use value from dynamically created widget in a slot

[giblit]

do you have something else calling the dbinfo function? thats the onlything I can think of im still a beginner at qt/c++ haha
oh and the reason I put slot in the example was because if in your function you want you can connect in t he main fucntion like this:

MainWindow::MainWindow(){
connect(pushButton,SIGNAL(clicked()),
this,SLOT(functionSlot()));
}
MainWindow::functionSlot(){
//do something
}

MainWindow::MainWindow(){
connect(pushButton,SIGNAL(clicked()),
this,SLOT(functionSlot()));
}
MainWindow::functionSlot(){
//do something
}

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[Cyrebo]

yes I called it twice, first with dbInfo(); then MainWindow::dbInfo();...

Do you know how to get the values from the spinbox for each person?

[giblit]

you could possibly send the values from the spinbox into a list of ints like

QList<int> spinboxValues;
spinboxValues << value;
for(int i = 0; i<numberofpeople; i++){
cout << spinBoxValues[i] << endl;
}

QList<int> spinboxValues;
spinboxValues << value;
for(int i = 0; i<numberofpeople; i++){
cout << spinBoxValues[i] << endl;
}

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[Cyrebo]

So this action is triggered when i click another button which an ok button slot to get the figures. How may I use all the variables in my function. I know in c you just type in the variable function name but that doesn't work on c++...

[giblit]

So this action is triggered when i click another button which an ok button slot to get the figures. How may I use all the variables in my function. I know in c you just type in the variable function name but that doesn't work on c++...

do you mean use the variables form the other function? if this is what you mean you could try this:

QList<double> spinboxValues;
double values;
mainWindow::dbinfo(){
//get values from spin box
}
void MainWindow::okbuttonslot(){
spinBoxValue << value;
}

QList<double> spinboxValues;
double values;
mainWindow::dbinfo(){
//get values from spin box
}
void MainWindow::okbuttonslot(){
spinBoxValue << value;
}

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that would mean when you press the button the value from your spinbox would be appended to the QList spinbox but you will probably have to use a boolen or something if you use this method otherwise each time you press the button it will append it to the end

[wysota]

do you mean use the variables form the other function? if this is what you mean you could try this:

QList<double> spinboxValues;
double values;
mainWindow::dbinfo(){
//get values from spin box
}
void MainWindow::okbuttonslot(){
spinBoxValue << value;
}

QList<double> spinboxValues;
double values;
mainWindow::dbinfo(){
//get values from spin box
}
void MainWindow::okbuttonslot(){
spinBoxValue << value;
}

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that would mean when you press the button the value from your spinbox would be appended to the QList spinbox but you will probably have to use a boolen or something if you use this method otherwise each time you press the button it will append it to the end

The thing is he/she doesn't know how to get the "value". Which he/she supposedly knows how to do in C (which works the same way in C++ for everyone else but not for him/her).

[Cyrebo]

It sort of worked but I think its printing out the memory address or something because its all hex...

Here is the output and this is for 3 inputs:

7.95446e-322
1.1117e-316
6.91643e-310
2.24083e-311
211
8.91041e-317

[giblit]

thats not hex...those are just realllllllllllllly small numbers think there is something wrong what is the code you are using to get the value?

[Cyrebo]

The thing is he/she doesn't know how to get the "value". Which he/she supposedly knows how to do in C (which works the same way in C++ for everyone else but not for him/her).

First of all, C isn't a GUI programming language, it is a I/O lower level language so you don't do things like sql, spinboxes and widgets its more programming like microchips...
Second of all, as you can see I'm still a novice to qt/c++ and nearly every programming language in the "C-Family" works in the same way, don't mean you can use em all the same way.

Personally I think qt/c++ is the best tool for GUI Programming period. So I'm trying to learn by practising and doing something worthwhile at the same time. Excuse me for seeking help in the Qt/Programming forum for help...

Back to the thread we're actually meant to be discussing not my programming knowledge of the C-Family...If you know how to get the values please tell me or let me work.

Thank you

--

thats not hex...those are just realllllllllllllly small numbers think there is something wrong what is the code you are using to get the value?

int numberofpeople = ui->verticalLayout->count();
    div(numberofpeople,2);
 
    for(int i = 0; i<numberofpeople; i++){
    qDebug() << spinboxValues[i];
    }

int numberofpeople = ui->verticalLayout->count();
    div(numberofpeople,2);

    for(int i = 0; i<numberofpeople; i++){
    qDebug() << spinboxValues[i];
    }

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[giblit]

well the number of people is how many people input values for example if you have two ppl that input values the number of people is two. im not sure what that verticalLayout is.
and what are you using to actually get the value from the spinbox? are you using this on the okButtonslot?

value = ui->spinboxName->value()

value = ui->spinboxName->value()

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[Cyrebo]

well the number of people is how many people input values for example if you have two ppl that input values the number of people is two. im not sure what that verticalLayout is.
and what are you using to actually get the value from the spinbox? are you using this on the okButtonslot?

value = ui->spinboxName->value()

value = ui->spinboxName->value()

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Yes I'm getting the values from when the okButton is clicked. The VerticalLayout is used to layout the names+spinboxes in as the name says a vertical layout. I'm dynamically adding the labels and spinboxes to it by the amount of people in the database at the time of creation. I half the value of the numberofpeoples because I have a label+spinbox for each person so thats just math. Whether I'm doing it the right way is what I'm not sure about.

[Cyrebo]

well the number of people is how many people input values for example if you have two ppl that input values the number of people is two. im not sure what that verticalLayout is.
and what are you using to actually get the value from the spinbox? are you using this on the okButtonslot?

value = ui->spinboxName->value()

value = ui->spinboxName->value()

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No but I copy value's values to another variable inside my okButton slot...So it's like:

The following is in dbInfo()

ui->verticalLayout->addWidget(label);
             ui->verticalLayout->addWidget(spinbox);
 
             values = spinbox->value();

ui->verticalLayout->addWidget(label);
             ui->verticalLayout->addWidget(spinbox);

             values = spinbox->value();

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Then okButton slot

spinboxValues << values;
    for(int i = 0; i<numberofpeople; i++){
        qDebug() << spinboxValues[i];
    }

spinboxValues << values;
    for(int i = 0; i<numberofpeople; i++){
        qDebug() << spinboxValues[i];
    }

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I'm getting this kind of output now for three spinboxes:

0
48
913
151259145
-1253538145
0

I was expecting 0,0,0 because Im only passing the initialised values which i thought would be default value of 0. How to get the user inputted values is what I need.

[giblit]

if you know how many spinboxes you are going to be using you could do this on the headers private:

QLabel *labelName[XAmount];
QSpinBox *spinBoxName[XAMOUNT];

QLabel *labelName[XAmount];
QSpinBox *spinBoxName[XAMOUNT];

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then on your mainfunction put something like this to declare the items

for(int i = 0; i<XAMOUNT; i++){
spinBoxName[i] = new QSpinBox;
labelName[i] = new QLabel;
}

for(int i = 0; i<XAMOUNT; i++){
spinBoxName[i] = new QSpinBox;
labelName[i] = new QLabel;
}

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then add how ever many spinboxes/labels you want at startup by adding them to the layout then send that amount to a variable called something like spinboxCount and on the okButtonSlot put something like this:

layout->addWidget(spinBoxName[spinboxCount+1]);
spinBoxCount += 1;

layout->addWidget(spinBoxName[spinboxCount+1]);
spinBoxCount += 1;

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then after that you can get the value of each spinbox easy by doing like

for(int i = 0; i<spinBoxCount; i++){
values[i] = spinboxname[i]->value();
}

for(int i = 0; i<spinBoxCount; i++){
values[i] = spinboxname[i]->value();
}

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[Cyrebo]

That's just the problem, I don't, the number is unknown as the spnboxes are created dynamically based on the number in the database. Is there no way to implement this if the number of spinboxes is unknown?

[wysota]

First of all, C isn't a GUI programming language

C and C++ are both general purpose languages. You can implement a graphical user interface as well using C (e.g. using GTK+ or WinAPI) as you can with C++ (e.g. using Qt or MFC).

it is a I/O lower level language so you don't do things like sql,

That's not true either. Most database client drivers (e.g. libmysql, libpg, etc.) were written in C or at least expose a C compatible interface which allows them to be used from within virtually any programming language out there that allows calling external routines.

spinboxes and widgets its more programming like microchips...

C++ was first developed by Bjarne Stoustrup around 1979 as an extension to C (its original name was "C with classes" later renamed to C++ which stands for "one more than C") and is 99% forward compatible with C. First widely acknowleged graphical user interface was created in 1963 (so even before C language was created) in Xerox labs (application was called Sketchpad) for a platform much weaker than todays microcontrollers so you can see there is no fixed relation between GUI, microchips and programming languages. If you want to go into discussions about programming languages then do your homework first and research the subject.

Second of all, as you can see I'm still a novice to qt/c++

So learn to walk first before you sign in for a marathon.

and nearly every programming language in the "C-Family" works in the same way, don't mean you can use em all the same way.

You can write your program in C and compile it with a C++ compiler and it will work exactly the same way as if you built it with a C compiler. If you're familiar with C then go ahead and build your UI with what you know -- you don't have to implement any classes or use any other C++ features to create a simple user interface using Qt (at least since Qt5 where you can connect signals to arbitrary functions).

So I'm trying to learn by practising and doing something worthwhile at the same time.

So far you are trying to learn by having others do your tasks for you. Save yourself trouble, spend a week with a C++ book and then come back to your original project. I assure you it will pay back. Otherwise you'll be scratching your head forever wondering why you get random values from an uninitialized array which suggests your issues are something more than simply lack of C++ skills. Sorry to be so blunt but I'm way past my days of political correctness (if anyone wants to discuss that, I invite them to Warsaw for a beer or a cup of coffee). If you want to learn programming then do it by learning and then programming and not vice versa.

[Cyrebo]

Ok I can be blunt too, you are acting ignorant especially since you say people program GUI's in C haha. Everyone knows c++ and java are used more for GUI programming because they are OBJECT ORIENTED. Of course its not impossible but who does GUIs in C???? Once you know C you can program in all of the C family. And are you really aruguing the fact that C is a low-level langauge???Really??? I've written nearly a thousand lines of C++ code for this singular program just because you feel you know everything about C++ doesn't mean everyone you come in contact with has to aswell. I'm sure you're a nice person in the real world but you really come across as rude and abrasive here. So you can save yourself the trouble and pick up a book on communication/interpersonal skills and come back to helping people you believe aren't as knowledgeable as you on forums.

GTK+/Qt are nearly identical in implementation, I don't know why you would even mention that. They are both OBJECT-ORIENTED. And also, GTK isn't available for all versions of Linux and seeing as Qt is native to my version of Linux...

Thanks I might upgrade to Qt 5.

[wysota]

Ok I can be blunt too, you are acting ignorant especially since you say people program GUI's in C haha.

Well, you can laugh all you want but this won't change the fact that people do program GUI in C.

Everyone knows c++ and java are used more for GUI programming because they are OBJECT ORIENTED.

I don't see how this is relevant to anything. I'm not saying C++ is not used for GUI programming, I'm saying C is a general purpose language that is fit for UI programming.

Of course its not impossible but who does GUIs in C????

You'd be surprised

Once you know C you can program in all of the C family.

Your case proves you wrong. You know C (at least you say so and I have no reason to not believe you) but apparently currently you are not able to program in C++.

And are you really aruguing the fact that C is a low-level langauge???

I'm not arguing anything however the level of C and C++ is usually considered the same (I wouldn't call it "low level" though -- assembly is low level, C/C++ is definitely higher level than assembly). Both are strongly typed, compiled, native symbol based languages. The fact that one is more object oriented than the other doesn't influence the level of the language.

I've written nearly a thousand lines of C++ code for this singular program

Well, that's your problem, not mine. I'm not saying I could do the same in 400 lines of code but then I'm not saying I couldn't either.

just because you feel you know everything about C++

I never said I know everything about C++. But I do know similarities and differences between programming languages I use.

doesn't mean everyone you come in contact with has to aswell.

I never said that too. The point is that you will gain much more if you focus on learning the language first before you start using it with a framework as complex as Qt. I noticed that I'm not the only one to tell you that. If one person tells you there is something wrong with you, you can ignore him. If two people tell you that you are sick -- think about seeing a doctor.

GTK+/Qt are nearly identical in implementation

Nnnno.... GTK+ is written in C, Qt is pure C++ -- how come possibly would they be "nearly identical" in implementation?

They are both OBJECT-ORIENTED

No, they are not.

This is the official GTK+ "hello world" tutorial (with comments stripped out) :

#include <gtk/gtk.h>
 
static void hello( GtkWidget *widget,
                   gpointer   data )
{
    g_print ("Hello World\n");
}
 
static gboolean delete_event( GtkWidget *widget,
                              GdkEvent  *event,
                              gpointer   data )
{
    g_print ("delete event occurred\n");
    return TRUE;
}
 
/* Another callback */
static void destroy( GtkWidget *widget,
                     gpointer   data )
{
    gtk_main_quit ();
}
 
int main( int   argc, char *argv[] )
{
    GtkWidget *window;
    GtkWidget *button;
 
    gtk_init (&argc, &argv);
 
    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
 
    g_signal_connect (window, "delete-event",
		      G_CALLBACK (delete_event), NULL);
 
    g_signal_connect (window, "destroy",
		      G_CALLBACK (destroy), NULL);
 
    gtk_container_set_border_width (GTK_CONTAINER (window), 10);
 
    button = gtk_button_new_with_label ("Hello World");
 
    g_signal_connect (button, "clicked",
		      G_CALLBACK (hello), NULL);
 
    g_signal_connect_swapped (button, "clicked",
			      G_CALLBACK (gtk_widget_destroy),
                              window);
 
    gtk_container_add (GTK_CONTAINER (window), button);
    gtk_widget_show (button);
    gtk_widget_show (window);
    gtk_main ();
    return 0;
}

#include <gtk/gtk.h>

static void hello( GtkWidget *widget,
                   gpointer   data )
{
    g_print ("Hello World\n");
}

static gboolean delete_event( GtkWidget *widget,
                              GdkEvent  *event,
                              gpointer   data )
{
    g_print ("delete event occurred\n");
    return TRUE;
}

/* Another callback */
static void destroy( GtkWidget *widget,
                     gpointer   data )
{
    gtk_main_quit ();
}

int main( int   argc, char *argv[] )
{
    GtkWidget *window;
    GtkWidget *button;

    gtk_init (&argc, &argv);

    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    
    g_signal_connect (window, "delete-event",
		      G_CALLBACK (delete_event), NULL);
    
    g_signal_connect (window, "destroy",
		      G_CALLBACK (destroy), NULL);

    gtk_container_set_border_width (GTK_CONTAINER (window), 10);

    button = gtk_button_new_with_label ("Hello World");

    g_signal_connect (button, "clicked",
		      G_CALLBACK (hello), NULL);

    g_signal_connect_swapped (button, "clicked",
			      G_CALLBACK (gtk_widget_destroy),
                              window);
    
    gtk_container_add (GTK_CONTAINER (window), button);
    gtk_widget_show (button);
    gtk_widget_show (window);
    gtk_main ();
    return 0;
}

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Where do you see anything object oriented here?

Fundamental concepts of object-oriented programming are abstraction, encapsulation, polymorphism and inheritance. The code I quoted is just a set of plain function calls -- no polymorphism, no encapsulation, no inheritance and practically no abstraction, no objects.

And also, GTK isn't available for all versions of Linux

GTK doesn't care about your Linux version. The fact that your distro may be missing precompiled packages for GTK doesn't mean you can't build GTK for it.

This discussion is going nowhere. The primary fact (ignoring all the other things) is that you are trying to use a language you don't know and which makes you confused and I (we?) am telling you to focus on the language itself (without Qt, just plain C++) before trying to employ it to solve complex problems. Without knowledge about classes, inheritance, using and overriding virtual methods you will not be able to use Qt efficiently. You can learn all that in a couple of days and then you will have a chance to understand how to use Qt. We can see that even scopes of visibility are giving you problems and they are the same in both C and C++. You either accept that fact or not.

[Cyrebo]

I don't agree with everything you said but one important part of you speil is that I don't know C++ well enough to implement something on this scale on that point I agree. I will learn it more in the future, atleast I hope to, that and Qt which I really like now but the thing is I need to get this done so its not really a matter of learning c++ right now but getting my program finished before a certain deadline. If I get this part of reading the values from the spinbox, I don't think I will have any more major problems in the future in getting it done which is why I'm asking.