how can i mark points on top of a Image?

I am trying to mark points on top of a image,
- I select the topleft and bottomright points on the image
- generate grid points on top of the image (something like this )
http://img169.imageshack.us/img169/9...otfigure11.jpg
- the grid should be cleared later

currently i created a ImageItem class derived from QpixmapItem

Code:

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#ifndef IMAGEITEM_H
#define IMAGEITEM_H
 
#include <QGraphicsPixmapItem>
#include <QtDebug>
#include <QGraphicsSceneMouseEvent>
#include <QPoint>
#include <QPainter>
#include <QObject>
 
class ImageItem : public QObject ,public QGraphicsPixmapItem
{
    Q_OBJECT
public:
    ImageItem();
    ImageItem(QGraphicsItem *, QGraphicsScene*);
public slots:
    void mousePressEvent(QGraphicsSceneMouseEvent *event);
signals:
    void mouseClicked(QPointF);
 
};
 
#endif // IMAGEITEM_H

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Code:

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#include "imageitem.h"
 
ImageItem::ImageItem()
{
}
 
ImageItem::ImageItem(QGraphicsItem *parent, QGraphicsScene* scene) : QGraphicsPixmapItem(parent,scene){
 
}
 
void ImageItem::mousePressEvent(QGraphicsSceneMouseEvent *event){
    emit mouseClicked(event->pos());
}

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i can get the topleft and bottomright points from the mousePressEvent
Now my problem is how can i draw points (which can be removed later) on top of QPixmapItem??:confused:

any ideas how to implement this? or if u have a sample code please share :cool:

That link looks like a form or dialog with a image. What about a label to display a image and QPainter to draw the points on top ?

Quote:

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Originally Posted by montamer

any ideas how to implement this? or if u have a sample code please share :cool:

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This is my code to emulate what happen when a user click a mouse button on a desktop and then moves the mouse. A dashed retangle is drawn on desktop to let user see "selection area". All this is done on a screenshoot image. There are
mainly 3 methods:

mousePressEvent =>get mouse coords, start coords
mouseMoveEvent =>get end coords and draw a rectangle on image,
mouseReleaseEvent =>restore original image

I hope you can use my code to do whatever you need.
Bye
Alberto

Code:

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.h:
int startx,starty,endx,endy,addable,printed;
QPixmap originalPixmap;//image where i draw
QPixmap copyPixmap;//temporary image
QPixmap savePixmap;//original image
QPen pen;
 
 
.cpp:
void Widget::mousePressEvent(QMouseEvent *event)
{    
    startx=event->globalPos().x()-offsetx+ui->scrollArea->horizontalScrollBar()->value();
    starty=event->globalPos().y()-offsety+ui->scrollArea->verticalScrollBar()->value();
    addable=1;
    QObject::disconnect(ui->lineEdit,SIGNAL(textChanged(QString)),this,SLOT(checkText(QString)));
}
 
void Widget::mouseMoveEvent(QMouseEvent *event)
{
    if(addable==1){
        if(printed==1){
            originalPixmap=copyPixmap.copy(QRect());
            ui->label->setPixmap(originalPixmap);
        }
        QPainter painter(&originalPixmap);
 
        painter.setPen(QPen(Qt::gray, 1, Qt::DashLine, Qt::RoundCap, Qt::RoundJoin));
	painter.drawRect(startx,
                         starty,
                         event->globalPos().x()-startx-offsetx+ui->scrollArea->horizontalScrollBar()->value(),
                         event->globalPos().y()-starty-offsety+ui->scrollArea->verticalScrollBar()->value() );
        painter.end();
        ui->label->setPixmap(originalPixmap);
        printed=1;
    }
}
 
void Widget::mouseReleaseEvent(QMouseEvent *event)
{
    printed=0;
    originalPixmap=copyPixmap.copy(QRect());
    ui->label->setPixmap(originalPixmap);
    if(addable==1){
        endx=event->globalPos().x()-offsetx+ui->scrollArea->horizontalScrollBar()->value();
        endy=event->globalPos().y()-offsety+ui->scrollArea->verticalScrollBar()->value();
        addable=2;
        connect(ui->lineEdit,SIGNAL(textChanged(QString)),this,SLOT(checkText(QString)));
    }
}

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