I *am* thankful.

[wysota]

"For instance each page has a pointer to the wizard object it is part of. "

you mean wizard() ?
Yes, you can cast it to a proper type and use your methods.


MyWizard *wiz = qobject_cast<MyWizard*>(wizard()); // or static_cast if MyWizard doesn't have Q_OBJECT macro
wiz->something();


Can I reimplement ::next ? http://doc.trolltech.com/4.5/qwizard.html#next [slot] (doesnt say virtual, but I'm no c++ expert)
Reimplement nextId().

[BillGates]

Thanks so much for the code snippet, I didnt find this anywhere, in no example! Perhaps they considered normal people would know this..(qobject_cast). I had no clue that that must be done :< Thank you

About ::next(), I understand you are saying to Not reimplement ::next, but reimplement ::nextId() instead. I want to do some stuff when the user clicks "next" so ::next() seems more intuitive.. Basically, you are saying to "do some stuff" not in ::next but in ::nextId() ?



i was thinking

void myWizard::next() {

..do some stuff...

QWizard::next();
}
is this wrong in any way ?



PS: apparently if I do in myWizard constructor :
setButton(QWizard::NextButton, mybuton);
connect ( mybuton, SIGNAL(clicked()), this, SLOT(my_slot()));

my_slot() is executed AFTER the next Page's initializePage() ?!?! (is this logical?)

[wysota]

Thanks so much for the code snippet, I didnt find this anywhere, in no example! Perhaps they considered normal people would know this..(qobject_cast). I had no clue that that must be done :< Thank you
It's there in many places, I assure you.


About ::next(), I understand you are saying to Not reimplement ::next, but reimplement ::nextId() instead. I want to do some stuff when the user clicks "next" so ::next() seems more intuitive..
No, in that case you need to reimplement QWizardPage::initializePage() on the next page you want to show.




PS: apparently if I do in myWizard constructor :
setButton(QWizard::NextButton, mybuton);
connect ( mybuton, SIGNAL(clicked()), this, SLOT(my_slot()));

my_slot() is executed AFTER the next Page's initializePage() ?!?! (is this logical?)
Yes, it's logical.


Read this article, it might help you understand how wizards work:
http://doc.trolltech.com/qq/qq22-qwizard.html

[BillGates]

ok, i dont know if this is normal or not.... but apparently after casting i cannot access data members of wiz-> or even methods of wiz that themselves access members of the wizard object. I get a SIGSEGV upon running the program... :( (tried with static_cast too, although i have the q_object macro)

[wysota]

Check if wizard() doesn't return 0 or that qobject_cast doesn't return 0.

[BillGates]

in myPage1 constructor:

qDebug()<< this->wizard() ; // outputs QObject(0x0)

myWizard *wiz = qobject_cast<myWizard*>( wizard() ); //also tried myWizard *wiz = qobject_cast<myWizard*>((myWizard*) wizard() );

if(wiz) { wiz->my_slot("testing") ; //does not get executed }




i set the Page in the myWizard constructor using : addPage( new myPage1( ) );

What am i screwing up?

[wysota]

Before you add the page to the wizard (which happens after the page constructor is executed) the page doesn't belong to the wizard so wizard() returns 0.

[BillGates]

I am so ashamed of myself. I am a complete idiot. I will give up programming and go be a janitor... Qt is great though....