QT QTextBrowser problem with setText

[fäbs]

HI,
i have a problem with my qt program.
first of all i have a QTextBrowser and a Button. when the button is clicked it should call a method from a c++ class like this:

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
 
}
 
MainWindow::~MainWindow()
{
    delete ui;
}
 
void MainWindow::on_Button_clicked()
{
    try{
        GUIController guiController;        
        guiController.somemethode();
 
    }
    catch (char const* err){
        cout << err << endl;
 
    }
 
}

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
   
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_Button_clicked()
{
    try{
        GUIController guiController;        
        guiController.somemethode();

    }
    catch (char const* err){
        cout << err << endl;

    }

}

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This called methode should do something and then call a method from mainwindow class which should set Text to the textBrowser like this:

GUIController::GUIController()
{
 
}
 
GUIController::~GUIController()
{
 
}
 
void GUIController::somemethode{
    ...
    ...
    mainwindow.printToOutput(("text"));
 
}

GUIController::GUIController()
{

}

GUIController::~GUIController()
{

}

void GUIController::somemethode{
    ...
    ...
    mainwindow.printToOutput(("text"));
   
}

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MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
 
}
 
MainWindow::~MainWindow()
{
    delete ui;
}
 
void MainWindow::printToOutput(QString text){
 
    ui->outputText->append(text);
 
}

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
   
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::printToOutput(QString text){
   
    ui->outputText->append(text);
   
}

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But the problem is that the text doesn't appear in the QTextBrowser.
Has anybody an idea whats the problem?
i googled a long time and i think the problem is something with the "render loop" of the gui but i don't know how to fix it.

Thanks for help!

[anda_skoa]

Your GUIController instance does not have any access to the MainWindow instance.
How do you expect the controller to affect an object it doesn't know about?

Cheers,
_

[fäbs]

sry i didn't post the header file of my guicontroller.

class GUIController
{
public:
    GUIController();
    ~GUIController();
    somemethod();
 
private:
    MainWindow mainwindow;
 
};

class GUIController
{
public:
    GUIController();
    ~GUIController();
    somemethod();

private:
    MainWindow mainwindow;
  
};

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so my guicontroller has a instance of mainwindow so i think its not an access problem...

i also started another test and changed my printtoOutput method like this:

void MainWindow::printToOutput(QString text){
    ui->outputText->setText("sdf");
    QMessageBox::information(this,"sd","test");
}

void MainWindow::printToOutput(QString text){
    ui->outputText->setText("sdf");
    QMessageBox::information(this,"sd","test");
}

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setText to my QTextBrowser has no effect, but QMessageBox appear.

---

Added after 9 minutes:

i also tried to set a text to my QTextBrowser and read the text from the QTextBrowser and push it to a QMassageBox.

void MainWindow::printToOutput(QString text){
    ui->outputText->setText("sdf");
    QMessageBox::information(this,"sd",(ui->outputText->toPlainText()));
}

void MainWindow::printToOutput(QString text){
    ui->outputText->setText("sdf");
    QMessageBox::information(this,"sd",(ui->outputText->toPlainText()));
}

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so in the MesageBox the text i set a line before ("sdf") appear, but not in the QTextBrowser as it should....

[anda_skoa]

sry i didn't post the header file of my guicontroller.

class GUIController
{
public:
    GUIController();
    ~GUIController();
    somemethod();
 
private:
    MainWindow mainwindow;
 
};

class GUIController
{
public:
    GUIController();
    ~GUIController();
    somemethod();

private:
    MainWindow mainwindow;
  
};

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so my guicontroller has a instance of mainwindow so i think its not an access problem...

And you are sure you want to access this second main window and not the main window that created the GUIController?

Cheers,
_

[fäbs]

OH NO
i solved the problem some minutes ago, thank you very much for your tipp!!!
i spent so much time searching the problem on the wrong place

of course the problem was accessing mainwindow.

now i changed my instance to:

MainWindow * mainwindow = (MainWindow *) qApp->activeWindow();

MainWindow * mainwindow = (MainWindow *) qApp->activeWindow();

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and everything work

thanks for help!!

[anda_skoa]

OH NO

Thought so

now i changed my instance to:

MainWindow * mainwindow = (MainWindow *) qApp->activeWindow();

MainWindow * mainwindow = (MainWindow *) qApp->activeWindow();

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and everything work

You could also pass "this" to the constructor of GUIController or to the method you are calling.

Cheers,
_