GroupItems in two states

Hello,

the following code draws 3 ellipses and one rectangle.
These 4 object are grouped in a QGraphicsItemGroup together.

What i want to do is to implement 2 states:

First state:
If the rectangles moves, the ellipses move too, like the code shows.


Second state:
This is where i do not find a solution.
I need a state where I make the ellipses moveable inside the rectangle , for example with a double click on the rectangle.
And if i click back outsite the rectangle, the ellipses fix back to the rectangle. (first state).
How i could do this?

Thx Andre

mainwindow.h

Code:

---

#include <QMainWindow>
 
#include "customitemellipse.h"
#include "customitemrect.h"
 
namespace Ui {
class MainWindow;
}
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
 
private:
    Ui::MainWindow *ui;
    QGraphicsScene     *scene;
    QGraphicsItemGroup *group;
};

---

mainwindow.cpp

Code:

---

#include "mainwindow.h"
#include "ui_mainwindow.h"
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    scene = new QGraphicsScene(this);
    ui->graphicsView->setScene(scene);
 
    group = scene->createItemGroup(scene->selectedItems());
    group->setFlags(QGraphicsItem::ItemIsSelectable | QGraphicsItem::ItemIsMovable);
 
 
    CustomItemEllipse *ellipse1 = new CustomItemEllipse();
    scene->addItem(ellipse1);
    group->addToGroup(ellipse1);
 
    CustomItemEllipse *ellipse2 = new CustomItemEllipse();
    ellipse2->setPos(mapToParent(QPoint(300,0)));
    scene->addItem(ellipse2);
    group->addToGroup(ellipse2);
 
    CustomItemEllipse *ellipse3 = new CustomItemEllipse();
    ellipse3->setPos(mapToParent(QPoint(0,300)));
    scene->addItem(ellipse3);
    group->addToGroup(ellipse3);
 
    CustomItemRect *rect       = new CustomItemRect();
    scene->addItem(rect);
    group->addToGroup(rect);
}

---

customitemellipse.h

Code:

---

#include <QGraphicsItem>
#include <QPainter>
 
class CustomItemEllipse : public QGraphicsItem
{
public:
    QRectF ellipse;
 
public:
    CustomItemEllipse();
    QRectF boundingRect() const;
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
 
};

---

customitemellipse.cpp

Code:

---

#include "customitemellipse.h"
 
CustomItemEllipse::CustomItemEllipse()
{
    ellipse = boundingRect();
    setFlag(ItemIsMovable);
    setZValue(10);
}
 
 
QRectF CustomItemEllipse::boundingRect() const
{
    return QRectF(0,0,75,75);
}
 
 
void CustomItemEllipse::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    painter->setBrush(Qt::gray);
    QPen pen(Qt::black, 3);
    painter->setPen(pen);
    painter->drawEllipse(ellipse);
}

---

customitemrect.h

Code:

---

#include <QGraphicsItem>
#include <QPainter>
 
class CustomItemRect : public QGraphicsItem
{
public:
    QRectF rect;
 
public:
    CustomItemRect();
    QRectF boundingRect() const;
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
};

---

customitemrect.cpp

Code:

---

#include "customitemrect.h"
 
CustomItemRect::CustomItemRect()
{
    rect = boundingRect();
    setFlag(ItemIsMovable);
    setScale(5);
}
 
QRectF CustomItemRect::boundingRect() const
{
    return QRectF(0,0,75,75);
}
 
void CustomItemRect::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{   
    painter->setBrush(Qt::white);
    QPen pen(Qt::black, 0.5);
    painter->setPen(pen);
    painter->drawRoundRect(rect);
}

---

Has anyone an idee, if there there is a helpful functionality form the QT-Framework, or it should this implements by hand.

Thx Andre

Hello,

i have a semi solution, but a i can not release the grouped items :

mainwindow.cpp

Code:

---

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
..... 
 
    CustomItemRect *rect       = new CustomItemRect();
    scene->addItem(rect);
    group->addToGroup(rect);
 
    //add this line 
    rect->setGroup(group);
 
....
}

---

customitemrect.h

Code:

---

class CustomItemRect : public QGraphicsItem
{
public:
     // add this line
    void setGroup(QGraphicsItemGroup *group);
};

---

customitemrect.cpp

Code:

---

CustomItemRect::CustomItemRect()
{
    rect = boundingRect();
    setFlag(ItemIsMovable);
    setScale(5);
 
    // add this line
    isGroup = false;
}
 
 // add this functions
 
void CustomItemRect::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
    qDebug()<<"Rect";
}
 
void CustomItemRect::mouseDoubleClickEvent(QGraphicsSceneMouseEvent* e )
{
        isGroup = !isGroup;
        customItemGroup->setHandlesChildEvents(isGroup);
}
 
void CustomItemRect::setGroup(QGraphicsItemGroup *group)
{
    customItemGroup = group;
}

---

But how i could send a mouse event on QGraphicsItemGroup item to trigger the doouble click function?

Thx