Movable QRubberband from one point to another - qt

Question

I have drawn a QRubberband on QLabel. i can resize it using QSizeGrip. Now I want to move it from one point to another using QMouseevents. Is there any one who can help me out.
void CropImage::mousePressEvent(QMouseEvent *event)
{
QLabel::mousePressEvent(event);
lastPoint = event->pos();
rubberband = new QRubberBand(QRubberBand::Rectangle,this);
rubberband->setGeometry(QRect(lastPoint, QSize()));
rubberband->show();
}
void CropImage::mouseReleaseEvent(QMouseEvent *event)
{
newPoint = event->pos();
}
this is my subclass part which is used for mouse events. the code is as following:
Resizable_rubber_band::Resizable_rubber_band(QWidget *parent) : QWidget(parent)
{
//tell QSizeGrip to resize this widget instead of top-level window
setWindowFlags(Qt::SubWindow);
QHBoxLayout* layout = new QHBoxLayout(this);
layout->setContentsMargins(0, 0, 0, 0);
QSizeGrip* grip1 = new QSizeGrip(this);
QSizeGrip* grip2 = new QSizeGrip(this);
layout->addWidget(grip1, 0, Qt::AlignLeft | Qt::AlignTop);
layout->addWidget(grip2, 0, Qt::AlignRight | Qt::AlignBottom);
rubberband = new QRubberBand(QRubberBand::Rectangle, this);
rubberband->move(0, 0);
rubberband->show();
}
void Resizable_rubber_band::resizeEvent(QResizeEvent *)
{
rubberband->resize(size());
}
void Resizable_rubber_band::mousePressEvent(QMouseEvent *event)
{
lastPoint = event->pos();
rubberband->childAt(lastPoint);
}
void Resizable_rubber_band::mouseReleaseEvent(QMouseEvent *event)
{
newpoint = event->pos();
int dragx=newpoint.x()-lastPoint.x();
int dragy=newpoint.y()-lastPoint.y();
band->move(0+dragx,0+dragy);
}
In this code, my problem is i am not getting the exact coordinates after dragging
thanks.
Ashish

Answer 1

Here is a quick example I made where you can move a QRubberBand using mouse events:
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QRubberBand>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
protected:
void mousePressEvent(QMouseEvent *e);
void mouseMoveEvent(QMouseEvent *e);
void mouseReleaseEvent(QMouseEvent *e);
private:
Ui::MainWindow *ui;
QRubberBand *rubberBand;
bool move_rubberband;
QPoint rubberband_offset;
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QMouseEvent>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
move_rubberband = false;
rubberBand = new QRubberBand(QRubberBand::Rectangle, this);
rubberBand->setGeometry(0,0,50,50);
rubberBand->show();
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::mousePressEvent(QMouseEvent *e)
{
if(rubberBand->geometry().contains(e->pos()))
{
rubberband_offset = e->pos() - rubberBand->pos();
move_rubberband = true;
}
}
void MainWindow::mouseMoveEvent(QMouseEvent *e)
{
if(move_rubberband)
{
rubberBand->move(e->pos() - rubberband_offset);
}
}
void MainWindow::mouseReleaseEvent(QMouseEvent *e)
{
move_rubberband = false;
}