How to dynamically add QPushButtons to UI - c++

Question

FYI I am using Qt Creator 3.3.2 on Linux Mint.
Okay first I would like to admit I have seen a few questions very similar to the one I am asking... Such as How to add a widget (QPushButton for example) dynamically to a layout built in designer. However (for whatever reason) I have had no success in either understanding the answer or implementing it. I am extremely new to Qt and this is my first project in it so please be through so I can understand the answer.
What I have so far:
The UI:
I have a scroll area named srcFolderPairSelect and under that (in the 'object' window) I have a scroll contents named scrLayFolderPairSelect. In a different section/area (different frame and layout) I have a button that is to add a button, to the before mentioned scroll contents, named btnAddNewFolderPair, upon click. PS: I need it to be able to be clicked more than once (need to be able to add multiple dynamic buttons to the scroll contents).
The header file:
#ifndef SYNCCENTER_H
#define SYNCCENTER_H
#include <QMainWindow>
namespace Ui {
class SyncCenter;
}
class SyncCenter : public QMainWindow
{
Q_OBJECT
public:
explicit SyncCenter(QWidget *parent = 0);
~SyncCenter();
private slots:
void on_btnAddFolderPair_clicked();
private:
Ui::SyncCenter *ui;
};
#endif // SYNCCENTER_H
The UI cpp (synccenter.cpp):
#include "synccenter.h"
#include "ui_synccenter.h"
SyncCenter::SyncCenter(QWidget *parent) : QMainWindow(parent), ui(new Ui::SyncCenter)
{
ui->setupUi(this);
}
SyncCenter::~SyncCenter()
{
delete ui;
}
void SyncCenter::on_btnAddFolderPair_clicked()
{
QPushButton* button = new QPushButton("test");
button->setVisible(true);
ui->scrLayFolderPairSelect->layout()->addWidget(button);
}
Also how do I form onclick events for the dynamic buttons?

Answer 1

In a very fast way you can do it like this:
void SyncCenter::on_btnAddFolderPair_clicked()
{
static int count{};
QPushButton* button = new QPushButton(QString("test %1").arg(++count), this);
button->setVisible(true);
connect(button, &QPushButton::clicked, [&count](){
std::cout << "Clicked button number: " << count << std::endl;
});
ui->scrLayFolderPairSelect->layout()->addWidget(button);
}
The main idea is to store slots(handlers), then, if you need - store buttons itselves.
This my "very fast" solution is based on not a good way of implementing this.
You have a lot of ways of implementing this, however, I think, the best solution is to create QButtonGroup because it has a signals such as:
void buttonClicked(QAbstractButton *button);
void buttonClicked(int id);
So, your code will be like:
class SyncCenter {
//....
private slots:
void buttonInGroupClicked(QAbstractButton *);
private:
QButtonGroup *buttonGroup;
};
SyncCenter::SyncCenter(/*...*/) {
buttonGroup = new QButtonGroup(this);
connect(buttonGroup, SIGNAL(buttonClicked(QAbstractButton*)), SLOT(buttonInGroupClicked(QAbstractButton*)));
}
void SyncCenter::buttonInGroupClicked(QAbstractButton *b) {
// do anything with your button
}
void SyncCenter::on_btnAddFolderPair_clicked()
{
static int count{};
QPushButton* button = new QPushButton(QString("test %1").arg(++count), this);
button->setVisible(true);
buttonGroup->addButton(button);
ui->scrLayFolderPairSelect->layout()->addWidget(button);
}