[solved]How to add a widget to window, when it is generated by method

[Lord of Noob]

Hi there,

I want in my app to generate some default Wifdget arrangements by a method.
For example:

//adds a label and a QTextEdit field to my window.
createItem(Name, InputType::Text);

My problem is that this is not working. If I try to return the objects from the Method, I run into an error which I do not understand as noob.

/usr/include/qt/QtWidgets/qlabel.h:142: Fehler: 'QLabel::QLabel(const QLabel&)' is private Q_DISABLE_COPY(QLabel)

If I define the naked pointers in the class as private variables the application Crashes.
Mainwindow.h

class MainWindow : public QMainWindow
{
   Q_OBJECT

public:
   MainWindow(QWidget *parent, std::string appname);
   ~MainWindow();
   void createCharItem(QString name, QString txtContent);
 private:
  //variables
  QVBoxLayout *section; //Stacks all items below each other
  QLabel *title;  // one Item to add
  //functions
  void createTitle(QString name);

}

implementation of void createTitle(QString name);

void MainWindow::createTitle(QString name)
{
     QLabel *title = new QLabel;
     title->setText(name);
     title->setLineWidth(40);
     int height = title->height();
     title->resize(this->width(),height);
     section->addWidget(title);
}

What do I miss?
Or how to do this?

[mcosta]

Hi and welcome to devnet,

can you show the implementation of createCharItem()?
QObject (or inherited classes) instances cannot be created on the stack (you have to use pointers)

[Lord of Noob]

@mcosta
Thanks the Welcome,

Ohh, I am sorry i was tired. The

 createTitle(); 

is a reduced version of

 createItem();

I do not have the createItem yet. It will look similar only it will consinst of a 1xQHBoxLayout,1xQLabel and 1xQTestEdit or 1xQSpinBox.

My Constructer of QMainWindow looks like:

MainWindow::MainWindow(QWidget *parent,std::string appname) :QMainWindow(parent)
{
   QTabWidget *charsheet = new QTabWidget;
   this->setCentralWidget(charsheet);
   QWidget *titlepage = new QWidget(this);
   QWidget *combatpage = new QWidget;
   charsheet->addTab(titlepage,"Heerosheeet");
   charsheet->addTab(combatpage,"combatsheet");
   QVBoxLayout *section = new QVBoxLayout(titlepage);
   createTitle(QString::fromStdString(appname));
/* If I do it this way it works ...
    QLabel *title = new QLabel;
    title->setText(QString::fromStdString(appname));
    title->setLineWidth(40);
    int height = title->height();
    title->resize(this->width(),height);
   section->addWidget(title);
   */
}

Ohh I just have seen if I move the

 section->addWidget(title); 

to main, it works. But why I can not use the add Widget Method in my own method?

Edit:

Ok, fixed one Bug: QLabel was wrong. But the program is still crashing this way.

void MainWindow::createTitle(QString name)
{
     title = new QLabel;
     title->setText(name);
     title->setLineWidth(40);
     int height = title->height();
     title->resize(this->width(),height);
     section->addWidget(title);
}

[Lord of Noob]

Okay, I now found 2 Exceptions:
QXcbWindow: Unhandled client message: "_E_COMP_FLUSH"
QXcbWindow: Unhandled client message: "_E_COMP_DUMP"

I think I can catch them, but I do not know what to do with these Errors...

Google is not makeing any sense.
Marking the Handler and press F1 is not doing something :-D

Any hints where to look?

[alex_malyu]

My problem is that this is not working. If I try to return the objects from the Method, I run into an error which I do not understand as noob.
/usr/include/qt/QtWidgets/qlabel.h:142: Fehler: 'QLabel::QLabel(const QLabel&)' is private Q_DISABLE_COPY(QLabel)

There is an attempt to copy QObject derived object, probably cause you return object not the pointer.

If You need to create object of QWidget (QObject) derived class in a function, function should look like:

QWidget* createWidget();

not a
QWidget createWidget (), cause in such case object will have to be copied and it is forbidden.

[Lord of Noob]

Cool, this works.
I return now a Pointer, and add it in one line to the screen.

I mark this solved. Even I still have no Idea why the one way does not work.

great thanks.

[SGaist]

Hi,

Because QObject is not a copyable class. See here for more information