[solved]Call class function in another cpp file

JohanSolo

OK, according to what I understood from your design, MainWindow spawns a CustomCode instance when requested. Therefore when constructing the CustomCode instance you know which MainWindow instance you have to connect to. If I were you I'd use the calling MainWindow instance as parent of the CustomCode instance. This would allow to connect the send_test() signal to the test() slot of your MainWindow instance.

TheHawk

How could I do that?

If I do this in mainwindow.cpp:

    codewindow = new CustomCode;
    codewindow->setParent(this);
    connect(codewindow,SIGNAL(send_test()),SLOT(test()));
    codewindow->show();

This makes it compile but instead of a seperate window the current mainwindow gets overwritten with the codewindow and the send_test() is in jsfunctions.h, not in CustomCode.h. Would I have to make a function that calls another function that calls the signal? Or am I missing it here? Sorry

Edit:

Succes!

I used : (in mainwindow.cpp)

void MainWindow::on_actionAdd_custom_logic_triggered()
{
    codewindow = new CustomCode;
    QObject::connect(&jsfunction,SIGNAL(send_test()),this,SLOT(test()));
    codewindow->show();
}

added extern jsfunctions jsfunction; to mainwindow.h and customcode.h
added jsfunctions jsfunction; in jsfunctions.cpp

and changed jsfunctions.h to

signals:
    void send_test();

public slots:
    void call_test()
    {
        emit send_test();
    }

Now it works! test() gets properly called and my UI actually changes. Many thanks! :)

PS: How do I change the topic to solved?

JohanSolo

I don't think it is necessary to have a static instance of jsfunctions to do this. Why did you add it? As far as I understand, the jsfunctions instance was meant to be used in the CustomCode instance? Assuming my hypothesis is correct, I would do the connect in the CustomCode, where both the MainWindow and jsfunctions instance are used:

void MainWindow::on_actionAdd_custom_logic_triggered()
{
    codewindow = new CustomCode( this );
    codewindow->show();
}

CustomCode::CustomCode( QObject* parent )
    : QMainWindow(parent)
    , ui(new Ui::CustomCode)
    , jsfunction( new jsfunctions() )
{
    connect( jsfunction, SIGNAL( send_test() ), parent, SLOT( test() ) );
}

@TheHawk said:
> PS: How do I change the topic to solved?

You can simply edit the topic title (IIRC by editing your first post),

TheHawk

I have no particular reason why I chose it to be static, I did it because after googling some errors it was suggested to use static.

Anyhow, your code indeed works as well and your assumption was correct! :)
I do have a little issue now. Calling codewindow = new CustomCode( this ); makes the new window always on top. I previously called codewindow = new CustomCode;, this made the 2 windows independant (if you clicked the one in the back it came to front). I don't really see an option how to fix this behavior besides using signals and slots at a click to bring a window up and lower the other one. Am I missing the obvious here?

thanks!

JohanSolo

I think you can tune this behaviour with the correct window flag, which is the second argument of the QMainWindow constructor.

Edit:
As another way to do it, you can pass a null pointer to the QMainWindow constructor in the CustomCode constructor, but still use the parent pointer in the connect statement.

TheHawk

I tried all the window flag settings without succes, it always stays on top.

How would I pass a null pointer to the QMainWindow constructor in the CustomCode constructor? Can't really get my head around it. Changing the call to:
codewindow = new CustomCode(0); or codewindow = new CustomCode; creates the desired effect but makes me unable to call the function (since no parent exists I think?).

Am I even calling the windowflag correctly?

void MainWindow::on_actionAdd_custom_logic_triggered()
{
    CustomCode *codewindow;
    codewindow = new CustomCode(0);
    //QObject::connect(&jsfunction,SIGNAL(send_test()),this,SLOT(test()));
    codewindow->setWindowFlags(Qt::Window);
    codewindow->show();

}

JohanSolo

I was thinking about

CustomCode::CustomCode( QObject* parent )
    : QMainWindow( 0 )
    , ui( new Ui::CustomCode )
    , jsfunction( new jsfunctions() )
{
    connect( jsfunction, SIGNAL( send_test() ), parent, SLOT( test() ) );
}

TheHawk

@JohanSolo

Ah yes, seems so obvious now. Works like a charm!

Thanks :)

JohanSolo

You're welcome! I'm glad I could help.

TheHawk

@JohanSolo

I got a question though (kinda off-topic). Would it be possible to create a signal from the MainWindow to a slot (or function) inside the javascript script that I evaluate inside CustomCode? So for example:

I want to plot a graph using the javascript script. I want that graph to use actual, changing values from mainwindow. So I would like to create a signal that triggers upon a value change and then call a function inside the javascript script to update the graph with the new values.

JohanSolo

@TheHawk said:

I got a question though (kinda off-topic). Would it be possible to create a signal from the MainWindow to a slot (or function) inside the javascript script that I evaluate inside CustomCode? So for example:

Better ask a new question in a new thread, for the future, it helps when looking for a problem on the forum.

You are free to define any signal / slot you want, so the short answer is yes.
You can emit a signal in MainWindowwhen the data needs to be reprocessed by the js script managed by CustomCode.

TheHawk

My apologies, I will create a new thread. Thanks for all your help! (and putting up with my stuff :) )