Add a custom widget in code to a MainWindow

[Steff]

Hy there,

i am new to Qt and Creator and have the following problem.

I whant to add an OpenGL QGLWidget to a QGuiApplication that i have created with the new project wizard. Then I add a new QTWidget (QT Designer Form Class) also over the wizard and change

class gl : public QWidget {

class gl : public QWidget {

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to

class gl : public QGLWidget {

class gl : public QGLWidget {

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in .h and .cpp

i alos add

#include "QGLWidget"

#include "QGLWidget"

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in the .h file

Now i need to create a new instance of my class here and connect it to the ui

GLTest::GLTest(QWidget *parent)
    : QMainWindow(parent), ui(new Ui::GLTest)
{
    // have to add it here
    ui->setupUi(this);
    // or here and how ?
}

GLTest::GLTest(QWidget *parent)
    : QMainWindow(parent), ui(new Ui::GLTest)
{
    // have to add it here
    ui->setupUi(this);
    // or here and how ?
}

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But i do not get it to work.
Can you give me an smale example?
I know that i have to add it to the CentraWidget.

[milot]

Hi Steff,

You have to create an instance of gl class like the following:

gl *g = new gl();

gl *g = new gl();

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where gl is the class that I've seen from your code.

The complete code from your question will be as follows:

GLTest::GLTest(QWidget *parent)
    : QMainWindow(parent), ui(new Ui::GLTest)
{
 
    ui->setupUi(this);
    gl *g = new gl();
 
    setCentralWidget(g); // where g is your instance of gl class.
}

GLTest::GLTest(QWidget *parent)
    : QMainWindow(parent), ui(new Ui::GLTest)
{

    ui->setupUi(this);
    gl *g = new gl();

    setCentralWidget(g); // where g is your instance of gl class.
}

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If you have any further questions, please don't hesitate to ask

[Steff]

Thank you for the fast reply.

Becaus of the defination of the Widget is:

class gl : public QGLWidget {
    Q_OBJECT
public:
    gl(QWidget *parent = 0);
    ~gl();
 
protected:
    void changeEvent(QEvent *e);
 
private:
    Ui::gl *m_ui;
};

class gl : public QGLWidget {
    Q_OBJECT
public:
    gl(QWidget *parent = 0);
    ~gl();

protected:
    void changeEvent(QEvent *e);

private:
    Ui::gl *m_ui;
};

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I thought i must add the parent element to the creation call.

gl *g = new gl(ui);

gl *g = new gl(ui);

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or

gl *g = new gl(this);

gl *g = new gl(this);

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But i din not try just to call it without this

Thank you