How do I subclass QDial to show notches values ?

mrjj

Hi
Well then subclass will work best as you can add support
for having a list of TickTexts or what u call them :)

Punt

@Punt
Ok
You can sublass it and override the paintEvent
make it paint as normal, and then paint the text on top.
But you show 4 texts, do you have more for real app?

I know how to subclass & override, but "make it paint as normal and then paint the text", I don't have any idea how to do it ...

mrjj

@Punt
Oh sorry being unclear
When you have overridden paint
in top you call the base class
void mycooldial::paintEvent( ..
QDial::PaintEvent(event); << call the normal paint

then after u paint text on top of it.

Punt

@mrjj
OK here I am :

.h :

#ifndef CUSTOMDIAL_H
#define CUSTOMDIAL_H

#include <QObject>
#include <QDial>

class CustomDial : public QDial
{
    Q_OBJECT

public:

    CustomDial(QWidget * parent = nullptr,
               double knobRadius = 5,
               double knobMargin = 5);

private:

    virtual void paintEvent(QPaintEvent*pe) override;

};

#endif // CUSTOMDIAL_H

.cpp :

#include "customdial.h"

CustomDial::CustomDial(QWidget* parent,
                       double knobRadius,
                       double knobMargin)
: QDial(parent)
{
    // Default range
    QDial::setRange(0,100);
}

void CustomDial::paintEvent(QPaintEvent* pe)
{    QDial::paintEvent(pe);

}

It seems to work, I have my QDial then I'll try to add my text...

But I have :

QMetaObject::connectSlotsByName: No matching signal for on_pushButton_pressed()
QMetaObject::connectSlotsByName: No matching signal for on_pushButton_clicked()
QMetaObject::connectSlotsByName: No matching signal for on_pushButton_released()
QMetaObject::connectSlotsByName: No matching signal for on_dial_valueChanged(int)

mrjj

Hmm
you dont show any connect statements?

So this from other part of project.

This might happen if you add slot by right clicking in Creator and then later rename slot or the button/widget
Its not related to the subclass as such.

Punt

@mrjj
Oh sorry my bad to disturb you for this..
This is SLOT that I used earlier to try things with QDial --'

Ok I'll try to paint my text now :)

mrjj

@Punt
Np. :)

Punt

Ok, I understand how it works.. I have an idea to determinate the position of my texts (unit cercle I guess).

But I have a problem, because for example (with a QDial 100x100) :

if I add text in (0,50) a part of the text will be on the QDial..
if I add text in (-10,50), a part of the text will be cut

I guess I have to extend the painting zone.. but I don't find anything...

mrjj

@Punt
Hi the
"Painting zone" is the size of the QDial
You cannot paint outside it using -100 for x
It clip clip as you saw.
You cannot increase this area unless its ok the QDial also becomes bigger.

Punt

@mrjj
Maybe I can reduce the QDial then ? Like the radius of the circle ?

Or last idea : I create a new class, in which I put an "aera" like a Widget (?), I add a QDial and I draw my "notches-text-values" (Still don't know how to call it xDD)

mrjj

@Punt
well maybe. i dont think so.
I think it uses all its area.
else u need to copy the paint function and alter it to allow
to paint smaller than the area.
You should look in source and see what it uses to better understand it.

mrjj

sorry I miss last part.

Yes also option to make a composite class where u have QDial in center ( in a layout) and
let ur class paint on top of it all.

Punt

@mrjj
I think I'll go for it !
It's the easiest solution I guess...

I'm done for today, I'll try it tomorrow :)
Thanks :)

mrjj

but since you already subclassed it, why not make it work 100% like u want?
Also need to be able to give list for the "tick words" etc.
So find the source and see the paitnevent
maybe its easy to modify for what u want.

mrjj

void QDial::paintEvent(QPaintEvent *)
{
QStylePainter p(this);
QStyleOptionSlider option;
initStyleOption(&option);
p.drawComplexControl(QStyle::CC_Dial, option);
}

So u can just change option.rect ( check name)
and you can control the size of the dial.

Punt

@mrjj said:

but since you already subclassed it, why not make it work 100% like u want?
Also need to be able to give list for the "tick words" etc.
So find the source and see the paitnevent
maybe its easy to modify for what u want.

If I create a composite class, I don't need anymore my subclass...
Well I don't know, I'll check tomorrow if it's easy (Because i'll probably have to change another thing on a QDial => but that's another thing x) )

I guess i'll update this topic tomorrow, so if someone has another idea, I take it :)

Edit for your last message : I'll check tomorrow, I go home and I can't work there :p

See you

mrjj

before u try composite, please try adjust paint first.
So little code.

Punt

@mrjj said:

void QDial::paintEvent(QPaintEvent *)
{
QStylePainter p(this);
QStyleOptionSlider option;
initStyleOption(&option);
p.drawComplexControl(QStyle::CC_Dial, option);
}

So u can just change option.rect ( check name)
and you can control the size of the dial.

I can't do "option.something" ...

mrjj

why not?
Look in help then?

http://doc.qt.io/qt-5/qstyleoption.html#rect-var

Punt

@mrjj
Now the problem is I can extend the area and write text in the right and in the bottom of the QDial (because the QDial is drawn (good english ?!) in the left-top (0,0) ). And I don't have any idea how to change that.. I searched if there is something like the position where qt draw of something like that, but didn't find it .. --'