How can I re-size the QGraphicViewItem using mouse

How can I change the QGraphicView Item size using mouse.this code generate the 2 rectangles,how can I change the sizes of those rectangles using mouse.
This image shows my expected result.

Attachment 12639

Code:

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#include "mainwindow.h"
#include "ui_mainwindow.h"
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
 
    scene = new QGraphicsScene();
    ui->graphicsView->setScene(scene);
    scene->setSceneRect(0,0,400,400);
 
    // Create the first red rectangle on the graphic scene
    QGraphicsRectItem *rect1 = new QGraphicsRectItem();
    rect1->setRect(10,50,100,50);
    rect1->setBrush(QBrush(Qt::red));
    rect1->setPen(QPen(QBrush(Qt::black),2));
    scene->addItem(rect1);
 
    // And create a second blue rectangle on the graphic scene
    QGraphicsRectItem *rect2 = new QGraphicsRectItem();
    rect2->setRect(150,100,115,75);
    rect2->setBrush(QBrush(Qt::blue));
    rect2->setPen(QPen(QBrush(Qt::black),2));
    scene->addItem(rect2);
}

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