Hi all,
I'm developing an ECG plotting device using a mini2440, I tried
using QWT but m facin certain probs implementing the lib on QT4, as a
result I moved to graphicsview...

I've uploaded a video of the same...

http://www.youtube.com/watch?v=NYa9nSU0yXE

But graphicsview is giving extremely slow results! on the host computer its
running fine, but not on mini2440, The code goes as follows:

#include <QtGui>
#include "plot.h"
#include "ui_plot.h"

plot:lot(QWidget *parent) :
QMainWindow(parent),
ui(new Ui:lot),
scene1( new QGraphicsScene()),
view1( new QGraphicsView ()),
slidery(new QSlider(Qt::Vertical,parent))
{
view1->setRenderHint(QPainter::Antialiasing);

slidery->setMaximum(100);
slidery->setMinimum(-100);
slidery->setValue(0);

ui->setupUi(this);

ui->horizontalLayout->addWidget( view1);
ui->horizontalLayout->addWidget( slidery);

view1->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff );
view1->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysO ff);

scene1->setItemIndexMethod(QGraphicsScene::NoIndex);

x1 = 0;
x2 = 0;
y1 = 0;
y2 = 0;

view1->centerOn(-100,0);

savebutton->setFixedHeight(50);
pausebutton->setFixedHeight(50);
plotbutton->setFixedHeight(50);

_Pen.setColor(Qt::gray);
_Pen.setWidth(1);


view1->setBackgroundBrush(QBrush(QColor::QColor(204,51,5 1,50),Qt::CrossPatter
n));
view1->setScene(scene1);
_Pen.setColor(Qt::red);

view1->show();
QObject::connect(&clicker, SIGNAL(timeout()), this,
SLOT(StartPlotting()));
clicker.start(16);
}

plot::~plot()
{
delete view1;
delete view2;
delete view3;
delete scene1;
delete ui;
}

void plot::changeEvent(QEvent *e)
{
QMainWindow::changeEvent(e);
switch (e->type()) {
case QEvent::LanguageChange:
ui->retranslateUi(this);
break;
default:
break;
}
}

void plot::StartPlotting()
{
x1=x2;
y1=y2;
x2=x1+2;
y2=-(slidery->value());

scene1->addLine(x1,y1,x2,y2,_Pen);
view1->ensureVisible(x2+5,y2,10,100,x2+5,10);
}
regards,
Abhinit