treeitem.h
<code C++>
#ifndef TREEITEM_H
#define TREEITEM_H

#include <QTreeWidgetItem>

class TreeItem : public QTreeWidgetItem
{
   public:
      QObject * obj;

      TreeItem () : obj (nullptr) { }
};

#endif // TREEITEM_H
</code>

mainwindow.h
<code C++>
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTreeWidget>
#include <QTableWidget>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void on_pushButton_clicked();

    void on_treeWidget_itemDoubleClicked(QTreeWidgetItem *item, int column);

private:
    Ui::MainWindow *ui;

    // #include <QTreeWidget>
    void showBranch (QTreeWidgetItem * target, QObject * obj);
    QTableWidgetItem * addLine (QString name, QString value);
};

#endif // MAINWINDOW_H

</code>

mainwindow.cpp
<code C++>
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QMetaProperty>

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

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

void MainWindow::on_pushButton_clicked()
{
    setWindowIcon(QIcon::fromTheme("weather-clear"));

    QObject * p = ui->pushButton;
    while (p->parent() != nullptr)
        p = p->parent ();

    showBranch (ui->treeWidget->invisibleRootItem(), p);
    ui->treeWidget->expandAll ();
}

#include "treeitem.h"

void MainWindow::showBranch (QTreeWidgetItem *target, QObject *obj)
{
    TreeItem * branch = new TreeItem ();
    target->addChild (branch);

    const QMetaObject * cls = obj->metaObject();
    branch->setText (0, obj->objectName() + " : " + cls->className ());
    branch->obj = obj;

    for ( QObject * t : obj->children() )
        showBranch (branch, t);
}

QTableWidgetItem * MainWindow::addLine(QString name, QString value)
{
    int inx = ui->tableWidget->rowCount ();
    ui->tableWidget->setRowCount (inx +1);

    QTableWidgetItem * cell = new QTableWidgetItem ();
    cell ->setText (name);
    ui->tableWidget->setItem(inx, 0, cell);

    cell = new QTableWidgetItem ();
    cell ->setText (value);
    ui->tableWidget->setItem(inx, 1, cell);

    return cell;
}

void MainWindow::on_treeWidget_itemDoubleClicked(QTreeWidgetItem *item, int column)
{
   TreeItem * node = dynamic_cast < TreeItem * > (item);
   if (node != nullptr)
   {
       ui->tableWidget->clear ();
       ui->tableWidget->setColumnCount(2);
       ui->tableWidget->setRowCount(0);

       QObject * obj = node->obj;
       addLine ("object name", obj->objectName());

       const QMetaObject * cls = obj->metaObject();
       addLine ("class name", cls->className());

       int cnt = cls->propertyCount();
       for (int i = 0; i < cnt; i++)
       {
           QMetaProperty prop = cls->property (i);
           QVariant v = prop.read (obj);
           QTableWidgetItem * cell = addLine (prop.name(), v.toString());
           if (v.type() == QVariant::Icon)
               cell->setData (Qt::DecorationRole, v);
       }

   }
}

</code>