Hi, how can I draw line & text in the specified area ?

[navid]

Hi all, how can I draw line & text in the specified area (please see enclosed picture) ?

[Uwe]

Are you talking about the legend ?

Uwe

[navid]

Hi Uwe,
I attached the final plot.

text and lines on top of the plot, show peaks position
text and lines on button of the plot, show area below curve between start & stop marks

[navid]

How can I draw plot same as the last enclosed paper picture?
Please example source code.

[navid]

Please introduce me with a start point

[navid]

Please ...
How can i draw line & text within legend?

[Uwe]

text and lines on top of the plot, show peaks position
text and lines on button of the plot, show area below curve between start & stop marks
Well, QwtPlot is a composite widget, that consists of a canvas, 4 scale widgets, a header, a footer and the legend.

Your picture shows a plot, where something is painted on the canvas above the canvas (a) and also something on the bottom scale, between the axis and the axis title (b).

For (a) you need to derive from QwtPlotCurve or implement a new type of plot item - don't now enough about the specific situation of your plot to recommend something. For (b) you need to derive from QwtScaleDraw, where you create the space for your extra labels by using setMinimumExtent().

Uwe

[navid]

Thanks for your reply.

I started with the following code:

class PlotCurve: public QwtPlotCurve
{
public:

PlotCurve(const QString &title = QString::null): QwtPlotCurve(title)
{
}

void setLabel(QString txt, QPointF pos)
{
data mydata;
mydata.pos = pos;
mydata.txt = txt;
strlst.append(mydata);
qDebug()<<"setLabel";

//try to run paintEvent

// this->show();
// this->plot()->update();

// QPaintEvent * pe = new QPaintEvent(QRect(pos.x(),pos.y(),100,20));
// this->paintEvent(pe);
}

void setLines()
{

}

void paintEvent(QPaintEvent *)
{
qDebug()<<"paintEvent";
QPainter * painter = new QPainter(this->plot()->paintEngine()->paintDevice());
painter->save();
for(int i=0; i < strlst.count(); i++) painter->drawText(strlst.at(i).pos,strlst.at(i).txt);
strlst.clear();
painter->restore();
}

private:

struct data{
QString txt;
QPointF pos;
};

QList<data> strlst;

};

but I can not run paintEvent !

I will be appreciated with your comments & suggestions.