QGraphicsItem mouse Press event return

Ducky

Hi all,

I am stuck at a peace of coding.

I have created two square's using QRectF in a QGraphicsview.

What i am trying to do is when a square is pressed a label outside the QGraphicsview shows a identification item of that square.

so if I press the right square it sets the label to "2 or right or 1234".

My square.CPP is
@#include "square.h"

Square::Square(int x, int y)
{
X= x;
Y= y;
Pressed = false;
setFlag(ItemIsSelectable);
}

QRectF Square::boundingRect() const
{
return QRectF(X,Y,100,100);

}

void Square::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{

QRectF rec = boundingRect();
QBrush brush(Qt::blue);

if(Pressed)

{
brush.setColor(Qt::red);
}
else
{
brush.setColor(Qt::green);
}

painter->fillRect(rec,brush);
painter->drawRect(rec);

}

void Square::mousePressEvent(QGraphicsSceneMouseEvent *event)
{

Pressed = true;
update();
QGraphicsItem::mousePressEvent(event);

}

void Square::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
{
Pressed = false;
update();
QGraphicsItem::mouseReleaseEvent(event);
}@

my mainwindow.ccp is.

@#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "square.h"
#include <QString>
#include <QtGui>
#include <QtCore>
#include <QObject>

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

scene = new QGraphicsScene(this);
ui->graphicsView->setScene(scene);

sq = new Square(0,0);
scene->addItem(sq);
sq = new Square(100,0);
scene->addItem(sq);

}

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

//void MainWindow::setLabel(QString value)
//{
// ui->label->setText(value);
//}
@

BlastDV

Hi there,

I see you're implementing your own "square" class. If you want something to happen everytime one of them is picked up, you may want to declare that class as a Q_OBJECT instead of just a plain C++ class. That will allow you to write signals for that object, and if you connect that signal to a slot on your main class, you will be able to detect stuff on your square class, like mouse picking. Then, it's only a matter of setting your label text to what you want to show.

That's an overview of how it could be done and how I would try to solve it.
If you're not familiar with Qt Objects, you may want to look at the docs.

Tell us what you did :)

Ducky

HI thanx for the replay.

It got me thinking and solved it in a way :).

As far did I only added singles that can be emitted white parameters.

is there some ware a list of mouse events that i can use for a QGraphicsItem.

Like :
right mouse button pressed.
moved into QGraphicsItem.
moved out QGraphicsItem.

so this is my square.cpp now

@#include "square.h"

square::square(int x, int y, QGraphicsObject *parent) :
QGraphicsObject(parent)
{
Pressed = false;
setFlag(ItemIsSelectable);
X = x;
Y = y;

}

QRectF square::boundingRect() const
{
return QRectF(X,Y,30,30);
}

void square::mousePressEvent(QGraphicsSceneMouseEvent *ev)
{
Pressed = true;
update();
QGraphicsItem::mousePressEvent(ev);
emit Mouse_Pressed(X,Y);
}

void square::mouseReleaseEvent(QGraphicsSceneMouseEvent *ev)
{
Pressed = false;
update();
QGraphicsItem::mousePressEvent(ev);
emit Mouse_Released(X,Y);
}

void square::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
QRectF rec = boundingRect();
QBrush brush(Qt::blue);
if(Pressed)
{
brush.setColor(Qt::red);
}
else
{
brush.setColor(Qt::blue);
}

    painter->fillRect(rec,brush);
    painter->drawRect(rec);

}@

and mij Dialog.cpp looks like.

@#include "dialog.h"
#include "ui_dialog.h"
#include "square.h"
#include <QLabel>

Dialog::Dialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::Dialog)
{
ui->setupUi(this);
scene = new QGraphicsScene(this);
ui->graphicsView->setScene(scene);
LineCounter = 0;
for (int i = 0; i < 25; ++i) {

    if (i==0){
       Hoog = i*30;
    }
    else {
        Hoog = Hoog +30;
    }

    if (LineCounter == 5){
       links = links+30;
       Hoog = 0;
       LineCounter = 1;
            }
    else{
       LineCounter = LineCounter +1;
    }
sq = new square(links,Hoog);
scene->addItem(sq);
connect(sq,SIGNAL(Mouse_Pressed(int,int)),this,SLOT(Mouse_Pressed(int,int)));
connect(sq,SIGNAL(Mouse_Released(int,int)),this,SLOT(Mouse_Released(int,int)));

}

}

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

void Dialog::Mouse_Pressed(int x,int y)
{
ui->label->setText(QString("Pressed X= %1, Y= %2 ").arg(x).arg(y));

}

void Dialog::Mouse_Released(int x, int y)
{
ui->label->setText(QString("Released X= %1, Y= %2 ").arg(x).arg(y));
}@