Composite Widget Tutorial

[tescrin]

In QWidget (documentation) it talks about building composite widgets and references a page that's supposed to have a tutorial on how to do it; though i couldn't find it.

Could someone point me in the direction of a thread or tutorial on (or explain) how to:
-Turn a qwidget into a container (I believe it is by default)
-Have it "contain" another widget

Again, I search the reference it gave, but it didn't seem to contain anything on containers/composite widgets. To clarify, I know how to do it in designer; I need to figure out how to do it.


I looked at the ui_myclass.h files to get an idea; it seems that it's enough to just say this during initialization?:

myContainerClass foo = new myContainterClass[B](ContainedClassName)[/B];

myContainerClass foo = new myContainterClass[B](ContainedClassName)[/B];

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[Zlatomir]

The simplest way is just to: create a QWidget, create a QLayout with that widget as parent and add other widgets to the layout:

QWidget w;
    //create a layout with parent
    QVBoxLayout *layout = new QVBoxLayout(&w); 
     //widgets that will be contained in QWidget
    QLabel* label1 = new QLabel("Label 1"); 
    QLabel* label2 = new QLabel("Label 2");
    layout->addWidget(label1); //add contained widgets to layout
    layout->addWidget(label2);
    w.show(); //show the widget

QWidget w;
    //create a layout with parent
    QVBoxLayout *layout = new QVBoxLayout(&w); 
     //widgets that will be contained in QWidget
    QLabel* label1 = new QLabel("Label 1"); 
    QLabel* label2 = new QLabel("Label 2");
    layout->addWidget(label1); //add contained widgets to layout
    layout->addWidget(label2);
    w.show(); //show the widget

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Or another way is to derive a class from QWidget and contain the widgets into that class, this creates a better "encapsulated widget" that can be reused easier.

//MyWidget.h file
#ifndef MYWIDGET_H
#define MYWIDGET_H
#include <QWidget>
 
//forward declarations
class QVBoxLayout;
class QHBoxLayout;
class QLabel;
class QPushButton;
 
class MyWidget : public QWidget //inherit from QWidget
{
    Q_OBJECT
public:
    MyWidget(QWidget* parent = 0); //don't forget to pass the parent
 
private: 
//contained widgets:
    QVBoxLayout *mainLayout;  
    QHBoxLayout *anotherLayout;
    QLabel *firstLabel;
    QLabel *secondLabel;
    QPushButton *firstButton;
    QPushButton *secondButton;
signals:
    //MyWidget's signals....
public slots:
    //MyWidget's slots example:
    // void firstButtonClicked();
    //...
};
#endif // MYWIDGET_H

//MyWidget.h file
#ifndef MYWIDGET_H
#define MYWIDGET_H
#include <QWidget>

//forward declarations
class QVBoxLayout;
class QHBoxLayout;
class QLabel;
class QPushButton;

class MyWidget : public QWidget //inherit from QWidget
{
    Q_OBJECT
public:
    MyWidget(QWidget* parent = 0); //don't forget to pass the parent

private: 
//contained widgets:
    QVBoxLayout *mainLayout;  
    QHBoxLayout *anotherLayout;
    QLabel *firstLabel;
    QLabel *secondLabel;
    QPushButton *firstButton;
    QPushButton *secondButton;
signals:
    //MyWidget's signals....
public slots:
    //MyWidget's slots example:
    // void firstButtonClicked();
    //...
};
#endif // MYWIDGET_H

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And in the constructor you initialize the pointers and add them to the layouts:

#include "mywidget.h"
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QLabel>
#include <QPushButton>
 
MyWidget::MyWidget(QWidget* parent) : QWidget(parent)
{
    mainLayout = new QVBoxLayout(this);
    anotherLayout = new QHBoxLayout();
 
    firstLabel = new QLabel("first label");
    secondLabel = new QLabel("second label");
    firstButton = new QPushButton("Fist button");
    secondButton = new QPushButton("Second Button");
 
    mainLayout->addWidget(firstLabel);
    mainLayout->addWidget(firstButton);
    mainLayout->addLayout(anotherLayout);
    anotherLayout->addWidget(secondLabel);
    anotherLayout->addWidget(secondButton);
}

#include "mywidget.h"
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QLabel>
#include <QPushButton>

MyWidget::MyWidget(QWidget* parent) : QWidget(parent)
{
    mainLayout = new QVBoxLayout(this);
    anotherLayout = new QHBoxLayout();

    firstLabel = new QLabel("first label");
    secondLabel = new QLabel("second label");
    firstButton = new QPushButton("Fist button");
    secondButton = new QPushButton("Second Button");

    mainLayout->addWidget(firstLabel);
    mainLayout->addWidget(firstButton);
    mainLayout->addLayout(anotherLayout);
    anotherLayout->addWidget(secondLabel);
    anotherLayout->addWidget(secondButton);
}

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